Abstract

The excessive usage of cement has caused incremental production of greenhouse gases which consequences lead to the overheating of the planet. These detrimental effects have highlighted the importance of using pozzolanic materials. Therfore, using alkali-activated concrete pavement instead of cement has been proposed. Moreover, using fiber concrete surfaces is a predominant method to repair the concrete pavement due to the high speed of performance and the reduction of the thickness. For this purpose, various amount of sinusoidal steel fibers, kortta embass and kortta twist were added to the alkali-activated concrete pavement. The results showed that with an increasing the fiber percentage, the compressive strength, flexural strength and the energy absorption, splitting tensile strength, impact resistance, skid resistance, resistance against freezing and thawing cycles is enhanced. On the other hand, the thickness of the concrete slab and water penetration into the concrete decreased. However, these cases are somewhat efficient for the sinusoidal steel fibers, and then the process begins to decrease.

Abstract

Alkali-activated concrete (AAC), which exhibits good mechanical strength and chemical resistance properties, has attracted emerging interest from the research perspective considering the sustainable development of construction materials. However, the corrosion mechanism at the steel-AAC interface is not yet well understood including the physical and chemical aspects, which leads to different accumulation and evaluation of corrosion products, compared to ordinary Portland cement (OPC) concrete. In this paper, concrete pull-out test and electrochemical techniques were used to investigate the bond-slip behaviour and the evolution of deterioration of AAC respectively. In addition, the current guidance of corrosion evaluation used for OPC concrete based on ASTM C876 is not suitable for AAC. Five mixed ratios of blended fly ash and slag AAC were investigated under two chloride environments and one non-chloride environment, i.e., (1) 3.5% NaCl salt fog spray in the environmental chamber; (2) 3.5% NaCl saltwater immersion; (3) tap water immersion. Electrochemical techniques include half-cell potential, linear polarization resistance and Tafel extrapolation method were used to determine the corrosion rate. The electrochemical results are validated through the comparison of the gravimetric loss of steel after corrosion and electrochemical loss from calculation.