Investigation on Flexural Strength and Stiffness of Pervious Concrete for Pavement Applications

Sustainability in pervious concrete paving mixtures is obtained through interconnected macropore structure that allows heat and mass transfer efficiently. Compressive strength and permeability characteristics of pervious concrete have been extensively investigated in the past. However, the flexural behavior of pervious concrete, which is an important mode of loading observed in the field, is still a conjecture. Furthermore, flexural strength and flexural stiffness are the basic design inputs to determine the pavement slab thickness. With this as the background, the objective of this study was to investigate the behavior of pervious concrete in flexure and propose predictive models to estimate flexural properties that form the key inputs for thickness design. Beam specimens from 15 pervious concrete mixtures with 3 replicates per mix type comprising different mix variables were prepared and tested for flexural properties in a closed-loop servo-controlled hydraulic testing facility. Flexural strength and stiffness were found to be in the range of 1.5–3.2 MPa and 8,000–15,000 MPa, respectively. The mixtures consisting of smaller sized aggregates depicted large energy absorption abilities compared to larger sized aggregates, which seemed to be more brittle in nature. The predictive models based on the basic properties were rational with fair to good correlations: 0.65 ≤ R²_adj ≤ 0.80. The models could be comfortably used in future to estimate flexural properties of pervious concrete in conjunction with the existing rigid pavement design methods that are envisaged to assist in arriving at rational thicknesses of pervious concrete slabs for field applications.