Assessing the impact of recycled concrete aggregates and metakaolin on the mechanical properties of pervious concrete.

AbstractPopulation growth and urban expansion have increased impervious surfaces, leading to environmental issues such as stormwater runoff and groundwater depletion. Traditional concrete, while durable, contributes to these problems. There is a need for sustainable construction materials that can address environmental challenges and reduce the consumption of natural resources. Pervious concrete, enhanced with recycled aggregates (RCA) and supplementary cementitious materials (SCMs) like metakaolin (MK) present a potential solution. This study aims to improve the mechanical and durability properties of pervious concrete by incorporating RCA and MK, assessing their effects on workability, density, porosity, permeability, compressive strength and flexural strength. The incorporation of RCA resulted in increased aggregate porosity compared to natural aggregates. Workability was assessed using the slump test, density was measured, and porosity and permeability were evaluated. The results showed that incorporation of RCA generally decreased workability, density and strength, while the addition of MK improved these properties by refining the microstructure. Specifically, mixes with 10% MK demonstrated better performance in terms of increased compressive and flexural strengths, improved density and reduced porosity. The ANN model showed high accuracy in predicting compressive and flexural strengths. The study concludes that RCA and MK can enhance the mechanical and durability properties of pervious concrete. [ABSTRACT FROM AUTHOR]