Effect Of Raw Material On Application Performances Of Superplasticizer

Because of its high water reducing ratio, small admixture and well restraint of slump loss, PCE has become one of critical material that be used for manufacturing HPC. The consumption of PCE in construction engineering presents rapid growth trend. In practical applications, it is discovered that concrete raw materials have a significant effect on the application performance of PCE, however, there are few articles about the subject. In order to better promote the application of PCE, this paper mainly studies the effect of raw materials, including cement, mineral addition and aggregate, on application performance of PCE.There is a problem of adaptability between different cement and different water reducers. The efforts of a water reducer on dispersity and retention capacity of diferent cement are diferent, which relates to mineral composition and fineness of the cement. The adsorption of PCE of tricalcium aluminate and brownmillerite on PCE is bigger than that of calcium silicate. As the hydration progresses, the hydration speed of tricalcium aluminate is faster, and the adsorption of PCE of the hydration products is small. Then there will be more water reducers released, as a result, water reducers concentration on surface of silicate phase rises, which makes the fluidity of cement mortar increase gradually. With the high concentration of brownmillerite, the hydration speed is lower, the adsorption of PCE is larger and the hydration of tricalcium aluminate consumes more water, then the fluidity of cement mortar reduces gradually. The grain shape of gypsum greatly affects the remaining fluidity of PCE. More hemihydrate gypsum will consume more water when contacted with water to produce dihydrate gypsum, then fluidity of cement mortar loses fast.In addition to cement, the concrete raw materials, including fly ash, mineral powder, silver stone and clay, remarkably affect the application performance of PCE. Entraining fly ash and mineral powder with high quality can increase the initial fluidity of cement mortar and the fluidity retention capacity.Quality of raw materials relates to quality of concrete. The mud content has a big effect on the performance of PCE, especially for Bentonite. The adsorption capacity of PCE of Bentonite is 50 times than that of cement, and Bentonite has a larger effect on application performance of PCE. On the same condition, effects of different water reducers on clay are different. This shows us that the effect of clay can be improved by changing the structure of the polymer to some extent. The adsorption capacity of PCE of silver stone is as much as that of cement, which showed that overhigh silver stone content affects concrete workability, however, proper silver stone can improve the compactness of concrete.