A comparative investigation into pavement thickness and cost of construction materials of stabilised flexible pavement with crumb rubber-modified asphalt

The economic feasibility of soil chemical stabilisation and asphalt crumb rubber (CR) modification in flexible pavement has not been investigated in recent research. It had been accomplished in this paper by comparing a conventional section comprised of unbound sub-base, unbound roadbase and conventional hot-mix asphalt (HMA) wearing course with a non-conventional section comprised of chemically-stabilised sub-base, unbound roadbase and CR-modified (CRM) HMA wearing course. The thickness of each layer in the two sections was determined using California bearing ratio (CBR) design chart and the cost of construction material was determined using the layer thickness and local material unit cost. The investigation concluded that sub-base stabilisation with 3% Portland composite cement (PCC) and wearing course modification with 1% CR resulted in the thinnest and most economical non-conventional section when compared to the conventional section. Sub-base stabilisation with 1% styrene-butadiene latex copolymer (TP) resulted in the thickest and costliest non-conventional pavement section.