Improvement of Asphalt Concrete Mixtures by Adding Pulverised Fuel Ash as Filler

Abstract

Consuming of by-product or waste materials in highway engineering is significant in the construction of new roads and/or in renovations of the existing ones. Pulverised Fuel ash (PFA), which is a by-product material of burning coal in power stations, is one of these materials that might be incorporated instead of mineral filler in hot asphalt mixtures.

Two types of surface course mixtures have been prepared one with conventional mineral filler i.e. ordinary Portland cement (OPC) while the second was with PFA. Several testings have been conducted to indicate the mechanical properties which were Marshall Stability and Indirect Tensile Strength tests. On the other hand, moisture damage and ageing have been evaluated by indicating Index of retained strength (IRS) and Long Term Aging (LTA), respectively.

In accordance to the experimental investigation, the new hot asphalt mixtures i.e. with PFA mineral filler are comparable with conventional mixture and comply with the requirements which are recommended for surface course by the Standard Commission for Roads and Bridges (SCRB) in Iraq.