Spent Foundry Sand (SFS)-Gum Arabic Admixed Concrete: X-Ray Diffraction, Microstructure, Acid and Sulphate Analysis

Concrete sustainability studies have opened opportunities in the use, and understanding of the characteristics, and performances of supplementary cementing materials (SCMs) using modern methods of investigation. The effect of spent foundry sand (SFS) with replacement levels of 10 and 20 % by wt. % of the fine aggregate (FA), 0.5 % dosage of gum Arabic (GA) on concrete, and its performance in acid and sulfate medium are presented. The investigations are carried out using crushed compressive strength test samples, prepared using a mix of 1: 3: 5, and cured for 28 days in water. The XRD analysis studied the crystalline and mineral phases of the concrete, the SEM-EDS analysis, the morphology (texture) and structural characteristics of the concrete samples, while the Acid and Sulphate analysis to understand the effects of these media on SFS-GA concrete. The results show that SFS and GA have acceptable characteristics for quality concrete. The XRD and SEM results show marked transformations in the crystalline and mineral phases, the morphology and structural characteristics of the hydration products of the concrete samples, because of the addition of GA and SFS, respectively. The performances of the concrete samples with GA and SFS, in the HNO3 medium show better performances than in the H2SO4 medium and better performances in Na2SO4 than in the MgSO4 medium with acceptable characteristics for quality concrete. The XRD and SEM results show marked transformations in the crystalline and mineral phases, the morphology and structural characteristics of the hydration products of the concrete samples, because of the addition of GA and SFS, respectively. The performances of the concrete samples with GA and SFS, in the HNO3 medium, show better performances than in the H2SO4 medium and better performances in Na2SO4 than in the MgSO4 medium