Investigation the Bond Behavior Between Concrete and Steel of the New Strength Class A550

Abstract

Representative experimental studies are necessary for the normative substantiation of the controlled parameters of the rolled products. The paper presents the results of experimental studies of the adhesion of reinforcement of the new strength class A550 with concrete. Statistical processing of the results is given. The main ones are defined. The experimentally evaluated specific bond strength indicators, kN/mm, of reinforcing steel d10–36 A550 in concrete classes B30–B40 demonstrated a stable increasing linear dependence on the relative bearing area of the transverse ribs f_R. This requires verification on other cross-sections of the rolled product and its rib parameters. However, it can be stated that with a probability of 0.95, accounting for the actual cross-sectional parameters in the improved method for evaluating the anchorage value of the rolled product will allow, within the scatter of properties even within a single batch, for a justified adjustment of the design bond strength between reinforcement and concrete by up to 15 % for small-diameter rolled products (up to 20 mm) and up to 10 % for larger diameters (20+ mm). For the latter, the rationalization of the normatively required large design anchorage lengths is the most effective and promising.