Experimental Investigation on the Shear Crack Development of Shear-Critical High-Strength Reinforced Concrete Beams

Abstract

The main propose of this work is to investigate the shear crack development and suggest the design formulas that can ensure serviceability and reparability for shear-critical high-strength reinforced concrete (HSRC) beam members based on the experimental data of ten full-size simple-supported beam specimens. According to the experimental results, the design formulas that can ensure the serviceability and reparability are recommended for shear-critical HSRC beam members. Additionally, relationship between shear stresses of member and widths of shear cracks are also built for the quantitative analysis of shear crack development. Based on the crack development of each specimen, the average ratio of the residual total shear crack widths to the residual maximum shear crack width for the HSRC beam specimens is approximately 4.5; then, in the crack-based assessment, this work recommends setting the ratio as 4.0 to estimate residual maximum shear cracking. Additionally, the ratio of maximum peak shear crack width to residual maximum crack width, it can be increased by shortening stirrup spacing and increasing stirrup strength, and its overall average value is 2.44. This work suggests the applicable value of a HSRC shear-critical beam to be 2.5. Besides of the post-earthquake damage assessment, these results can also be used to build the performance-based design for HSRC structures.

Shear Crack Control for High Strength Reinforced Concrete Beams Considering the Effect of Shear-Span to Depth Ratio of Member

“…For HSRC beam specimens in Chiu et al (2014), the design formula (Eq. (2)) recommended in AIJ (2010) to ensure serviceability under long-term loading can be used to control the peak maximum shear crack width less than 0.3 mm.…”

“…While focusing only on HSRC shear-critical beam and column members, the research conducted by Chiu et al (2014) investigated the relationship between the residual deformation and the residual shear crack width by conducting a full-size experiment. Based on the crack development of each specimen, the average ratio of the residual total shear crack widths to the residual maximum shear crack width for the HSRC beam specimens is approximately 4.5.…”

“…According to Chiu et al (2014), stresses that are calculated using Eqs. (1) and (3) exceed measured stresses.…”

“…Additionally, a crackbased damage assessment plays a major role in estimating repair costs of a building. Despite the numerous crack-based damage assessments of RC members or structures, related studies have focused mainly on normal-strength RC with little attention paid to HSRC structural members (Chiu et al 2014 andSoltani et al 2013). A crack-based damage assessment can also estimate post-earthquake residual seismic capacity or facilitate damage-controlled design (performance-based) for a building structure.…”

“…Design compressive strength of the concrete is 70 and 100 MPa, and the shearspan to depth ratio is 1.75, 2.00, 2.75, 3.25 and 3.33. Additionally, investigation of the shear crack behavior of HSRC beam members also includes HSRC beam specimens with a shear-span to depth ratio of 3.33 conducted by Chiu et al (2014).…”