Effect Of Curing In Organic Gel On Properties Of Cement Mortar

In order to achieve high strength,good workability and high durability,modern concrete often needs to increase the amount of cementing material and reduce the water-cement ratio,which will increase the early shrinkage of concrete.Excessive early shrinkage can cause shrinkage cracks in concrete,affecting their use.The internal maintenance technology provides new methods and ideas for solving the problem of early contraction.On the basis of improving the early shrinkage of concrete,try the following research:(1)A kind of organic hydrogel material(Aquagels)with high water absorption rate was prepared by heating,condensing and drying wheat starch as raw material,which is abbreviated as Aq material.Through experimental research,it was found that the optimal utilization rate of wheat starch raw materials was:gelatinization stirring time was 45 min,and grinding time was 20 min.(2)The effect of Aq material on the early shrinkage of mortar under different dosages and different particle sizes was studied.Through the shrinkage test,it was found that the shrinkage value of the mortar first decreased and then increased with the increase of the amount of the mixture.When the Aq content was 5%,the shrinkage of the mortar was minimized.In the test of self-shrinkage characterized by internal relative humidity,it was found that when the particle size of Aq is small,the internal humidity is higher at the same age as the dosage increases.(3)The effects of different molecular weight and different particle size organogel particles on the strength and durability of mortar were studied.The results of the strength test show that the Aq-doped material reduces the early strength of the mortar.The carbonation test results show that the carbonization depth of the mortar with the particle size of 1.18 mm is smaller than that of the mortar with the particle size of 0.6 mm,indicating that the mortar with 1.18 mm particle size has good carbonation resistance.It can be seen from the sulfate attack test that the Aq material with a particle diameter of 0.6 mm can improve the sulfate attack resistance of the mortar.The mercury intrusion test results show that the Aq material increases the early porosity of the mortar,resulting in a decrease in strength.As the age increases,Aq particles continuously release water,which promotes the further hydration reaction of cement particles and improves the degree of hydration,so that it can have good durability.