Analysis on Flexural Behavior of UHPFRC Beams based on Tensile Stress-Crack Opening Relationship

摘要

The objective of this study is to investigate the differences between the tensile stress-crack opening relationships of the small size notched beam and the real size beam which were made of two ultra-high performance fiber reinforced concretes (UHPFRCs) having different volume fractions and lengths of fibers. The stress-crack opening relationships of two UHPFRCs were first obtained from the inverse analysis for the small size notched beam tests. In addition, the three types of real size beams were manufactured for each mix: (1) plain beam, (2) beam with tensile reinforcement, and (3) beam with both tensile and compressive reinforcements. The flexural tests of the plain and reinforced beams were conducted up to a failure state. The load-deflection curves of the plain and reinforced UHPFRC beams calculated based on the tensile stress-crack opening relationship of the notched beams did not give an accurate prediction on the measured load-deflection curves of the real size beams. The tensile stress-crack relationships accurately fitting the measured load-deflection curves were additionally found, and the difference in the tensile stress-crack opening relationships of the small size notched beams and the real size beams was analyzed in this study.