Mechanism Research Of Clay On The Adsorption Performance Of Ploycarboxylate Superplasticizer

Have appeared mud in the aggregate absorbing the ploycarboxylatesuperplasticizer with the application of ploycarboxylate superplasticizer in the actualengineering, which lower concrete performance seriously, main showing less liquidityconcrete, slump loss too fast, strength and durability reduce obviously.This study choose montmorillonite, illite and kaolinite three kinds of clay mineralsand through the experiment analyzed the effect on ploycarboxylate superplasticizer ofdifferent clay minerals, research shows montmorillonite has the greatest effect in thedispersivity of ploycarboxylate superplasticizer, the flowability is zero after1h whenclay content is more than4%; montmorillonite has the strongest adsorption capacity ofploycarboxylate superplasticizers, which adsorption properties is more than2.5timesthan the cement particle adsorption, the adsorption of kaolinite is weakest. Clayadsorption increases with concentration of ploycarboxylate superplasticizer, and getsaturated adsorption finally; Simulating the adsorption model for ploycarboxylatesuperplasticizer through relevant experimental data, the results show that the clayadsorption of ploycarboxylate superplasticizer in conformity with the Langmuiradsorption model, the Freundlich adsorption model and Lagergren adsorption model.Saturated adsorption capacity of montmorillonite, illite and kaolinite are calculated byLangmuir isotherm adsorption model for ploycarboxylate superplasticizers, thesaturated adsorption capacity of montmorillonite is12.76mg/g, the saturated adsorptioncapacity of illite is11.11mg/g, the saturated adsorption capacity of kaolinite is7.69mg/g. Simulating the adsorption strength and the adsorption ability by the Freundlichadsorption model of clay on ploycarboxylate superplasticizer, and result shows theadsorption intensity decreased with the increase of temperature, but the adsorptioncapacity is gradually increasing with the increase of temperature. Simulating theadsorption rate by the Lagergren adsorption model of clay on ploycarboxylatesuperplasticizers, and result shows the adsorption rate is reduced as the temperature increases, which is not conducive to the adsorption of clay on ploycarboxylatesuperplasticizers.Studied Adsorption form of clay on ploycarboxylate superplasticizers by IR andXRD spectra microscopic test means, research shows that ploycarboxylatesuperplasticizers molecules adsorbed by clay get into clay structure inside; Puttingforward a measures of mud resistant agent to improve liquidity on ploycarboxylatesuperplasticizers of clay in Wuhan area by using the adsorption mechanism of clay.