Effect of geogrids on interface shear strength properties of recycled crushed brick

Construction and demolition (C&D) materials are defined as the materials obtained from demolition activities such as crushed concrete, crushed brick, and reclaimed asphalt. The disposal of these materials in landfills is a major problem for the environment. The urgency and significance of recycling C&D materials has been raised because of the scarcity of natural aggregates, difficulties in finding landfill, and other environmental concerns. Hence, the present paper describes the physical and geotechnical characteristics of recycled crushed brick (CB) to reuse in different civil engineering applications. The laboratory experiments involved modified compaction test, particle size distribution, specific gravity, water absorption, and Los Angeles abrasion. Furthermore, the interface shear strength properties of the CB material with geogrids and their performance as a pavement subbase material was ascertained by using a large direct shear testing (DST) apparatus. The higher tensile strength triaxial geogrid was found to attain higher interface shear strength properties than that of the lower tensile strength biaxial geogrid. The DST results, however, indicated that the interface shear strength properties of the geogrid-reinforced CB material were less than that of the respective material without reinforcement. The results were also found to meet the peak and residual shear strength and local road authority requirements for typical construction materials in civil engineering applications.