DBSB DIVISION 2

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Bridge

Special Provisions


Division 2



RFP



DBSB DIVISION 2


DBSB
-
2105

BRIDGE ABUTMENT CONSTRUCTION

DBSB
-
2301

BRIDGE APPROACH PANELS

DBSB
-
2360

PLANT MIXED ASPHALT PAVEMEN
T

DBSB
-
2401

(2401) CONCRETE BRIDGE CONSTRUCTION

DBSB
-
2401.1

CONCRETE AGGREGATE FOR BRIDGES

DBSB
-
2401.2

FALSEWORK AND FORMS AND BRIDGE SLAB PLACEMENT

DBSB
-
2401.3

BEAM TIE DOWNS FOR SLAB CONSTRUCTION

DBSB
-
2401.4

BRIDGE SLAB

DBSB
-
2401.5

PLACEMENT OF CONCRETE IN HIGH ABUTMENTS

DBSB
-
2401.9

JOINT FILLER AND SEALING

DBSB
-
2401.11

FINISH OF CONCRETE S
URFACES

DBSB
-
2401.13

FINISH OF INPLACE CONCRETE

DBSB
-
2401.16

ORDINARY SURFACE FINISH

DBSB
-
2401.18

TEXTURE PLANING OF B
RIDGE SLABS

DBSB
-
2401.20

Curing Bridge Deck Slab

DBSB
-
2401.21

POST TENSIONING SYSTEM

D
BSB
-
2401.22

CURING BRIDGE SLAB

DBSB
-
2401.23

Integral Concrete Diaphragms

DBSB
-
2401.24

LATE PLACEMENT OF CONCRETE WEARING COURSE

DBSB
-
2401.25

PLACING SUBSE
QUENT CONCRETE POURS

DBSB
-
2401.26

CURING BRIDGE DECK SLABS (FULL DEPTH MONOLITHIC SILICA
FUME DECKS)

DBSB
-
2401.27

CONCRETE CONSTRUCTION REQUIREMENTS

DBSB
-
2401.28

MASS CONCRETE

DBSB 2401.29

(2401) CAST
-
IN
-
PLACE CONCRETE SEGMENTAL SUPERSTRUCTURE
CONSTRUCTION

DBSB
-
2401.30

ANTI
-
GRAFFITI COATING

DBSB
-
2401.31

Arc
hitectural Surface Finish (Single Color)

DBSB
-
2402

(2402) STEEL BRIDGE CONSTRUCTION

DBSB
-
2402.2

Dimensional Tolerances

DBSB
-
2402.3

Fracture Critical Steel

Bridge Members

DBSB
-
2402.4

Expansion Joint Devices

DBSB
-
2402.5

MODULAR BRIDGE JOINT SYSTEM

DBSB
-
2402.6

METAL RAILING

DB
SB
-
2402.7


POT BEARING ASSEMBLIES

DBSB
-
2402.10

Bolted Connections

DBSB
-
2402.15

BRIDGE DECK DRAINAGE SYSTEM

DBSB
-
2403

(2403) TIMBER BRIDGE CONSTRUCTION

DBSB
-
2404

(2404) CONCRETE WEARING COURSE FOR BRIDGES

DBSB
-
2404.1

Concrete Wearing Course 3U17A

DBSB
-
2404.3

Texture Planing of Bridge Slabs

DBSB
-
2405

(2405) PRESTRESSED CONCRETE BEAMS

DBSB
-
2405.1

Prestressed Concrete Fabricator Certification


Bridge

Special Provisions


Division 2



RFP


DBSB
-
2405.2

Steel Intermediate Diaphragms

DBSB
-
2405.4 PRESTRESS TRANSFER

DBSB
-
2405.5


Prestress Transfer

DBSB
-
2405.6

PRECAST CONCRETE SEGMENTAL SUPERSTRUCTURE
CONSTRUCTION

DBSB
-
2411

MEC
HANICALLY STABILIZED EARTH WALLS WITH PRECAST
CONCRETE PANELS

DBSB
-
2433

(2433) STRUCTURE RENOVATION

DBSB
-
2433.1


STRUCTURE REMOVALS

DBSB
-
2433.2

Remove Con
crete Bridge Deck

DBSB
-
2433.3

ANCHORAGES

DBSB
-
2433.4

Grouted Anchorages

DBSB
-
2433.5

BRIDGE PENETRATING SEALER

DBSB
-
2433.
6

REMOVAL OF EXISTING STEEL MEMBERS

DBSB
-
2433.7


BRIDGE DECK CRACK SEALER

DBSB
-
2433.8

REINFORCEMENT BAR ANCHORAGE (POST
-
INSTALLED)

DBSB
-
2442

(2442) REMOVA
L OF EXISTING BRIDGES

DBSB
-
2442.1

SALVAGED MATERIALS

DBSB
-
2451

(2451) STRUCTURE EXCAVATIONS AND BACKFILLS

DBSB
-
2451.1

STRUCTURE EXCAVATION

DBSB
-
2451.2

AGGREGATE BACKFILL

DBSB
-
2451.3

FOUNDATION BACKFILL

DBSB
-
2451.4

FOUNDATION PREPARATION (PIERS)

DBSB
-
2451.6

Foundation Explor
ation

DBSB
-
2451.7

Foundation Preparation for Pile Bent Pier(s)

DBSB
-
2452

PILING

DBSB
-
2452.1

PILE AUTHORIZATION

DBSB
-
2452
.2

EQUIPMENT FOR DRIVING

DBSB
-
2452.3

Pile Tip Protection

DBSB
-
2452.4

Pile Points

DBSB
-
2452.6

Pile Load Test

DBSB
-
2452.8

SUBSTITUTION FOR STEEL H
-
PILING

DBSB
-
2452.11

EXTENSIONS AND SPLICES

DBSB
-
2453

DRILLED SHAFT CONSTRUCTION

DBSB
-
2461.2

BRIDGES WITH FULL DE
PTH MONOLITHIC SI
LICA FUME DECKS

DBSB
-
2461.4

CONCRETE MIX FOR MASS CONCRETE ELEMENTS

DBSB
-
2471

STRUCTURAL METALS

DBSB
-
2476.1

METHODS FOR PAINT REMOVAL AND WASTE DISPOSAL

DBSB
-
2476.2

CONTAINMENT AND DISPOSAL OF WASTE MATERIALS

DBSB
-
2478.1

(2478) ORGANIC ZINC
-
RICH PAINT SYSTEM

DBSB
-
2478.2

Removal of Soluble Salts

DBSB
-
2479

(2479) INORGANIC ZINC
-
RICH PAINT SYSTEM

DBSB
-
2511

(2511) RIPRAP


Geotextile Filter Type IV (Modified)

DBSB
-
2514.2

(2514) SLOPE PAVING

DBSB
-
2545

CONDUIT SYSTEMS

DBSB
-
2557.1

(2557) FENCING


Bridge

Special Provisions


Division 2



RFP


DBSB
-
2557.2

(2557) FENCING



DBSB
-
2105

BRIDGE ABUTMENT CONSTRUCTION


The provisions of Mn/DOT 2105 are hereby modified a
s follows:


Add the following paragraph to 2105.3
:



The Contractor shall determine the time delay required between placing of the
approach fill to the full height and cross section, and the start of construction of each abutment,
according to the Foundati
on Analysis and Design Report. Construction of each abutment shall
not start until the time delay has passed. The approach fill construction shall extend a distance of
at least 15

m (50

feet) behind the abutment as measured along the centerline of the ro
adway.




Bridge

Special Provisions


Division 2



RFP


DBSB
-
2301

BRIDGE APPROACH PANELS


The provisions of Mn/DOT 2301 are hereby modified as follows:


Add the following
:



This work shall consist of furnishing all materials, labor, and equipment required
to construct bridge approach panels. The work

shall be performed in accordance with all
applicable provisions of Mn/DOT 2201, 2301, 2502, 2506, the referenced standard detail plates,
and the following:



Approach panel construction shall be scheduled and performed in a manner
consistent with the re
quired traffic provisions.


DBSB
-
2301.1

Reinforcement bars shall be epoxy coated in accordance with 3301.


