10 August 2015
Posted in Center Information
The Structural and Durability Performance of Glass Modified Concrete
PI: Dr. Ali Ghahremaninezhad
Sponsored by the Florida Department of Transportation - State Materials Office
In an effort to help the State of Florida reach its recycling goal of 75%, this proposal aims to investigate the feasibility of incorporating waste glass in concrete infrastructures. Research on finding ways to incorporate waste glass in construction materials has been motivated by environmental concerns over the limited capacity of available landfill sites as well as greenhouse gas emissions generated during the production of construction materials. In this study, the effect of recycled glass powder on the hydration, mechanical properties, durability behaviors and microstructure of cement-based materials were investigated using relevant experimental methods. The results of this study indicated that incorporation of glass powders as cement replacement showed an overall improvement in concrete compressive strength, mortar compressive strength and flexural strength, more noticeably, at late ages of curing. Results of accelerated mortar bar tests did not show alkali-silica-reaction (ASR) expansion resulting from use of glass powders in mortars. More interestingly, it was found that glass powders at replacement levels of 10% and 20% were effective in suppressing alkali-silica reactivity in cementitious materials containing reactive aggregate. Concrete modified with glass powders were found to exhibit improved resistance to chloride permeability. It was noted that reduction in chloride permeability increased with increasing replacement levels of cement with glass powders studied in this project. Glass powders used in this study were shown to be more effective than fly ash in increasing the resistance to chloride permeability. Glass powders were observed to increase the hydration heat and hydration rate in the early age of cement pastes. This behavior was in contrast with the retardation effect of fly ash on hydration. X-ray diffraction analysis and thermogravimetric analysis indicated the pozzolanic property of glass powders in cement pastes.