Mohammad T. Awwad
Hot mix asphalt concrete is produced by properly blending asphalt, coarse and fine aggregates in addition
to filler at temperatures ranging from 80 to 1650C. This research work is directed to study the effect of
replacing the conventional aggregates by the recycled light weight aggregate concrete (LWAC) on the
properties of the produced asphalt mix. The research studied the optimum asphalt content and the effect of
some parameters on the properties of the recycled LWAC.
The research included studying thirty-six Marshal Specimens lie in four main groups. Each group was
made from crushed LWAC in addition to a comparison gruop used the pumice instead of the crushed
LWAC. The LWAC mixes contained (0%, 10%, 15% and 20%) of silica powder content.
The density, stability, flow, percentages of the air voids in the compacted mixture (VTM), compacted
mineral aggregate (VMA) and the voids filled by asphalt (VFA) were investigated for all the studied
The main conclusions drawn from the current research implies that the optimum percent of asphalt was
7.5% for the different percentages of silica powder ratios. The presence of voids in the light weight
aggregates and the porosity of the obtained concrete affected largely the behavior of the obtained mix.