Study On The Factors Influencing The Tensile Bond Strength Of Dry Mixed Mortar

In recent years,due to national development,technological progress,environmental protection and other factors,the pre-mixing mortar industryhas developed to a new height! However,in the process of quality inspection of dry mixed mortar,we found that the qualifying rate of 14 D tensile bond strength of dry mixed plaster mortar is only 57 %,and some products have quality problems.For this reason,the factors influencing the tensile bond strength of dry mixed mortar were analyzed and studied,and the experimental research was carried out from the aspects of material composition and detection methods of dry cement mortar.Through the research,it was found that:1.When using natural sands for product production,the clay content of sand is mixed at the rate of 0 %,2 %,4 %,6 %,8 %,10 %,12 %,14 %,16 %,18 %,and the tensile bond strength is gradually dissipated.At the time when the clay content reaches 16 % and 18 %,even less than 6 groups of effective data of the tensile bond strength test were found to have failed,This requires mortar enterprises to strictly control the amount of sand mud in production.2.Based on the characteristics of regional production,the test and research of replacing 5 %,10 %,15 %,20 %·,25 %,30 %,35 %,40 % and 45 % of cement with the slag of the power plant were carried out.The dregs of power plant obviously decrease the tensile bond strength of 14 d mortar and 28 d compressive strength.3.The use of additives can significantly improve the performance of mortar by adding hydroxypropyl methylcellulose ether to mortar in the proportions of 0.005 %,0.05 %,0.10 %,0.15 %,0.20 %,0.25 %,0.30 % and 0.35 % respectively.4.Based on the JGJ/T70-2009 Standard for Testing Basic Performance of Building Mortar,the 14 d tensile strength of dry mixing mortar was tested.The data obtained were often the bond strength between the mix mortar and the epoxy resin binder,not the true bond strength of the mix mortar and the base mortar,and the data success rate was low.The test data can reflect the true tensile bond strength of mortar.This paper studies the influencing factors of the tensile bond strength of dry mixed plaster mortar,finds the way for the enterprises to improve the quality of the mortar,and provides reference for the production.