Bulletin of Association of Consulting Civil Engineers

ostentationabioticInternet and Web Development

Jul 5, 2012 (5 years and 1 month ago)

1,790 views

CMY K
CMY K
CMY K
CMY K
of
Association of Consulting Civil Engineers (India)
BULLETIN
Vol. No. 10 No. 1
QUARTERLY
January-March 2011
e

Y
e
l
e
i
a
b
r
u

-
J


2
r
0
e
v
1
l
i
0S
# 2, U. V. C. E. Alumni Association Building, K. R. Circle, Bangalore - 560 001
Phone
Tel/Fax
: 91-80-22247466
: 91-80-22219012
E-mail : admin@accehq.net
Website : www.accehq.net
Winner of the ACCE- SIMPLEX AWARD 2010 for Innovative Design of Structures other than Industrial Structure
MADRAS CEMENTS LTD.
Flat No. 100-100/1, M-Floor, Eden Park, No. 20, Vittal Mallya Road, Bangalore – 560 001.
Tel: 080- 4122 6500/03/07 Fax: 080- 4112 6515
Bulletin of ACCE (I) 3 January - March 2011
ACCE (I) Office Bearers
Chairman : RAVINDRANATH B. V.
Advisory Committee
Dr. MANAMOHAN R KALGAL, Dr. R.JAGADISH, Mr. SHINGAREY AMOL M
Mr. RANGANATH D, Mr. UMESH B RAO, Mr. RATNAVEL S, Mr. S. PICHAIYA
Editorial Committee
Dr. M N HEGDE, Dr V RAMACHANDRA, Dr. R N PRANESH, Dr. R V RANGANATH
Mr. M. SANJAY KUMAR JAIN, Mr. K G K MOORTHY
Secretaries of all Centres (Ex Office Members)
Bulletin Committee
ACCE BULLETIN
Vol. 10 January - March 2011 No. 1
Avinash D. Shirode President
Hemant Hari Dhatrak Vice-President (West)
T. Senthil Nayagam Vice President (South)
Dr. M. U. Aswath Secretary General
Badarinaath Singri Treasurer
Umesh B. Rao Imm. Past President
Ravindranath B. V.Imm. Past Secretary General
Raghunath B. N.Imm. Past Treasurer
Printed and published by
RAVINDRANATH B. V.
on behalf of the Association of Consulting Civil Engineers (India) and printed at Abhiram Graphics, # 2, Anugraha,
4th Cross, 8th Main, Papaiah Garden, BSK 3rd Stage, Bangalore – 560 085 and published at 2, UVCE Alumni Association Building, K R Circle, Bangalore – 560 001.
Editor:
RAVINDRANATH B. V.
MAG(3)/NPP/166/2003-04, CMM/BNG/DELL/PP/156/21-2002
C ON T E N T S
ABOUT COVER PAGE
ACCE - SIMPLEX AWARD 2010 FOR INNOVATIVE DESIGN
OF STRUCTURES OTHER THAN INDUSTRIAL
STRUCTURE AWARDED TO TANDON CONSULTANTS
PVT LTD., NEW DELHI
A Grade Separator at Mukarba Chowk, Delhi, proposed
in 2005 at this important nerve centre was experiencing
chaotic traffic jams. The challenges around the project
site included a Heritage structure, Graveyard, Sanitary
land fill, major Electrical sub-stations, Nallahs, Live water
mains, Optic fibre/ other cables and Gas pipelines. The
task on hand was to tackle these challenges and design
an aesthetically pleasing structure. The main flyover
along the outer ring road is designed using steel-
concrete composite tub girder. Slip roads, Loops, Bridge
over drain and open stilted portion are constructed using
RCC integral Voided Slab. The integral bridge concept
offers merits like superior performance for sharp radius
of plan curvature, elimination of expansion joints and
bearings. The uplift that is likely to occur in a curved
bridge is absorbed by integral piers. The end piers
where there is practice of providing bearing even in the
integral bridge, also become very critical for design if
the curvature is extended in this zone. This complexity
was eliminated by replacing large diameter single pier
into small diameter twin piers. The small diameter twin
pier in longitudinal direction offer flexibility for temperature
and shrinkage forces and improves torsion rigidity in
transverse direction which is required for sharp curvature
bridges. A unique solution of providing two independent
piers for the separated voided slab at expansion joint
locations was proposed. At intermediate locations, large
diameter pier is provided. The work commenced in
December 2005, was completed during October, 2008.
Tandon Consultants Pvt Ltd. (TCPL) was established in
1986 to undertake specialist consultancy services in
the filed of structural engineering. TCPL specialise in
design of large and complex structures and consists of
carefully trained professionals geared to produce high
President’s Message............................................4
From the Editorial Desk........................................4
From Secretary General’s Desk............................5
ACCE AWARDS 2011 - Call for Nominations.........6
Eugène Freyssinet his incredible journey
to invent and evolutionize prestressed
concrete construction.....................................7
The Alternative Building Materials and
Technologies for Individual Housing
in Coastal Karnataka....................................13
Estimating the Strength of Concrete -
Maturity Method...........................................19
Whitetopping – A case study...............................33
An Experimental Study on Carbonation of
Concrete under accelerated carbonation.......37
News From ACCE(I) Head Quarters....................46
News from ACCE(I) Centres................................46
ACCE (I) Membership Additions........................48
Professional Directory.........................................49
Thanks To Patrons..............................................50
Continued on page 42
Bulletin of ACCE (I) 4 January - March 2011
PRESIDENT’S MESSAGE
From the Editorial Desk
Dear Members of the ACCE(I) Family,
Wish you a Very HAPPY AKSHAY TRUTIYA 2011.
Let me inform you that the Building Committee under the leadership of Shri A. Nirmal
Prasad had done extensive work in identifying various buildings for the Head Quarter
office and also trying to get land from the local authorities. It is in the process and hopefully
in near future HQ will have its own premises. As everyone knows that the cost of land or
building in a metro city like Bangalore is very high and hence it is the duty of all the
members to fulfill this dream by contributing financially to this noble cause.
Our team started in 2009 at Davangere with a vision document planning for various activities. There were various
committees constituted and each committee had done excellent work within a short span of two years. The most
important had been the celebration of Silver Jubilee of ACCE(I) and it was a grand show under the dynamic leadership
of Shri Ajit Sabnis. The major achievement is the revision of Bye-Laws of ACCE(I) in tune with the global scenario and
other organisations in the profession. The major laudable achievement is introduction of Student membership category
which is the need of the day. Revision of Bye-Laws was a hurriculan task and was carried out by the team of Shri D.
Ranganath. The Awards committee led by Shri Umesh B. Rao had done excellent work by delinking the programme
from AGM and giving sufficient time to award winners which was made memorable by the Hyderabad Centre under
Shri P. Suryaprakash and Shri S. P. Anchuri. There is only one addition of new centre of Karim Nagar but there is
considerable increase of membership.
There had been excellent work done by Dr. M. U. Aswath, Secretary General, Shri Badarinath Singri, Treasurer and
very dynamic Manager Shri S. D. Annegowda. My role as President was negligible with hardly any contribution. The
whole work was done by the HQ other office bearers and the staff.
ACCE(I) will flourish under the new team of HQ office bearers, Shri B.S.C. Rao, Shri Ajit Sabnis and Shri P. S.
Deshpande. They will march ahead with the vision for the all round development of the ACCE(I) with the support and
contribution of all the members. I wish them all the success.
With very warm personal regards,
Avinash D. Shirode
Dear Fellow Members,
Greetings to all from HQ.
We have recently concluded the elections for new office bearers. The results will be
announced by Secretary General in the next AGM. It's welcoming to note that many
members participated to vote in a democratic way to elect the new office bearers. I would
have appreciated if more members come forward to cast the votes and participate in the
election process. New team will pave way for new thought process and new vision to
achieve and further the objectives of the Association. I wish the new team every success.
I urge members to contribute to the bulletin in the form of articles, news items around your
town, topics of interest that can shared with others, professional tips etc., which makes
the bulletin livelier to read.
Best wishes
Ravindranath BV
Bulletin of ACCE (I) 5 January - March 2011
From Secretary General’s Desk
Dear Members,
Some time back, I had written in the bulletin that all our engineers should involve themselves in
social activities for the betterment of the society. One of the ways we can contribute is to extend
technical support and knowledge sharing with the general public. The awareness of the public in
critical issues of building construction will enable them to demand for better quality from the
builders. In this direction ACCE (I) in association with THE HINDU the national news paper is
bringing out a column called BUILD-FORUM on Saturdays in PROPERTY PLUS supplement.
Build – Forum, the public query column by property Plus, invites questions related to technical/structural/civil aspects
of buildings. The questions will be answered by professionals connected to the Association of Consulting Civil Engineers
(I). The readers can send the queries to
ranju@thehindu.co.in
We are quite successful in this initiative and already the column BUILD-FORUM is getting popular among the readers.
For the benefit of our members I am giving below the details of the articles in The Hindu, the online links are also
provided.
