Mechanical Properties of Concrete Made from Different Expanded Lightweight Aggregates

The objective of the present study is to provide a databank and comprehensible design equations of the mechanical properties of concrete prepared using different expanded lightweight aggregates. For the statistical database, 25 lightweight aggregate concrete (LWAC) mixtures using expanded bottom ash and dredged soil granules were tested under design compressive strengths of 18, 24, and 35 MPa (2.61, 3.48, and 5.08 ksi) and targeted oven-dried densities between 1300 and 1800 kg/m(3) (81.6 and 112.4 lb/ft(3)). Wherever feasible, the mechanical properties measured in the present concrete specimens were compared with those data compiled from LWAC specimens made of expanded clay and/or fly ash granules. The mechanical properties including the moduli of elasticity and rupture, stress-strain relationship, splitting and direct tensile strengths, shear friction strength, and bond strength were proposed as power functions of the compressive strength and oven-dried density of concrete. The mechanical properties predicted using the proposed equations closely agreed with the test results; the coefficient of variation of the ratios between the experiments and predictions was mostly less than 0.18. In addition, the proposed formulae for the compressive strength development and stress-strain relationship corresponded adequately with the experimental response of LWAC. Meanwhile, the design equations of the fib model resulted in overestimations while predicting the early-strength gain, direct tensile strength, and bond strength of LWAC. Overall, the proposed equations possessed adequate potential to property evaluate the different mechanical properties of concrete prepared using expanded lightweight aggregates.