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29 Νοε 2013 (πριν από 3 χρόνια και 4 μήνες)

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IPRO 306:
AGGREBIND

BLOCKS

FALL 2012

AggreBind

is a water
based geo
-
polymer and
soil stabilizer:


Environmentally safe


Capable of binding virtually any
soil without baking or cement


Mixed with soil as liquid and cures
to a permanent solid via self
cross
-
linking


Originally developed for road
construction using minimal
equipment



BACKGROUND

FALL 2012


Began experi menti ng wi th
AggreBi nd

as a bi nder for bl ocks
for use i n devel oped countri es as a greener al ternative to
bri cks or CMUs (aka “ci nder bl ocks”)


Tested vari ous mi xtures of sands and other soi l s i n manual
bri ck maki ng process


Goal of 2000 psi compressi ve strength, reached 537.6 psi

SUMMER IPRO


Establish

the maximum compressive
strength of
AggreBind

block


Explore

new production and
fabrication processes


Optimize

the cure time of these
blocks


Consider

alternative non
-
structural
applications of the
product

MISSION STATEMENT

FALL 2012

TEAM ORGANIZATION

Instructor

Research

Background
Research

Fabrication

Block Mold

Block
Tests

Documentation

Final
Presentation

Poster

FALL 2012

Establish

Used the fol l owi ng testi ng gui del i nes:


ASTM standard bri ck si ze for compressi on testi ng


½ length Utility brick: 3
-
5/8” x 3
-
5/8” x 5
-
13/16”


Intermedi ate testi ng usi ng shop press


Fi nal testi ng i n the l ab


Goal of 2000 psi

ESTABLISHING MAXIMUM STRENGTH

ALTERNATIVE COMPARISON


FALL 2012

Traditional Blocks

Alternative Blocks

Clay Brick


Concrete

Masonry Unit
(CMU)

Calstar

Block

AggreBind

Block

Binding Agent

Clay

Portland Cement

Fly Ash

Styrene
-
acrylic
Polymer

Environmental

Impact


Kiln firing
energy
intensive

40% world
energy use

12% of world’s
CO
2
emissions


85% lower
embodied energy

Byproduct of coal
burning


Similar

energy to
Calstar

No kiln firing or
use of cement


Cure Time

2
-
5 days

3 days to ship

28 days

full cure

1

day to ship

28 days
(manufacturer
recommended)

Compressive
Strength

1
--
15000

psi

1
-
5000 psi

7200 psi

???

Explore

EXPLORE



Wood vs. Steel Mol d


Compaction:
h
and vs.
m
easured mechani cal


New
mi xture scheme, no l onger mi xed by
hand


Larger
pool of bri ck sampl es and mul ti ple
rounds of bri cks

MIX VARIATION

FALL 2012

FABRICATION PROCESS

1. Pour AGB into soil mixture

FABRICATION PROCESS

2. Mix thoroughly

FABRICATION PROCESS

3. Pour mixture into metal mold

FABRICATION PROCESS

4. Compact mixture

FABRICATION PROCESS

5. Remove brick from metal mold

FABRICATION PROCESS

6. Cure brick for testing

FABRICATION PROCESS


FALL 2012

2
.

1
.

3
.

4.
.

5.
.

6
.

ELSTON

BLOCK MANUFACTURING


Our process based on commercial block
manufacturing machinery


Elston block tour


Metal mold filled with mixture, compacted,
mold slides off upwards and blocks set aside
to cure

ROUND 1

ROUND 1

STRENGTH TEST RESULTS

Mold Compression

500 psi

1000 psi

Mixture

Aggrebind :
Water

14 Day

28 Day

14 Day

28 Day

Sand


90%

Small Rocks


10%

1:2

110 psi

90 psi

250 psi

1200 psi

Sand


80%

Limestone


10%

Concrete


10%

1:2

210 psi

240 psi

240 psi

180 psi

1:4

200 psi

150 psi

130 psi

150 psi

Sand


60%

Limestone


30%

Small Rocks


10%

1:2

850 psi

900 psi

950 psi

700 psi

1:4

500 psi

250 psi

300 psi

800 psi

Torpedo Sand


50%

Limestone


25%

Light Aggregate


25%

1:2

850 psi

1000 psi

1200 psi

1250 psi

Test a variety of bricks to determine the effects of:


AggreBind to water ratio


Compaction pressure


Curing time (14 days vs. recommended 28 days)


Soil mixture (more sand vs. more limestone)




ROUND 1 TESTING DATA

FALL 2012


Compression to failure test


Basic test using shop press


Cheap and effective initial
testing




ROUND 1 RESULTS



ROUND

1 RESULTS

Bui l t on resul ts of Round 1:


Min. two of each brick mixture


1000 psi compaction pressure


1:2 ratio of AGB to water

Conducted of fi ci al strength testi ng


Computer
-
controlled


Greater need for flat specimens

ROUND 2

0
200
400
600
800
1000
1200
1400
0
0.5
1
1.5
2
2.5
3
3.5
4
Strength (psi)

Strain (%)

50% Limestone, 25% Sand, 25% Small
Aggregate (12 days)


Strongest Mixture:

50% limestone
25% sand
25% light aggregate


Maximum strength
of 943.2 psi


Average strength of
820.5 psi


ROUND 2 RESULTS

0
100
200
300
400
500
600
700
800
900
1000
Red-1
Red-2
Red-3
Strength (psi)

50% limestone mixture, 28 day cure

Optimize

A variety of methods:


Proven by Rounds 1 and 2


14 Days


Li mestone vs. sand


Tested for Round 3


Oven Curi ng


Catal yst


Iron Powder (for strength)


IMPROVING CURE TIME

Test condi ti ons:


All bricks wrapped in foil


All 50% limestone mixture


Oven temp. at 200 F


Durations of 0,2,4,8 hours


Two bricks w/iron powder


Resul ts:


Optimum oven cure 4 hrs


12
-
day maximum strength:
1157 psi


Iron powder ineffective


ROUND 3

0
200
400
600
800
1000
1200
1400
0
2
4
6
8
Compressive Strength (psi)

Cure Duration (hrs)

Oven Cured 50% Limestone Mixture

Oven Cured
w/Iron Powder

OVERALL RESULTS

Consider


Recycled Materials


Styrofoam


Rubber


Plastic

CONSIDER

POTENTIAL APPLICATIONS

Low grade brick applications
(1000
-
1500 psi)


-
Decorative interior facing
brick

-
Walkway paver

-
Facing brick outdoors in
warmer and drier regions

COMPETITIVE BLOCK PRICE


*No current market price for AggreBind



Modular
Calstar

Brick

Standard
block

Concrete
masonry unit
(CMU)

AggreBind

block

Total Cost

$1.4/Unit

$1.25/Unit

$1.42/Unit

$1.37/Unit*

Fall 2012


Optimize oven curing process


Continue to explore additives:


Fly ash


Slag


Further Testing:


Fire


Weathering

FUTURE OF AGGREBIND

FALL 2012


Establ i shed hi gher maxi mum strength of
AggreBi nd

bl ock


Compaction Pressure


AGB:Water

Ratio


Oven Curing


Limestone Mixture



Ef fecti ve teamwork and coordi nated smal l groups

CONCLUSION