Application And Research Of Manufactured Sand And Stone Powder In Commercial Concrete In Jinzhong Area Of Shanxi

In recent years,the development of national economy and the growth rate of investment is relatively stable,the yield of commodity concrete in China has been increased year by year.The annual total output has reached 1.792 billion cubic meters,the price with the national implementation of environmental governance,enterprise reform policy as well as raw materials prices have a rapid growth.As a short time non renewable resource,natural sand,with the implementation of the strict limited exploitation by the state,its price is rising and the market is short,demand exceeds supply.With the rectification of coal and electricity enterprises,the prices of fly ash and mineral powder are also increasing rapidly.To solve the problem of shortage of raw materials and rising prices is the key problem for the development of commercial concrete at present.As fine aggregate,manufactured sand has been used in commercial concrete gradually,but the understanding of the traditional concept,the manufactured sand has not been trusted by the commercial concrete enterprises.As a fine particle,stone powder has not been widely used in concrete.This article from the manufactured sand and stone powder application in concrete as the main line,according to the different strength mix proportion design,work performance,according to the mechanical properties of C30 concrete,impermeability,shrinkage,frost-resistance and raw material cost analysis was carried out comprehensive analysis,providing effective parameters for the better promotion manufactured sand and powder,and make a reference for the development of regional commodity concrete.Through a large number of experimental results,it is shown that the working performance,impermeability and shrinkage performance of C30 concrete with manufactured and washed sand are good,the compressive strength of 28 d is 43.7 Mpa.The performance of concrete is improved by replacing fly ash and mineral powder with stone powder,the amount of limestone powder in 7.5% ~ 15% can increase the compressive strength.When the content of stone powder is in the range of 7.5% to 12.5%,the anti permeability of concrete is improved.When the content of stone powder reaches a range of 15% to 20%,its impermeability ability is somewhat reduced,but it can guarantee the impervious grade of C30 strength grade concrete.When the content of stone powder reaches the range of 20% to 25%,its anti permeability ability is obviously decreased.When the content of stone powder is in the range of 7.5% to 15%,the shrinkage of concrete can be reduced and the shrinkage rate of early concrete can be slowed down.When the content of stone powder is in the range of 15%,it has little effect on the mass loss rate of concrete.When the content of stone powder is within the range of 7.5% ~ 20%,the relative dynamic elastic modulus of the early 75 freezing and thawing cycles is slower,and the later change is more and more obvious.When the stone powder content is 7.5%,the relative dynamic elastic modulus is very small with that of the non admixture.The cost price of concrete raw material combined with manufactured sand and washed sand is 30 yuan per cubic meter lower than that of natural sand concrete.The concrete price of different amount of limestone powder according to the proportion of B,C,D,E,F were decreased by 32,36,38,34,42 yuan / cubic meter,especially with the combination ratio C,its technical and economic benefits are best.The trend of the total output of concrete in the past 5 years in Shanxi,the manufactured sand and powder concrete can save material cost up to 1.89 billion yuan in a year,single C30 concrete can save a cost of 0.76 billion yuan,its potential economic benefits are huge.