# Abrasion-Resistant and Temperature Control of
## 1 Introduction  
In China, large-sized hydropower projects are mainly distributed in western alpine and gorge regions. Restricted by topography, geology and other conditions, there are numerous spillway tunnels of large-size, high single-tunnel discharge with high flow rate. For example, under the verified flood level, the spillway tunnel of Dagangshan hydropower station has a maximum flood discharge capacity of 3352 m\({}^{3}\)/s and the highest flood discharge flow rate of approximately 42 m/s. The average annual service time of the spillway tunnel is more than 2000 h, and the high frequency of use ranks the topof the same type of power stations in China. Therefore, higher requirements are put forward for the anti-scouring and abrasion resistance of the concrete in the spillway tunnel. Therefore, anti-scouring and abrasion-resistant concrete is generally adopted in construction; however, this gives rise to a series of problems, such as high temperature control requirements and difficult crack control. In the case of temperature cracking being accompanied with long-term scouring by high-velocity water flows carrying sediments, it will further result in cavitation erosion and seriously threaten the safe and stable operation of spillway tunnels and hydropower stations, not to mention the extremely high cost of repair. In this sense, studying the anti-scouring and abrasion-resistant performance and temperature control technology of lining concrete for large-sized spillway tunnels is of vital theoretical significance and practical value. Generally, anti-scouring and abrasion-resistant concrete is used for spillway tunnel lining and the performance of this type of concrete mixed with fly ash, silica fume and fiber has been extensively investigated. [PERSON] et al. [1] found that class F fly ash concrete with up to 15% cement replacement was acceptable for structural applications of abrasion erosion resistance. [PERSON] et al. [2] and [PERSON] et al. [3] reported that if 15% of cement was replaced with fly ash, the abrasion increased with the fineness of fly ash. However, with a fly ash content of 30%, the abrasion resistance of concrete turned out to be lower than that without fly ash. [PERSON] [4] found that abrasion resistance could be improved approximately by 40% when 40% fine aggregate was replaced with fly ash. [PERSON] et al. [5] concluded that if the replacement percentage exceeded 15%, fly ash concrete showed lower resistance to abrasion-erosion compared to non-fly ash concrete. The utilization of silica fume was a typical strategy to improve the abrasion erosion resistance of concrete [6; 7; 8]. However, the amount of silica fume should be considered with caution as excessive silica fume might lead to cracks. [PERSON] and [PERSON] [9] found that the resistance to wear of concrete containing silica fume as a fine aggregate replacement was consistently better with increasing amounts of silica fume up to 10%. [PERSON] and [PERSON] [10] found the abrasion resistance of concrete was improved by the addition of silica fume due to the increase in tensile modulus. [PERSON] [11] reported that the abrasion resistance increased with respect to the increase in silica fume addition. For concrete with a 1-mm width surface crack, and if the water flow impinged directly into the crack, the abrasion rates were nearly 13% and 25%, respectively, higher than that of the intact mixture. The toughness and durability of concrete can be significantly improved by the addition of fibers. [PERSON] and [PERSON] [12] found that the incorporation of latex and steel fiber did not improve significantly the mechanical and hydraulic abrasion resistance of such high-strength concrete (HSC). [PERSON] [13] found that the addition of steel or synthetic fibers did not cause any appreciable change in the abrasion resistance of concrete. [PERSON] et al. [14] found that the inclusion of polyester fibers in high volume fly ash concrete (HVFA) improved abrasion resistance. [PERSON] et al.