Test Study on Size Effect of Flexural Performance of RC Free Beams

Experimental studies on size effect of flexural behavior of reinforced concrete beams are not carried out fully. Standard values are based on test results of small-size components, which are different from large-size components in practical engineering. For size effect on quasi-brittle materials such as concrete, related researches have been carried out for many years, but related test study combined with concrete structures or components are not sufficient. This article is based on experimental study of 13 reinforced concrete free beams, obtaining test data during different loading stage, such as carrying capacity, deflection, steel and concrete strain etc. Test results show that size effect of flexural behavior of RC free beams is mainly reflected in reinforcement yielding stage and concrete crushing stage. The negative size effect due to concrete material is not significant. Yet internal force arm and longitudinal reinforcement have a positive size effect on flexural behavior, strength and ductility reserves show a growing trend with specimen size increasing. The safety of calculation theory of bearing capacity in code is verified indirectly.