1.Safety first, always: Stability of high-rise buildings depends on factors such as height, width and configuration
of the structure, March 12, 2011,
http://www
.hindu.com/pp/201
1/03/12/stories/201
1031250280200.htm
2.Know the significance of sunshades: In our enthusiasm to achieve newer styles in the design of buildings, we
should not overlook certain time-tested basic rules, advises, Mar 19, 2011,
http://www
.hindu.com/pp/201
1/03/19/
stories/201
1031950290300.htm
3.Ideal designs need collaborative efforts: Beams that are visible inside homes are not commentaries on
buildings being unsafe. They form part of the structural get-up of a design, march 26, 2011
http://www
.hindu.com/pp/201
1/03/26/stories/201
1032650440200.htm
4.Safe design of staircase: April 2, 2011
http://www
.hindu.com/pp/201
1/04/02/stories/201
1040250470200.htm
5.No ceiling for ceiling heights: A high ceiling is an inspiration, improves productivity and provides a strange
sense of freedom, April 9, 2011
http://www
.hindu.com/pp/201
1/04/09/stories/201
1040950410300.htm
6.For the right plumbing techniques: Improper plumbing designs cause leakages in pipes and damage the
building, April 16, 2011
http://www
.hindu.com/pp/201
1/04/16/stories/201
1041650320200.htm
7.Passing on a new look, making a style statement: The building envelope design must include structural
integrity, moisture/temperature/noise control and regulation of air flow. An article related to building cladding, April
23, 2011
http://www
.hindu.com/pp/201
1/04/23/stories/201
1042350300200.htm
8.Bamboo adds to the building strength: with earthquakes occurring frequently, the basic care that should be
taken is in the material that we use in construction. An article related to bamboo in building industry, April
30,2011
http://www
.hindu.com/pp/201
1/04/30/stories/201
1043050520300.htm
I invite the members to involve in this activity and send the willingness to
admin@accehq.net so that the queries will
be forwarded for comments. The local centers of ACCE (I) can start similar activity in association with the local news
papers and other media.
With best regards,
Dr.Aswath M.U.
Bulletin of ACCE (I) 6 January - March 2011
ACCE AWARDS 2011 - CALL FOR NOMINATIONS
1.ACCE-BHAGWATI AWARD for Outstanding Design for Industrial Plant/ Structures. Instituted by: Bhagawathi
Associates Pvt. Ltd., Mumbai.
2.ACCE-SIMPLEX AWARD for Innovative Design of Structures other than Industrial. Instituted by: Simplex
Concrete Piles (India) Pvt. Ltd., Calcutta.
3.ACCE L & T ENDOWMENT AWARD for Excellence in Construction of Industrial Structure. Instituted by: L
& T, ECC Construction Group, Chennai.
4.ACCE BILLIMORIA AWARD for Excellence in Construction of High Rise Building. Instituted by: B E
Billimoria & Co. Pvt. Ltd., Mumbai.
5.ACCE SOM DATT AWARD for Excellence in Construction of Transportation Projects. Instituted by: SOM
DOTT Builders, Delhi.
6.ACCE SARVAMANGALA AWARD for Excellence in Construction of Civil Engineering projects other than
industrial plant & transportation projects. Instituted by: Sarvamangala Constructions, Chennai
7.ACCE GOURAV AWARD for Significant Contribution to Civil Engineering Consultancy. Instituted by: Gourav
Engineers, Bangalore
8.ACCE CDC AWARD for Best Software Package in Civil Engineering. Instituted by: Computer Designs
Consultants, Chennai
9.ACCE NAGADI AWARD for Best Publication (Book) in Civil Engineering. Instituted by: Nagadi Consultants
Pvt. Ltd., Delhi
10.ACCE AWARD: For Creative Applications of Building Materials for Durability. Instituted by: Association of
Consulting Civil Engineers (India)
11.ACCE INSWAREB AWARD for Effective Use of Blended Cement in Design and Construction of Civil
Engineering Projects. Instituted by: INSWEREB of Vishakapatnam.
12.ACCE FOSROC AWARD for Effective Use of Construction Chemicals in Civil Engineering Projects. Instituted
by: Fosroc Chemicals (India) Ltd., Bangalore.
13.ACCE-JMC AWARD for Best Construction by Budding Company of India. Instituted by JMC Projects (India)
Limited, Chennai.
14.ACCE-GAMMON AWARD for Effective Use of Construction Materials/Systems In Construction Resulting
In National Savings. Instituted by: Gammon India Limited, Mumbai.
15.ACCE- L&T FORMWORK AWARD for Best Use of Formwork In Civil Engineering. Instituted by Larsen &
Toubro Limited, ECC Division) Chennai.
16.ACCE ESSEN AWARD for Appropriate Use of Construction Chemicals & Epoxy for Rehabilitation /Retrofitting
of Civil Engineering Structure by Consultants. Instituted by Essen Supplements India Ltd., Secunderabad.
17.ACCE- Er. P T Mase Memorial Award for Innovative Structural Design by
upcoming structural Designer Instituted by: P T Mase & Associates, Nagpur.
18.ACCE MEGH STEELS AWARD for Excellence in the use of Rectangular/ Square Hollow Sections in Steel
Structures. Instituted by: Megh Steels Private Limited, Bangalore.
Nominations are invited from Consulting Engineers, Designers, Planners, Construction Agencies, Computer
Software Developers and Authors. The works completed in the above areas during the last 3 years are to be
submitted on or before 30
th
July 2011 in a prescribed Proforma. Proforma can be down loaded from
the website:
www.accehq.net These awards will be presented during the ACCE ANNUAL Awards Function
to be held on third week of October 2011 at Nagpur.
for more details please contact:
Chairman, Awards Committee
ASSOCIATION OF CONSULTING CIVIL ENGINEERS (INDIA)
No. 2, UVCE Alumni Association Building, K. R. Circle, Bangalore - 560 001
Tel: 91-080-2224 7466 Tel/Fax: 91-080-2221 9012
E-mail: admin@accehq.net Website: www.accehq.net
Bulletin of ACCE (I) 7 January - March 2011
EUGÈNE FREYSSINET
HIS INCREDIBLE JOURNEY TO INVENT AND EVOLUTIONIZE
PRESTRESSED CONCRETE CONSTRUCTION
Authors : Pierre Xercavins, Daniel Demarthe and Ken Shushkewich
Presented at fib-days 2010 at Delhi by C.R. Alimchandani
t has been just over 100 years when EUGÈNE FREYSSINET
STARTED HIS CAREER IN 1905 in Moulins, France as
Ingénieur des Ponts et Chaussées (Engineer of Bridges
and Roads). He approached problems in a graphic way
using free hand drawings and simple calculations in the
margins and sometimes used Graphic Vector resolution
where required.. He built numerous bridges in the Moulins
region. The Praireal-sur-Besbre Bridge built in 1907, a three
hinged arch with a span of 26 m was the first bridge in the
world to have the arch lifted from the formwork by the use of
hydraulic jacks at the crown hinge. This was created by
Freyssinet in a very early stage of his career.
One of the fortunate events in the
life and career of Eugène
Freyssinet was his close
association with likeminded
contractors François Mercier,
Claude Limousin and Edme
Campenon.
Freyssinet patented Prestressed
Concrete (pre-tensioning) in 1928,
the Flat Jack in 1938 and the
concrete anchorage (post
tensioning) in 1939. We will discuss this later in this lecture.
One of the fortunate events in the life and career of Eugène
Freyssinet was his close association with likeminded
contractors like François Mercier, Claude Limousin and
Edme Campenon.
Freyssinet patented Prestressed Concrete (pre-tensioning)
in 1928, the Flat Jack in 1938 and the concrete anchorage
(post tensioning) in 1939.
After the first stage of development of prestressing,
Freyssinet had a small group of dedicated, brilliant
colleagues (they were all geniuses with an IQ of over 160).
Yves Guyon, his Associate, gave prestressing its
mathematical basis, Pierre Xercavins, who joined in 1950
was involved in large projects with Eugène Freyssinet, he
soon followed Yves Guyon to become the Technical Director
of Europe Etudes which was the design subsidiary of
Société Technique pour l'utilisation de la Précontrainte
(STUP), which was created in 1944 to spread the knowledge
of Freyssinet's inventions relating to Prestressed Concrete
across the world they designed many bridges in France
and internationally. Pierre Xercavins was awarded the
Fédération Internationale de la Précontrainte (FIP) Medal in
1970 for outstanding work in Prestressed Concrete
Structures and the Albert Caquot Prize in 1991 for being the
best Civil Engineer in the world. He also designed many
other large and complex structures most notably the
Montreal Olympic Stadiaii, Ekofisk and Ninian Offshore
Platforms, the last two being the first and the tallest
Prestressed Concrete oil platforms in the world. Pierre
Xercavins had the same approach to conception of
structures as Eugène Freyssinet.
I was able to observe the works of Eugène Freyssinet and
be a disciple of Xercavins for 2½ years. Between 1958 and
1963 I shared the enthusiasm of Pierre Xercavins to spread
the knowledge of Prestressing with engineers all over the
world. In 1963 I was sent to work by Yves Guyon for the
newly opened design office of STUP in India: STUP
Consultants Pvt. Ltd. STUP Consultants Pvt. Ltd. has now
worked in 36 countries, has 1400 Engineers, Architects and
Technicians and support staff and still carries on
Freyssinet's, Guyon's and Xercavin's mission. I therefore,
would like to offer this tribute to these great men by presenting
a summary of the Article made by Pierre Xercavins about
Eugène Freyssinet "EUGENE FREYSSINET HIS
INCREDIBLE JOURNEY TO INVENT AND REVOLUTIONIZE
PRESTRESSED CONCRETE CONSTRUCTION" a short
time before Mr. Xercavins passed away in 2008. Whenever
I was at the limit of my knowledge, from 1958 up to the time
he passed away, I was able to get advice from Pierre
Xercavins. I also met along with Mr. Xercavins, Mr. Yves
Guyon, the First Technical Director of STUP France and Mr.
