Numerical and parametric study of the yield stress limits of reinforcement bars in clay block masonry structures

Abstract

abstract: The Brazilian Standard Structural Masonry considers for the maximum tensile stress (fs) of the reinforcements embedded in the grout in clay blocks with smooth surfaces several limits of the yield stress for the reinforcement (fyk). This work aims to analyze the limits of the yield stress of reinforcement bars in clay block masonry structures by numerical and parametric analysis in push-out and pull-out tests, varying the type of grout and reinforcement diameter. A numerical study was performed using a 3D-model with the DIANA® software based on the Finite Element Method. The parametric study confirmed that the limits obtained in this research for reinforcement diameter of 8 mm, 10 mm, 12.5 mm and 16 mm are in agreement with the limits specified by the Brazilian Standard, with exception of the 20 mm diameter, which limit was lower than indicated by the Standard. The tensile stress limits of the embedded reinforcement progressively reduce with increasing rebar diameter, being the failure is dominated by the bond strength of the block/grout interface.

Keywords

• yield stress
• bond strength
• block/grout interface
• finite element
• clay blocks