The Effect of Superplasticizer on Performance of Roller Compacted Concrete Pavement Containing High Volume Fly Ash

Abstract

The use of roller compacted concrete pavement (RCCP) has increased noticeably over the last few decades, given its economic and environmental benefits. This type of concrete is known for its ability to incorporate natural wastes, such as fly ash. Moreover, to improve the performance and enhance the workability of RCCP, superplasticizer can be used. This study aims to investigate the effect of superplasticizer on the performance of high volume fly ash (HVFA) in RCCP. In achieving this aim, different mixtures of RCCP were prepared, where fly ash replaced 50% of the cement content, in addition to adding superplasticizer in quantities equal to 0%, 0.25%, 0.50%, and 0.75% by weight of the cementitious content. The results showed that up to 0.75% superplasticizer content that there was first, a positive relationship between the superplasticizer content and the compressive, splitting-tensile, and flexural strength. Secondly, increasing the superplasticizer content from 0% to 0.75% caused a noticeable improvement in the workability of the HVFA RCCP and caused a decrease in Vebe time of around 12 s. lastly, superplasticizer caused a reduction in porosity of HVFA RCCP and increased water absorption. Accordingly, this study revealed that it is possible to produce workable and durable concrete with high strength by adding superplasticizer to HVFA RCCP.