Eugène Freyssinet, whenever the solution of a problem
required their advice. I have also to explain the role played
by Mr. K.K. Nambiar, the first Indian Chief Engineer of the
erstwhile Madras State P.W.D. and Yves Guyon in setting up
STUP Consultants Pvt. Ltd. in India, without the technical
courage of Mr. K.K. Nambiar and his accepting Prestressed
Concrete for the Palar Bridge, the use of this technique by
India would have been much delayed - they encouraged the
creation of STUP Consultants Pvt. Ltd. by becoming
respectively the first Chairman and a Founder Director of
this Company.
WORLD RECORD SPAN LENGTH BRIDGES
The long-term relationship between Freyssinet and the
contractor Mercier started with Veurdre Bridge. During their
period together Freyssinet designed and built concrete Arch
Bridges, which successively broke his own world records
for span length. Due to financial constraints and
bureaucratic obstacles, money was not available for the
Veurdre Bridge and two other bridges across the Allier River:
Boutiron Bridge, and Mercier's friend Regnier was interested
in the third bridge at Chatel-de-Neuvre. They made a bold
proposal undertaking to build all three bridges together for
630,000 Francs, which had been allocated for the Veurdre
Bridge alone; Mercier assuming total financial responsibility
and Mr. Freyssinet the technical responsibility. The proposal
never had to pass an Inspection Committee as Freyssinet
had to do the Design for Mr. Mercier and supervision of the
same for the Government - also Mercier agreed to be paid
only after the work was completed.
Bulletin of ACCE (I) 8 January - March 2011
The main problem during construction was the decentering
of the long arches that were subjected to creep and
shrinkage. This was achieved by using thrusts created
directly, following the procedure first used on Praireal-sur
Besbre Bridge. After constructing the Veurdre Bridge,
Freyssinet kept on observing the behaviour of the same. It
was a very flat arch with a depth to span ratio of 1:15.
Fig. 2: Veurdre Bridge (72.5 m span) (1911-1912)
He observed deformations due to creep and shrinkage first
slowly and then rapidly till collapse seemed inevitable and
he and his loyal workers replaced the Decentering Jacks in
the early morning when no one was around and raised all
three vaults at once to the correct levels. The bridge regained
its shape and behaved perfectly until 1940, when it was
destroyed during the IInd World War.
This bridge on the Lot River consists of a plain concrete
arch with a span of 96 m, a world record at the time.
Fig. 3: Villeneuve-sur-Lot Bridge (96 m span) (1914-1920)
Construction was started in 1914 but was soon stopped
due to the Ist world war. The bridge was completed after the
war in 1920.
The most interesting aspect of the bridges from the point of
view of construction was the use of Decentering Jacks -
previously spans collapsed during decentering when the
span was greater than 70 m. Freyssinet used them not
only for striking the formwork, but also for correcting stresses
after construction created by deformation of the arch due to
creep and shrinkage. Thus it was possible to carry out this
procedure at any time during the lifetime of the bridge.
Today, the bridge remains as natural in its urban setting as
it did when it was first built. The bridge has reddish exposed
brick arcades that hide the spandrels resting on the arch
and let the bridge blend well with the buildings in town.
The Lot Bridge was followed by Saint-Pierre-du-Vauvray
Bridge of 131 m span in 1922-23 which again held the
world record at the time.
Plougastel Bridge (3 spans at 186 m) (1925 - 1930)
The Plougastel Bridge on the Elorn River near the City of
Brest, close to its harbour, consists of three reinforced
concrete arches each having a span of 186 m (610 ft), a
world record at the time. The reinforced concrete trussed
double deck accommodates a roadway on the upper deck
and a railway on the lower deck (the railway over the bridge
was never completed).
Fig.4 : Plougastel Bridge (3 spans @ 186 m)
For this construction, Eugène Freyssinet took advantage of
the tides to bring on floating barges, an enormous wooden
truss, which was used for the successive construction of
the three arches. The truss was built on the riverbank,
launched at high tide with the aid of two barges, and installed
for the construction of the first arch. After completion of a
span, prestressing was used for raising up the arch from
the centering, the centering truss was then lowered and
floated into position for construction of the second arch,
and then the third arch.
Prestressed Concrete Patent (1928) (Pre-tensioning).
Freyssinet first had the idea of compressing concrete by
prestressing. It took twenty five years of laboratory tests
and profound thought to discover the difficulties involved
and the ways to over come them.
Fig.5 : Pre-tensioning (Forclum electricity poles)
He applied for a patent for a "Fabricating Process for
Reinforced Concrete Elements". The process was adapted
to precast beams, pipes, sleepers, poles, etc.
At the time of the patent, in 1928, the Scientific Community
did not believe in prestressing. Thus, Freyssinet decided
to go out alone to demonstrate the merits and possibilities
of prestressing, risking all his fortune, energy and reputation.
He thus started producing electricity poles at the Forclum
plant at Montargis in France.
He perfected the grinding fineness of cement to increase
its strength, improved on his previous invention of
mechanical vibration, invented steam curing and perfected
the industrial precasting process. The result was a
complete technical success but a total commercial failure
due to the depression of 1929.
In five years, he lost his entire fortune that he had
accumulated during his past career. He never regretted it
because he had obtained technical results for more
important than all of those which he achieved between 1905
and 1928.
Flat Jack Patent (1938).
Eugène Freyssinet next invented the Flat Jack for
compressing the raft of the Portes de Fer Dam in Algeria
and immediately after that on a much grander scale for
raising the height of the Beni Badhel Dam in Algeria by 7 m
to bring it up to 67 m. the patent was applied for in 1938 and
validated in 1939.
Bulletin of ACCE (I) 9 January - March 2011
Fig.6 : Flat jack (schematic)
The Flat Jack is made of two stamped steel sheets
connected by welding. By hydraulically introducing a fluid
under pressure, the flat jack is inflated and can develop
considerable force. It is a remarkable device for its power,
lightness, and low cost. The fluid can be oil, resin, grout,
cement, or other ingredients. The Flat jack can be used to
vary the compressive forces applied with time to allow for
adjustments of structures after their construction. The flat
jack has been used on a great many projects around the
world, including the Montreal Velodrome described in this
paper.
CONCRETE ANCHORAGE PATENT (1939) (Post
Tensioning).
Eugène Freyssinet applied for a patent for "Tensioned Cable
Anchorage System for Prestressed Concrete Construction".
The patent was issued in 1947 (because of the war).
The system consists of 12 Nos. 5 mm diameter parallel
steel wires locked or anchored in a concrete anchorage
cone by a tensioning jack. The steel wires which were
threaded through the anchorage consisting of a reinforced
concrete cylinder having a central conical hole (female cone)
and a central fluted conical block (male cone). The steel
wires were tensioned simultaneously with the aid of a jack
and locked-off by the male cone inside the female cone
while under tension. The wires transmitted their tension to
the structure via the anchorage.
This invention allowed tensioning to be achieved by resting
on the concrete directly. The prestressing cable could be
long or short, rectilinear or curvilinear, and positioned inside
or outside the structure (external prestressing as well as
internal prestressing). The force in the prestressing cable
could be adjusted during construction. This system gave
the engineer a wide liberty in the position and intensity of
prestress that he/she wished to develop, and has been
used in the construction of most of the large structures since
that date.
The original 5 mm wires were progressively replaced by 7
mm wires, then 8 mm wires and then by seven wire strands.
In the case of the concrete anchorage of 1939, the capacity
was 20 T which was replaced by a steel anchorage in 1960
with a capacity of 150 T. Individual wedges for each strand
came into existence in 1965 and a capacity of 200 mt was
achieved.
SAVING THE LE HAVRE MARITIME STATION FROM
COLLAPSE.3
The Maritime Station in Le Havre completed in 1933 for the
ocean liner Normandie, was sinking 25 mm (1 in) per month
into a deep layer of clay, and according to Freyssinet
"Imminent collapse seemed to be inevitable. He wrote,
I proposed a solution which, despite its boldness, was
adopted without argument as it constituted the only possible
hope of avoiding disaster".
Fig.8: Le Havre Maritime Station
The strengthening of this building in 1934 is considered to
be the first use of devices for prestressing. In the first stage,
Freyssinet strengthened the foundations to make them
monolithic by use of external prestressing by Cables and
Jacks at their extremities and then increased the bearing
capacity of foundations by adding piles that were driven in
segments until they reached layers of soil which could carry
the loads without abnormal sinking.
Fig.9 : Le Havre Maritime Station elevation
Freyssinet solution consisted of adding new footings (B)
between the existing footings (A) to make the entire unit a
monolithic prestressed horizontal element. The unit was
prestressed with parallel wires turned around two reinforced
concrete end anchorages One anchorage was displaced
by hydraulic jacks having a force of up to 1000 mt (1100
tons). The link between the old and new concrete was
assured by the general compression of the whole. The
moveable anchorage was fixed by concreting the free space
and the jacks were removed. The wires forming the cables
were covered by concrete to protect them from corrosion.
The A units supported columns above while the B units had
sockets in them to drive piles through.
