The impact of coarse aggregate content on infiltration rate, structure and other physical & mechanical properties of pervious concrete

Abstract

In the paper, the impact of the percentage content of coarse aggregate on concrete structure and properties (such as density, infiltration rate, water absorption and compressive strength) is analysed. To achieve the aim, 5 concrete mixtures differentiating by the content of 8/16 fraction coarse aggregate (50, 70, 80, 90, 100%) are formed. The mixture with 80% of 8/16 fraction aggregate additionally has 0/4 fraction sand. Concrete mixtures have been densified with and without vibration; in such a way, ten different batches have been formed. After analysing the concrete properties, it is found that the most appropriate composition of concrete mixture based on compressive strength and infiltration rate was WPC2 where 70% of 8/16 fraction aggregate is used without fine sand. The compressive strength of such concrete densified by vibration after 28 days equals to 10 MPa, the infiltration rate – 10000 cm/h; non-vibrated specimens have compressive strength which is approximately 7 MPa and infiltration rate of 15000 cm/h. The highest infiltration rate (over 20000 cm/h) is obtained when only coarse aggregate 8/16 fraction is used in concrete mixture; however, the compressive strength of such concrete is approximately 3 MPa.