350 likes | 634 Views
IPRO 306: AggreBind BLOCKs . FALL 2012. Background. 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
E N D
IPRO 306: AggreBind BLOCKs FALL 2012
Background 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 FALL 2012
Summer IPRO • Began experimenting with AggreBind as a binder for blocks for use in developed countries as a greener alternative to bricks or CMUs (aka “cinder blocks”) • Tested various mixtures of sands and other soils in manual brick making process • Goal of 2000 psi compressive strength, reached 537.6 psi
Mission Statement • Establish the maximum compressive strength of AggreBindblock • Explore new production and fabrication processes • Optimizethe cure time of these blocks • Consideralternative non-structural applications of the product FALL 2012
Team Organization FALL 2012
Establishing Maximum Strength Used the following testing guidelines: • ASTM standard brick size for compression testing • ½ length Utility brick: 3-5/8” x 3-5/8” x 5-13/16” • Intermediate testing using shop press • Final testing in the lab • Goal of 2000 psi
Alternative Comparison FALL 2012
EXPLOre • Wood vs. Steel Mold • Compaction: hand vs. measured mechanical • New mixture scheme, no longer mixed by hand • Larger pool of brick samples and multiple rounds of bricks
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 6. 1. 5.. 2. 4.. 3. FALL 2012
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 • 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 • Compression to failure test • Basic test using shop press • Cheap and effective initial testing FALL 2012
Round 2 Built on results of Round 1: • Min. two of each brick mixture • 1000 psi compaction pressure • 1:2 ratio of AGB to water Conducted official strength testing • Computer-controlled • Greater need for flat specimens
Round 2 Results • Strongest Mixture:50% limestone 25% sand 25% light aggregate • Maximum strength of 943.2 psi • Average strength of 820.5 psi
Improving Cure Time A variety of methods: Proven by Rounds 1 and 2 • 14 Days • Limestone vs. sand Tested for Round 3 • Oven Curing • Catalyst • Iron Powder (for strength)
Round 3 Results: • Optimum oven cure 4 hrs • 12-day maximum strength: 1157 psi • Iron powder ineffective Test conditions: • 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
Consider • Recycled Materials • Styrofoam • Rubber • Plastic
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 Fall 2012
Future of aggrebind • Optimize oven curing process • Continue to explore additives: • Fly ash • Slag • Further Testing: • Fire • Weathering FALL 2012
Conclusion • Established higher maximum strength of AggreBind block • Compaction Pressure • AGB:Water Ratio • Oven Curing • Limestone Mixture • Effective teamwork and coordinated small groups