Effects of Additives on Concrete-Rebar Adherence

Abstract

In composite reinforced concrete elements formed by concrete and rebar, only if these two materials work together, reinforced concrete elements can fully function. The significant factor that will ensure working together is the bond strength, which is called adherence. The higher the value of this force, the harder the rebar is to pull out from the concrete. In this experimental study, the effect of concrete additives and aggregate type on the bond strength and the amount of elongation of the reinforcement without stripping from the concrete was investigated. For this purpose, 28-day compressive strength and adherence force and reinforcement elongation amounts of the concrete mixtures produced by using mineral, chemical and fiber additives for two different aggregate series, crushed stone and gravel, and two different cement dosages, were observed. In addition, by using 3 different rebar in terms of diameter and surface properties, the effect of these properties on concrete-rebar adherence was revealed. As a result of the study, the use of crushed stone aggregate, hyperplasticizer additive, mineral additive and ribbed rebar with 18mm diameter increased the bond strength compared to the reference samples.