Influence And Research On The Properties Of Dry-Mixed Mortar

Dry-mixed mortar is widely used for its properties of excellent quality, convenient construction, multifunction in effect Europe, Japan, USA and other counties. Thickening power is a new type of admixture for fresh mortar, it can make the thickening and water retention together. According to the mechanism of cement hydration, thickening power includes the inorganic material,the organic material , thickening power is a kind of non-lime and non-airentraining water retention materials. The ratio of water retention of thickening power is 99.1%. It is safe,asepsis and non-radio activity, through physics function to make the mortar thickening and water retention.In this article, the influence of the component of thickening power on the rheologic behavior of the cement paste and water-retentive was studied. A incorporation enable viscosity and yield value increased and then decreased, and 2% in volume reaches its maximum value; B incorporation enable viscosity and yield value increased content over 0.3% viscosity can not work; C incorporation enable viscosity and yield value of the 9% reached maximum. After that the influences of the components of thickening power on water-retentive,consistency and the ratio of water retention of mortar was studied, then chose three group of base components of thickening power and fixed their dosaged and studied the ratio of water retention of mortar to chose the best. The influence of the component of thickening power on the mechanical performance ( the compressive strength, the flexural strength, the ratio of flexural strength) was studied ,A makes compressive strength down,flexural strength up, pack up the ratio of flexural strength; B makes the compressive strength and flexural strength decrease, but the ratio of flexural strength increases; C makes the compressive strength and flexural strength decline ,the ratio of flexural strength increases. At last, it studied the effects of thickening power on durability, such as frost resistance and shrinkage, A makes shrinkage decline and improves the frost resistance; B increases the frost resistance; C makes shrinkage increase, decrease the frost resistance.The results show that Thickening power has good effect on both fresh and hardened mortar. Thickening power enhances water retention of fresh mortar significantly , increases the shrinkage of hardened mortar , improves the ratio of flexural strength to compressive strength of hardened mortar.