Fig.7 : Post-tensioning (concrete anchorage cone and
tensioning jack)
Bulletin of ACCE (I) 10 January - March 2011
Fig.10 : Le Havre horizontal prestressing of footings
Fig.11 : Le Havre anchorage for horizontal prestressing of
footings
Fig. 12 : Le Havre existing columns above and the sockets
for new piles below the combined footing
The second part of the Freyssinet solution was to install
700 piles, 25 to 30 m (82 to 98 ft) long that extended to
sound layers of soil. The piles were cast inside the building
in 2 m (6.6 ft) sections, and were assembled by prestressing
and driven into the ground using special jacks designed by
Freyssinet. Vibration, compression, and steam curing of
the concrete were all used to improve the rate of casting
and quality of concrete. The piles were then prestressed
against the footing by means of hydraulic jacks having a
vertical prestressing force of 320 mt (352 tons). The
settlement immediately ceased as soon as the first piles
were installed.
The result was both spectacular and convincing, and at once
earned Freyssinet a worldwide reputation. This created the
opportunity for a meeting between Eugène Freyssinet and
Edme Campenon, and started the collaboration between
the two in 1934 on the entire range of construction projects
of the Campenon Bernard group, a collaboration that finally
was destined to ensure the development of prestressing.
PROLIFERATION OF FREYSSINET TECHNOLOGY
AROUND THE WORLD.
With success at Le Havre, the contractor Edme Campenon
offered Eugène Freyssinet "the chance to experiment, apply,
and develop his invention of prestressing and his ideas on
concrete construction, on the entire range of sites of the
Campenon Bernard group". Later in 1943, Edme
Campenon created a special division called STUP (Societe
Technique pour l'Utilisation de la Précontrainte) [Technical
Company for the Use of Prestressing] for the "development,
protection, and implementation of the techniques of which
M. Freyssinet is the inventor". In 1961 STUP created a
design company, Europe Etudes, so as not to restrict the
development of prestressing technique to the sole use of
its original inventor and developer. STUP also wanted to
spread this technology all over the world. With this aim, in
1963, STUP started its design bureau in Mumbai - STUP
Consultants Pvt. Ltd. Today, STUP Consultants Pvt. Ltd.
employs over 1400 Engineers, Architects, Technicians and
supporting staff and has designed and implemented
projects in 36 countries. Today, STUP Consultants Pvt. Ltd.
is active in all branches of Civil and Structural Engineering,
Architecture of Buildings as well as of Airports - including
the associated Mechanical and Electrical Engineering. In
1976, STUP France changed its name to Freyssinet
International instead of STUP, which soon after became
known as Freyssinet International. The group, at that time,
included a prestressing supplier, which was a disseminator
of technical information around the world (Freyssinet
Company), a contractor (Campenon Bernard), and a
designer (Europe Etudes). In 1982 STUP Consultants Pvt.
Ltd. separated from the Freyssinet Group as it wished to
become an independent consultant.
INVENTION OF PRECAST SEGMENTAL CONSTRUCTION:
The Luzancy Bridge over the Marne River (started in 1941
and completed in 1946 after the war), was the first of a new
generation of precast segmental bridges designed and
constructed by Eugène Freyssinet. It has a span of 55 m
(180 ft), a world record at the time, and was built to replace
an old suspension bridge. It is very light in appearance and
has a remarkable span to depth ratio of 1: 45.
Fig.13 : Luzancy Bridge (55 m span) (1941-1946) (first
precast segmental bridge)
The Luzancy Bridge was visited sixty years after completion
in October 2007 by me along with other members of the
Freyssinet Association. It is in pristine condition and the
concrete of the precast segments is of excellent quality.
Fig.14 : Luzancy Bridge in 2007
The bridge is an 8 m (26 ft) wide portal frame comprised of
three box girders that were precast in segments and
assembled on site in sections. The bridge was prestressed
longitudinally and transversely with 12 - 5 mm diameter
Bulletin of ACCE (I) 11 January - March 2011
tendons, and vertically with 5 mm pre-tensioning wires that
were stressed prior to concreting. It was erected by
launching equipment consisting of masts and stay cables
(one of the most imaginative systems ever used for the
assembly of prefabricated bridge elements).
The middle box girder being erected is 39 m long and
weighs 90 T. All three of Freyssinet's inventions for
prestressing (pre-tensioning, flat jacks, and post-tensioning
were used here).
Fig.15 : Luzancy Bridge during construction
The Underground Basilica at Lourdes takes its inspiration
from the Esbly Bridge of the Luzancy lineage. The structure
was conceived by Eugène Freyssinet in only fifteen minutes,
designed by Jean Chaudesaigues, and constructed by
Campenon Barnard from 1956 to 1958. It consists of only
29 portal frames and can accommodate 20,000 people.
Fig.16 : Underground Basilica at Lourdes (capacity: 20,000
people)
Fig.17 : Pierre Xercavins speaking
at the 50th anniversary of the
Basilica of St. Pius X at Lourdes on
March 14, 2008 (photo courtesy :
Association Eugène Freyssinet).
Choisy-le-Roi Bridge (1962-1964)
Jean Muller also a genius like Xercavins worked as a close
collaborator and eminent disciple of Eugène Freyssinet in
Campenon Bernard and Company, pioneered match-cast
technology in the early sixties with the Choisy-le-Roi Bridge
over the Seine River in France. On this bridge, he used for
the first time, precast segmental box girder technology with
match-cast epoxy-coated joints. I visited the site with Jean
Muller, while outsiders were not allowed to visit unless the
bridge was completed and put into service. (In the precasting
yard the previously cast segment was used as the end form
for the next segment, in order to obtain perfect contact
between adjacent segments and to get directly the final
profile of the deck). This bridge has three continuous spans
of 37.5m - 55m-37.5m (123ft-180ft-123ft), with a total width
of 28.4m (93 ft) that was divided into two parallel single cell
box girder bridges. A total of 148 precast segments were
fabricated using the long-line casting method. Typical
segments weighed 20mt (22 tons). The bridge was erected
in balanced cantilever using a floating crane.
Fig. 18 : Choisy-le-Roi Bridge (1962-1964) (first precast
segmental "match-cast" bridge)
Bear River Bridge (1971-1972)
The Bear River Bridge near Digby, Nova Scotia in Canada
was the first precast segmental box girder bridge built in
North America using the match-cast method with epoxy-
coated joints. This curved bridge is 609 m (1998 ft) long
with six interior spans of 80.8 m (265 ft) and two exterior
spans of 62.1 m (204 ft). The bridge is 12.0 m (39.5 ft) wide.
The 145 segments were cast in a plant located near the
bridge site using two short-line casting cells each producing
one segment per day. The segments weighed a maximum
of 82 mt (90 tons), and were placed by a 180 mt (200 ton)
mobile crane on land or on a barge over water. The bridge
was designed by A.D. Margison and constructed by Beaver
Marine Ltd., with construction engineering assistance
provided to the Contractor by Europe Etudes under the
leadership of Pierre Xercavins and Daniel Demarthe.
Fig.19: Bear River Bridge (1971-1972) (first precast
segmental "match-cast" bridge in North America Montreal
Velodrome (1973-1976)
The Montreal Velodrome for the 1976 Olympic Games pays
tribute to Eugène Freyssinet because it incorporates so
many of his prestressing and construction techniques. This
very flat airy vault of prestressed concrete and is supported
at four abutments only, and is inscribed in a rectangle of
172 m by 130 m. The covered area without intermediate
supports is 16, 000m2 .
Completed Structure
Bulletin of ACCE (I) 12 January - March 2011
One of the most interesting phases of construction was the
decentering (the transfer of loads from the false work to the
permanent supports at the abutments).
Structure during construction.
By placing flat jacks at the four abutments and jacking to an
amount equal to the calculated reactions, the roof slowly
rose until the entire weight of the structure was taken by the
four abutments only. A total of 226 flat jacks each with a
capacity of 1000 mt were used for the decentering. Once
the loads were transferred, the false work was removed
giving a clear span of 172 m.
The veledrome was designed by Trudeau, Gascon, and
Lalancette with technical assistance provided by Europe
Etudes under the leadership of Pierre Xercavins and Daniel
Demarthe.
Flat jack scheme at Abutment
The main structural elements are six arches which spread
away from the Z abutment, and meet again in pairs on
either side of the W, X and Y abutments. Two secondary
arches connect the X abutment to the W and Y abutments.
The arches are comprised of 142 precast segments that
are built using the match-cast method with epoxy-coated
joints, and erected on temporary false work. A network of
63 double Y-shaped beams span between the arches. The
structure is completed with cast-in-place concrete joining
the arches to the abutments.
Caracas Viaduct during construction Bridge(1) completed
Bridges (2)and (3) completed Caracas Viaduct Completed
(1951-1953)
Orly Airport Bridge (1957 - 1959)
I visited this bridge under construction when I was a trainee-
it was the first continuous bridge in the world.
Orly Airport Bridge (1957 - 1959)
Saint Michel Bridge (1959 - 1962)
It has portals with slim piers in the direction of the water
flow during floods. This was the first prestressed concrete
portal bridge carrying Railway lines.
