The scope of this project is a combination of material science engineering and mechanical engineering. Overall, the main goal of this project is to develop a lightweight concrete that maintains its original strength profile. Initial research has shown that a plastic-concrete composite could create a more lightweight concrete than that made using the typical gravel aggregate for concrete, while still maintaining the physical strength that concrete is known for. This will be accomplished by varying the amount of plastic in the aggregate. If successful, this project would allow concrete to be used in applications it would typically not be suitable for.<br/>After testing the strength of the concrete specimens with varying fills of plastic aggregate it was determined that the control group experienced an average peak stress of 2089 psi, the 16.67% plastic group experienced an average peak stress of 2649 psi, the 33.3% plastic group experienced an average peak stress of 1852 psi, and the 50% plastic group experienced an average stress of 924.5 psi. The average time to reach the peak stress was found to be 12 minutes and 24 seconds in the control group, 15 minutes and 34 seconds in the 16.7% plastic group, 9 minutes and 45 seconds in the 33.3% plastic group, and 10 minutes and 58 seconds in the 50% plastic group. Taking the average of the normalized weights of the cylindrical samples it was determined that the control group weighed 14.773 oz/in, the 16.7% plastic group weighed 15 oz/in, the 33.3% plastic group weighed 14.573 oz/in, and the 50% plastic group weighed 12.959 oz/in. Based on these results it can be concluded that a small addition of plastic aggregate can be beneficial in creating a lighter, stronger concrete. The results show that a 16.7% fill ratio of plastic to rock aggregate can increase the failure time and the peak strength of a composite concrete. Overall, the experiment was successful in analyzing the effects of recycled plastic aggregate in composite concrete. <br/>Some possible future studies related to this subject material are adding aluminum to the concrete, having better molds, looking for the right consistency in each mixture, mixing for each mold individually, and performing other tests on the samples.
The scope of this project is a combination of material science engineering and<br/>mechanical engineering. Overall, the main goal of this project is to develop a lightweight<br/>concrete that maintains its original strength profile. Initial research has shown that a<br/>plastic-concrete composite could create a more lightweight concrete than that made using the<br/>typical gravel aggregate for concrete, while still maintaining the physical strength that concrete is<br/>known for. This will be accomplished by varying the amount of plastic in the aggregate. If<br/>successful, this project would allow concrete to be used in applications it would typically not be<br/>suitable for.<br/>After testing the strength of the concrete specimens with varying fills of plastic aggregate<br/>it was determined that the control group experienced an average peak stress of 2089 psi, the<br/>16.67% plastic group experienced an average peak stress of 2649 psi, the 33.3% plastic group<br/>experienced an average peak stress of 1852 psi, and the 50% plastic group experienced an<br/>average stress of 924.5 psi. The average time to reach the peak stress was found to be 12 minutes<br/>and 24 seconds in the control group, 15 minutes and 34 seconds in the 16.7% plastic group, 9<br/>minutes and 45 seconds in the 33.3% plastic group, and 10 minutes and 58 seconds in the 50%<br/>plastic group. Taking the average of the normalized weights of the cylindrical samples it was<br/>determined that the control group weighed 14.773 oz/in, the 16.7% plastic group weighed 15<br/>oz/in, the 33.3% plastic group weighed 14.573 oz/in, and the 50% plastic group weighed 12.959<br/>oz/in. Based on these results it can be concluded that a small addition of plastic aggregate can be<br/>beneficial in creating a lighter, stronger concrete. The results show that a 16.7% fill ratio of<br/>plastic to rock aggregate can increase the failure time and the peak strength of a composite<br/>concrete. Overall, the experiment was successful in analyzing the effects of recycled plastic<br/>aggregate in composite concrete.<br/>Some possible future studies related to this subject material are adding aluminum to the<br/>concrete, having better molds, looking for the right consistency in each mixture, mixing for each<br/>mold individually, and performing other tests on the samples.
Effects of Aggregate Packing Density on the Mechanical Properties of Ultra-High Performance Concrete
In this study, aggregate material evaluation and testing was conducted for use in the mix design of the UHPC mixes that were carried out and tested. Each mix employed the same general UHPC mixture design with the only difference being the aggregate proportions of #4, #8, and #10 nominal size aggregates. The purpose of using a UHPC mix design that was independent of aggregate proportioning was to evaluate the effects of varying aggregate particle packing densities. Increased particle packing density of UHPC provide improved mechanical performance by decreasing the distance between particle within cured UHPC, thereby producing significant increases in compressive strength, tensile strength, durability, and service life of UHPC when compared to standard concrete. For this study, particle packing densities of 0.509, 0.521, 0.540, and 0.552 were employed and evaluated on the basis of compressive strength and tensile strength to determine the optimum UHPC mix design.