Waste marble based self compacting concrete reinforced with steel fiber exposed to aggressive environment

Abstract

Degradation of self-compacting concrete (SCC) exposure to the aggressive environment is a key issue that decreases the service life of the SCC structure. To reduce the amount of damage produced by the acid, the fibers bridge the cracks and restrict their spread. Therefore, SCC is reinforced with steel fibers at varying percentages from 0 to 2.0 %. Marble waste as filler materials (10 % by weight of sand) was also added to improve the microstructure. The SCC is exposed to a 4 % sulfuric acid solution for a specified period. The mechanical performance of SCC was evaluated through visual inspection, mass loss, compressive, and tensile strength. Furthermore, the durability of SCC was judged by dry density, water absorption, and permeability tests. Cracking behavior and performance at elevated temperatures of SCC exposed to the acid environment were also evaluated. Microstructure analysis was evaluated through scan electronic microscopy and simultaneous thermal analysis. Results indicate that the SCC performance under an aggressive environment was considerably improved with the addition of steel fiber and marble waste. The synergic effect of steel fiber as a reinforcement and marble waste as filler shows a positive impact on strength, durability, performance at elevated temperatures, and the microstructure of SCC. Maximum mechanical improvement was observed at a 1.5 % addition of steel fiber which shows 10 and 20 % more compressive and tensile strength respectively. Furthermore, steel fiber improved ductile failure by allowing warning (cracks) and avoiding abrupt failure. However, a higher dose of steel fiber (beyond 1.5 %) decreased the SCC performance due to a lack of flowability. Therefore, the study concluded that steel fiber should be used up to 1.5 % addition.