The effect of fly ash and superplasticizer on the performance of roller compacted concrete pavement

• Main Author: Alaa Hasan Mohammad Alnusair
• Format: text::Thesis
• Language: English
• Published: 2023

Roller compacted concrete pavement (RCCP) is a good replacement for the conventional concrete from the economic and environmental aspects. RCCP can incorporate waste materials like fly ash. In this way, cement utilization and production can be reduced. This study aims to investigate the performance of the fly ash RCCP by achieving three objectives. Firstly, by comparing the performance of the RCCP that contains different sets of fly ash, secondly, by investigating the performance of the superplasticized high volume fly ash, and thirdly, by investigating the impact of aggregates gradation on the performance of high volume fly ash RCCP. High volume fly ash RCCP was studied on F50, which has 50% content of fly ash. To achieve the first objective, five mixtures were used, in which fly ash replaces the content of the cement by five percentages 0%, 10%, 30%, 50%, and 70%. To achieve the second objective, different mixtures of RCCP were prepared, in which the fly ash replaced 50% of the cement content, and superplasticizer was added in quantities equal to 0%, 0.25%, 0.50%, and 0.75% of the cementitious content. While to achieve the third objective, the mixtures of RCCP contained either standard sand or non-standard sand. The results of the first objective showed that increasing the fly ash content in the RCCP causes a reduction in the compressive strength, tensile strength, and flexural strength. The results of the second objectives showed improvements in the strength, the durability, and the workability of the RCCP when adding superplasticizer. While the results for the third objective showed no significant change in the compressive strength, flexural strength, or split-tensile strength when using standard or non-standard sand.