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Determination of what one-inch of slump does to the Ultimate Compressive Strength (UCS) of concrete and what percentage of design strength was achieved after seven days.
Objective: Determination of what one-inch of slump does to the Ultimate Compressive Strength (UCS) of concrete and what percentage of design strength was achieved after seven days. Analysis: The UCS of a 6x12 inch concrete test cylinder was tested in the Universal Stress/Strain machine, the load was applied until failure. For 1.5" slump the UCS was 108.5 kips. The 4" slump had a UCS of 85 kips. Therefore, 1" of slump decreases the UCS of the concrete by approximately 9.4 kips. The concrete sample was designed to have strength of 4000psi after 28 days of curing. The 1" slump sample, after 7 days of curing, had approximately 96% of the designed strength. The 4ö slump had approximately 75% of the designed strength. The sample that was allowed to cure for about 1.5 years and had 117% of the designed strength. Poisson's Ratio is the absolute value of the lateral compressive strain divided by axial strain. This will show the relationship between the lateral and axial strains to determine the deformation of the concrete specimen under a compressive load. Poisson's Ratio Lateral Axial Load Poisson's psi in/in in/in kips Ratio 0 0 0 0 0 1000 0.00303 0 28.5 0 2000 0.0068 -0.0002 56.5 -34 3000 0.01275 * 85 0 The concrete specimen displayed conical fracture in the specimen upon inspection after failure. The course aggregate showed shear fracturing in the individual members demonstrating the limiting factor in concrete design is the strength of the course aggregate. Stronger aggregate mixture would create a stronger concrete mixture and result in a higher ultimate compressive strength. |
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