Effect of fly-ash on the performance of asphalt concrete mixes

Abstract EN

At last year, effectively fly ash has been used in producing high performance concrete mixes with limited used in asphalt pavements.

This is possibly due to the performance advantage that fly ash equipped to asphalt mixes in now days.

A bituminous paving mixture is a mix of coarse aggregate, fine aggregate and bitumen mixed in suitable proportion to result strong and durable mix to bear traffic load.

In this paving mix, normally limestone and fly ash are used as filler material.

In this research , the performance of asphalt concrete mixes modified with fly ash as a partial replacement of limestone dust mineral filler were evaluated.

Four replacement rates were used; 0, 1, 2, and 3 percent by weight of aggregate.

Asphalt concrete mixes were prepared at their optimum asphalt content and then tested to evaluate their engineering properties which include moisture damage, resilient modulus, permanent deformation and fatigue characteristics.

These properties have been evaluated using indirect tensile strength, uniaxial repeated loading and repeated flexural beam tests.

Mixes modified with fly ash were found to have improved fatigue and permanent deformation characteristics, also showed lower moisture susceptibility and high resilient modulus.

the result showed that a rate changed from 1 to 3 percent has shown an increase in resilient modulus for addition of fly ash as a filler substitute and the resilient modulus for mixes with 3 percent fly ash was 1.31 times that for mixes with 0 percent fly ash.

The altering of fly ash as a filler substitute from a range (1-3) percent has modified the fatigue property of the asphalt concrete mixes as determined by flexural test, Significantly, to modify the asphalt concrete manner taken the percent of fly ash 2, and to produce the mixes more durable , higher resistance to distresses by adding the local knowledge.