Effect of Selected Commercially Available Corrosion Inhibitors in Kenya on Bond Strength of Reinforced Concrete.

Abstract

Corrosion of reinforced concrete water structures generates tensile stress within the concrete and reinforcement interface influencing the service life of structures. This research investigated the influence of selected commercially available corrosion inhibitors in Kenya in combination of selected brands of ordinary Portland cement on the bond behavior of reinforced concrete members. To achieve the desired objective, samples in concrete of characteristic strength of 25N/mm2, 9 cylinders each of 150mm diameter x 300mm long each for four corrosion inhibitors and one control experiment were cast with an embedded rebar of 10mm diameter and 110mm long. For each series 9 cubes of 150mm x 150mm and 9 cylinders of 150mm diameter x 300mm long were cast for compressive strength and split tensile strength test respectively. After 24 hours the cast specimens were demolded and immersed in curing tanks for 27 days and tested for bond strength. The physical and chemical properties of the materials were investigated for compliance to relevant applicable British and Kenyan standards for conformity to acceptable criteria. The concrete materials were batched by weight and mixed by a lab electric pan concrete mixer in batches of 0.009 m3. The concrete batches were tested for consistency by the slump and compaction factor tests. The result show that bond strength increased with all selected corrosion inhibitors in combination with each respective cement brand. A bond strength model that correlated significantly with Orangun et al and Stanish et al model has been proposed.