Study Of The Mechanical Properties Of The Extra Fine Sand Concrete

The resource of super-fine sand is abundant in the area of Kaifeng, but medium sand is extremely short. Because of the shortage of technology, only medium coarse sand was used for concrete whose design strength grade is more than C15, and the super-fine sand in the engineering construction in the area of Kaifeng couldn't be used. The resource of super-fine sand wasn't fully used. The price of medium coarse sand which taken from Shangdong and Suiping Henan was much higher with transportation cost than the super-fine sand from local area. The super-fine sand concrete which meet the need of engineering project was brought forward through experimental study in the dissertation. And the super-fine sand concrete could cut down the waste of resource, reduce engineering cost, and bring more benefit to Kaifeng.The main research content is the performance of super-fine sand concrete. First of all, the concrete with super-fine sand which conforms to strength and workability requirement was prepared. Through the experiment, the effect of sand rate, water-cement ratio, water dosage and consumption of cement to workability, strength and durability were studied.And the concrete mixing process's slump, cohesion, water conservation were also studied in order to find the super-fine sand concrete which meer the need of workability. Based on the research on the relation between cubic compressive strength and the water-cement ratio, the curve was given out and the experiment verification was made.Through the research on the relation between compressive strength and the curing age, the formula was deduced. The comparison experiment was done between the super-fine sand concrete and the medium sand concrete with the same sand rate and different water-cement ratio. The result showed that the performances are approximately the same.The experiment research was taken on the super-fine sand concrete with special requirements as impermeability, ability of transported by pumping, high strength. The UEA expanding agent was used in order to compensate the shrinkage of concrete, improve the density, permeability of concrete. And the experiment on the mixing process's slump, workability, compressive strength, confined expansion radio in water and impermeability were made separately. In order to prepare the super-fine sard concrete with ability of transported by pumping, "Double-admixing Method" was used in the dissertation,by which the retardation super plasticizer and fly ash were mixed in the concrete at the same time. The experiment research was also taken on the mixing process's slump, workability, gas content, bleeding rate and quantity under pressure, slumps retention value. Above results met the demand of pumping, and compressive strength also met the design demand. C60 super-fine sand high-strength concrete mixed with super plasticizer and fly ash was also studied.Test data shows that the result achieve the expectations.Performance Experimental Study on the mechanical properties, dimension stability and durability of Super-fine Sand Concrete which has specific requirement were taken.And the result indicate that those performances of super-fine sand concrete were quite close with Medium Sand concrete's.As a result, the concrete which has good performance of impermeable and pumping can be got with super-fine sand.