Effect Of Organic Silicon On The Durability Of Cement Mortar

Cement based materials in the field of civil construction has a widely applied,has high compressive strength,high elastic modulus,but under some special conditions,such as low temperature freezing and thawing,high pH,high seepage pressure,cement based materials are vulnerable to damage,durability is difficult to meet the requirements of the construction project,Compared to the preliminary studies show that the coated silicone polymer cement mortar(SPM,silicone polymer cement mortar)and ordinary cement mortar(M,ordinary cement mortar),with smaller elastic modulus,excellent anti permeability performance,anti acid,anti erosion,anti chemical corrosion characteristics;but few studies for mixed with silicon cement mortar,this paper mainly through the silicon doped to ordinary cement mortar to study the effects of organosilicon to cement mortar durability(including frost resistance,anti permeability,crack resistance,dry shrinkage performance and anti carbonation and acid alkali corrosion resistance).Through the freezing experiment,obtained silicone polymer cement mortar(SPM)and ordinary cement mortar(M)in the same freeze-thaw cycle of the quality loss rate and strength loss rate,when the content is not greater than 3%,with the increase of freeze-thaw cycles,the mass loss of SPM rate is less than that of M,when adding the amount of up to 5%,the weight loss of the SPM with KH-550 and the rate of KH-570 to M,in the freeze-thaw cycle number reaches 200,M and SPM mass loss rate of no more than 5%,in line with the cold condition of the cement mortar freeze-thaw requirements;in the process of freezing and thawing cycles,the strength loss of SPM the rate is less than that of M,in the freeze-thaw cycle number more than 100,the strength loss of M and SPM increased the trend is more obvious;in the freeze-thaw cycle number reaches 175,the strength loss rate of M reached nearly 25%,the strength loss rate of SPM was below 25%;Through the anti acid and alkali corrosion experiment,soaking in acid solution in SPM compressive corrosion coefficient is larger than the corrosion resistance coefficient of M,with the addition of organosilicon amount of SPM increased corrosion resistance coefficient increased gradually;soaking in alkali solution in the loss of compressive strength of SPM and M rate was greater than 1,immersion in alkaline environment on the compressive strength of cement mortar with enhancement.Immersion in the acid solution in cement mortar anti corrosion resistance coefficient with the adding amount of organic silicon increases,indicating that together with the addition of silicone not only improves the corrosion resistance of cement mortar and with increase of dosage,this enhancement effect is more obvious.The corrosion resistance coefficient of cement mortar immersed in alkali solution was not obvious with the increase of the amount of organic silicon,but the coefficient was more than 1.The corrosion resistance of SPM2 in cement mortar with three kinds of organic silicon SPM1,SPM2 and SPM3 was respectively the best,and the corrosion resistance of SPM3 was the worst.The shrinkage rate of SPM was smaller than that of M by shrinkage test,and the shrinkage rate of SPM gradually decreased with the increase of the content of organic silicon;By cracking test,SPM unit crack area compared with the M to be small,indicating that the siloxane add has a certain effect of anti crack of cement mortar;Portland cement mortar in crack test crack width than silicone polymer cement mortar width to and cracking unit area to;adding organosilicon SPM1 and SPM2,SPM3 cement mortar unit crack area with the increase of dosage of silicone gradually become smaller,content is 5% cement mortar cracking area of the unit reached the minimum value in the.The crack resistance of SPM2 in cement mortar with three kinds of organic silicon is the best,which shows that the addition of organic silicon plays a role in inhibiting the crack.And in the case of the crack width is almost the same,the addition of silicone cement mortar cracks compared with no silicone cement mortar produced cracks have better anti permeability effect;From permeability experiment,silicone polymer cement mortar has better anti permeability performance than normal cement mortar,with the increase of organosilicon amount and anti permeability role gradually increased,and SPM2 has the best anti permeability of Cement mortar with three kinds of organic silicon silicone,It notes that the proper amount of adding organosilicon polymer cement mortar can significantly increased the role of anti permeability;Compared with the carbonization depth of SPM and M,the carbonation depth of SPM is much shallower than that of M by carbonation test.It is known that the addition of silicon can greatly reduce the carbonization rate of mortar.