Prediction of chloride ingress for palm kernel shell concrete

Abstract

Steel reinforcement corrosion emanating from ingress of chloride into concrete is the key reason for weakening of concrete structures globally. Infiltration of chloride into concrete happens by absorption and diffusion. On the other hand, reinforced concrete containing supplementary materials is more susceptible to corrosion exposure due to its high permeability. In this paper, two concentrations of sodium chloride (NaCl) were applied on concrete containing palm kernel shell as full replacement to granite. Concrete cube specimens of Grade 20 were cast into 150 mm by 150 mm by 150 mm moulds, and their workability were determined by compacting factor and slump tests. The hardened specimens were soaked in sodium chloride (NaCl) solution of 3% and 6% concentration. Spray, Absorption and Compressive strength tests were conducted at 7, 14, 21 and 28 days. Equations were generated by means of the data gotten from the laboratory tests to forecast the chloride penetration depth into the palm kernel shell concrete under the conditions considered in this work. The models generated revealed that absorption affected chloride ingress into the concrete significantly at 6% NaCl concentration. The models also reveal that the cover to reinforcements in Palm Kernel Shell Concrete subjected to chloride attack should be more than what is presently endorsed for reinforced concrete structures.