CHARACTERISTIC OF CEMENT CONCRETE WITH RECYCLED ASPHALT PAVEMENT AGGREGATES

Document Type : Original Article

Abstract

Recycled asphalt pavement (RAP) is the removed and/or reprocessed pavement material containing asphalt and aggregate. The use of RAP in asphalt pavement has become a common practice in the construction of new, and reconstruction of old, hot mix asphalt pavements. Nevertheless, limited researches have been done to examine the potential of incorporating RAP into concrete. Since RAP contains asphalt, it is very likely that the toughness of concrete made with RAP could be improved. An alternative use of RAP is to use it as an aggregate in Portland cement concrete (PCC). Concrete pavements using concrete with a lower modulus of elasticity would have a lower chance of cracking. On the other hand, the optimal concrete mixture for concrete pavement was a concrete with a proper combination of low modulus of elasticity, and adequate flexural strength. This study evaluated the feasibility of using concrete containing RAP for concrete pavement applications. Twenty four different concrete mixes containing different percentages of RAP (0%, 15%, 30%, 45%, 60% and 100%) were produced in the laboratory.Different cement content with (250, 300 and 350 kg/m3) and type F fly ash with content (0%, 15%, and 30%) as replacement by cement weight were also used. Moreover, polypropylene fibers with volume fractions of 0%, 0.5% and 1% was used. The present study focused on the mechanical properties of the concrete, mainly, compressive strength, splitting tensile strength, flexural strength that were evaluated. The test results indicated that RAP could be incorporated into Portland cement concrete without any modification to the conventional equipment or procedures. There was a systematic reduction in the compressive, flexural and split tensile strengths with the incorporation RAP in concrete as compared with that of a reference concrete without RAP.

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