Development of lightweight aggregate from sewage sludge and waste glass powder for concrete

In this study, wet sewage sludge was used as the principle material and waste glass used as the additive to manufacture lightweight aggregate (LWA). The effects of different mass ratios of waste glass to sewage sludge and sintering temperatures on the aggregate properties were investigated. The selected LWA was used as coarse aggregate for producing lightweight concrete (LWC) with high workability. Results showed that the used of waste glass improved sintering temperature, decreased water absorption and increased failure point loading and bulk density of aggregate. The addition of 30–50% of waste glass produced the high quality LWA with bulk density lower than 2 g/cm3, water absorption lower than 10% and failure point loading as high as 892 N. Workable lightweight concrete with the 28-day compressive strength of 49 MPa was obtained. Results of surface resistivity and ultrasonic pulse velocity of LWC indicated that the produced LWC could be considered as good quality concretes.