Experimental investigations of cracking in reinforced concrete beams of different depth

Abstract

The study carried out at Vilnius Gediminas Technical University (Vilnius Tech) reports test results on cracking of seven RC beams of the rectangular section. The beams were subjected to a short-term loading under a four-point bending configuration. The experimental program was aiming at evaluating the effect of section height, reinforcement ratio, and bar diameter on cracking of RC beams. The beam cross-sections were designed to have two different cases of section heights (200 and 600 mm), reinforcement ratios (0.36% and around 1.9%), and bar diameters (Ø10 and Ø20 mm). The paper reports test results on mean and maximum crack spacings, as well as mean and maximum crack widths recorded using digital cameras and an electronic microscope. These characteristics were compared to the predictions by Eurocode 2 and Model Code 2010. For the beams with high reinforcement ratio, the mean and maximum crack width predictions by the Eurocode 2 and Model Code 2010 were close to the test results. However, the calculated values for the beams with low reinforcement ratio at most load levels notably exceeded the test results.