Research And Design Optimization On Manufactured-sand Concrete

The fine aggregate is one of the basic raw materials of the concrete. The quality of the aggregate plays an important role in workability of flesh concrete and physic mechanics property and duration of the harden concrete. It is a convention to optimizing natural medium and coarse sand as fine aggregate at home and abroad. China is a large country with extremely uneven distributed resource of excellent nature sand. With the develop of the construction is more and more,Such questions as the imbalance between supply and demand of excellent nature sand resource is aggravated day by day. Manufactured sand has the similar physical properties with natural sand with extensive materials. So the way by which natural sand is substituted by manufactured sand concrete produce apparent economic and social benefits. After all,there is a big difference between the mechanism-sand and natural sand and mechanism-sand concrete may not be able to play its unique advantages by current codes. So it is significant to implement research on Optimization Design of mechanism-sand concrete.Based on these facts,preparation, admixture’s workability and mechanics property of mechanism-sand concrete were research on the basis of experiments in this paper. The main research contents:(1) According to the characteristics of the fiber and the application requirements of engineering practice,find out the influence factors of the orthogonal test contain the mechanism-sand replacement rate the water binder ratio,the sand ratio and water reducer respectively. In this paper,choose orthogonal table and determine various experimental ratio and use range method and variance method to study the influence of mechanism-sand concrete of main performance factors,then guide to ensure the optimal ratio of fiber reinforced concrete comprehensive performance in the next step.(2) Based on the particle shape and graduation of mechanism-sand, the concept of mechanism-sand replacement rate was proposed, which made conducive to yield stress and would not affect its workability. According to the theory of Bolomey and the theory of Fuller, the theoretical value of good mechanism-sand replacement rate was calculated. The results computed using the developed equations were checked with the test ones.(3)According to certain amount of testing data on compressive strength and slump of mechanism-sand concrete, numerical model which can predict and evaluate its strength and working performance was established, and combined with Pareto optimal solution and genetic algorithm to perform the multi-objective optimization on the compressive strength and slump under multiple factors.