Dry Shrinkage And Resistance Method Of Green High Durable Concrete

The paper take cracking performance of concrete with high volume mineral admixtures as main subject investigated, study the dry shrinkage of concrete with high volume mineral admixtures in development, discuss different admixture quantity, fiber type and quantity influence on dry shrinkage of concrete by 23 different mixture proportions test. On the basis of test and computer technique, the paper set up a dry shrinkage model of GHDC. The main achievements can be summarized as follows:(1) The concrete with high content mineral admixtures exhibit large drying shrinkage with low patio of water and mixer. The dry shrinkage develops rapidly in the first seven days, and the increasing of dry shrinkage is comparatively slower between the seventh and sixtieth day and get steady after the sixty day.(2) Both of slag and fly ash could reduce the dry shrinkage of concrete with high volume mineral admixtures, but silica fume could greatly increase the drying shrinkage. The comprehensive analysis of economy and superimposed effect is that concrete have certain content of slag and fly ash shows good potential in engineering.(3) Steel fiber, polypropylene fiber and polyester fiber all have good drying shrinkage resistance on concrete with high volume mineral admixtures, and the effect of drying shrinkage resistance will get better with the increasing module of the fiber. The effect caused by fiber hybrid technique uncertainly increase with the increasing of hybrid number, and also has relations with the collocation of hybrid fiber.(4) On the analysis of cracking resistance to dry shrinkage and early-age plastic shrinkage, concrete have certain content of polypropylene fiber and polyester fiber or have certain content of expansion agent, polypropylene fiber and steel fiber shows good potential in engineering.(5) Long-time drying shrinkage of 23 different samples concretes were tested, and set up a dry shrinkage model of GHDC standard sample.