Saint Michel Bridge (1959 - 1962)
CONCLUSIONS
Freyssinet repeatedly stated, "I was born a builder". Indeed,
he became totally immersed in the building of his structures,
"becoming simultaneously engineer, contractor, carpenter,
form worker, steel worker, cement specialist". In the words
of Jean Montagnon "If Eugène Freyssinet had been a
musician, he would have been a composer, an instrument
maker, an instrumentalist, and a conductor." Freyssinet also
stated repeatedly that he had invented an entirely new
material which led to "a revolution in the art of building". He
continued to design and build until his death. Included in
his latter structures are the three arch bridges of the Caracas
Viaduct from 1951 to 1953, the Underground Basilica at
Lourdes from 1956 to 1958, the Number 10 Bridge at Orly
Airport from 1957 to 1959, and the Saint-Michel Bridge at
Toulouse from 1959 to 1962. The Saint-Michel Bridge
opened in March 1962, three months before Freyssinet's
death. Eugène Freyssinet has been proclaimed as one of
the most complete engineers of the 20th century and is
certainly one of the greatest builders in world history. I
present this paper with some emotion as it includes slices
of my life.
Structural Layout Flat jack layout at Abutment
Decentered structure
(172 m span)
Caracas Viaduct
(1951-1953)
Bulletin of ACCE (I) 13 January - March 2011
The Alternative Building Materials and Technologies for Individual
Housing in Coastal Karnataka
RAJENDRA KALBAVI RAO,
Project Director D. K. Nirmithi Kendra, National Institute of Technology Karnataka, Surathkal
SUDEEP KUMAR SHETTY,
Rachana consultants, , 1
st
floor, Venkataramana Arcade, Bhavanthi Street, Mangalore
JOHN KENET D’SOUZA,
Consulting Engineer, 1
st
Floor, Krishna Complex, MG Road, Kodailbail, Mangalore
Introduction
World hates change, yet, it is the only thing
that has brought progress- Charles Kettering.
‘Normal is boring’ is the common saying. Man needs
change in every aspect of life, for which construction is
no exception. He needs change, needs different designs,
needs variety, needs choices and other options before
he decides. The various research Organizations in the
country and world wide are in continuous investigation
to develop different alternative materials and
technologies. These vary from basic materials like stone
and sand to finishing materials like paints and coatings.
As science and technology advances, it is becoming
challenging work to the scientists to give an improvised,
fault free and performance oriented products and
technologies to suit the general public. List of building
materials to choose from has become very exhaustive
and expensive results in the urge to develop newer and
different materials to suit local condition and to suit the
varying human requirements.
Costal Karnataka
The cities in costal Karnataka are situated attached to
Arabian Sea. Mangalore is located at 12°-52’N latitude
and 74°-49’E longitude. The average rainfall is 3875 mm
between Junes to September every year. The ambient
temperature varies minimum from 17°c to a maximum
37°c.The maximum average humidity is 93% in July and
average minimum humidity is 56% in January. There are
only 2 seasons, namely rainy season and summer
season. Generally days are warm through out the year.
Sloped roof with Mangalore tiles are commonly used,
before invention over concrete. Bricks, cement, steel,
aluminium, plastic products, paints, polished stone,
ceramic products, etc. are the commonly used materials
of construction today. Modern day house construction
involves in construction of framed structure with lintels
and chajjas and RCC for roof slabs. Those who can afford
will have air conditioned rooms and others will keep large
openings for ventilation and comfort inside the house.
Why Alternative building Materials and
technologies
Selection of materials and technologies for the building
construction should satisfy the felt needs of the user as
well as the development needs of the society, without
causing any adverse impact on environment. The first
energy crisis of 1973 was perhaps the trigger, which lead
to the concept of Alternative Building Technology.
Technologies of the Developed West often could not meet
these requirements and many thinkers argued in favour
of a middle path and this approach is the genesis of the
Alternative Technology movement. With the development
of science and technology alternative materials and
technology is available, right from the basic materials
like cement to building blocks, from foundations to
finishing items. Few of them are explained below.
Building Blocks
Naturally occurring laterite stone blocks are commonly
used in coastal areas. Fig.1. The concrete blocks have
spearheaded the construction industry with varying sizes
form brick to laterite. The investment is very low and it
can be produced throughout the year as compared to
the brick industry. Fig.2
Burnt Clay Hollow Blocks:-
These are burnt high clay blocks made by a process of
extrusion. The wall thickness of the hollow block is often
as low as 15 to 20 mm. They come in various sizes from
laterite block to brick.
Stabilized Mud Blocks
Soils when compacted using external energy, the density
of the soil reaches a maximum value at the optimum
moisture content (OMC). The value of OMC and the
maximum density depends on the energy input during
compaction. The compressive strength of the soil, in the
dry state, depends on the density. Thus the process of
mechanical compaction can lead to densification and
strengthening of the soil. Addition of stabilized additives
like Cement, lime or bitumen further improves the
densification during saturation. These blocks can be
produced locally with manually operated machines with
suitable mould sizes. Fig 3
Stone Blocks using recycled wastes
The BIS specification IS: 12440 give the details of this
technique. It is a very simple technology involving using
odd sized stones, which are shaped by a layer of
concrete surrounding the stone. Steel moulds resting
on level ground can be used to place the odd shaped
stone in the centre of the mould. Lean concrete is now
poured in the space between the stone and the mould.
Block sizes matching to laterite or concrete blocks are
commonly used. Compressive strength in the range of
5.0 to 7.0 MPa can be easily achieved.
Masonry construction techniques
English bond is the most common mode of construction
in India. When Concrete blocks are used, the blocks
have to be kept in ‘Stretcher bond’ leading to a wall
Bulletin of ACCE (I) 14 January - March 2011
thickness of 100,150 or 200mm and a course height of
200mm as shown again in Fig.2. When stabilized mud
blocks of size 230x190x100mm are used, either a header
bond with wall thickness of 230mm or a stretcher bond
of 190mm wall thickness can be used. The concept of
rat-trap bond was popularized by Ar.Laurie Baker in Kerala
in the seventies. This involves keeping bricks on edge
creating a gap in the thickness of the wall. About 25% of
the bricks can be saved by this process. The cavity
created within the wall offers thermal comfort inside the
house. Fig 4&5
Arches, Corbels and Reinforced brick lintels
Masonry arches are the age old construction techniques
can still today replace concrete lintels. Arches can be
circular, segmental or even flat. (Fig 6 & 7) These are
also used in the masonry foundations between the
corners to save on earthwork excavation and materials.
Corbels (Fig 8) and arches give aesthetic look to the
structure while carrying the desired load. Reinforced brick
lintels are the one used or small openings up to 1.8m
with and nominal reinforcement of 3-8 mm in CM 1:3
and bricks laid on edges with the same mortar.
Ferro Cement Elements
Ferro cement is a special form of reinforced concrete. It
is a composite material consisting of cement-sand mortar
(matrix) reinforced with layers of small diameter wire
meshes. It differs from conventional reinforced concrete
primarily by the manner in which the reinforcement is
arranged within the brittle matrix. The success of ferro
cement in various terrestrial applications can be
attributed to ready availability of materials locally, need
of low level technology for its production, better utilization
of available human resources and architectural flexibility.
Ferro cement products are so versatile that they have
reached common man’s kitchen to drawing room furniture
to commercial structures. It is all geared to replace timber
in all the areas of construction. (Fig 9)
Alternative Roofing Systems:-
Due to invent of extensive research done by various
institutions various technological options are available
for implementation. The research for an alternative roof
must be based on a simultaneous satisfaction of several
objectives.
1.Withstand imposed dead and live loads.
2.Prevent leakage during rainy season
3.Provide a secure enclosure
4.To be cost effective
5.Provide a durable comfort in the interior
6.Give aesthetics to the structure
Roofs can be
i) Pre fabricated roof
ii) Partially prefabricated roof
iii) Cast in-situ roof
Few of the technologies commonly used in coastal
Karnataka are explained below.
a) Filler Slab Roofs:-
Filler slab roofs are basically solid reinforced concrete
slabs with partial replacement of the concrete in the
tension zone by a filler material. The filler material could
be cheaper and lighter. A number of filler materials can
be thought of a) Brick or brick panel, b) Mangalore tile,
c) Stabilized mud block d) Hollow concrete block, e)
Hollow clay tile block etc. Size and shape of the filler
material are governed by the factors like slab thickness,
code guidelines on spacing of reinforcement bars, desired
ceiling finish etc and has to be carefully selected. This
is a cast in situ system and is widely accepted and is
most suitable for tropical Climate and for buildings in
coastal region. The laying of this roof is in line with
conventional technique. The form work is done at desired
height and shape, the filler material is placed and the
reinforcement is tied and the concrete is laid. This method
also satisfies all the requirements of the code and the
needs of the common man. Layout of filler material
(Hollow clay block roofing block) along with the
reinforcements before the pouring of the concrete and
the ceiling (with regular Mangalore tile) after completion
are shown in figure. (Fig 10, 11 & 12)
b) The Concept of Composite Beam and Panel
Roofs:
This system is similar to the traditional wooden rafters
and wooden planks used as attic in the olden days. Now
we are using concrete beams and planks made of
materials like brick, ferro cement, stabilized mud blocks
etc are used. The roofing system consists of panels and
beams cast separately and assembled such that the
system behaves like a T-beam. The beams can be fully
pre cast or partially pre cast beams. These types of
roofing systems can be broadly grouped into two
categories viz: Flat panel roof and curved panel or jack-
arch roof, based on the shape/geometry of the panel.
Since the panels and beams are cast separately and
then assembled, there should be proper shear connection
between them to achieve composite action for the system
to behave as an integral structural unit. The flexibility of
composite beam and panel roofs arises out of the fact
that the materials for the beams and the panels could
be of two different materials and the composite action
between them could be achieved by proper shear
connectors. Both the beams and the panels can be
precast and then assembled into a roofing system. In
case of precast beams, the beams are partially cast
and hence they require some props while assembling
the roofing system. These roofs can be laid flat or with
gentle slope. Fig 13.
