The Study On Green High-performance Compound Concrete Mixed With Spontaneous Combustion Gangue And Slag

In allusion to the the problem of the frost crack of the concrete structures and the salinization in the Yellow River area and the arid, cold and windy weather of NingXia, based on the abundant waste material resources of spontaneous combustion gangue and slag of Ningxia, this paper studies the mechanical and anti-permeability performance of the high-performance compound concrete mixed with spontaneous combustion gangue and slag through the orthogonal experiment, covariance analysis, macroscopic and microcosmic experiment. The author confirmed the most optimum scheme and made a sample of this kind which has well workability, high strength and anti-permeability performance. The main results are as follows:(l)The scheme of making high-performance compound concrete mixed with spontaneous combustion gangue and slag is feasible. The match ratio of concrete which can reaches 50MPa after 28 days under the standard curing condition is confirmed and the most optimum scheme is A₁B₁C₂D₃E₂, viz. water-cement ratio is 0.33, the amount of spontaneous combustion gangue is 10% of the binding material, fineness of spontaneous combustion gangue is 4600 cm2/g, the mixed slag is 10% of the binding material, sand percentage is 0.39, and the total amount of mixed minerals reaches 20% of the binding material.(2)The water-cement ratio has great influence on the strength of the high performance concrete as the same as the ordinary concrete. In high-performance concrete's need of low water-cement ratio and good workability, the selection of suitable additive is vital. Moreover, the super fine slag powder has the effect of reducing water and suitable sand percent can improve the workability of the high-performance concrete.(3)The comparison of anti-permeability experiment between the high-performance concrete and ordinary concrete indicates that the high-performance concrete has excellent anti-permeability performance (The anti-permeability index is 3.5MPa.).(4) The micro structure chart of high-performance concrete indicates that the hydrated product of the concrete is greatly changed, the hole's characteristic is effectively adjusted, so that the compaction degree of concrete increases, the number of harmful holes is greatly reduced and the hole's structure is well-distributed. And then the mechanical and anti-permeability performances of the concrete have greatly improved.(5)The experimental results indicate that the two mixing materials have mutual benefit for and complementary effect on the concrete, their superposition effect on the concrete is superior to which are used separately.The studies on green high-performance compound concrete mixed with spontaneous combustion gangue and slag have the great significance for developing green civil engineering material and realizing the rational distribution and sustainable development of cement concrete industry, and provide the theoretical foundation for the design and application of concrete structure in NingXia and even the west China. In addition, the results suggest a new method for improving the production of concrete, and have certain value in application, and remarkable social, environmental and economic benefit, and willhave a bright future.