Flange Strain Measurement in Shear Critical RC T-Beams

This paper provides an analysis of the strain measurements and distributions obtained from testing two reinforced concrete T-beam specimens for the purpose of assessing the contribution of the flange to the shear strength. The specimens were instrumented throughout the flange and the compressive zone of the web region in order to obtain comprehensive data required for the understanding of shear resistance mechanisms and quantification of the flange contribution to the shear resistance of reinforced concrete T-beams. It was found that the formation of shear cracking results in significant redistributions of strain through the measured region. Redistributions of compressive strains transversely away from the web region and vertically away from the top surface of the flange were observed. The resulting distributions throughout the specimen were highly nonlinear. In light of the results of this investigation, the assumptions made in the application of existing methods available for prediction of the shear resistance of reinforced concrete T-beams are discussed, and proposed improvements to these methods are also discussed.