Bulletin of ACCE (I) 15 January - March 2011
c) Masonry Domes and Vaults:
Romans rediscovered the use of the arch, and the vault.
However, they often used semicircular barrel vaults built
out of concrete. The vaulted constructions spread to
Europe and one can see vaults in Roman architecture of
England. The vault construction was no longer confined
to mosques in this region. The superiority of the brick
masonry vault over the conventional construction using
timber palaces, granaries, ammunition stores were some
of the important structures where the vaulted construction
was readily accepted. A thin layer of nominally reinforced
concrete over and above the unreinforced masonry can
vastly enhance the performance of masonry roofs. Fig
14. Use of modern materials like glass fiber reinforced
plastic as externally attached reinforcement can also
provide additional flexibility and strength.
d) Mangalore tiles over ferro cement rafters and
reapers.
Mangalore tiles over wooden supporting structure are
accepted and adopted technology since centuries. It is
most suitable roof for the coastal region in the tropical
county like India. Timber of good quality is not available
as per requirement and above that it is expensive material.
Concrete and ferrocement can be a suitable substitute
alternative replacement for implementing Mangalore tile
roofing system. The size and the shape can match the
timber and the member can be designed as per
requirement on IS codes.
The wall plate, the rafters and the reepers are
manufactured to design in a factory and shifted and
erected at site. These structures are unlike wood are
fire resistant, termite resistance, anti fungal, low
maintenance and it has a long life then compared to
timber structures. It is a look-a-like structure and one
cannot make out the difference between the conventional
and alternative method once erected. Fig 15.
Energy efficient and eco friendly:
Considerable amount of energy is spent in the
manufacturing processes and transportation of various
building materials. Conservation of energy becomes
important in the context of limiting of green house gases
emission into the atmosphere and reducing costs of
materials. A comparison of energy in different types of
masonry has been studied. Energy in different types of
alternative roofing systems has been discussed and
compared with the energy of conventional reinforced
concrete (RC) slab roof. It is found that total embodied
energy of load bearing masonry buildings can be reduced
by 50% when energy efficient/alternative building
materials are used. Table1.
Conclusion
Opening up of the Indian market has given the common
man to look for the latest and the best suited material
and technique for his suited budget and needs. Table 2
shows the cost benefit in using these technologies. With
internet available at nook and corner of the state, every
man is well informed and has access to knowledge super
highway. Recently lot of materials and techniques are
coming to the market and the common man is confused
to use, adopt, judge and implement the right technology.
We Engineers with all the technical back ground and
experience should have the updated knowledge to use
the appropriate technology at right place at correct time
with proper technical design, supervision and
implementation. Thus the efforts of the scientists and
researchers will have a value addition and a dream come
true for the common man. Fig1. The only shortfall is the
information which reaches the common man gradually
and all the building materials and technologies are time
tested over the years, it takes its own time to prove its
credibility and durability requirements.
References:
[1] A.J.Joseph Increasing the service life of low-cost
buildings, Building Materials for Low-Income
Housing, Oxord & IBH Publishing Co.Pvt.Ltd. New
Delhi. P 335-340.
[2] Harrison S. W, Sinhat B. F, A study of alternative
building materials and technologies for housing in
Bangalore, India Construction and Building
Materials Vol. 9, No. 4, January 1995, pp. 21 l-211.
[3] Jagadish K. S, venkatarama Reddy K. S, Nanjunda
Rao, Alternative Building Materials and
Technologies.2008.New Age International
Publishers. New Delhi.
[4] Jamal M. Khatib, Sustainability of construction
materials. Woodhead publishing Limited.New Delhi.
P 85,86 & 116.
[5] Venkatarama Reddy B. V, Sustainable building
technologies, Current Science, Vol. 87, NO. 7, 10
OCTOBER 2004, pp 899-907.
[6] Venkatarama Reddy B. V, and Jagadish K.S.,
Embodied energy of common and alternative building
materials and technologies, Energy and Buildings
35 (2003) 129–137.
[7] Venkatarama Reddy B.V., Jagadish K.S. / Energy
and Buildings 35 (2003) 129–137, Energy and
Buildings 35 (2003) 129–137, Embodied energy of
common and alternative buildingi materials and
technologies .
[8] Ross Spiegel, Dru Meadows, Green Building
Materials, John wiley & sons, Inc. Professional/Trade
Division,605 Third Avenue, New Yark,N.Y.10158-
0012.P 9,27-30.
[9] S.Q.Jamal and A.S.Sheikh, The use and
Performance of soil stabilized blocks in flood affected
rural areas, Building Materials for Low-Income.
Bulletin of ACCE (I) 16 January - March 2011
Table 2. Cost savings of Innovative technologies over conventional options
S.No Innovative Technologies Conventional Options % of saving
1 230mm thick wall 330mm brick walls 5
3 Rat trap bond walls English/Flemish bond 25
4 Hollow blocks walls Hollow blocks walls 20
5 Tiles over RCC rafters Tiles over timber rafters 25
6 Brick panel with joists RCC 20-25
7 Ferro cement shell roofing RCC 40
8 Filler slab roofing RCC 22
9 Jack arch brick roofing RCC 15
10 Precast blocks over inverted T-beams RCC 25
11 Corbelling for lintels RCC lintels 40
12 Brick arch for lintels RCC lintels 30
13 Hollow clay block walls & corners 20
14 Hollow roofing block RCC slabs 15-25
15 Precast ferro cement shelves Timber/concrete 35-45
Table 1.
Energy in different roofs/floor systems
Number Type of roof/floor Energy/m2 Equivalent of RC
of plan area (MJ) solid slab energy (%)
1 RC slab 73.0 100
2 SMB filler slab roof 59.0 80.8
3 Composite brick panel roof 56.0 76.7
4 Burnt clay brick masonry vault roof 57.5 78.8
5 SMB masonry vault roof 41.8 57.3
6 Mangalore tile roof 22.7 31.1
7 Ferro concrete roof 15.8 21.6
8 RC ribbed slab roof 49.1 67.3
Fig 1. The residence of Mr. Kenet D’souza( Co author)
constructed using Laterite stone blocks and alternative
building technologies
Fig 4 Layout for rat-trap bond construction
Bulletin of ACCE (I) 17 January - March 2011
Fig 2. Hollow concrete block laid with stretcher bond
for wall construction
Fig 3 Stabilized Mud block under production.
Fig 6. Brick arches in place of lintels and beams
Fig 5. Brick wall constructed with rat-trap
bond technique.
Fig 10 Hollow clay block Filler slab before pouring of
concrete
Fig 7. Flat arch with brick masonry to avoid lintels.
Bulletin of ACCE (I) 18 January - March 2011
Fig 11 Filler slab ceiling after completion
Fig 9 Cross section of a Ferro cement member
Fig 8. Large corbels can replace lintels, arches and
beams.
Fig 15. Mangalore tiles supported on Ferro cement
rafters and reepers.
Fig 14 View of a circular brick vault
Fig 13. Ceiling view of a brick panel roof.
Fig 12 Filler slab ceiling using Mangalore tiles after
completion.
Bulletin of ACCE (I) 19 January - March 2011
Estimating the Strength of Concrete - Maturity Method
Bharathi Ganesh,
Asst. Prof., Dept. of Civil Engg., Global Academy of Technology, Bangalore
Dr. H. Sharada Bai,
Professor, Faculty of Engineering – Civil, UVCE, Bangalore University, Bangalore
Introduction
Many operations like when to strip forms, when to post-
tension, when to remove shores, and when to terminate
cold-weather protection are based on reaching a
minimum level of concrete strength development.
Waiting too long is very expensive but acting prematurely
with out confirmation of strength measurement may
cause the structure to crack or collapse. Few cases of
failures of structures (Fig. 1) under construction due to
form stripping and shore removal at improper time have
been witnessed. More timely knowledge of compressive
strength evolution at required time interval during concrete
hardening process is needed, in order to achieve savings
in many ways during construction and also to improve
safety.
Fig. 1 Failures of
Structures due to form
stripping and shore
removal at improper time
Although there are several procedures predicting concrete
compressive strength, reliable methodologies involve
either extensive testing or voluminous databases. Hence
a simple and fast methodology is required to
consequently predict compressive strength evolution. A
simple and efficient method based on the parameters -
activation energy and the degree of reaction of cement,
can be used for a rapid prediction of the mechanical
properties of concrete and particularly the evolution of
compressive strength.
Fig.2 Effect of Curing Temperature on the Rate of
Strength Gain
At early age, the mechanical properties of cement-based
materials are time-dependent and involve hydration of
cement. The hydration process is a thermally-activated
chemical reaction, directly related to the development
of strength which depends on rate of reaction. The
integral over time of the rate of reaction gives the degree
of reaction.
Bulletin of ACCE (I) 20 January - March 2011
Measurement and Predictions of mechanical properties
of concrete are possible by a method based on the
empirical relationship between the degree of reaction
(hydration) in terms of duration of hydration, &
temperature of concrete during hardening process.
Maturity method is one such method, which is used to
predict the compressive strength evolution of concrete,
based on the determination of maturity indexes. These
indexes lead to the prediction of the evolution of
compressive strength of concrete at a required period
after pouring it or from the instant of adding water to the
mix.
