Study On Synthesization And Action Mechanism Of Aliphatic Hydroxy Sulphonate Condensate Superplasticizer

The requirement for concrete admixture becomes higher and higher with thedevelopment of the high performance concrete and ready-mixed concrete,Thesulfonated acetoned-formaldehyde resins, namely aliphatic hydroxy sulphonatecondensate superplasticizer, is a new high range water-reducing agent arising in the1990s.It is more and more welcomed for its good performance, such as the cheap price,the high water reduction rate and the good compatibility with cement. But up to now thesynthesizing of process and reaction mechanism is still seldom studied. Water-soluble sulfonated acetone-formaldehyde resins were synthesized by usingacetone, formaldehyde,Na2SO3and Na2S2O5 as major materials.The optimum schemewere investigated by orthogonal design and the optimum synthesization conditions weregiven in the paper.The method was proposed to prevent the gelatin. In order to explainthe phenomenon observed the possible reaction is discussed in the paper. By comparing the fluidity of cement paste and the fluidity-loss with other waterreducing agents,we find it has better dispensing property and keeping workability thanUNF-5.By testing setting time it is obtained that it didn't influence the hydratingprocess in the cement paste. By measuring surface tension,adsorptive content and Zeta potential of thesuperplasticizer solution, the action mechanism was studied. The aliphatic hydroxysulphonate condensate didn't reduce surface tension.By measuring its adsorptivecontent,we find that its adsorptive content is higher than UNF-5 and its adorptionfollowed the rule of Langmuir. Measuring of Zeta potential of cement particlesindicated that higher zeta potential leads to better dispersibility for usedsuperplasticizer.Its zeta potential is higher than UNF-5.The electrostatic repulsionmechanism is predominating effect for the aliphatic hydroxy sulphonate condensate.