Chloride permeability through different specimen surfaces of blast-furnace slag cement concrete with and without air-entraining agent

Abstract

Numerous research has investigated the effects of blast furnace slag as a cementitious or substitute cementing material on the characteristics of concrete. Blast furnace slag cement (BFSC) shows promise in the concrete permeability domain, where this extra cementing ingredient enhances the chloride attack resistance of concrete. Four mixtures of BFSC concrete made with 0.5, and 0.6 water-to-cement ratios (w/c) were studied. The effect of using an air-entraining agent (AEA) and a change in the surface of tested samples (top, bottom, and side) on the chloride penetration and its diffusion coefficient has been investigated. The properties of fresh and hardened concrete were determined. This research has its novelty for the first time, where the chloride contents were determined through specimens' top, bottom, and side surfaces using potentiometric titration. The results indicated that the air-entraining agent and w/c ratio had inversely affected the invested concrete properties. The measured total and soluble chloride content at a depth of 20∼30 mm is less than the limits of the corrosion threshold for the three studied surfaces. Also, changes in the w/c ratio, cement content, and AEA affect the diffusion coefficient.

Keywords

• Air entraining agent
• Blast-furnace slag cement
• Concrete
• Potentiometric titration
• Chloride permeability
• Total chloride