Effect of carbon fiber on mechanical properties and dimensional stability of concrete incorporated with granulated-blast furnace slag

Concretes with binary and ternary blends of Portland cement, granulated-blast furnace slag (GGBS), and carbon fiber (CF) were prepared to investigate their effects on mechanical performance, drying shrinkage and creep behaviors. Nine types of concrete mixtures were prepared and tests were conducted during a long testing period which was up to 180 days. Research showed that GGBS and CF played a detriment effect on short-term compressive strength. GGBS could improve the workability of concretes, while CF presented an opposite effect. Concrete with the addition of CF showed superior drying shrinkage resistance and creep resistance, while GGBS increased the drying shrinkage and creep potentials. The coupling effect of GGBS and CF on the drying shrinkage and creep performance highly depended on the relative content of GGBS and CF. Analysis of variance (ANOVA) was performed to analyze the importance of GGBS and CF on the drying shrinkage and creep performance. Results showed that test period, content of GGBS, and content of CF were all significant factors in influencing the drying shrinkage and creep behaviors. Models to predict the drying shrinkage strain and creep coefficient were proposed by considering different proportions of cement, GGBS, and CF, and the models give promising results. Besides, the cost-benefit analysis and the environmental impact were also quantitively studied, and results showed that concretes incorporated with 20% GGBS in mass and 0.1% or 0.2% CF in volume presented both good cost-benefit effectiveness and low environmental impact. (c) 2019 Elsevier Ltd. All rights reserved.