EXPERIMENTAL INVESTIGATION ON SUSTAINABLE FIBROUS LIGHTWEIGHT LECA-BASED CONCRETE WITH FINE RECYCLED AGGREGATES

The world is moving towards the use of sustainable concrete due to its ability to reduce environmental pollution caused by the presence of waste arising from the demolishing of old buildings or those collapsed as a consequence of earthquakes. The combined effects of fine recycled concrete aggregate (RF), light expanded clay coarse aggregate (LECA), and steel fibres (SF) on the properties of concrete were investigated in the present study. The evaluated properties were slump test, compressive strength, flexural strength, splitting tensile strength, density, and water absorption. The prepared concrete specimens were also evaluated, considering non-destructive tests through ultrasonic pulse velocity and rebound hammer tests. Findings indicated that the inclusion of RF with LECA as a partial and full replacement of gravel in both fibrous and non -fibrous concrete resulted in a drop in compressive, splitting, and flexural strength by an average of 17%, 22%, and 25%, respectively when 50% LECA was used. Furthermore, when 100% LECA was used, the drop became more pronounced, with decreases of 39%, 42%, and 45%, respectively. However, the use of hooked steel fibre at 0.75% compensated for this adverseness, and the strengths of the mixes were generally higher than those of the reference mix, which was produced with normal -weight aggregates.