Performance of dry cast concrete blocks containing waste glass powder or polyethylene aggregates

Dry-cast concrete blocks are a popular building material; however, to improve the economic and environmental sustainability of this industry, its dependence on natural aggregate and Portland cement needs to be reduced. To further this goal, blocks with up to 25% of the cement replaced with waste glass powder (WGP) or up to 15% of the sand replaced with high density polyethylene (HDPE) or low density polyethylene (LDPE) polymer pellets were produced in an industrial plant. The physical, mechanical and durability properties of the individual blocks and the mechanical properties of the block assemblages were tested. Based on statistical analyses, the blocks with 10% WGP as cement replacement performed similarly to the control blocks. The block properties were sensitive to the use of either type of polyethylene aggregate, which resulted in a decrease in strength and an increase in water absorption. Acceptable performance was achieved when 3–6% of the sand was substituted with polymer pellets.