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The effect of UV-treated plastic reinforcement in cement-based materials

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The preceding paper analyzes the effects of UV radiation in plastic reinforcement and its effects on the fracture properties of cement-based materials. Three point tests were performed on notched beams, which called for the consideration of the Type II Size Effect. A comparison of the ductility of beams with and…

The preceding paper analyzes the effects of UV radiation in plastic reinforcement and its effects on the fracture properties of cement-based materials. Three point tests were performed on notched beams, which called for the consideration of the Type II Size Effect. A comparison of the ductility of beams with and without polyethylene plastic powder reinforcement was done through the calculation of the fracture parameters Gf and cf, which represent the initial fracture energy and the characteristic length respectively. Although there was an observed increase in ductile behavior and properties in beams with polyethylene reinforcement, there did not seem to be a significant effect caused by the UV radiation. The hydrophilicity of the polyethylene powder was successfully increased through UV radiation and validated through water retention tests, which showed that the UV-treated polyethylene was retaining more water than the non-treated polyethylene, yet there was no extra increase in ductility of the cement beams compared to using non-treated polyethylene. The Type II Size Effect analysis was performed and compared to the stress analysis results of the experiment. For future research, it is recommended that a higher volume of polyethylene per 1000 grams of cement powder be used, as well as increasing the strength of the UV chamber to achieve a larger increase in the hydrophilicity of the polyethylene. Also, perhaps using more precise equipment to cut the notches in the beams would be helpful in ensuring that all specimens are identical and there is no error in notch depth caused by inaccurate use of the hacksaw or radial saw. Further experiments will be conducted.
ContributorsMardambek, Karim (Author) / Hoover, Christian (Thesis director) / Kazembeyki, Maryam (Committee member) / Civil, Environmental and Sustainable Eng Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2019-05

Design of Experiment to Measure Temperature-Dependent Fracture Properties of Polymethyl Methacrylate (PMMA)

Description
This paper discusses the design of experimental setup and procedures to characterize polymethyl methylate (PMMA) at its glass transition temperature by studying its strain fields, process zone, and crack speed under different loading conditions. These loading conditions are different steady-state temperatures and initial crack lengths. Steady-state temperature testing uses a…

This paper discusses the design of experimental setup and procedures to characterize polymethyl methylate (PMMA) at its glass transition temperature by studying its strain fields, process zone, and crack speed under different loading conditions. These loading conditions are different steady-state temperatures and initial crack lengths. Steady-state temperature testing uses a temperature control loop. Crack speed / resistivity testing is set up using a voltage drop method. From initial steady-state temperature testing, it was confirmed that the behavior of a PMMA sample becomes more ductile at higher temperatures, and that it is plausible for a crack process zone to be measured using DIC as temperature increases. From finite element simulations, it was validated that the crack speed is not constant relative to an initial crack length.
ContributorsKwan, Brandon (Author) / Oswald, Jay (Thesis director) / Hoover, Christian (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05