Abstract: “This paper investigates the structural behavior of reinforced concrete beams made with locally available natural lightweight scoria aggregates. A series of 4 full scale structural lightweight reinforced concrete beams 2.9 m long, with a rectangular cross-section of 250×300 mm were designed, cast and tested under 4 points bending test. The effect of varying the compressive strength from 25 to 45 MPa on the load-deflection and moment-curvature responses of under reinforced beams with a reinforcement ratio of 0.25 of the balanced steel ratio was studied. Data presented include the load-deflection and moment curvature responses of the beams tested. The investigation revealed that the flexural behavior of the lightweight reinforced concrete beams was comparable to that of normal weight reinforced concrete beams with relatively larger deflections and curvatures. Test results showed a significant reduction in ductility of lightweight reinforced concrete beams with the increase in compressive”

Keywords: lightweight concrete, flexure, reinforced concrete beam, moment, curvature, deflection.