Development On The Waterproofand Crack-Resistance Mortar Used For The New Walling Material Masonry

Based upon the cracks, which are exposed in the new walling material masonry because of the traditional mortar, above all, the causes are analyzed. Then the way of solving the problem from the point of view of material is put forward. Namely, Polyer HPMC(hydroxypropyl methyllcellulose), composite mineral powder, and superplasticiser are used to modify the traditional cement mortar. It improves the strength grade and the bond strength of the mortar, and decreases the shrinkage of mortar , and also increases the property of crack-resistance greatly. Therefor, the cracks in the wall and leakage of masonry would be in control. And new walling materials would be used wildly.In this paper, firstly, the variations of flowability and strength of mortar with the addition of HPMC are studied. Sencondly, the influences of the addition of HPMC on the physical properties(including water-cement ratio ^ stratication of mortar ^ the bulk density), the mechanical properties(including the compress strength A the flexural strength,, the ratio of the flexural strength to the compressive strength), and the durability(including the carbonation property, the permeability, the shrinkage property)of mortar are studied. Thirdly, the effects of composite mineral powder on the performances of mortar are studied. Finally, the effects of superplasticiser on the performances of mortar are studied. Thus, the rational rate of the new mortar is concluded. Furthermore, the pratice effect of the new mortar is confirmed through the test of mechanical properties of masonry. In the end of the paper, the effect of cement hydration and the micro-mechanism of HPMC^ the composite mineral powder ^ superplasticiser , wether they are single or not composite, are studied by XRD, SEM, and pore structure analysis.The waterproof and crack-resistance mortar used for the new walling material masonry is developed via lots of studies. For example, when the phymer-cement rate is 0.05%, the cement-sand rate is 1.0 : 3.0, the water-cement rater is 0.54 , the new mortar's bonding strength is 2.29MPa with the traditional mortar. The compressive strength of the new mortar is 28.5MPa. The value of shrinkage of the new mortar is 106 x 10"6m/m less than the traditional mortar. Compared with the traditional mortar, the permeability-resistance of the new mortar is increased 2 grade. And the ratio of flexural strength to compressive strength of the new mortar increase 47.3 %. Therefore, the general performances of the new mortar are increased, especially for the bond strength and the property of waterproof and crack-resistance.