Study On Influence Of Calcium Acrylate Solid On The Performance Of Cement

The study on cement modified by acrylate solution proved that, acrylate solution couldoptimize pore structure, improve corrosion resistance of cement stone and could increase thelong-term compressive strength, strengthen the cement matrix. But it was very complex toprepare acrylate solution and it was not convenient for transportation. Aiming at this problem,calcium acrylate solid was made in this paper and the mechanical performance, corrosionresistance and hydrating property of cement modified by calcium acrylate solid werestudied.Calcium acrylate solid that made in the lab was added into cement. After adding watercalcium acrylate solid could polymerize under the action of initiator, accelerant andcross-linking agent as cement hydrating.In this paper, the influence of calcium acrylate solid and auxiliaries on mechanicalperformance and corrosion resistance to sulfate studied by orthogonal experiment; Afterconfirming the optimal experimental formula, the influence of calcium acrylate solid onmechanical performance of mortar and resistance to chloride penetration of concrete werestudied; Polymerization of calcium acrylate in simulative cement internal environment wasstudied by FTIR in this paper. Then the influence of calcium acrylate solid on hydrationprocess and hydration products studied by hydration heat analysis, DSC-TG, XRD and SEM,respectively.Study on the effect of calcium acrylate solid on the strength and sulfate resistance ofcement by orthogonal experiment indicated that early-age strength decreased by addingcalcium acrylate and all auxiliaries, whereas, latter strength increased obviously. The optimumproportion of calcium acrylate was1wt%in proportion to cement, cross-linking agent, initiatorand accelerator were15%,3%and1.5%in proportion to calcium acrylate solid, respectively.This result coincided G3group in orthogonal experiment. Corrosion resistance coefficient ofG3group is not the greatest but it’s better than the blank sample, it increased by11.6%. Bystudying resistance to chloride ion penetration performance of cement modified by calciumacrylate solid，it was found that the calcium acrylate solid could obviously improve theresistance to chloride ion permeability of concrete. The decline of the chloride ion permeabilityof the28d and56d and90d were32.86%,54.27%and38.49%, respectively when calcium acrylate solid content was1.5%, the dosage of cross-linking agent was15%, the dosage ofinitiator and accelerator were1%.This paper studied the influence of calcium acrylate solid on the hydration performance indifferent aspects by different methods. It was found that, calcium affected formation of AFt atthe early age, restrain the transformation of AFt into AFm. There is less Ca(OH)2in cementmodified by calcium acrylate solid. The hydration degree of28d displayed that, calciumacrylate promote hydration of cement at later period. The morphology of hydration productswas affected, there were many network C-S-H(ΙΙ) in modified cement.According to the study on performance of cement modified by calcium acrylate solidcombining mineral admixtures, it was found that, the combination was not so good forimproving compressive strength of cement. The combination of calcium acrylate and fly-ashmake the resistance coefficient greater than blank sample and sample with calcium acrylatesolid only. When dosage of calcium acrylate solid and slag were1.5%and10%, respectively,the resistance coefficient increased obviously and was greater than sample with calciumacrylate solid only.