HPMC manufacturer-Hydroxypropyl methylcellulose can improve the dispersibility of cement mortar
Anti-dispersion is an important technical index to measure the quality of anti-dispersant. Hydroxypropyl methylcellulose is a water-soluble polymer compound, also known as water-soluble resin or water-soluble polymer, it is a hydrophilic polymer material that increases the consistency of the mixture by increasing the viscosity of the mixed water . Water can dissolve to form solutions or dispersions. Experiments show that when the dosage of naphthalene-based superplasticizer increases, adding superplasticizer will reduce the dispersibility of fresh cement mortar. This is because the naphthalene-based superplasticizer is a surfactant. When the water reducing agent is added to the mortar, the water reducing agent is oriented on the surface of the cement particles, so that the surfaces of the cement particles have the same electric charge, and the electric repulsion leads to the formation of the cement particles. The flocculation structure is disassembled and the moisture in the structure is released, causing the loss of part of the cement. At the same time, it was found that the dispersion resistance of fresh cement mortar became better and better with the increase of HPMC content.
1. The addition of HPMC has a significant retarding effect on the mortar mixture. With the increase of HPMC content, the setting time of mortar is prolonged. Under the same amount of HPMC, underwater molding mortar is better than air. Molding takes longer to set. Special signage is good for underwater concrete pumping.
2. Fresh cement mortar mixed with hydroxypropyl methylcellulose has good cohesive properties and hardly bleeds.
3. The amount of HPMC and the amount of water used in mortar showed a significant increase after the first decrease.
4. The addition of water reducing agent improves the problem of increasing the water demand of the mortar. However, the amount of mortar must be reasonably controlled. Otherwise, the underwater dispersion resistance of fresh cement mortar may be reduced.
5. There is no significant difference in the structure of the cement slurry samples mixed with HPMC and blank samples. The structure and density of grout samples placed in water and poured into the air did not differ much. The 28d underwater molding is slightly brittle. The main reason is that the addition of HPMC greatly reduces the loss and dispersion of cement in the cast cement, but also reduces the density of the cement stone. In the case of ensuring underwater non-dispersive effects in the project, the number of HPMCs can be minimized.
6. Using HPMC underwater non-dispersible concrete admixture, controlling the admixture is beneficial to the strength. Experiments show that the strength ratio of concrete formed in water to that of molded objects in air is 84.8%, and the effect is remarkable.