DBSB
-
2301.2

The preformed material utilized for sealing the E8 expansion joints shall be one of
the following or an approved equal:



(A)

"Pressure
-
R
elief
®

(Ceramar
®
)" as marketed by the W.R. Meadows, Inc., P.O.
Box

338, Hampshire, IL 60140.
http://www.wrmeadows.com



(B)

"EVA
-
SEAL
®
" manufactured by E
-
Poxy Engineered Materials, LLC,
10

Broadway, Albany, NY 1
2202.
http://www.e
-
poxy.com




E
-
8 Pressure relief joint material shall be installed in accordance with the
manufacturer's recommendations and as follows:



(A)

Expansion joint filler material used for a 100

mm (
4

in
ch
) pressure relief joint
consists of a preformed foam product having minimum dimensions of 115

mm
(
4.5

inches
) in width (may be laminated) and 200

mm (
8

inches
) in depth. Each section
shall have a minimum length of 3

meters (
10

feet
). When the concrete
depth is greater
than the depth of the pressure relief material, fill the void below the material with
polystyrene. The material shall be installed under compression with a lubricant adhesive
applied to the concrete contact surfaces.



(B)

Saw or form the

joints 100

mm (
4

inches
) wide by the full
-
depth of the slab.
Inspect to assure that the inside walls of the joint have been sandblasted, are dry, smooth
and free of debris and loose particles. Apply tape to the top 25

mm (
1

inch
) of the inside
walls to
prevent the lubricant adhesive from contaminating the concrete bonding surfaces
of the subsequently placed hot pour joint sealer.



(C)

Paint the inside walls of the joint with lubricant adhesive at the rate of
approximately 1

liter per 4

meters (
1

gallon
per 50

lineal feet
) of joint.



Bridge

Special Provisions


Division 2



RFP




(D)

Pinch the bottom of the material together and push down into the joint. Walk the
material down into the joint; use a sledgehammer and a 2X4 if necessary. When butting
two pieces together, paint the ends with lubricant
adhesive.



(E)

Install the foam relief joint material so that the top surface is depressed to a depth
of approximately 22

mm (
7/8

inch
) below the concrete surface. After proper installation,
remove the tape and fill the void on top of the foam material w
ith approximately 13

mm
(
1/2

inch
) of Mn/DOT

3723 or 3725 hot pour joint sealer to a level of 9.5

mm ± 6.3

mm
(
3/8

inch ±1/4

inch
) below the surface. The hot joint sealer should only slightly melt into
the foam pressure relief joint material. To prevent
excessive melting of the joint material,
place the hot
-
pour sealer at the lower end of the temperature specification. Check for
correct temperature by placing hot pour sealer on a sample of waste foam material
.



Bridge

Special Provisions


Division 2



RFP


DB
SB
-
2360

PLANT MIXED ASPHALT PAVEMENT



Wh
en a bituminous wearing course is specified for use on temporary bridges and
widenings, the
mixture shall meet the requirements of Mn/DOT

2360.5H "Asphalt Mixtures
Measured by the Square Meter (
Yard
) per Specified (mm) (
inch
) Thickness". Density shall be
obtained using 2360.6C the Ordinary Compaction Method. A control strip will not be required.




Bridge

Special Provisions


Division 2



RFP


DB
SB
-
2401

(2401)

CONCRETE BRIDGE CONSTRUCTION



The provisions of Mn/DOT

2401 are modified and/or supplemented with the
following:



Delete the first sentence

of the first paragraph of 2401.3G:



Cure newly placed concrete by providing protection against rapid loss of
moisture, freezing temperatures, high temperatures, abrupt temperature changes, vibration
exceeding a normal or reasonable limit as described in
the Bridge Construction Manual chapter
.362, shock waves, and prematurely applied loads.



Add the following to the end of the second paragraph of 2401.3G:



All sections not included in superstructures……………..45


DBSB
-
2401.1

CONCRETE AGGREGATE FOR BRIDGES


The provisions of 2401.2A shall apply except as modified herein:


For projects within District 4:



Class A Coarse Aggregate, as defined in 3137.2B, shall be used in all concrete for
bridge railings, posts, curbs, sidewalks, and median strips poure
d separately from the bridge
deck. Coarse aggregates for use in other portions of bridge superstructures shall meet
requirements for Class A or Class C aggregate, except that coarse aggregate requirements for
precast concrete members fabricated under 2405

shall be as specified in 2461.2D.



For projects within District 1, District 2, District 3, and Metro:


Delete the second paragraph of 2401.2A and substitute the following paragraph therefor:



Class A or Class C coarse aggregate, as defined in 3137.2B,
shall be used in all
concrete for bridge superstructures, except that coarse aggregate requirements for precast
concrete members fabricated under 2405 shall be as specified in 2461.2D.



For projects within District 6, District 7, and District 8:


Delete t
he second paragraph of 2401.2A and substitute the following therefor:



Class A Coarse Aggregate, as defined in 3137.2B, shall be used in all concrete for
bridge superstructures, except that coarse aggregate requirements for precast concrete members
fa
bricated under 2405 shall be as specified in 2461.2D.






Bridge

Special Provisions


Division 2



RFP


DBSB
-
2401.2

FALSEWORK AND FORMS AND BRIDGE SLAB PLACEMENT


Delete paragraphs 2, 3, and 4 of 2401.3B2 and substitute the following:



If required, the Contractor shall prepare detailed Falsework and Form
s Plans and
Specifications for each bridge on the Project. The Falsework and Forms Plans and Specifications
along with associated design calculations shall be submitted to Mn/DOT as required per the
Contract. Design of the falsework and forms shall be in a
ccordance with AASHTO "Guide
Design Specifications for Bridge Temporary Works". The Plans and Specifications shall be
prepared by an engineer, thoroughly checked by a second engineer for completeness and
accuracy, and certified by a professional engineer
licensed in the State of Minnesota. The
documents shall include sufficient details so that construction of the proposed system can be
completed solely by reference to the Plans and Specifications. The design criteria shall be shown
on the first sheet of
the Plans.



As a minimum, falsework plans shall contain the following:


(1)

The size of all load
-
supporting members and all transverse and longitudinal
bracing. Connection details for load
-
supporting members must be included. For box
girder structures,
the drawings must show the falsework members supporting sloping
exterior girders, deck overhangs and any attached construction walkways.


(2)

All design
-
controlling dimensions must be shown, including beam length and
spacing; post location and spacing; ove
rall height of falsework bents; vertical distance
between connectors in diagonal bracing; and similar dimensions that are critical to the
design.


(3)

The location and method by which the falsework will be adjusted to final grade
must be shown.


(4)

Unless

a concrete placing schedule is specified in the Contract, the falsework
plans must include a superstructure placing diagram showing the proposed concrete
placing sequence and/or the direction of pour, whichever one is applicable, and the
location of all c
onstruction joints. (For relatively simple structures, this requirement may
be satisfied by a note on the plans.)


Add the following to 2401.3B4:



The Contractor shall not be permitted to place the concrete for structures
supported by falsework until: (
1)

Plans and Specifications meeting the above requirements have
been provided to the Engineer; (2)

the engineer who has certified plans and specifications for the
falsework and forms has inspected the falsework after erection; and (3)

the engineer inspecti
ng
the as
-
constructed falsework certifies in writing that all details are approved.




Bridge

Special Provisions


Division 2



RFP




Add the following to 2401.3F3b(1):



At least two weeks in advance of casting Bridge Slab concrete, the Contractor
shall provide detailed plans for placing the concrete,

including the Contractor's scheme for
supporting screed rails for the Bridge Slab and schedules setting forth the rate of concrete
delivery. The minimum rate of concrete placement shall be 80 cubic yards per hour.



If concrete is cast by means of a pump
ing operation, the Contractor shall maintain
a standby pump or crane capable of delivering an uninterrupted flow of concrete in case of a
pump breakdown.




Bridge

Special Provisions


Division 2



RFP


DBSB
-
2401.3

BEAM TIE DOWNS FOR SLAB CONSTRUCTION


Add the following two paragraphs to 2401.3C1:



W
hen end span lengths are less than 80% of the adjacent span length and the
bridge slab is to be placed in one continuous pour, provisions shall be made to prevent uplift of
the beams (during the placement of the concrete in the slab) at the abutment where
the slab pour
terminates, the Contractor shall be required to either counterweight or to rigidly tie down the
beams at that abutment before the placement of the concrete in the slab is started.



