Experimental Study on Compressive Strength of Concrete with Composite Solid Waste and Steel Fiber
To promote the use of solid waste in concrete production and solve the problem of secondary envi-ronmental pollution caused by the large accumulation of solid waste,factors such as coal gangue and gravel replacing coarse aggregate,coal gangue and sand replacing fine aggregate,steel fiber content and fly ash re-placing cement are used as influencing factors.A four factor and four level orthogonal experimental method is designed to explore the influence of solid waste and steel fiber on the compressive strength of concrete cube.Multiple analysis methods are used to obtain the primary and secondary factors,optimal dosage and strength prediction models at different factor levels.SEM is used to analyze the microstructure of different materials and the strengthening mechanisms at the micro level.It is concluded that the degree of influence of various factor on the compressive strength of the cube is as follow:the replacement rate of fly ash>the replacement rate of coal gangue and gravel>the content of steel fiber>the replacement rate of coal gangue and sand.The combination with the highest strength has a replacement rate of 30%for coal gangue and gravel,15%for coal gangue and sand,1.2%for steel fiber,and 10%for the replacement rate of fly ash.The obtained strength prediction model has high accuracy and can predict the strength within the range se-lected by the proposed orthogonal experiment.
coal ganguefly ashsteel fibercompressive strengthorthogonal test