Investigating the Performance of Hot Mix Asphalt Modified with Chemical Additives. (Dept. C)

The Egyptian roads suffer from many distresses, which depends to a significant extent on the mechanical properties of the asphaltic layer. Therefore, scientists and engineers are constantly trying to improve the mechanical properties of the asphaltic mixtures. One common method of improving the performance of asphaltic mixtures is the use of different types of additives. The objective of this research is to study the effect of using chemical additives on the mechanical properties of hot mix asphalt (HMA). Three chemical additives were used. The additives were Addicrete PVS, Adibond 65 and Silica gel, that were added with different ratios of 5, 10, 15 and 20 % by the weight of optimum asphalt content in addition to the original mix. Marshall test, Indirect tensile strength test and Moisture susceptibility test were conducted on the investigated mixes. Testing results on the modified mixes were compared with the original mix. The results show that exploitation of Addicrete PVS and Silica gel at 10% content enhanced the worth of Marshall stability, Marshall stiffness, indirect tensile strength, TSR and improved the value of flow whereas decreased the value of bulk density compared to the control mix. Also, the results showed that the most effective content at that adding of Adibond 65 yielded the most effective results was 15%.