The Contractor shall furnish to Mn/DOT for Acceptance com
plete details of the
methods s/he proposes to use to hold down the beams at the location mentioned above, including
required uplift capacities at least two weeks in advance of commencing tie down construction.
Counterweights shall not be removed nor tie d
owns released until at least seventy
-
five (75)
percent of the slab in the span where the devices are used is in place.






Bridge

Special Provisions


Division 2



RFP


DBSB
-
2401.4

BRIDGE SLAB


Add the following two paragraphs to 2401.3C1:



For bridges having skews 20 degrees or greater, the finishing

machine shall
operate such that the longitudinal axis of the machine is generally parallel to the centerline of
bearings of the substructure units.


Delete the provisions of 2401.3E1 and substitute the following paragraph therefor:



Immediately prior to
placing concrete against a construction joint in the bridge
slab, the surface of the in place concrete shall be coated with an approved bonding agent or
grout.





Bridge

Special Provisions


Division 2



RFP


DBSB
-
2401.5

PLACEMENT OF CONCRETE IN HIGH ABUTMENTS


Add the following paragraph to 2401.3C1:



To reduce the effects of shrinkage in abutment concrete, there shall be a 72 hour
delay between concrete pours of adjacent sections that have vertical construction joints.




Bridge

Special Provisions


Division 2



RFP


DBSB
-
2401.9

JOINT FILLER AND SEALING


The provisions of 2401.3J1 are supplement
ed as follows
:




Prior to installation of sealing materials, concrete curing shall be completed. A
minimum of 7 days drying is required prior to application of sealers. Sawcut joints shall be
sandblasted and blown clean and the concrete surfaces shall b
e dry at the time sealer is installed.



Preformed joint material if used, shall be as detailed in the plans and in
conformance with the following requirements.


1.

Bituminous felt shall comply with AASHTO M33, modified to the extent
that the load required

to compress the test specimen to 50 percent of its thickness
before test shall be not more than 8274 kPa (1200 psi).


2.

Cork shall comply with Mn/DOT 3702 and AASHTO M153 Type II.


3.

Polystyrene shall comply with the following:



Type


Minimum



Charac
teristics





Compressive Strength





(5 percent deflection)

___________________________________________________________________________


A


207 kPa (30 psi)


Closed Cell








Expanded Polystyrene

__________________________________________________
_________________________


B


69 kPa (10 psi)


Molded Polystyrene

___________________________________________________________________________



Testing for compressive strength of polystyrene shall be in accordance with
ASTM D 1621. The Contractor shall f
urnish evidence that the material meets these
requirements.


Delete the provisions of 2401.3J2 and substitute the following
:



All cracks that develop in the deck surface shall be sealed with an approved
methylmethacrylate or epoxy. Crack density less than

10 linear feet of cracks per 100 sq
uare

f
ee
t
of deck can be individually sealed. Crack density more than 10 linear feet of cracks per 100
sq
uare

f
ee
t of deck will require flood coat sealing.




Bridge

Special Provisions


Division 2



RFP


DB
SB
-
2401.11

FINISH OF CONCRETE S
URFACES


Cure concrete for a
minimum of 28
D
ays

or as recommended by the manufacturer

prior to applying special surface finish (SSF)

or acrylic paint
. Thoroughly flush all surfaces that
are to receive SSF with clean water not more than 24 hours before commencing with the SSF
finishin
g.


A.

Special Surface Finish


The provisions of 2401.3F2c apply except as modified herein:


Two coats of SSF

shall

be re
quired on the exposed concrete surfaces as
designated below for all bridges.




Railposts



Barrier Railings or Parapets (other than Type
F)



Outside surfaces of barrier railing



Edges of platforms



Edges of stairway treads



Stairway risers



Wingwalls



Copings



Edges of slabs



Bottom of overhangs



Abutments



Piers/pier cap


The finish color for all special surface finish shall match Mn/DOT standa
rd color
"Gray
-
Modified" on file in the Mn/DOT Chemical
Laboratory

(651
-
366
-
5548),
unless
otherwise

specified
in

the Visual Quality
Manual
. Paint shall be free of toxic metals and
shall not contain toxic pigments.


Apply a top coat of 100% acrylic paint (
Mn/DOT Spec.

3584) in the color
specified.


Provide a test area, 1

meter x 1

meter (
3

foot x 3

foot
), for final color selection.
The final color selection must be approved by the Visual Quality Manager.


Add the

following sentence after the fourth sentence

in the second paragraph of
2401.3F2c:


Furnish only one
A
pproved system of mortar, bonding agent, water, and 100

percent

acrylic paint (meeting Mn
/
DOT
Standard Specification
3584) from the
Mn/DOT
Approved

Product List of Special Surface Finish

System.






Bridge

Special Provisions


Division 2



RFP


(ht
tp://www.dot.state.mn.us/products/index.html) to
produce the color specified in
the Contract Documents
.


B.

Finishing Roadway Faces and Tops of Barrier Railing


1.

The roadway faces
,

tops of barrier railings (and medians), if
conventionally formed, shall b
e finished in accordance with
Standard
Specification
2401.3F2d
and the following
:


a)

Concrete placement, form removal, and finishing operations shall
be planned and executed so that the surface finishing can be started
immediately after forms are removed.

The roadway face forms may be
removed as soon as the concrete can retain its molded shape. However, in
no case shall the elapsed time between concrete placement and initial
surface finishing exceed 24 hours.


b)

After completion of the curing period, t
he roadway faces and tops
of the barrier railings (and median) shall be painted with
two coats of an

A
pproved acrylic paint conforming to
Standard Specification
3584. The
color the acrylic paint shall conform to Mn/DOT
standard color “
Gray
Modified


on fi
le in the Mn/DOT Chemical Laboratory (651
-
366
-
5548)
unless otherwise

specified
in

the Visual Quality
Manual
.
Paint shall be
free of toxic metals and shall not contain toxic pigments.

The paint shall
be applied at a rate of 300

ft
2

per gallon. The
Contract
or shall suspend the
painting operation
if

the air and surface temperature
s

do not meet or
exceed the manufacturer’s recommendations
.


2.

The roadway faces and tops of barrier railings (and median), if slipformed,
shall be finished in accordance with the
following:


a)

The railing shall be lightly broomed immediately after passage of
the slipformer.


b)

The roadway face and top of the barrier railing shall be coated as
described above for the conventionally formed railing.


C.

Finishing Precast Concrete G
irders


Two coats of acylic paint
shall

be re
quired on the exposed concrete surfaces as
designated below for all bridges




Outside face of fascia girder



Bottom of bottom flange of all girders






Bridge

Special Provisions


Division 2



RFP


The finish color for
the acrylic paint

shall match Mn/DOT s
tandard color "Gray
-
Modified" on file in the Mn/DOT Chemical
Laboratory

(651
-
366
-
5548),
unless

otherwise
specified
in

the Visual Quality
Manual
. Paint shall be free of toxic metals and shall not
contain toxic pigments.



The paint shall be applied at a rat
e of 300

ft
2

per gallon. The
Contractor

shall

suspend the
painting operation if

the air and surface temperature
s

do not meet or exceed the
manufacturer’s recommendations
.








Bridge

Special Provisions


Division 2



RFP


DBSB
-
2401.13

FINISH OF INPLACE CONCRETE


Add the following paragraph to 2401.3F
2c:



When a "special surface finish" as described in 2401.3F2c is required on exposed
concrete surfaces, the concrete surfaces shall be etched by sandblasting before applying the
special surface finish.





Bridge

Special Provisions


Division 2



RFP


DBSB
-
2401.15

Architectural Concrete Texture (Ran
dom Batten)


A.

Description of Work




This work consists of applying a random batten architectural texture to designated
concrete surfaces of bridges and walls.


B.

Textured Concrete Surface Forming System



The forming system shall produce a textured eff
ect of variable
-
width parallel ribs
similar to the profile shown in the Design Documents. Relief shall be ¾ inch.


