The Counterbalance of the Adverse Effect of Abrasion on the Properties of Concrete Incorporating Nano-SiO2 and Polypropylene Fiber Based on Pore Structure Fractal Characteristics

Abstract

Abrasion damage is a typical hydraulic structure failure and considerably impacts the durability of buildings. In severe circumstances, it can even prevent hydraulic structures from being used and operated normally. Thus, it is essential to research abrasion-resistant hydraulic systems that are more durable, inexpensive, safe, and ecologically friendly, given its unavoidable characteristics. In this context, five dosages of nano-SiO2 and three dosages of fibers are selected to evaluate and analyze the modification effect of nano-SiO2 and polypropylene fibers on the abrasion resistance of concrete. The evolution of the concrete properties was characterized based on the abrasion resistance strength. Moreover, the mineralogical composition and microstructure characterization were investigated through X-ray diffraction and scanning probe microscope. Mercury intrusion porosimetry was applied to determine the pore-structure parameters of concrete, such as pore-size distribution and the fractal characteristics. The results indicate that nano-SiO2 improves the abrasion resistance of concrete by densifying the pore structure and promoting the formation of hydration products. Results reveal that the excessive dosage of fibers agglomerates in the concrete to form an unsubstantial pore structure due to poor dispersibility. The fractal dimension of the pore structure exhibits a close relationship with the abrasion resistance strength of concrete. The implications of these findings inform the design of abrasion and erosion resistance for hydraulic engineering structures.