للكاتبين
Maram M. Saudy1, Omar O. Omar2, Mohamed R. El-Mitiny2
1Civil Engineering Department, Faculty of Engineering, Cairo University, Egypt
2Highway Engineering, Faculty of Engineering Department, Cairo University, Egypt
ABSTRACT
There is a lack of knowledge on the performance of locally produced Hot Mix Asphalt
concrete (HMA) under different Egyptian local environmental and loading conditions. Such
knowledge is very important to properly design HMA mixes to suit sites with different
prevailing conditions. To overcome this problem, there is a need for sufficiently predicting
asphalt mix performance in order to design suitable mixes with better performance. From this
point, this research aims at predicting the expected asphalt mix performance based on
studying the behavior/response of different local mixes under different design and
environmental factors including; fine aggregate type (natural versus manufactured sand),
aggregate gradation (the mid band gradation of locally used 4C versus that of 4B), mineral
filler type (cement dust versus stone filler), temperature, and loading time. The final findings
of this research demonstrated that, using manufactured sand instead of natural sand results in
better resistance to rutting but adversely affect fatigue cracking resistance. Whereas,
gradations 4B and 4C result in almost similar performance under similar conditions. Finally,
using cement dust instead of stone filler as mineral filler results in moderate to high increase
in rutting resistance and a substantial increase in fatigue cracking resistance at hot
temperatures and conversely a decrease in fatigue cracking resistance at moderate to cold
climatic conditions. As for the effect of environmental and loading factors, it was found that;
resilient modulus decreases significantly with the increase in temperature and with increasing
loading time.