Textured concrete surfaces shall be formed by using a commercial form liner
system or the use of batten strips attached to the forms. Eit
her forming system shall
attach easily to the forms and be removable without causing concrete surface damage.
The forming system shall be designed to form surfaces conforming to the design intent
including the shape, lines, and dimensions shown in the Des
ign Documents, and to avoid
visible pattern repeats. Pattern features shall be matched at the edge of grooves to
minimize visible pattern repeats and make the concrete surface appear uniform and
continuous without seams and form marks.



Commercial form
liners shall be made of high
-
strength urethane elastomer and
shall be capable of withstanding anticipated concrete pour pressures without leakage or
causing physical defects.


Subject to compliance with requirements, form liner material shall be obtained
f
rom one of the following manufacturers:


a.

Scott System, Inc.

b.

Customrock International, Inc.

c.

Fitzgerald

d.

Milestones, Inc.

e.

Other manufacturers Approved by Mn/DOT.


C.

Submittals


Within 30 days of NPT2, the Contractor shall submit the foll
owing information to
the Engineer for Approval:


1.

Commercial form liner product data including manufacturer’s technical
information, label analysis, and application instructions for each material
proposed for use.


2.

Laboratory test reports showing tha
t physical or performance property
requirements of the commercial form liner system are met by materials proposed


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Special Provisions


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for use.


3.

Shop drawings indicating form liner layout and termination details.
Indicate backup, rustication, reveal, and chamfer strip loca
tions. Include jointing,
form tie location, pattern placement, pattern match details, and end, edge and
other special conditions. Indicate tolerances and procedure of installation and
separation.


4.

A 4
-
foot x 4
-
foot (minimum) sample of formed pattern s
hown in the
Design Documents.


5.

A sample of form ties that will be permanently embedded in the concrete,
submit actual samples.


6.

The Contractor shall demonstrate his workmanship by completely
finishing an architectural concrete textured mock
-
up using
Approved form liner
materials; methods and workmanship including, but not limited to, concrete mix,
form release agents, joint sealing, vibrating and form stripping practices, and
ordinary surface finish. The mock
-
up shall be unreinforced, vertically
-
cast

and of
concrete construction to determine the surface texture resulting from use of form
liner products. The minimum size of the mock
-
up shall be
8

inches

thick, 5

feet

wide and 4
feet

high.



The finished effect shall closely duplicate the desired appea
rance of the
finished textured concrete surface. An unsatisfactory mock
-
up shall be replaced
with a newly constructed mock
-
up by the Contractor.


D.

S
urface Preparation


All exposed textured concrete surfaces shall receive ordinary surface finish in
accor
dance with Mn/DOT Specification 2401.3F2a following the water
-
blast cleaning
specified below.



Following removal of forms including form liners, minor defects shall be finished
to blend with the balance of the pattern surface. Visible vertical or horizon
tal seams or
conspicuous form marks shall be repaired to the satisfaction of Mn/DOT.


All concrete surfaces that receive the architectural concrete texture shall be water
-
blasted to break the surface film and to remove all laitance detrimental to the finis
h
coating system performance. Sandblasting will not be allowed for cleaning concrete
surfaces, as it will reduce the specified surface texture. Pressure washing with water at a
pressure of
3000

psi

at a rate of three

to four

gallons

per minute using a fa
n nozzle held
perpendicular to the surface at a distance of o
ne to two feet

shall be used.



Completed prepared surfaces shall be free of blemishes, discolorations, surface


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voids and conspicuous form marks to the satisfaction of Mn/DOT. The Contractor sha
ll
correct any surface defects.


E.

Surface Finish



The textured concrete areas shall be finished with special surface finish in
accordance with the requirements of DBSB
-
2401.11.


F.

Construction Requirements



Release agent(s) shall be verified to be
compatible with the form liner and paint
system to be applied to the textured concrete surfaces. It shall be non
-
staining and
exhibit no adverse effects to the concrete surface. Release agent shall be applied in
accordance with the approved form liner ma
nufacturer’s directions.



Form ties shall be made of non
-
corrosive materials when the portion permanently
embedded in the concrete is less than 1
½ inch

from the finished surface.



All materials shall be stored, prepared, applied, and cured according to p
roduct
manufacturer directions, with special attention given to recommended temperature range.



Position form ties and accessories shall be positioned in pattern joints and high
points of finished wall. Openings shall be boxed using polystyrene filler ma
terials at
each tie location to facilitate form tie disengagement without excessive spalling, chipping
or damaging the concrete. Tie holes shall be finished in accordance with Mn/DOT
Specification 2401.3F2a using approved patching materials.



Formwork sh
all be stripped in accordance with the form liner manufacturer’s
recommendations after the concrete has gained sufficient strength to avoid surface
damage. Finish form tie holes in accordance with Mn/DOT Specification 2401.3F2a
using approved patching mat
erials.


Prior to reuse, form liner surfaces shall be cleaned and repaired to the satisfaction
of Mn/DOT. Split, frayed, delaminated or otherwise damaged form liners shall not be re
-
used for any architectural texture work; nor shall patched form liner be
re
-
used for
exposed concrete surfaces, except as authorized by Mn/DOT.




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DBSB
-
2401.16

ORDINARY SURFACE FINISH



Add the following to the fourth paragraph of 2401.3F2a:



At locations where a surface is not exposed or a surface is concealed to public
viewin
g so that the appearance of the completed structure will not be adversely affected, cavities
caused by removal of falsework brackets, form ties or hanger rods may be filled with an
approved silicone caulk. The cavities shall be thoroughly cleaned prior to

filling with caulk.



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DB
SB
-
2401.18

TEXTURE PLANING
OF BRIDGE SLABS


Planing of the bridge deck shall be required on all monolithic bridge slab decks (bridges with
no overlay) that are located in the Mn/DOT Metro District.



Delete the 3
rd

paragraph of 2401
.3F3b(3) and substitute the following:



Special care shall be taken in finishing roadway surfaces in the vicinity of
expansion devices and other locations where breaks in continuity occur to ensure a smooth riding
surface.



After the concrete has been co
nsolidated, screeded, floated, and carpet dragged,
curing shall be applied as soon as possible.



Upon completion of curing, a surface smoothness check will be made on the
roadway surface. The final surface shall meet the tolerance requirements of 2401.3F
3b(3).
Surface areas not meeting the specified tolerances shall be corrected by removal and replacement
or by grinding the high spots to the extent directed by the Engineer prior to beginning surface
texturing operations. Nonconforming areas that are not

satisfactorily corrected shall be subject
to 1503.



After completion of work required to meet surface tolerance, the Contractor shall
texture the roadway surface in a longitudinal direction by planing the hardened concrete by
diamond saw
-
blade grinding.

The entire surface area of the roadway except the area within
500

mm (
20

inches
) of the curb shall be planed to a uniform texture. The surface shall have a
finished texture with the width of the grooves between 2.5

mm (
1/10

inch
) and 3.3

mm
(
1/8

inch
) at

a distance of between 2.0

mm (
5/64

inch
) and 3.0

mm (
1/8

inch
) apart. The
grooves shall not be less than 0.8

mm (
1/32

inch
) or more than 3.0

mm (
1/8

inch
) in depth. The
actual textured surface in any selected 0.5

meter (
1.5

feet
) by 30

meter (
100

foot
)
longitudinal
strip shall not be less than 98% of the surface area.



During planing operations, joints must be adequately protected against damage
and special care shall be taken to avoid damage to expansion devices. Planing shall be done in a
manner that

will provide a smooth riding surface at expansion joints and at the ends of the
concrete wearing course. After completion of the planing, the permissible surface deviation will
be 3

mm (
1/8

inch
) in 3

meters (
10

feet
) measured with a straightedge laid lo
ngitudinally and
3

mm (
1/8

inch
) in 1

meter (
3

feet
) measured transversely at right angles to the centerline of
roadway.



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All slurry material shall become property of the Contractor and must be disposed
of as per Mn/DOT

2104.3C3, as approved by Mn/DOT, an
d as described in this special
provision.



