Introduction This report contains the test results from the preparation and testing of the concrete mix design for the foundation of a construction project. The mix should meet the requirements of a 28-day compressive strength of 4000 psi and have a 2- to 4- inch slump. Additionally, the 14-day strength must also be at least 3500 psi for the project.
Results:
The concrete mix was designed based on ASTM C192; however, the slump of the mix was not in accordance to ASTM 143 because the measured slump was greater than 6 inches. So, all the requirements for ASTM C192 were not met. The mixture was combined in a rotating mixer using proportions of fine aggregate, cement, fly ash, an admixture, and water. Due to time constraints, the specimens …show more content…
The unit weight was used to determine the air content, yield, and cement content of the foundation concrete. The unit weight was determined by subtracting the weight of the empty measure from the weight of the measure filled with concrete mix in pounds. Then the difference was divided by the volume of the measured. The air content was measured in accordance with ASTM C231. The filled measure, used to determine the unit weight, was also used to determine the air content. The air content was measured as 6.0% using a type B meter and did not exceed the allowable 8%. The yield was determined by dividing the total weight of all materials by the unit weight of the concrete determined by the previously discussed method. As stated in ASTM 138, the relative yield is the ratio of the actual volume of concrete used to the volume of concrete, which the batch was designed to produce. Example calculations of each measurement can be found on the sample calculation page (Appendix, pg. 6). Individual weights of apparatuses, materials, and other recorded measurements can be found on the raw data sheets (Appendix pgs. 7-10). The test cylinder specimens used for compressive strength testing were prepared in accordance to ASTM C31. The methods for the number of layers and rodding were determined based on the 6-inch by 12-inch plastic molds. The molds were placed in an upright position on a flat surface for a 24-hour time period. After 24 hours, the cylinders were then stripped from the molds and placed in a humidity room, where the cylinders cured for an additional 13 days at a temperature of 23 degrees Celsius at 95 percent
Results:
The concrete mix was designed based on ASTM C192; however, the slump of the mix was not in accordance to ASTM 143 because the measured slump was greater than 6 inches. So, all the requirements for ASTM C192 were not met. The mixture was combined in a rotating mixer using proportions of fine aggregate, cement, fly ash, an admixture, and water. Due to time constraints, the specimens …show more content…
The unit weight was used to determine the air content, yield, and cement content of the foundation concrete. The unit weight was determined by subtracting the weight of the empty measure from the weight of the measure filled with concrete mix in pounds. Then the difference was divided by the volume of the measured. The air content was measured in accordance with ASTM C231. The filled measure, used to determine the unit weight, was also used to determine the air content. The air content was measured as 6.0% using a type B meter and did not exceed the allowable 8%. The yield was determined by dividing the total weight of all materials by the unit weight of the concrete determined by the previously discussed method. As stated in ASTM 138, the relative yield is the ratio of the actual volume of concrete used to the volume of concrete, which the batch was designed to produce. Example calculations of each measurement can be found on the sample calculation page (Appendix, pg. 6). Individual weights of apparatuses, materials, and other recorded measurements can be found on the raw data sheets (Appendix pgs. 7-10). The test cylinder specimens used for compressive strength testing were prepared in accordance to ASTM C31. The methods for the number of layers and rodding were determined based on the 6-inch by 12-inch plastic molds. The molds were placed in an upright position on a flat surface for a 24-hour time period. After 24 hours, the cylinders were then stripped from the molds and placed in a humidity room, where the cylinders cured for an additional 13 days at a temperature of 23 degrees Celsius at 95 percent