Analysis of mechanical-physical properties of cement based mortar made with mineral materials and its usage for strengthening of RC beams

Document Type : Research Article

Author

Civil engineering department, Faculty of engineering, Ferdowsi university, Mashhad, Iran

Abstract

The present study investigates the properties of cementitious mortars in which different portions of cement were replaced with mineral materials including electric arc furnace dust (EAFD), red mud (RM), marble powder (MP), and glass powder (GP). Compressive strength at ages of 7, 28, and 90 days, tensile strength at ages of 7 and 28 days, water absorption with durations of 30 minutes, 24 hours, and 72 hours after 90 days of curing, and chemical resistance against sulfuric acid tests were carried out on hardened specimens cured for 28 days. The results show that replacing 15% of cement with marble powder significantly increased the compressive strength of specimens cured for 7, 28, and 90 days. Furthermore, replacing cement with 5 and 15% glass powder or 5% of red mud increased the tensile strength. In order to investigate the performance of the repair mortars, one of them was chosen for strengthening RC beams. Three RC beams were manufactured and tested through 4-point bending scheme. The results indicate that the load-carrying capacity of the strengthened beam by CFRP sheet and repair mortar was the same as the specimen strengthened by CFRP sheet and epoxy resin, and was 60% higher than that of un-strengthened specimen.

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