Mechanical Properties of Modified Porous Concrete Incorporating Different Types of Lightweight Aggregate

Abstract

The objective of this experimental study is to explore the impact of utilizing two kinds of lightweight aggregates ،as partial substitutions for natural coarse aggregate ،on the porous concrete mechanical performance. The study focuses on splitting tensile, compressive and flexural strength tests of such type of concrete incorporated pumice and LECA at a replacement volumetric ratio of 10%. The effect of internal curing provided by the lightweight aggregates on compressive strength was also examined. To enhance the mechanical performance styrene butadiene rubber (SBR) was added to selected mixes. The results obtained showed that replacing natural coarse aggregate with LECA significantly increased compressive strength while pumice led to a reduction. The inclusion of SBR further improved compressive strength particularly in the LECA mix under dry curing conditions where a maximum strength of 15.4 MPa was recorded. Although the incorporation of both lightweight aggregates initially led to a decline in tensile and flexural strengths, the addition of SBR effectively minimized these losses resulting in significant improvements especially in mixes containing pumice. Furthermore, the LECA mix under dry curing achieved a compressive strength of 10.7 MPa relative to 8.8 MPa for the reference mix which highlights the benefits of internal curing via pre-wetted lightweight aggregates. Overall, the findings obtained suggest that the combination of LECA and SBR delivers superior mechanical performance making it a promising solution for parking lots, pavers, and light traffic roads.