Prediction model for hardened state properties of silica fume and fly ash based seawater concrete incorporating silicomanganese slag

• Published in: Journal of Building Engineering 2021-09, Vol.41, p.102356, Article 102356
• Main Authors: Ting, Matthew Zhi Yeon, Wong, Kwong Soon, Rahman, Muhammad Ekhlasur, Selowarajoo, Meheron
• Format: Article
• Language: English
• Subjects: Limestone; Marine sand; Optimization; Prediction model; Seawater
• ISSN: 2352-7102; 2352-7102
• DOI: 10.1016/j.jobe.2021.102356

Growing concrete consumption has gradually depleted conventional resources. This research incorporates silicomanganese (SiMn) slag, marine sand and seawater as alternative concreting materials. The use of SiMn slag to replace limestone as coarse aggregate enhances sustainability, though reducing strength and durability of concrete. This research aims to enhance the SiMn slag concrete by incorporating silica fume (SF) and fly ash (FA). The interaction of SF and FA on strength, durability and workability of concrete is investigated by statistically evaluating the experimental result. In this regard, the polynomial function prediction model is developed using the Response Surface Method (RSM) for the optimization of SF and FA contents. Analysis of variance (ANOVA) using p-value at significance level of 0.05 showed that the models were statistically significant and had marginal residual errors. All models had high fitness with R2 value ranging from 0.853 to 0.999. Adequate precision of models was above 4, indicating that the models had a low prediction error and were fit for optimization. Optimization indicated that a combination of 11.5% SF and 16.3% FA produced concrete that met the optimization criteria. Experimental validation showed that the highest prediction error was 3.4% for compressive strength, 3.2% for tensile strength, 4.9% for sorptivity and 18% for chloride permeability. The optimized concrete exhibited compact microstructure with good bonding between aggregate and cement paste. By using the established linear equation with SiMn slag concrete, the models also predicted the compressive strength of limestone concrete containing SF and FA with an error of between 0.9% and 5.4%. •Silica fume and fly ash improves the strengths of silicomanganese slag concrete.•Synergy of silica fume and fly ash decreases sorptivity and chloride permeability.•Prediction model developed as polynomial function is fit for concrete optimization.•11.5% silica fume and 16.3% fly ash maximizes strength and minimizes permeability.•Linear equation describes correlation of silicomanganese slag and limestone concrete.