高性能潮喷混凝土基准配合比试验研究OA

In order to explore the influence of different components on concrete strength,a full-scale model test of the TBM water diversion tunnel lattice high-performance wet shotcreting support structure was conducted based on a water diversion tunnel project in Xinjiang.Based on the benchmark mix ratio of high-performance wet shotcreting,the influence of key factors such as cementitious material dosage,water cement ratio,silica fume content,sand ra-tio and fiber content on the strength of high-performance wet shotcreting were studied under a single variable.The research results indicate that:1)The dosage of cementitious material needs to be coordinated with parameters such as water cement ratio and admixture,the high-performance wet shotcrete exhibits the best compressive strength at all ages with the optimal dosage of cementitious material of 480 kg/m3.2)When the content of silica fume is 7％to 10％,the compressive strength of high-performance wet shotcreting is better.The compressive strength reaches its peak with 7％content of silica fume.3)By coarse aggregates with a particle size of 5～10 mm,a sand ratio of 0.41 can achieve the highest compressive strength for high-performance wet shotcreting.4)When the fiber content is 3～9 kg/m3,the compressive strength and splitting tensile strength of high-performance wet shotcreting show a single peak variation characteristic of first increasing and then decreasing.Among them,the strength reaches its peak at all ages when the optimal fiber content is 6 kg/m3.5)The final benchmark mix ratio for high-performance wet shotcret-ing is determined as follows:the dosage of cementitious material is 480 kg/m3,the water cement ratio is 0.38,the dosage of silica fume is 7％,the sand ratio is 0.41,the fiber dosage is 6 kg/m3,the dosage of water reducer is 1.2％,and the dosage of accelerator is 7％.Under the mix ratio,both the mechanical and construction properties of the concrete are excellent.