Advantages of mortar additive hydroxypropyl methylcellulose

When it comes to mortar admixtures, we should first understand the effect of ordinary mortar on its performance. As the basis for the selection of mortar admixtures, hydroxypropyl methylcellulose is one of the best.

The commercialization of mortar is mainly the market reform made by the state from the two aspects of environmental protection and quality control. Mortar is generally mixed with dry powder, which causes a lot of dust pollution. The other is the guarantee of construction quality. The original ordinary mortar is mostly mixed mortar, in addition to cement and sand, the larger amount is lime paste. Lime paste has three main functions: water retention, workability, providing mortar strength and reducing shrinkage stress caused by cement hardening through setting and expansion. Therefore, many digesters will be seen at the construction site, and limestone production consumes high energy and causes serious pollution, so the country gradually banned the application of lime paste. Therefore, now the admixture of commercial mortar is to replace the role of lime paste, so the selection criteria of mortar additives are water retention, improvement of construction and anisotropy, and reduction of cement dry shrinkage stress. In recent years, hydroxypropyl methylcellulose has played a great role in the building materials industry, and many new types of mortar have been developed. And hydroxypropyl methylcellulose has no harm to the environment, it is also an environmental friendly mortar admixture.

At present, the main additives of mortar are as follows:

1. Thickening powder thickening powder is a mortar modifier developed by Shanghai Institute of construction science. Its performance in all aspects is OK. The proportion of thickening powder with relatively low transportation cost and unit price will be very large, which makes its promotion across the country meet a bottleneck. At present, the thickened powder all over the country is not the real thickened powder.

2. Mortar King mortar king is actually a kind of air entraining agent mainly composed of sodium dodecyl sulfonate, which only has air entraining function in mortar. It is far from replacing lime paste in real sense, and it is harmful to engineering quality. Air entrainment will inevitably lead to the decrease of mortar strength, and the absence of water retention also makes the appearance of hollow Valley cracking tend to be common.

3. Bentonite no matter what kind of bentonite, its performance of water retention and improvement of workability are not bad, but its fatal weakness is that the dry shrinkage is relatively large, which is the same direction deformation for cement dry shrinkage, strengthening each other, and it is easier to crack.

4. Hydroxypropyl methyl cellulose hydroxypropyl methyl fiber has absolute advantages in terms of water retention performance and construction improvement, and can effectively reduce the shrinkage and cracking of mortar, and improve the yield of mortar. Hydroxypropyl methylcellulose has the function of air entrainment. When adding hydroxypropyl methylcellulose, the dosage, viscosity and air entrainment should be considered.

Hydroxypropyl methylcellulose has many advantages, and also has a great development space in the building materials market.