The study of the mechanical properties of concrete cylinders using recycled lightweight aggregates

Abstract

Sustainability is now a high priority in civil engineering because engineers are now more aware of the environmental risks and the limit of resources. Recycling reduces energy consumption and waste and conserves in-danger resources, civil engineers started to recycle normal-weight and lightweight concrete. The main goal of this research is to study the properties of concrete when recycled lightweight aggregates are used. Three mixes were produced, all of which had a w/c ratio of 0.6 and same proportions of cement, sand, and gravel were used for one of them and two different types of lightweight aggregates for the two others. The lightweight crushed aggregates of the concrete cylinders were used to make recycled lightweight concrete; workability, splitting tensile strength, compressive strength, and density were studied, analyzed, and compared to previous concrete results. The results showed that replacing lightweight aggregates with recycled lightweight aggregates has significantly improved the properties of the concrete, as the strength after 28 days increased from 2.26 MPa to 8.27 MPa, the density increased from 1208 kg/m3 to 1852 kg/m3, and the workability almost remained constant.