Effect of Aggregate Size and Compaction on the Strength and Hydraulic Properties of Pervious Concrete

Abstract

Pervious concrete is one of the emerging sustainable materials that has recently gained the attention of many researchers. The importance of pervious concrete mainly depends on its application and on a modern integrated approach in which it is employed to reduce the effects of flooding. The main goal of this experimental analysis is to study the significance of aggregate size and the degree of compaction on the mechanical and hydraulic properties of pervious concrete. Eleven concrete mixture proportions were investigated by controlling the constituents with different aggregate fractions. The important variables considered were the aggregate sizes, viz., 0/4 mm, 4/8 mm, and 8/16 mm, with four different degrees of compaction. The porosity of the concrete structure was obtained by the partial filling of the voids in the aggregates with cement paste. The ingredients of the pervious concrete were also varied to study their significance and to evaluate the predominant factor that controls the mechanical and hydraulic properties based on the test results. Tests were conducted to determine properties such as compacting factor, compressive strength, splitting tensile strength, abrasion resistance, porosity, and hydraulic conductivity. The study revealed that the degree of compaction was one of the critical factors governing the strength and hydraulic properties of the pervious concrete; the maximum strength and minimum hydraulic conductivity were achieved with a higher degree of compaction. The test results imply that the cement content is the predominant factor determining the fresh and tensile properties of the pervious concrete, rather than the size of the aggregates used. In addition, the results also illustrated that the highly compacted pervious concrete samples made with 4/8 mm aggregates exhibited improved abrasion resistance and strength properties, but slightly reduced hydraulic conductivity, despite the designed porosity.