Optimization of Concrete Composites Using CCBs as Additives Joshua L. Baker

1. Fold or cut poster here Fold or cut poster here Fold or cut poster here Fold or cut poster here Optimization of Concrete Composites Using CCBs as AdditivesJoshua L. Baker Rockdale Magnet School for Science and Technology OPTIONALLOGO HERE OPTIONALLOGO HERE Experimentation Procedures (continued) Introduction Data Analysis (continued) Experimentation Procedures • Coal combustion byproducts have potential for use in concrete composites. If a mix ratio of these byproducts that allows for a strong, yet flexible end product can be achieved, it will be possible to apply the concept to other building materials once the composites’ environmental interactions can be investigated. Concrete from each mix is poured into fourteen molds each, fifty-six in total, and then are left to set in room conditions for three days. The cylinders are then removed from their molds and placed into a curing room for another four days. Seven days after being poured in the molds, three samples from each group are placed in a hydraulic wedge, and the compressive strength and ultimate load data for each is obtained. The data and averages for each group are obtained in this way. Each of the four concrete mixes was created using a concrete mixer. Hypothesis • Research Hypothesis: If 25% of the standard cementitious material or fine aggregate is respectively replaced with Class C fly ash or bottom ash, then the resulting composite will perform within a 20% margin of similarity to the control. • Sub-hypothesis: Mix 2 (25% Class C fly ash, 75% Portland cement, sand, stone) will perform similarly to or better than the control mix. A small amount of the first mix was poured into a unit weight container, and the unit weight was obtained. The cover was placed on the container, sealed, and the air content data was obtained. The unit weight container was cleaned out and the process was repeated with the remaining mixes. Rationale Successfully using CCBs as additives at a 25% replacement rate would greatly decrease negative human environmental impact stemming from dumping of these wastes in landfills and provide a strong, environmentally-responsible composite that can be adapted to new uses. Data Analysis ANOVA Data: • Ultimate Load (Day 7): p = 0.005; 0.005 < 0.05; Null hypothesis rejected • Compressive Strength (Day 7): p = 0.005; 0.005 < 0.05; Null hypothesis rejected Experimental Design Diagram Discussion and Conclusions • Based on the currently available data from experimentation and from data analysis, Mix 2 performed within the 20% margin of similarity to the control for its average compressive strength and ultimate load, thus rejecting the null hypothesis • The data gathered for Mix 3 performed outside of this margin, supporting the null hypothesis • More ultimate load and compressive strength data will be collected at the Day 90 curing point A small amount of freshly-mixed concrete is poured into a mold and leveled off. The mold is then lifted off from the concrete, and the concrete is allowed to spread out. The slump, the distance the concrete spreads out is measured for each mix. Materials Future Research • Hydraulic Wedge • Concrete Mixer • Plastic 4” x 8” Cylindrical Molds, 42 • CEMEX® Portland Cement, 76.52 lbs. • Headwaters Class C Fly Ash, 6.94 lbs. • Natural Sand, 155.10 lbs. • Headwaters Bottom Ash, sieved, 12.96 lbs. • Stone, Granite, 252.87 lbs. • Water, 40.29 lbs. • Investigating the potential environmental effects the composites may have in certain conditions • Determination of the toxicity of CCBs and their flammability at different burn stages Acknowledgements RMSST: John Hendrix Ernst Enterprises: Tony Dowdy TEC Services: Steven Maloof and Technicians Brian Wolfe