All concrete residue and water (slurry) resulting from concrete texture planning
must be continuously vacuumed from the surface, captured, and containerized for further
handling or processing. The slurry must no
t be permitted to flow across lanes occupied by
traffic, flow into drainage facilities or discharge anywhere within the highway Right of Way.
The Contractor must submit a slurry disposal or reuse plan at the preconstruction conference for
approval by Mn/D
OT.



The method to manage the slurry may require separation of the solids from the
liquids. This separation may be achieved mechanically by centrifuging or passively by allowing
settlement of the fines to occur in a temporary impermeable lined containmen
t area. If a
temporary containment area is used within the highway Right of Way, a Site Plan as per 1717
will be required for Mn/DOT's approval. The minimum Site Plan shall include methods for
storm water protection at the temporary containment area, a d
escription of the proposed
separation method, and the process for final removal and restoration of the disturbed containment
area. For any method used to separate the liquid from the solids, the Contractor shall identify the
name and location of the POTW
(publicly owned treatment works facility) that the liquids will
be deposited in, or how the processed water will be reused by the Contractor.



As part of the slurry disposal or reuse plan, the Contractor must be able to
provide, upon request, documentatio
n that identifies the name and location of the MPCA
permitted lined mixed municipal solid waste (MMSW) or industrial landfill that the solids will
be deposited in, or identifies any alternative methods of disposal or reuse that meet
environmental requireme
nts of regulated industrial waste.



The Contractor shall hold Mn/DOT harmless for any fines or sanctions caused by
the Contractor's actions or inactions regarding compliance with concrete slurry management and
disposal. All materials and labor for instal
lation of storm water protection practices,
maintenance, control, removal and disposal for the management of concrete slurry is incidental
to the bridge deck texture planning operation.



Planed areas not meeting requirements may, at the option of Mn/DOT,
be
replaced, re
-
planed or left as is and accepted for payment subject to a price reduction of $2.70
per square meter (
25

cents per square foot
) but, in all cases, positive surface drainage shall be
provided.





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DBSB
-
2401.
20

Curing Bridge Deck Slab


If a br
idge deck slab and wearing course are constructed monolithically and if this bridge deck
slab surface will be tine textured and not planed, the following shall apply.



Delete the first sentence of the 12
th

paragraph of 2401.3G and substitute the
following
:



After completion of the tine texturing for bridge deck slab and after free water has
disappeared from the surface, the Contractor shall apply a membrane curing compound meeting
the requirements of Mn/DOT specification 3754, section

B (Requirements for
Concrete
Pavement Membrane Curing Compound). The curing compound shall be applied with Approved
power
-
operated spray equipment. The Contractor shall place the membrane cure material
homogeneously to provide a uniform solid white opaque coverage on all ex
posed concrete
surfaces (equal to a white sheet of paper). The membrane cure shall be placed within
20

minutes
of
final strike
-
off of the concrete

unless otherwise directed by Mn/DOT. Failure to comply with
this provision will result in a price reduction

for the concrete item involved in accordance with
Mn/DOT Spec.

1503. The curing compound is not a substitute for the cure specified below, but
is required for moisture retention until the conventional wet curing material can be placed.
Conventional wet
curing shall be applied as soon as the concrete can be walked on without
indenting the finished surface. The deck slab surface shall be kept continuously wet with clean
fresh water for an initial curing period of at least 7 days. The Contractor must prov
ide adequate
personnel to ensure that the deck surface is maintained in a wet condition on weekends and/or
holidays.



Delete the entire section of 2401.3K.





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DBSB
-
2401.21

POST TENSIONING SYSTEM



A.

Description of Work



This work shall consist of prestr
essing concrete by the post
-
tensioning method.
The applicable provisions of Mn/DOT

2401 and 2405, and the following:



This work includes:


1.

Design calculations
, shop

and working drawings.


2.

Furnishing and installing the ducts and prestressing strands

or bars
,
including positioning devices for the tendons and
any other
appurtenant items
necessary for the particular system to be used.


3.

Furnishing and installing the tendon anchorage system.


4.

Furnishing, protecting, and installing prestressing tendo
ns.


5.

Modulus of Elasticity testing and i
n
-
place friction testing
(when ordered)
.


6.

Post
-
tensioning the system.


7.

Grouting the ducts and anchorage blockouts upon completion of the
stressing operations.


8.

Protection of anchorages, clean
-
up, and other

work necessary for
installation of the system.


9.

Furnishing a 4
-
way articulating flexible borescope.


10.

Application of temporary corrosion protection measures (if used).


The Contractor shall engage a post
-
tensioning construction engineer (PT
Engineer
)
who

is a professional engineer
and

has a minimum of 4 years of cumulative
verifiable
relevant experience in the design and construction of post
-
tensioned bridge structures obtained
over the past 12 years. The PT Engineer shall direct and supervise the e
ngineering services
required to construct the post
-
tensioned structures in accordance with the Contract Documents.


All of the Contractor’s post
-
tensioning grouting operations shall be under the
direction of experienced supervisory personnel who have 3 yea
rs of
verifiable
relevant
experience over the past ten years in construction of grouted post
-
tensioned structures and have
successfully completed training in a grouting technician certification program,
and who hold
current certification from either

the Am
erican Segmental Bridge Institute’s grouting certification
program or
the
Post
-
Tensioning Institute
’s

grouting certification program.




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Conduct all stressing and grouting operations in the presence of the PT Engineer.
Coordinate and schedule all post
-
ten
sioning activities to facilitate inspection by the PT Engineer.


All components of a system shall be stamped with the supplier’s name, trademark
and size corresponding to catalog designation. Post
-
tensioning systems consist of an assembly of
components for

various sizes of strand or bars assembled and pressure tested. Post
-
tensioning
systems
will be
A
pproved

for use

based on
previous
prequalification testing. Prequalification
testing shall
have been

performed by an independent testing laboratory. Testing
conducted for
other State transportation agencies may be accepted as prequalification testing at the discretion
of
Mn/DOT
.

The Contractor shall submit evidence of prequalification of all systems proposed
for use with the working drawings.

Furnish all comp
onents of a post
-
tensioning system from a
single supplier, whenever feasible.



The Contractor shall arrange for a representative of the post
-
tensioning
manufacturer to provide on
-
site supervision

for all post
-
tensioning work and to provide
consultation an
d guidance with respect to post
-
tensioning

materials supply,

installation, stressing
and tendon grouting. The post
-
tensioning manufacturer’s field representative (PTMFR) shall be
on
-
site at the project and/or

at

the precast facility to provide supervision

and consultation as
specified below.

The PTMFR shall be on
-
site:


1.

During the first week of duct and anchorage installation,

2.

During the first
5

strand

and first 5 bar

stressing operations,

3.

During the first
5

grouting operations,

4.

A minimum

of once every 3 months of post
-
tensioning installation,
stressing or grouting operations, but not less than twice each calendar year
from the time of initial installation of ducts through stress of tendons of
last concrete pour with post
-
tensioning on the

Project.


B
.

Terminology


The following definitions apply to
post
-
tensioned
bridge construction:


1.

Anchorage Assembly: An assembly of various hardware components which secures a

tendon at its ends after it has been stressed and, imparts the tendon force in
to the
concrete.


2.

Anticipated Set: The wedge set assumed to occur in the design calculation of the post
-
tensioning
forces at the time of load transfer.


3.

Bar: Post
-
tensioning bars are high strength steel bars, normally available from 5/8 to 1

3/4 inch diame
ter and usually threaded with very coarse thread.


4.

Bearing Plate: Any hardware that transfers the tendon force directly into a structure or the




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ground.


5.

Bleed: The autogenous flow of mixing water within or its emergence from, newly placed

grout, caused by
the settlement of the solid materials within the mass.


6.

Coupler: A device used to transfer the prestressing force from one partial length

prestressing tendon to another. (Strand couplers are not permitted.)


7.

Duct: Material forming a conduit to accommodate
prestressing steel installation and

provide an annular space for the grout which protects the prestressing steel.


8.

Family of Systems: Group of post
-
tensioning tendon assemblies of various sizes which

use common anchorage devices and design. All components
within the family of systems
shall be furnished by a single supplier and shall have a common design with varying
sizes.


