Evaluation of Superplasticized Mortars Containing High Volume Basic-Oxygen Slag Fine Aggregate Replacing Sand against Sea Water Attack

Abstract

The influence of superplasticizer addition on durability reinforcement of cement mortars made with basic-oxygen blast-furnace slag fine aggregate (BOF) as completely substitute for natural sand after being exposed to sea water solution for 6 M was evaluated by determining physico-mechanical characteristics in terms of water absorption and compressive strength in addition to microstructure analysis. In this procedure, all studied mixtures were doped with 1% and 2% SP. After the initial treatment of samples in tap water for 28 days, they were subjected to sea water solution for 6 M using water/binder ratios of 0.35 and 0.45. The new hydration phases and microstructure of hardened specimens were identified by X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The results showed that superplasticized cement mortars with slag fine aggregate blended with 2% SP offered better properties and microstructure than their counterparts with natural sand against sea water attacks. Therefore they can be used in offshore structure applications.