Effect of Crushed Glass on Skid Resistance, Moisture Sensitivity and Resilient Modulus of Hot Mix Asphalt

Road quality is one of the most important factors concerning the safety of transportation. Adequate skid resistance of a road surface allows drivers to maintain effective control on their vehicles and maneuver when necessary to avoid accidents. Using waste glass in asphalt mixtures is advantageous from the point of technical, environmental and economic perspectives. This study focuses on the topic of asphalt containing crushed glass, also known as glasphalt, by evaluating the skid resistance and moisture sensitivity of these mixtures. Therefore, a laboratory method was used, in which two types of continuous gradation of hot mix asphalt were chosen based on the Iranian highway asphalt paving code (Code No. 234). The fine aggregates, up to 15% of the total aggregate content, were replaced with glass particles in three different gradations. Skid resistance was evaluated in a British pendulum tester, moisture sensitivity by modified Lottman test, and resilient modulus in a UTM machine. Specimens with a moisture sensitivity problem were improved by using zycotherm as an anti-stripping agent. It was found that the crushed glass particles improved skid resistance by up to 20%. The moisture sensitivity test showed that some glasphalts were susceptible to stripping issue, which can be solved by using 0.1% zycotherm in terms of bitumen weight. Finally, findings revealed that glass particles improved resilient modulus of specimens.