9.

Fluidity: A measure of time, expressed in seconds necessary for a stated quantity of grout

to pass through the orifice of a flow cone.


10.

Grout: A mixture of cementitious materials and water with or without mineral additives

or admixtures, proportioned to produce a pumpable consistency without segregation of
the constituents, when injected into the duct to fill the space around the prestres
sing steel.


11.

Grout Cap: A device that contains the grout and forms a protective cover sealing the post
-
tensioning

steel at the anchorage.


12.

Inlet: Tubing or duct used for injection of the grout into the duct.


13.

Outlet: Tubing or duct to allow the escape of a
ir, water, grout and bleed water from the

duct.


14.

Post
-
tensioning:
The application of a compressive force to the concrete by stressing
tendons or bars after the concrete has been cast, cured and has reached the specified
strength. The force in the stressed

tendons or bars is transferred to the concrete by means
of anchorages
.


15.

Prestressing Steel: The steel element of a post
-
tensioning tendon, which is elongated and

anchored to provide the necessary permanent prestressing force.


16.

Post
-
Tensioning Scheme or La
yout: The pattern, size and locations of post
-
tensioning

tendons provided by the Designer on the Design Documents.


17.

Post
-
tensioning System: An assembly of specific models of hardware, including but not

limited to anchorage assembly, local zone reinforcemen
t, wedge plate, wedges, inlet,
outlet, couplers, duct, duct connections and grout cap, used to construct a tendon of a



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particular size and type. The entire assembly must meet the system pressure testing
requirement. Internal and external systems are consid
ered independent of one another.


18.

Pressure Rating: The estimated maximum pressure that water in a duct or in a duct

component can exert continuously with a high degree of certainty that failure of the duct
or duct component will not occur (commonly referre
d to as working pressure).


19.

Set (Also Anchor Set or Wedge Set): Set is the total movement of a point on the strand

just behind the anchoring wedges during load transfer from the jack to the permanent

anchorages. Set movement is the sum of slippage of the w
edges with respect to the
anchorage head and the elastic deformation of the anchor components. For bars, set is the
total movement of a point on the bar just behind the anchor nut at transfer and is the sum
of slippage of the bar and the elastic deformatio
n of the anchorage components.


20.

Strand: An assembly of several high strength steel wires wound together. Strands usually

have six outer wires helically wound around a single straight wire of a similar diameter.

Tendon: A single or group of prestressing ste
el elements and their anchorage assemblies

imparting prestress forces to a structural member or the ground. Also, included are ducts,

grouting attachments, grout and corrosion protection filler materials or coatings.


21.

Tendon Size: The number of individual
strands of a certain strand diameter or the

diameter of a bar.


22.

Tendon Type: The relative location of the tendon to the concrete shape, internal or

external.


23.

Thixotropic: The property of a material that enables it to stiffen in a short time while at

rest,

but to acquire a lower viscosity when mechanically agitated.


24.

Wedge Plate: The hardware that holds the wedges of a multi
-
strand tendon and transfers

the tendon force to the anchorage assembly
.
(Commonly referred to as anchor head)


25.

Wedge: A conically shap
ed device that anchors the strand in the wedge plate.



DBSB
-
2401.21.1

Working Drawings



A.

General:



Working drawings of the proposed prestressed concrete members shall be
submitted in accordance with the requirements of
the Contract Documents

and these

special provisions.




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The Contractor shall prepare composite drawings in plan, elevation and section
which show to scale the relative positions of all items that are to be embedded in the
concrete, the concrete cover, and the embedment depth for the portio
ns of the structure
that are to be temporarily or permanently prestressed. Such embedded items include the
prestressing ducts, vents, anchorage reinforcement and hardware, and reinforcing steel
strand. Such drawings shall be adequate to ensure that there

will be no conflict between
the planned positions of any embedded items, and that concrete cover will be adequate.
If, during the preparation of such drawings, conflicts are discovered, the Contractor shall
revise the working drawings for one or more of
the embedded items, or proposed changes
in the dimensions of the work as necessary to eliminate the conflicts or provide proper
cover. Any such revisions shall be approved by the Engineer before work on an affected
item is started.



The Contractor shall
submit with the working drawings a system of tendon
identification, individually and in groups, to expedite the tasks of the Contractor and
Mn/DOT in mutual pursuit of the installation and Acceptance of the post
-
tensioning
process.



The
working
drawings s
hall show the method and procedure of jacking and the
type, size, and properties of the strands or bars and the anchorage assemblies. The
number of strands per tendon shall be shown. Details shall be included for any additional
reinforcing steel required

to resist the concrete bursting stresses in the vicinity of the
anchorage assemblies. The sizes, shapes, and dimensions shall be shown for the ducts.
Lay
-
out dimensions for locating the ducts along the tendon path shall be shown at
intervals
of 1.25 m (
4 ft) for round duct and flat duct loaded with strand and at 300 mm
(1ft) for flat duct without strand
, and shall also be shown at anchorages, low points, high
points, and points of inflection. Vent locations and details of the vents shall also be
include
d on the drawings.





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The drawings shall include complete details of the method, materials, and
equipment proposed for use in the
post
-
tensioning

operations. Such details shall outline
the method and sequence of jacking, show complete details of the prestr
essing steel,
anchoring devices, type of enclosures, block
-
outs, and show all other data pertaining to
the post
-
tensioning system or operations. Submit calculations to substantiate the
prestressing system at each stage of erection and procedures to be used

including

stress
-
strain curves typical of the prestressing steel to be furnished, required jacking forces,
elongation of tendons during tensioning, prestress losses including seating losses,
parameters, and the final working forces. These calculations sh
all show a typical tendon
force after applying the expected friction coefficient, and anticipated losses including
anchor set losses. Elongation calculations shall be revised when necessary to properly
reflect the modulus of elasticity
and/or friction and
wobble of the tendon system

as
determined from

strand modulus of elasticity

and

in
-
place friction tests in accordance
with Section 5.7, Division II, Guide Specifications for Design and Construction of
Segmental Concrete Bridges. Calculations shall also pr
ovide stresses in the anchorages
and distribution plates.



Submit complete details of the apparatus and method to be used by the Contractor
for the
modulus of elasticity

test described under DBSB
-
2401.21.3
, when applicable
.


Submit a complete description
of the procedures for grouting the tendons
including the name of the supplier of the pre
-
packaged material for grout as required
under Section DBSB
-
2401.21.2. Describe the equipment to be used for mixing and
pumping the grout, qualifications of field pers
onnel, duct repair procedures, methods
used to control the rate of flow within the ducts, theoretical grouting volume calculations,
vent and injection port details, duct cleaning methods prior to grouting, mixing and
pumping procedures
.




Within 30 calend
ar days of award of the Contract, the Contractor shall submit a
proposed temporary corrosion inhibitor to Mn/DOT for
A
pproval, if the Contractor intends
to employ temporary corrosion protection. Submit copies of the product description,
including chemical

composition and intended use, manufacturer’s published application and
maintenance instructions, material safety data sheet, a list of recent and relevant applications
of the product including the owners name and current telephone number, a list of those
states
which have previously approved the product for application within post
-
tensioning ducts for
purposes of preventing or mitigating corrosion of post
-
tensioning steel.



The Contractor shall submit the results of tests described in Section DBSB
-
2401.
21.2G of these Special Provisions.



B.

Design Requirements:


1.

Materials and devices used in the
post
-
tensioning

system shall conform to
the requirements in Section DBSB
-
2401.21.2.





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2.

The net compressive stress in the concrete after all losses shall be
determined and shown
in the submitted calculations
.


3.

The distribution of individual tendons at each section shall be determined
and shown on the Working Drawings.


4.

The ultimate strength of the structure with the proposed
post
-
tensioning

system, stres
ses in the concrete and prestressing steel at all sections and at all
stages of construction and all work and materials shall meet the requirements of
the AASHTO
LRFD Bridge Design Specifications
(referred to hereafter as
AASHTO) including all Interim Speci
fications, the requirements of the Design
Criteria noted on the
Design Documents
, and the AASHTO Guide Specifications
for Design and Construction of Segmental Concrete Bridges as applicable.


