Ordinary concrete is silicate. In the case of air or water vapor, silicate ions will undergo a hydrolysis reaction, and the generated hydroxyl groups and metal ions will combine to form hydroxides with less solubility (alkaline chemical properties). When the temperature rises, after the water vapor evaporates, the hydroxide precipitates out of the wall. As the water evaporates, the hydroxide precipitates on the surface of the concrete cement. As time goes by, the original decorative paint or paint is lifted , It is no longer attached to the wall, it whitens, peels, and falls off. This process is called “efflorescence.” Therefore, it is not efflorescence caused by hydroxypropyl methylcellulose.
In the collected information, there is such a phenomenon: a client spraying concrete on a concrete wall will cause efflorescence, but no efflorescence in the brick wall, indicating that the concrete wall is used for cement silicate (strong alkaline salt) Too much content. Weathering caused by water jets causes weathering. No silicate on the brick wall will not happen to the base. Therefore, the appearance of efflorescence and spraying is not important.
First, the basement concrete cement Portland content decreased.
Second, use the anti-alkali back coating agent and pour the solution into the quartz capillary plug to prevent Ca(OH)2, salt and other substances in the water from intruding to cut off the efflorescence.
The third is to prevent water intrusion and do not use large amounts of water before construction.
It can be used in the efflorescence cleaning agent on the market. The cleaning agent is a colorless translucent liquid made of non-ionic surfactant and solvent. It has a certain effect on the efflorescence cleaning of some natural stone surfaces. But before use, be sure to make a sample test block to test the effect and decide whether to use it.