Size effect on tensile strength of lightweight aggregate concrete: A numerical investigation

Lightweight aggregate concrete (LWAC) showed an obvious brittleness when subjected to the tensile stress, and the related size effect issue was crucial for the analysis and design of structural LWAC. The random aggregate structure was used to establish finite element models, and materials parameters were calibrated by using existing test data. Influences of the ratio of water-to-binder (W/B) materials, grading of lightweight aggregate (LWA), the strength of LWA and the relative strength of interfacial transitional zone on the tensile strength and the size effect of LWAC were evaluated. Finally, the results of simulations were applied to conduct a regression analysis on classical size effect law. It was concluded that the grading of LWA had a relatively more minor influence on the size effect of LWAC in tension, while the W/B ratio and the strength of LWA significantly affected the size effect due to the alteration of the concrete strength. Formulas for parameters in classical size effect law were developed by using the results of numerical analysis.