Use of Secondary Aluminum Slag Powder on the Strength of Non-Load-Bearing Lightweight Concrete Blocks

Secondary aluminum slag powder is generated as a by-product in various industrial processes, such as the manufacture and machining of aluminum parts, as well as in the production of aluminum sheets and profiles. It is therefore considered a waste material by the industry. The main objective was to evaluate the influence of secondary aluminum slag powder in the production of lightweight concrete blocks, using traditional curing. A total of 192 non-load-bearing lightweight concrete (LCB) blocks were manufactured by incorporating secondary aluminum slag powder (SASP) as an aerating agent, at 0, 3, 6 and 9% by weight of cement. Properties such as unit weight, air content, density, absorption, suction and compressive strength of the masonry units and LCB prisms were examined. The main results showed that unit weight and air content increased by 12% to 45%, with samples up to 9% SASP. However, mechanical properties, such as compressive strength of the units and prisms, decreased by up to 58.26% and 67.24%; nevertheless, they meet the minimum national regulatory requirements. LCBs with the optimum SASP ratio can be used in various construction applications, such as interior partitions, non-structural enclosures, and decorative elements.