Experimental Study of the Influence of Natural Lightweight Aggregates on Some Physical Properties of Porous Concrete Pavement and Providing the Relationship between Compressive Strength and Porosity

Porous concrete pavement reduces surface runoff volume, prevents flood and reinforces groundwater resources. In this research, effects of replacing concrete aggregates (25, 50, 75 and 100%) by pumice, scoria and zeolite lightweight aggregates in porous concrete on physical properties including compressive strength and porosity were investigated. Preparation of concrete samples and testing was performed in the Concrete Technology Laboratory of Semnan University. Statistical analysis of the results was performed by using SAS 9.4 software. Results showed that by replacing lightweight aggregates in the porous concrete and removing the course aggregates, certain trend was observed among the samples. As the porosity increases, the compressive strength of the samples is reduced. The highest average compressive strength in porous concrete samples was observed in substitution of 50 and 25 percent scoria with aggregates (11.08 and 10.76 Mpa, respectively). The highest average porosity was observed in the sample containing 100% pumice as aggregates, which was 55.95% more than the control sample. Based on the obtained empirical relationship (R2=0.9), the compressive strength of porous concrete can be estimated for different porosities of porous concrete samples. Due to the abundance, economical values, high porosity and reduction of urban runoff, the proposed lightweight natural aggregates of this study have great potential to be used in pavements, especially in areas with low traffic.