The effect of the temperature after similar elapsed times
of hydration, changes with the Thermal Expansion
Coefficient (TEC), and this coefficient depends on curing
temperature (fig.2) and the degree of hydration. To
perform predictions of compressive strength evolutions,
knowledge of maturity indexes is required. Maturity
indexes need to be determined experimentally for each
concrete type.
Originally, hardening time was intended to be an
equivalent of setting time. Studies of the mechanism of
force transmission between sensors and concrete-matrix
indicate that hardening time depends on the degree of
concrete hydration.
The methodology presented here assumes that the
hardening time is an indicator of the degree of reaction.
The relationship between the hardening time and the
degree of reaction is an important issue for the extension
of the methodology to the general field of hardening
materials.
Values of hardening time depend on the following factors
• degree of reaction which in tern depends on factors
like type of materials and machineries used in
making concrete, temperature of hydration, time
etc.
• features of sensors such as thermal expansion
properties and stiffness.
The basis of this methodology
The basis of this methodology involves passing from
mechanical properties of concrete (hardening time) to
thermodynamic chemical properties (activation energy
and rate constant) and back again to mechanical
properties (compressive strength).
What is Maturity Method
The maturity method is a nondestructive technique that
is used to estimate the in-place strength of concrete by
accounting for the effects of temperature and time on
strength development. ASTM standard practice for
estimating concrete strength by maturity method is
ASTM 1074.
Why Maturity Method
Proper method of quality control is essential in every
construction because test samples do not reflect the
influence of temperature extremes, weather conditions,
Cylindrical Specimen critical curing conditions, concrete
thickness and any number of other actual job site
conditions. Fig. 3 shows curing conditions of deck cured
by Heating & Covered with full jacketing. And also the
cylindrical specimen cured at the same site.
Principle
Maturity Method is based on the principle that the extent
of hydration of a concrete mixture and, therefore, the
strength at any age is based on the thermal history of
the concrete. Using the thermal history of a concrete
mixture and a maturity function, a maturity index that
quantifies the combined effects of time and temperature
can be calculated and plotted against the strength of
the concrete by means of a strength-maturity relationship
(fig.4).
Fig.3 shows curing conditions
Fig.4. Maturity Strength Relationship
Maturity Index
The relationship between the temperature history of a
concrete and its strength can be empirically determined,
and is called its maturity index. Concrete of a given mix
at the same maturity has approx. the same strength,
regardless of the temperature and time history that made
up that maturity.
Maturity Function
There are two alternate functions for computing the
maturity value from the measured temperature history
Bulletin of ACCE (I) 21 January - March 2011
of the concrete, the Nurse-Saul equation and the
Arrhenius equation.
The maturity function, known as the Nurse-Saul equation,
is used to compute the TTF as follows:
M(t) = (Ta -To) * t
where: M(t) = the TTF - Time Temperature Factor at age
t, degree-days or degree-hours,
t = a time interval, in days or hours,
Ta = average concrete temperature during time interval -
t °C, and
To = datum temperature = -10 °C.
The information used to make these decisions is usually
obtained from field cured cylinders, pullout tests, or
penetration testing. Some codified methods use similar
concepts by inserting the final setting time into maturity-
strength equations and Maturity methods are yet to
become popular used in practice.
Scope
Maturity method is a modification of ASTM C 1074
covering the procedures for estimating concrete strength
by means of the maturity method.
A relationship must be established between the maturity
values and the concrete strength, as measured by
cylinder testing. The development of the maturity-strength
curve shall be performed using project materials and the
proposed concrete mix design. The contractor shall be
responsible for the development of the maturity curve.
The Mix Design Expert shall monitor the curve
development. The temperature monitoring process of the
concrete construction is the responsibility of the
contractor and shall be monitored by the Engineer.
Acceptance of the concrete shall be based upon the 28-
day cylinder strength.
Instrument - Sensors
The maturity method involves the measurement of three
key parameters time, concrete temperature and concrete
strength. Using one of two widely-used expressions, a
temperature-time factor with units of “Degree Hour” is
calculated by multiplying concrete temperature, with
respect to a datum, by the elapsed time (in hours) after
the concrete was batched. The temperature of fresh
concrete is measured using Temperature Sensors (Fig.5)
Concrete maturity can also be measured in the laboratory
or field using strength test specimens.
Working of Sensors
Insert two temperature sensors at the required place of
measurement appropriately depending on the type of
construction. After concrete hardens, both sensors
measure only the deformation of the concrete matrix and
the difference between the deformations measured by
the two sensors remains constant. The hardening time
is defined as the time when the derivative of the difference
between the deformations measured by these sensors
by setting initial reading in standard sensors.
In ASTM C 1074, “Standard Practice for Estimating
Concrete Strength by the Maturity Method, 32 °F (0 °C)
is recommended as the datum temperature for concrete
(containing Type I cement in US)
A relationship between degree-hours and actual concrete
strength, for a given mixture, can be determined by
graphing each actual strength data and the corresponding
degree-hours.
Fig. 5 Temperature Sensors & Field Measurements
Procedure for Field Measurements
1. Establishing Maturity Strength Relationship for
a particular site / mix used at site.
• Prepare at least 15 cylindrical specimens (fig.6)
according to Kentucky Method 64-305. The mixture
proportions and constituents of the concrete shall
be the same as the concrete whose strength will
Bulletin of ACCE (I) 22 January - March 2011
be estimated using this practice. The concrete shall
be produced using the same equipment as that
which will produce concrete for the project. The
cylinders may be cast at the concrete plant or the
job site. Since there is a direct relationship between
the w/c (water/cement) ratio and strength, the
concrete used to develop the maturity-strength
relationship shall be at the maximum w/c ratio
expected during production.
Fig.6. Maturity Strength Relationship
• Moist cure the specimens in a water bath or in a
moist room meeting the requirements of KM 64-305.
• Perform compression tests at five different ages. Test
three specimens at each age and compute the
average strength. If a low test result is due to an
obviously defective specimen, discard the low test
result. The tests shall be spaced such that they are
performed at somewhat consistent intervals of time
and span a range in strength that includes the
opening strength desired. The table.1 gives
suggested test times. Test 3 is the target test. This
is only a guide and may need to be modified
depending on specific mixtures and conditions.
• At each test age, record the average maturity value
for the instrumented specimens.
Use the spreadsheet available to determine the
maturity-strength relationship. This spreadsheet
can be found on the Materials Web Page at The
TTF number corresponding to the desired
compressive strength. This curve is used to
determine when the concrete has reached desired
strength.
Table 1. Approximate Test Times
Mix Strength in MPa
Test 1 Test 2 Test 3 Test 4 Test 5
Class X 2 days 3 days 4 days 5 days 6 days
Class X/24 6 hours 10 hours 12 hours 14 hours 24 hours
Class X /48 24 hours 36 hours 48 hours 60 hours 72 hours
Class X /72 48 hours 60 hours 72 hours 84 hours 96 hours
Acceptance Criteria
• The R2 value can be found on the maturity curve
chart. The computed R2 value of maturity curve
obtained from regression analysis of the maturity
strength relationship (fig.7) shall be 0.95 or higher.
When R2 value is below 0.95 the curve is
unacceptable and a new curve will be required.
Fig.7. Maturity Strength Relationship – fox a Particular
mix at Field
Precautions
While evaluating concrete maturity using small test
specimens, it is extremely important to insulate them
from heat loss to minimize the time needed to develop
the strength-maturity relationship. If small test specimens
are not insulated during curing, strength development
will be slowed because the volume of concrete is small.
2. Strength measurement of In-situ concrete
• Insert temperature sensors at mid-depth of the
pavement and a minimum of 12 inches from the
edge of the concrete. They should be placed in the
plastic concrete as soon as possible. Avoid placing
the sensors near reinforcing steel. A threaded rod
with a wing nut may be used to insert the sensors
in the pavements and immediately removed.
Consolidate the concrete around the sensor as
needed. The rod can be marked for various insertion
depths. This device will allow the placement of the
sensors with minimal disturbance to the concrete.
Sensors should be placed in the concrete where
the temperatures are expected to be the coolest.
• For a normal day production, randomly place two
sensors to determine the maturity. They shall be
located in the last 100 feet of pavement placed.
• Embed temperature sensors in the centers of at
least two cylinders. Connect the sensors to
• One or more maturity meters (fig.8). Use the average
of the readings to develop the maturity
strength curve.
• Connect the sensors to maturity instruments (Fig.
9) and activate the recording devices as soon as is
practicable.
