Study On Dry-mixed Superfine Sand Mortar For Bonding Ceramic Tiles

In order to overcome the main shortcomings existing in the production, construction, and application of bonding mortar in our country, and improve its workability, adhesive capacity, crack resistant and climate resistant to meet the need of thin-layer construction of ceramic tile bonding greatly, some systemic investigations have been carried out on the preparation mechanism and method of dry-mixed superfine sand mortar for bonding ceramic tiles, action mechanism of various additives, aiming to promote the development of high performance mortar for bonding ceramic tile.MC is the high-efficiency water- retentive agents which will decrease the bleeding ratio and delamination degree of mortar, and improve its cohesion and sagging resistant significantly. The water retentive capacity of mortar is increased as a function of MC iscosity and is not done any more again when MC viscosity exceeds 40000 MPa·s. Generally, the suitable dosage of MC is 0.2-0.3%. Addition of redispersible latex powder is the efficient way to increase the adhesive strength of dry-mixed mortar. Among various polymer adhesive agents, the integrative modification effect of VAE is the best. VAE can increase the workability, adhesive strength, toughness, crack energy and strain of dry-mixed mortar significantly. Generally, the suitable dosage cf VAE is 0.5-1.0%. Both polymer fiber and glass fiber have evident reinforcing effect on cement mortar, in which the reinforcing ability of polypropylene fiber is the best. The addition of polypropylene fiber decreases the shrinkage ratio of mortar and increases its tensile strength, crack energy, and the max strain, i.e. its toughness rises and brittleness falls. Polypropylene fiber reduces the crack width and crack qualities, that is to say the crack resistant of mortar is remarkably improved. Its suitable dosage is 0.8-1.2%. By modification with water- retentive agents and organic bonding admixtures, one dry-mixed superfine sand mortar used as ceramic tile bonding can be prepared with good workability, adhesive capacity and climate resistant. The test results indicate that this mortar has some excellent performances such as good sagging resistant, little slippage amount less than 2mm, sufficient open time and bonding strength over 1 MPa after opening for 10 minutes, which meets the need of thin construction of ceramic tile...