Corrosion Resistance Analysis of Tire Waste Steel Fiber Reinforced Self-Compacting Concrete Using Rapid Chloride Penetration Test

Corrosion of reinforced concrete structures induced by chloride contamination primarily causes structural damage and premature degradation, affecting safety, reliability, economics, and environmental performance. The development of self-compacting concrete (SCC) and Fiber-Reinforced Concrete (FRC) are among the most emerging developments in concrete technologies and significantly improve its strength and durability. SCC has excellent mechanical strength and is denser but has a brittle failure and is susceptible to cracking. In contrast, FRC increases the interfacial bond between constituent materials due to the presence of fiber, which increases its resistance against cracking. Researchers are still questioning whether adding fiber to self-compacting concrete enhances corrosion resistance against chloride penetration. This work develops a tire waste steel fiber reinforced self-compacting concrete (TWSFRSCC) and investigates its influence against corrosion together with other constituent materials such as water and superplasticizer (SP). Sixteen mixtures with different water-cement ratios (0.4 – 0.5), SP content (1 % - 1.8 %), and TWSF amount (0.71 % - 3.29 % or 5 - 15 kg/m3) and one additional plain SCC were prepared and tested for rheological properties. In addition, the Rapid Chloride Penetration Test (RCPT) was performed on a 100 mm-diameter, 50 mm-thick concrete cylinder. Nine of seventeen mixtures meet EFNARC SCC rheological requirements. The study indicated that water and SP are the main factors affecting the rheological properties of concrete, altering segregation resistance and bleeding. The findings indicate that increased TWSF content leads to higher chloride penetration. This is attributed to the enhanced interconnectivity of the fiber, which forms more pores around the fiber, serving as entry paths for chloride ions. Additionally, the increase in TWSF content also enhances the specimen's electrical conductivity, which increases the charge passed. However, the presence of fiber still produces 11 out of 16 mixtures with moderate chloride penetration, where the TW3 mix attains a maximum decrease of 46.98 % against plain SCC, which attains high chloride penetration. This indicates that TWSF attracts the chloride ion to bond on the fiber first before penetrating the specimen, acting as a sacrificial anode. It was concluded that TWSF can strengthen the SCC and be applied in constructing marine structures.