28
EVENTS AT GLANCE
ACCE (I) Headquarters
29
EVENTS AT GLANCE
BANGALORE CENTRE
30
EVENTS AT GLANCE
MANGALORE CENTRE
31
EVENTS AT GLANCE
MANGALORE CENTRE
32
EVENTS AT GLANCE
NAGPUR CENTRE
3rd Governing Council Meeting held at Bangalore on 7th March 2011
ACCE(I) HQ. counting of ballot papers
Quantity calculation made simple
e
earth
work
play with sections
digital terrain modeling
made affordable
e contours
Import section and alignment data from Excel, Field Book /
CAD for generation of C/S and L/S
Generates Section for multiple profiles / multiple layers
Provision for customized profiles or shapes for various
requirement like irrigation, roads, railways etc
Generates Area / Volume Reports in Excel and CAD
with interpolation facility
Modify Sections graphically
Import data from Total Station,Traverse correction,
Interpolation
Import data from CSV, Excel or CAD for Contour
generation
Generate Contours directly within your
CAD software
Draw Section for any alignment fixed on the
Contour map
Generate Grid Elevations or Block Levels from
existing Contours map
Generate Contour Area / Volume and
estimate capacity
Import data from CSV, Excel or CAD for Quantity
Estimates / Quantity Takeoffs
Earthwork for fixed formation level or betweentwo surfaces
Generate quantity calculation reports using
multiple methods
Generate interim Earthwork reports during
progress of projects for payments
Generate Earthwork calculations for Stepped or
Sloping surface
E Contours
E Earthwork
E Sections
Er. Arshal Azeem Yakhub
email : arshal@esurveying.net
Phone : +918892916010
CENTRAL MARKETING OFFICE
ZONAL MARKETING OFFICE :
BANGALORE :
‘Industry House’, 5th Floor, Fair Field Layout
45, Race Course Road, Bangalore - 560 001
Tel : 080-22250748, 22250749
Fax : 080-22204839
CHENNAI :
23, Anna Salai, Little Mount
(Above Swaraj Mazda Show Room)
Saidapet, Chennai - 600 015
Tel : 044-42328003, 42328018
Fax : 044-42328017
DELHI :
12th Floor, Ambadeep Building
K.G. Marg, Cannaught Place
New Delhi - 110 001
Tel : 011-23315007-10
Fax : 011-23315000
KOLKATA :
‘Constantia’, 7th Floor,
11, Dr. U.N. Brahmachari Street
Kolkata - 700 017
Tel : 033-30214100, 30214400
Fax : 033-30214490, 30214590
MUMBAI :
A’ Wing, Ahura Centre, 1st Floor
Mahakali Caves Road, Near M.I.D.C. Office
Andheri (East), MUMBAI - 400 093
Tel : 022 - 66917800, 66928400, 66917274
Fax : 022-66928401, 66917250
MUMBAI :
‘A’ Wing, Ahura Centre, 1st Floor
Mahakali Caves Road, Near M.I.D.C. Office
Andheri (East), MUMBAI - 400 093
Tel : 022 - 66917800, 66928400, 66917274
Fax : 022-66928401, 66917250
Bulletin of ACCE (I) 31 January - March 2011
• When the strength at the location of a sensor is to
be estimated, read the maturity value (Fig.10) from
the instrument. The strength of the concrete can be
determined from the spreadsheet or calculated from
the curve equation.
Fig. 8. Maturity Meter
Fig. 9 Measurement on Fresh Concrete
Fig. 10 Reading – Maturity Meter
Advantages of the test
• Maturity-based testing can reduce project costs by
eliminating the need to cast and test compressive
or flexural strength specimens.
• Once a strength-maturity relationship is established
for a particular concrete, temperature histories can
be used to predict the strengths of samples of the
same concrete subjected to different temperature
conditions.
Disadvantages of the test
• The strength and degree-hour relationship will vary
for different mix proportions and material selection.
Therefore, a fresh relationship must be established
for a given concrete mix before a specific project
begins.
Limitations of test
• There are, however, limitations to using either test
specimens or the maturity method to determine the
in-place concrete strength. With the maturity
method, a change in cement performance during a
project (due to different loads or lots of material)
could produce variability in results.
• Test specimens on the other hand may contain
flaws or lose heat during curing and not be
representative of in-place concrete performance.
Until sufficient experience has been obtained with
a given mix, the most reliable way to determine
concrete strength is to use both strength and
maturity measurements to determine concrete
strength.
• Changes in material sources, proportions,
admixtures, and mixing equipment all affect the
maturity value of a given concrete mixture. Therefore,
development of a new maturity curve is required for
any change to a concrete mix.
Correction for results
Direct reading maturity devices are preset with initial
temperature reading for an assumed temperature below
which cement hydration ceases. The displayed values
may have to be corrected if this assumed temperature
differs from the true temperature below which hydration
ceases.
ASTM standard practice tells how to make the
corrections.
Benefit from Maturity Testing
• Pulling cables and stripping forms as soon as
possible leads to project acceleration. Curing
times are usually cut dramatically, especially in the
winter.
• Improve site safety by not stripping forms or
stressing cables too soon.
• Improve concrete quality by learning the
temperature history of the concrete. Compensate
for changes in field conditions on-the-fly.
• Save money by assessing cold weather protection
to ensure sufficient temparatures for curing without
wasted heating.
• Allows in-place strength determination of critical
areas of a structure.
• Non-destructive, inexpensive and cost-effective.
Application of method
In practice, the maturity-based test method can be used
to
• To estimate the strength of in-place concrete at a
given point in time.
• To estimate concrete strength in full-depth pavement
repairs.
• After developing the correlation between degree-
hours and actual strength, a contractor or
transportation agency can use the maturity method
Bulletin of ACCE (I) 32 January - March 2011
to open a newly-repaired concrete pavement to traffic
without testing a specimen for strength.
• Maturity testing can provide an alternative to strength
testing in determining when a newly built concrete
pavement can be opened to traffic.
∙ The information obtained from field cured concrete
test specimen is used to make the important
decisions on To decide when to strip forms, when
to post-tension, when to remove shores, and when
to terminate cold-weather protection are based on
reaching a minimum level of concrete strength.
• Early form removal especially in cold weather
• Speeds up construction
• Requires less form/shoring inventory
• Allows other trades early access
• Sooner completion date
• Increases profits
• Method can be used in
Post-T
ensioned S
tructures
/
High-Rise Buildings /
Tunnel and Jump Forms /
Early Forms Removal /
Bridges /
High-Early
Pavement Patches /
Main-Line Paving /
Saw-Cut
T
imes /
Airport /Runways/T
axiways /
Driveways /
Pre-Cast/ Prestressed /
Tilt-Up /
Mass Concrete(fig.
11 & fig.12 )/
Cold W
eather Concreting /
Hot W
eather
Concreting.
• Improve concrete quality by learning the temperature
history of the concrete. Compensate for changes in
field conditions on-the-fly.
• Reduce Costs and improve performance of concrete
by optimizing mix designs
• Lower cement factors, controlled heat of
hydration, at lower cost
• Important in the age of cement shortages /
sustainable construction
• Monitor critical areas of a structure.
• A Non-destructive, inexpensive and cost-effective
method.
Recognized, recommended and referenced test
Methods:
• ASTM C1074, “Standard Practice for Estimating
Concrete Strength by the Maturity Method.”
• ACI 306 (Chapter 6), 228 and many other references
• SHRP C376
• AASHTO
• OSHA Sec. 1926:171:B(c)
Summary & Conclusions
Expressing necessity of Maturity test in another way -
Any time-sensitive placement where knowing the in-place
strength would be beneficial for quality, engineering or
economic reasons.
Compressive strengths of several widely used concrete
mixtures have been successfully predicted using a
procedure that involves early age deformation monitoring.
This methodology allows a fast and accurate prediction
of compressive strength on site. Seventy-two hours are
sufficient to gather the necessary data and provide
accuracy of less than 8% error. It is also an attractive
procedure for the determination of the activation energy
and the rate constant. More timely knowledge of
compressive strength evolution will lead to savings during
construction and improve safety.
Fig.11 Monitoring Temps allows earliest cessation of
external heating operations
Continued on page 48
Bulletin of ACCE (I) 33 January - March 2011
WHITETOPPING – A CASE STUDY
Dr. V. Ramachandra ,
Asst. Vice President (Tech. Services), UltraTech Cement Ltd., Bangalore
1. Introduction:
Concrete Roads were first built by Romans (300 BC –
476 AD). They were quite innovative in the construction
with the use of innovative materials viz., use of
‘Pozzolana’ cement from the village Pozzouli near Italy,
horse hairs as fibres in concrete, admixtures in their
primitive form (like animal fat, milk & blood). These
roads, scientifically designed and constructed had a long
life and thus lead to the adage ‘ all (concrete) roads
lead to Rome’.
Portland Cement Concrete (PCC) overlay on an existing
bituminous pavement is commonly known as White
topping. The principal purpose of an overlay is either to
restore or to increase the load carrying capacity or both,
of the existing pavement. In achieving this objective,
overlays also restore the ride-ability of the existing
pavements which have suffered rutting and deformations,
in addition to rectifying other defects such as loss of
texture. In our country, bituminous overlays have been
popularly constructed in the past mainly due to abundant
supply of bitumen, its amenability to stage construction
and manageable traffic conditions, in terms of volume
and axle loads in addition to the comfort levels of
construction methods among engineers.
It was also making economic sense to make bituminous
pavements as it was relatively cheaper. In recent times
all these advantages are reversed viz., petroleum industry
is using refined processing technology leading to
reduction in the production of bitumen leading to
increased imports, favourable cost economics of cement
concrete and rapidly changing traffic scenario (in terms
of volume as well as axle loads). In addition, rapid
developments in concrete material technology and
mechanization (both in concrete production & its laying)
are favouring concrete overlays as a sustainable option.
In recent times PPP (Public-Private Partnership) models
are becoming popular in road construction shifting the
focus on selection of overlays based on life-cycle costs
rather than initial costs. India is currently producing
about 240 million tonnes of cement and cement industry
is quite matured and equipped to meet the challenges
in terms of various grades of cements as well as high
quality blended cements suitable for making Pavement
Quality Concrete (PQC).
Concrete overlays have been used to rehabilitate
bituminous pavements since 1918 in USA. There has
been a renewed interest in whitetopping, particularly on
Thin White Topping (TWT) and Ultra-Thin White Topping
(UTWT) over Conventional White Topping. Based on