The role of hydroxypropyl methyl cellulose in dry mortar

Usually all dry mortar products, hydroxypropyl methyl cellulose without exception are required to be added. Its main function is to improve the water retention capacity of mortar, improve the fluidity and construction performance, improve the initial strength of cement mortar, to avoid cracking, especially in the high water absorption base and high temperature construction performance is more obvious.

Under the premise of adding a certain amount of hydroxypropyl methylcellulose in dispersed emulsion powder, the influence of hydroxypropyl methylcellulose on the bending, compressive and tensile bond strength of cement mortar; The effect of HPMC on the porosity and pore size distribution of cement mortar was studied by mercury injection method.

The results show that the tensile bond strength of cement mortar with cellulose ether is improved. After adding methyl cellulose ether, the bending strength and compressive strength of cement mortar are greatly reduced. The greater the use, the lower its strength. After adding hydroxypropyl methyl cellulose ether, with the increasing dosage, the bending strength of cement mortar appeared a turning point, increasing first and then decreasing, and the compressive strength gradually decreased. The usage should be controlled at 0.1%-0.3%. After adding HPMC into the cement mortar, the pore distribution area increases, the number of small holes increases, the number of large holes decreases, and the average pore size decreases.