5.

The Contractor shall fully design and detail, as required, th
e elements
where a
post
-
tensioning

system is proposed to be used.


6.

The Contractor shall submit complete shop drawings including the
prestressing scheme and system, reinforcing steel, and concrete cover; and design
calculations (including short and lon
g term prestress losses) to the PT Engineer
for approval and for Mn/DOT’s Acceptance.


DBSB
-
2401.21.2

Materials



A.

Prestressing Material




1.

Prestressing Steel





a.

Strand:


Uncoated, Grade 1860 (270 ksi), low
-
relaxation
uncoated seven
-
wire strand pe
r ASTM

Designation

A 416M and Mn/DOT 3348.




b.

Bar:


Uncoated, Grade 1035 (150 ksi), high
-
strength,
coarse thread bar per ASTM
Designation

A 722M,
Type II
, including supplementary requirements
.

The
maximum weight requirement of ASTM
Designation: A 722
M

will not apply. In addition to
the requirements of ASTM Designation: A 722
M
,
for deformed bars, the reduction of area shall be
determined from a bar from which the deformations
have been removed. The bar shall be machined no
more than necessary to remove

the deformations
over a length of 12 inches, and reduction will be
based on the area of the machined portion.





The proper use of strand and bars is predicated upon the use of suitable



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accessory materials. Details from the manufacturer for the use of th
ese materials
shall accompany the shop and working drawing submittals.




2.

Bar Couplers




For permanent applications, the use and location of post
-
tensioning bar
couplers is subject to approval by the PT Engineer. Where post
-
tensioning bars
are coupled
, the assembled units shall develop at least 95

percent

of the
guaranteed ultimate tensile strength (GUTS) of the bar, tested in an unbonded
state without exceeding the anticipated set. The couplings of post
-
tensioning bars
shall not reduce the elongation
at rupture below the requirements of the post
-
tensioning bar itself.




Only threaded type couplers shall be used with post
-
tensioning thread
-
bars. Post
-
tensioning thread
-
bars shall be threaded into the coupler to ½ the length
of the coupler ± ¼ inch so th
at when two bars are coupled in a coupler, the length
of each bar positively engaged in the coupler shall be half the coupler’s length
within the acceptable tolerances.




No coupling or splicing will be permitted to be used with strands.




3.

Prestress A
nchorages and Grout Caps



Secure all prestressing steel at the ends by anchoring devices
A
pproved by
Mn/DOT. The anchorages shall develop at least 95

percent

of GUTS of the
prestressing steel, tested in an unbonded state without exceeding the anticipated
set.
The anchorage shall be so arranged that the prestressing force in the tendon may be
verified prior to removing the stressing equipment.





Fit all post
-
tensioning anchors with permanent, heavy duty, (non
-
metallic)
fiber reinforced plastic grout ca
ps. Use permanent grout caps made from fiber
reinforced polymer. The resins used in the fiber reinforced polymer shall be either
nylon, Acrylonitrite Butadiene Styrene (ABS) or polyester. For products made from
nylon, the cell class of the nylon accordin
g to ASTM D5989 shall be S
-
PA0141
(weather resistant), S
-
PA0231 or S
-
PA0401 (ultimate strength not less than 10,000
psi with UV stabilizer added). For products made from nylon a cell class of S
-
PA0141 (weathering resistant) is required.

Seal the cap with

“O” ring seals or
precision fitted flat gaskets placed against the bearing plate. Place a grout vent on
the top of the cap. Grout caps must be rated for a minimum pressure rating of 150
psi. Use ASTM A240 Type 316L stainless steel bolts to attach the c
ap to the
anchorage. When stainless steel grout caps are supplied, provide certified test reports
documenting the chemical analysis of the steel.



Grout caps shall have a port capable of being sealed with a threaded plug for
secondary filling of the cap
with grout or inspection.




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The body of the anchorage shall be galvanized

in accordance with ASTM A123
.
Other components of the anchorage including wedges, wedge plate shall not be
galvanized.

Local zone reinforcement that protrudes into the deck or tha
t contacts
deck reinforcement shall be stainless steel. Stainless steel local zone reinforcement,
if used, shall not contact uncoated or regular bar reinforcing steel nor shall it contact
galvanized items.




Anchor plates for PT bars shall be galvanized
. The anchor nut and coupler shall not
be galvanized.



Provisions shall be made to enable the inspection for voids and bleed water in the
grout caps and anchorage trumpets after grouting of the tendon has been completed
with the aid of a borescope for
all strand anchorages whose anchor has five or more
strands.

Inspection provisions shall also conform to that indicated in the
Design
Documents
.




Cast anchorages with grout outlets suitable for inspection from either the top or front
of the anchorage. T
he grout outlet shall serve a dual function of grout outlet and post
-
grouting
bore
scope inspection. The grout outlet shall be drillable from either direction using
a straight bit to facilitate
bore
scope inspection directly behind the anchor plate.
Where
ne
cessary to facilitate straight bores into the anchorages/ducts for post
-
grouting inspection,
mandrels shall be used to keep grout hoses straight during concrete placements.

Two
castings of the same type each providing singular inspection entry locations a
re acceptable.



Anchorages shall be set in a plane normal to the axis of the tendons such that uniform
bearing on the concrete is assured. Anchorages shall be supplied with a steel reinforcing
spiral
when additional local zone reinforcement is required
.



The use of two
-
part wedges which show any sign of slippage or failure to grip the
tendon without exceeding the anticipated set, shall be immediately discontinued and the
Contractor shall be required to furnish and use acceptable alternative three
-
part w
edges for
anchoring post
-
tensioning strands.



Dead end anchors for post
-
tensioning tendons with strand shall not be used.



Bond head anchors that use splayed wires shall not be used.








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Testing of anchorage devices shall be performed by an independen
t testing
agency in accordance with the procedures described in Article

10.3.2 of AASHTO LRFD
Bridge Construction Specifications. The anchorage device shall meet the acceptance
criteria specified in AASHTO LRFD Bridge Construction Specifications
Article

1
0.3.2.3.10 for a moderately aggressive environment using samples representing
the type of prestressing steel and concrete strength to be used on the project. The test
specimen shall be assembled in an unbonded state and, in testing, the anticipated anchor

set shall not be exceeded. Certified copies of test results for the anchorage system shall
be supplied to the PT Engineer and Mn/DOT.



For tendon anchorages, the design and furnishing of local zone reinforcement in
accordance with AASHTO (in addition
to the reinforcement shown on the working
drawings) shall be the responsibility of the Contractor.



Prestress anchorage devices shall effectively distribute prestressing loads to the
concrete and shall conform to the following requirements.



a.

The beari
ng stress in the concrete created by the anchorage plates shall not
exceed the values per AASHTO.



b.

Bending stresses in the plates or assemblies induced by the pull of the
prestressing steel shall not exceed the yield point of the material in the anchor
age
plate when 95 percent of the ultimate strength of the tendon is applied. Nor shall
it cause visual distortion of the anchor plate.



The PT Engineer and Mn/DOT shall be provided with certified test reports from an
A
pproved independent testing laborato
ry verifying compliance with this requirement,
for each type and/or size of anchoring device.



Prestress anchorage devices shall include grout outlet/inspection ports and
accessories which permit inspection of the anchorage zones with a borescope.



Grout
ing Component Assembly Pressure Test: Assemble

anchorage and grout cap
with all required grouting attachments (grout tube, valves, plugs, etc.).

Seal the
opening in the anchorage where the duct connects. Condition the assembly by

maintaining a pressure of
1.03 MPa (
150 psi
)

in the system for 3 hours. After
conditioning, the assembly

must sustain a
1.03 MPa (
150 psi
)

internal pressure for
five minutes with no more than
103 kPa (
15 psi
)

reduction in

pressure. For systems
using the same anchorages, grout caps
and grouting attachments as a

previously
A
pproved system, the Grouting Component Assembly Pressure Test may include

documentation from a previous submittal with written certification that the same
components are

being utilized in both anchorages.




Trumpe
ts associated with anchorages will be made of either ferrous metal or



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polypropylene plastic material conforming with the requirements of these special
provisions. The thickness of the trumpet at the transition location (choke point)
will not be less than t
he thickness of the duct.



