| Polycarboxylate high performance water reducer (PC) has been always a hot spot inconcrete field because of its advantages, such as high water reducing rate, goodslump-retention， low dosage and programmable molecular structure. Nowadays, ester andether are mainly two types of PC in market. Comparing with ester PC, ether PC has simplesynthesis process and equipment,low cost, short production cycle,and so on. With thedevelopment of modified poly-ether macro-monomer, the comprehensive performance ofether PC has greatly improved,including water reducing, slump-retention and so on. Whichmakes ether PC more competitive in market.In this paper, using modified poly-ether (TPEG), unsaturated carboxylic acid (A3),unsaturated sulfonate (M-K-1) as main raw materials. By radical polymerization, waterreducer was synthesized with persulphate (I-M-2) as initiator. The proportion of raw materialswere determined by the way of orthogonal test. At the same time, the molecular structure ofsynthesized PCs water reducers were characterized by infrared spectrum (IR) and gelpermeation chromatography (GPC), and further studied temperature,dropping speed, holdingtime, pH and other factors to set the best mixing proportion on synthetic process.Through a series of cement paste,mortar and concrete experiment,it indicated thatZZ-PC water reducer had good dispersive and dispersive retentivity of cement paste, goodrheological property and little thixotropy of mortar under low dosage, and that concretewater-reducing ratio was25.02%under dosage of0.20%solid weight,1h slump-retentionration kept95%,and compressive strength ratios at3d,14d,28d were165.5%,169.4%,153.6%.The comprehensive properties of synthesis ether PCs can be improved by compoundtechnology.The test studied that ZZ-PC was compounded with other kinds of water-reducersto improve fluidity and retention of cement mortar,and that compounded with differentretarders to enhance fluidity-retention of cement mortar and retarding effect of cement paste. |
PDF Full Text Request