Statistical Analysis of Structural Lightweight Aggregate Concrete Modification Factors

Structural lightweight concrete has broad applications in sustainable and resilient infrastructure.Applying porous aggregates improves the primary characteristics of lightweight concrete, such as lowdensity and thermal insulation. However, the porosity of aggregates tends to reduce the tensile strength andmodulus of elasticity of lightweight concrete compared to normal-weight concrete samples with the samespecified compressive strength. Hence, these values need modification in code regulations that usecompressive strength as the primary parameter for design specifications. Current procedures fordetermining modification factors utilize simplistic approaches based on the equilibrium density of concreteor the overall classification of coarse and fine aggregates as normal-weight or lightweight. Thus, applyingthese modification factors to obtain the nominal capacity of concrete concerning flexure, shear, bond, anddeflection involves concerns for reliability and accuracy. This paper employs statistical procedures todetermine modification factors for structural lightweight concrete containing lightweight aggregatessourced from mining, rotary-kiln production, recycled contents, and byproducts. The proposed methodutilizes an extensive database of experimental data to evaluate the physical and mechanical properties oflightweight aggregates and their concrete prototypes using statistical measures. Results distinguishparameters influencing the behavior and performance of structural lightweight concrete. Conclusionsprovide supplemental design guidelines for determining the tensile, flexural, shear, and bond strength ofstructural lightweight concrete and the moduli of rupture and elasticity.