Alternately, the trumpet material may be a polyethylene or polyolefin containing
antioxidant(s) with a minimum Oxidation Induction Time (OIT) according to
ASTM D 3895 of not less than 20 minutes. Test the remolded finished poly
olefin
material for stress crack resistance using ASTM F 2136 at an applied stress of
2.40 MPa (348 psi). resulting in a minimum failure time of 3 hours.




4.

Sampling and Testing of Materials



Sampling and testing of all materials for the post
-
tensionin
g system shall
be in accordance with the requirements of
the Contract Documents
. The “site”
referred to herein shall be considered as the location where the material is to be
installed, at the bridge construction site.



Furnish samples for testing as des
cribed below for each manufacturer for
pre
-
stressing strand and bar to be used on the project. With each sample of pre
-
stressing strand or bar furnished for testing, submit a certification stating the
manufacturer minimum guaranteed ultimate tensile streng
th of the sample
furnished. The Contractor shall provide Mn/DOT with samples of the following
materials, selected from the job site by the PT Engineer, from the pre
-
stressing
steel used for post
-
tensioning operations:



a.

Strand
: Three randomly selected
samples, 1.5 m (5 ft) long, per
manufacturer, per size of strand, per shipment, with a minimum of
one sample for every 10 reels.


b.

Bars
: Three randomly selected samples, 1.5 m (5 ft) long, per
manufacturer, per size of bar, per heat of steel, with a mini
mum of
one sample per shipment.


c.

Permanent couplers
: Three
randomly selected
units of 0.5 m (2 ft)
lengths of bar/tendon, each equipped with one coupler and
fabricated to fit the coupler, per manufacturer.


d.

Anchorage assemblies
: Two
randomly selected

samples per size,
per manufacturer.


e.

Ducts:

For each type of duct material, one
randomly selected
sample 1.2m (4 ft) long per manufacturer, from each production lot
or per 3,035 linear meters (10,000 linear ft) whichever is greater.



One of each of t
he
strand and bar
samples furnished to represent a Lot will
be tested. The remaining sample(s), properly identified and tagged, will be stored
by the PT Engineer for future testing. In the event of loss or failure of the
component, the stored sample will b
e utilized to evaluate for minimum strength
requirements. For
A
cceptance of the Lot represented, test results must show that



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100

percent

of the Lot achieves the
minimum yield strength and
guaranteed
ultimate tensile strength.

The strand manufacturer shall

provide results of the two
most recent 1000
-
hour relaxation tests performed on strand of the same type and
size to be furnished to the Project. For Acceptance of the strand, relaxation
properties must meet the requirements of ASTM A 416 and be performed
on
strand of similar manufacturing processes and base materials as strand to be
furnished to the Project.




A
L
ot

is that parcel of components as described herein. All bars, of each
size from each mill heat of steel and all strand from each manufactu
red reel to be
shipped to the site must be assigned an individual Lot number and must be tagged
in such a manner that each such Lot can be accurately identified at the job site.
Submit records to the Engineer identifying assigned Lot numbers with the heat
, or
reel of material represented. All unidentified prestressing steel, or bars received at
the site will be rejected. Also, loss of positive identification of these items at any
time will be cause for rejection.



Low relaxation strand shall be clearly id
entified as required by ASTM A
-
416. Any strand not so identified will not be acceptable.



The Contractor shall furnish manufacturer’s certified reports covering the
tests required by these Special Provisions to the PT Engineer and Mn/DOT. A
certified te
st report stating the guaranteed minimum ultimate tensile, yield
strength, elongation and composition shall be furnished for each Lot of
prestressing steel. When requested, typical stress
-
strain curves for prestressing
steel shall be furnished. A certifi
ed test report stating strength when tested using
the type prestressing steel to be used in the work shall be furnished for each Lot of
prestress anchorage devices.



Release of Materials: Release of any material by the PT Engineer shall
not preclude subs
equent rejection if the material is damaged in transit or later
damaged or found to be defective.



B.

Ducts


1.

General



Use only plastic duct, steel pipe or a combination of plastic duct and steel
pipe.
All duct material shall be sufficiently rigid to
withstand loads imposed during
placing of concrete and internal pressure during grouting while maintaining its shape,
remaining in proper alignment and remaining watertight and pass the pressure test
requirements herein.


Use smooth plastic duct in all pos
t
-
tensioning systems used for
external tendons

except where steel pipe is required. Use corrugated plastic duct in all
post
-
tensioning systems used for all internal tendons except where steel pipe is required.





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Furnish ducts with end caps to seal the duct

interior from contamination. Ship
in bundles, which are capped and covered during shipping and storage.


The duct system, including splices and joints shall effectively prevent
entrance of cement paste or water into the system and shall effectively contai
n
pressurized grout during grouting of the tendon.


Steel pipe and plastic duct may be
connected directly to each other when the outside diameters do not vary more than ±
0.08 inch. Use a reducer when the diameters of the steel pipe and the plastic duct a
re
outside of this tolerance.


Splices or connections between segments of the ducts, or ducts and inlets or
outlets,
or ducts and anchorages or trumpets,
shall be leak proof and positively sealed
with a heat sealed joint, a neoprene coupler with permanent
stainless steel banding
clamps, mechanical coupler, or other Mn/DOT
A
pproved permanent waterproof and
corrosion resistant connection meeting these Special Provisions. If an adhesive or
sealant is used to make the connection, the adhesive or sealant shall
not be applied to
the exterior of the duct. The use of adhesive tape (including duct tape) for these
connections will not be allowed.


Heat shrink sleeves having uni
-
directional circumferential shrinkage shall be
manufactured specifically for the size of t
he duct being coupled consisting of an
irradiated and cross linked high density polyethylene backing for external
applications and linear
-
density polyethylene for internal applications. Adhesive must
bond to steel and polyolefin plastic materials.

Ensure t
he heat shrink sleeves have an adhesive layer that will withstand

65
degrees C (150 degrees
F
)

operating temperature and meet the requirements of the
following table:





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Property

Test Method

Minimum Requirements

Internal Application

External Application

Minimum Fully
Recovered Thickness


2.34 mm (92 mils)

2.82 mm (111 mils)

Peel Strength

ASTM D 1000

29 pli

46 pli

Softening Point

ASTM E 28

72
o
C (162
o
F)
102
o
C (216ºF)

Lap Shear

DIN 30 672M

600 kPa (87 psi)

400 kPa (58 psi)

Tensile Strength

ASTM D
638

20 MPa (2,900 psi)

24 MPa (3,480 psi)

Hardness

ASTM D 2240

46 Shore D

52 Shore D

Water Absorption

ASTM D 570

Less than 0.05%

Less than 0.05%

Color


Yellow

Black

Shrinkage


33%

23%


Install heat shrink sleeves using procedures and methods in accor
dance
with the manufacturer’s recommendations.



2.

Duct Type Designation





Key to Duct Material:


A
-

Galvanized Rigid Steel Pipe








B

-

Corrugated Plastic











C

-

Smooth

Plastic





Epoxy coated metal ducts shall not be used.










All ben
ds shall be smooth without kinking or crimping of the duct.




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3.

Specific Material Properties


a.

Type A
-

Galvanized Rigid Steel Pipe



Steel pipe duct shall be galvanized steel pipe conforming to the
requirements of Mn/DOT Spec.

3362 Schedule

40. The pi
pe shall be bent so as to
accurately conform to the alignment of the tendon taking into consideration the
minimum bending radius shown in the working drawings.



Type A duct material shall be bent to a uniform radius along a curve
extending between tangent

points. The pipe shall be clearly marked for correct
vertical orientation near each end and at the midpoint of the pipe.




Ensure that steel pipes used in the tendon anchorage zones are equipped
with a shear transfer mechanism. Test and provide writte
n certification that the
shear transfer mechanism can resist at least 60 percent of the tendon GUTS in a
shear transfer pull
-
out test described below:


Shear Transfer Mechanism Pullout Test Procedure:

1)

Cast Anchorage, Shear Transfer Mechanism and Duct in a
test block of
concrete with minimum dimensions of 2’