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CFST arch bridge has a compact structure, beautiful shape, strong bearing capacity, construction convenient, cost-effective and high, by a bridge-building widespread concern. However, the steel tube and core concrete synergy decided the key to project success or failure of the concrete filled steel tube. How to implement the core concrete steel pipe sufficiently dense packing is to ensure synergy between the two primary factors, the core concrete requires the use of a good dense packing of self-compacting Expensive Concrete. The mechanism of sand as an economical and environmentally friendly engineering materials, solve the mountainous project construction sand shortage, transportation difficulties, chippings waste accumulation pollution problem. However, the mechanism of sand stone powder content, sharp particles and more angular, graded poor constraints in the application of self-compacting concrete. The study preparation mechanisms sand Thus, self compacting concrete filled steel tube has a very challenging and good economic, social and environmental value. State Road Hurong Creek Bridge steel pipe arch concrete background for the study, demonstrated the feasibility of using high-performance concrete mechanisms sand preparation C60 steel pipe, high powder content of mechanism sand self compacting concrete filled steel tubular technology mechanisms sand high-strength steel pipe concrete application provides a reference example. The completion of the research work are as follows: 1. Combined engineering background with concrete materials characteristics, the technical requirements of the the C60 mechanism of sand concrete filled steel tubular. Performance tests of raw materials of steel pipe concrete through the the C60 mechanism of sand, the key material preferred. And through water-cement ratio, the amount of cementitious material, mechanism gravel powder content, the percentage of sand, expansive agent varieties and ash, mineral admixtures variety and dosage of the concrete compressive strength and limit the expansion test optimization of C60 sand mixture ratio self compacting concrete filled steel tube. 3. Optimized with the ratio of the work, mechanical properties, volume stability, heat of hydration, durability and other key performance test. Systematically studied the mechanism gravel powder content in the range of 3-10% of the of C60 steel pipe concrete, mechanical properties, and limit the expansion, compressive creep, the impact of the performance and durability of resistance to plastic shrinkage cracking and river sand concrete performance comparison. The results showed that the mechanisms sand the C60 steel pipe concrete powder content of 7% in the work of slightly worse, but limit the expansion in the mechanical properties, durability indicators comparable with river sand concrete, even better than the river sand concrete. 4 to carry out the the C60 mechanism of sand concrete filled steel tubular engineering applications, and to explore the mechanisms of sand steel pipe concrete pouring. The results show that the good performance of concrete construction, and strength to meet the design requirements, concrete filled steel pipe dense.
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