Organic-inorganic Compound Admixture For Dry-mix Mortar

With the continuous development of new building material and the improvement of the people’s life quality, modern architecture industry requires more to the performance of dry-mix mortar product, such as high water retention capacity, low ratio of compressive strength to flexural strength and so on. To meet these requirements, many kinds of organic materials such as redispersible emulsion powder, cellulose ethers and so on. but due to the high cost of polymer admixture, the dry-mix mortar could not be promoted further. So there is desperate need of a dry-mix mortar admixture, which could cut the mortar cost down under the premise of keeping the excellent properties of mortar. If this kind of admixture is obtained, the dry-mix mortar will be more competitive in the domestic market.In this paper, based on a large number of documents and lecture, the present situation of the development of the dry-mix mortar and research of water retaining agent were summarized. This study proposed to prepare compound water retaining agent in organic-inorganic substances combination way, and successfully obtained expanded perlite powder-polymer emulsion powder compound admixture and glucose-bentonite compound water retaining agent using expanded perlite powder, a kind of industrial waste, and low grade bentonite as main component. The specific study and collusions are presented as follows.Expanded perlite powder-polymer emulsion powder compound admixture has very good improving function to the performance of dry-mix mortar; the industrialization was carried out on the two production line of enterprise for nearly one year, after that the previous formula was modified and the production process and production equipment corresponding to the formula were also adjusted. After using compound admixture, the raw material cost of polymer insulation dry-mix mortar and anti-crack dry-mix mortar declined 10%and 22%respectively. The glucose-bentonite inhibits the retardation of glucose while maintaining its water retention feature by free glucose molecule adsorption into the interlayer of bentonite. The compound water retaining agent could improve the performance and the cost was just 3/4 of cellulose ethers. Process of preparing glucose-bentonite compound water retaining agent of industrialization is designed as followed:suitable bentonite was added into glucose solution with concentration at 10 mg/L. pH of the mixture was adjusted to 12-13. then the mixture was trapped about 8 h, dried at 105-110℃, finally was grinded to powder.