Measurement of Hydraulic Conductivity of Crumb-Rubber Masonry Concrete Using Falling-Head Method

Abstract

This paper experimentally measures the hydraulic conductivity of crumb-rubber modified masonry concrete using the falling head method. Six mix  batches using a mix ratio of 1:1.5:3 and a water-cement ratio of 0.42 was used to produce masonry concrete containing 0%, 5%, 10%, 15%, 20% and  25% crumb-rubber particles partially replacing coarse granite by volume. The results reveals that the reference masonry concrete (0%CR) have a  hydraulic conductivity of 9.88 x 10^-11 m/sec while the 5, 10, 15, 20 and 25% have hydraulic conductivity of 1.68 x 10^-10 m/sec, 2.34 x 10^-10 m/sec, 3.26  x 10^-10 m/sec, 4.03 x 10^-10 m/sec and 4.51 x 10^-10 m/sec respectively; which indicates that the hydraulic conductivity of the modified masonry  concrete increased with addition of more crumb-rubber content up to 25%. The outcome of this study implies an increase in the ability of the  modified masonry concrete to allow surface water to percolate through it which will be highly desirable for use as an alternative for pervious  concrete in area with low surface water runoff.