No abstract

During the past years different researchers have studied the causes of failure of flexible pavements and they offered variety of alternatives for solving these failure problems such as rutting, fatigue and low temperature cracking which are sourced from moisture susceptibility and also temperature sensitivity of either asphalt, aggregate or the asphalt mixture as a whole. This study is conducted to determine the optimum amount and potential applicability of zycotherm nanomaterial in asphalt and asphalt concrete mixtures with two different systems: directly applying to bitumen and diluting and applying to aggregate in order to address the solution of potential failure problems in flexible pavements. The study is carried out experimentally by conducting tests on bitumen and bituminous mixtures. Tensile strength test and retained stability tests were performed on bituminous mixture in order to measure the tensile strength ratio (TSR) and the retained stability index (RSI), which are both the indexed parameters to determine the mixture resistance to de-bonding and disintegration in the presence of water. Penetration, softening point, RTFOT, PAV, BBR and DSR tests were also performed on bitumen to determine the effect of zycotherm on bitumen's contribution on rutting, fatigue and low temperature cracking of the mixture. It is found that using zycotherm material greatly increases the resistance of asphalt mixture to moisture induced damages and also increases its resistance to rutting, fatigue and low temperature cracking.