Environmentally friendly interlocking concrete paving block containing new cementing material and recycled concrete aggregate

This paper investigates the properties of concrete block made from industrial waste materials. Two by-products, calcium carbide residue (CR) and bagasse ash (BA), were combined and used as a substitute binder for Portland cement, and 100% recycled concrete aggregate (RCA) was used to replace natural aggregate in making interlocking concrete paving block. The results showed that the densities of the concrete blocks with unmodified CR and BA as a binder were decreased, moreover, their water absorptions were higher than those of concrete blocks with high fineness of binder. The compressive strength of some concrete block can be sufficiently high to meet the requirement for interlocking concrete paving block in accordance with Thai Industrial Standard (TIS 827), which is higher than 40.0 MPa at the testing age of not less than 7 days. The abrasion resistance of concrete block is likely to be decreased compared to normal concrete due to the RCA in the mixture; however, the abrasion resistance can be improved by increasing the fineness of binder. These remarkable results indicate that CR, BA and RCA in suitably mixed proportions can be used as a good choice for an alternative material to make environmentally friendly interlocking concrete paving block.