Study On Admixture Of Dry-Mixed Mortar

On the basis of reviewing and analyzing the research on the status in quo of the modifying mechanics of dry-mixed mortar admixture at home, the author held that the admixture with such as cellulose ether, adsorptive phyllosilicate and pulverized lime that are mostly used at home all exist limitations and deficiencies in the performance to a certainty and have not much economy benefit. To solve these problems and promote the application of dry-mixed mortar in our country, the author adopted a method of composite admixture to modify the existing shortcomings of the present dry-mixed mortar admixture.The composition of the admixture were primary elected though exploratory experiments on the likely existing inorganic and organic composition. Metakaolin, micro slag power and milled rock power were selected as the likely inorganic compositions and cellulose ether, high efficiency water reducing agent were selected as the likely organic compositions though a series of experiments.The proper organic and inorganic compositions were selected to synthesis the dry-mixed mortar admixture after series of exploratory experiments. According to the performance requirement in DJ/TJ08-502A-2000 and DBJ 15-XX-2004, the influences caused by the compositions of the dry-mixed mortar admixture were researched systematically. There kinds of composite dry-mixed mortar admixture for plastering and two for masonry were gained though orthogonal experiment and the optimally-amount filled experiment. The admixture of the highest performance and lowest cost for both plastering and masonry was gained though analyzing and coMParing the synthesis performance and cost of several kinds that had been researched.Aiming at the problems that the proper mixing quantity of fly ash and air content in dry-mixed mortar with cellulose ether admixture, the author has proceeded systematical research on their influences on all aspects of the construct mortar. Through analyzing the results of the experimentations contrastively, the proper ranges for the mixing quantity of fly ash and air content in dry-mixed mortar are put forward.In order to extend the range of selected materials and fill up the blank of application at home, the author has made profound researches about the influences on the performance of dry-mixed mortar caused by palygorskite which is a sort of endemic resource yielded in Jiangsu . The palygorskite's mechanism of action has also been researched. It was find that palygorskite could improve the water retention of dry-mixed mortar to a certainty. The aperture frame of the mortar could also be improved notably with only a little X-type palygorskite being added. Consequently the intension and impervious performances of the mortar are greatly improved. Dry-mixed masonry mortar admixture of good quality can be prepared if palygorskite and milled rock power are composite. Meanwhile it was find that tempered Z-type palygorskite had apparent ash effect, so it can be applied as carrier of the admixture in order to improve the performance of the dry-mixed mortar. Several kinds of admixture were gained though researching the mechanics of modifying the mortar by palygorskite, and no reports have been found at home till now. This finding is not only a notable innovation but also of great economy benefit and society benefit.