SIZE EFFECT IN SHEAR OF CONVENTIONAL AND SHEAR-STRENGTHENED RC BEAMS WITH EB-FRP: STATE OF KNOWLEDGE AND RESEARCH NEEDS

Abstract

The size effect is known to have a major impact on shear strength of conventional reinforced concrete (RC) beams. This has been demonstrated through well documented data from numerous research studies since the 1960s. However, few studies have been conducted to investigate the size effect of RC beams shear-strengthened with externally bonded fiber reinforced polymer (EB-FRP). This is particularly relevant since the empirical equations and analytical models proposed by design guidelines for predicting the FRP contribution to shear resistance were developed on the basis of experimental laboratory test data on relatively small beams, with no consideration of the size effect. Therefore, the applicability of such models to large-size beams has not been thoroughly assessed and may well be questionable in view of some preliminary investigations. The objective of this investigation is to highlight the size effect on concrete shear strength of RC beams, either conventional or shear-strengthened with EB-FRP. The present study includes: i) extensive literature review and development of a database on the size effect; and (ii) identification and analysis of the parameters of major influence on the size effect. The research needs on the size effect of RC beams shear-strengthened with EB-FRP are also identified in this investigation