Laboratory investigation on skid resistance of hot mix asphalt pavement with nano crumb rubber contribution

As the number of vehicles increases, the increasing number of used tires becomes an important issue, which needs to be handled so as not to become waste. One method that has been widely used is to process used tires into Crumb Rubber which in the field of road pavement can be utilized as added material. Hot mix asphalt concrete has a service life based on the mixture's mechanical strength, but its slip resistance is another important thing. The slip resistance is influenced by the composition of asphalt concrete aggregate as well as temperature. The increase of asphalt concrete mixture, whose content will experience an increase in temperature, will decrease the value of its slip resistance because asphalt becomes softer, which will result in a decrease in the bonding ability between asphalt and aggregate. Crumb Rubber is refined into Nano-sized particles in hot mix asphalt concrete. The percentages of Nano Crumb Rubber used in asphalt content are 0%, 2.5%, and 5% by using the dry process method. This skid resistance test is performed by using a British Pendulum Tester and carried out under various temperature conditions, 26 ˚C, 30 ˚C, 35 ˚C, 40 ˚C, and 45 ˚C. Test results have shown that at normal temperature (25 °C) asphalt modification is smaller than the asphalt mixture of virgin asphalt. However, at temperatures above 40 °C the opposite occurs, especially in the addition of 2.5%. The addition of Nano Crumb Rubber 2.5% has reduced the effect of high temperature more than 40 °C on the asphalt mixture.