In water conservancy hydropower, railways, bridges, oceans, ports and other projects, due to unreasonable building design, construction is not standardized, improper maintenance caused by underwater concrete defects, or because of geological causes of water karst passage, cavities and caves . Such underwater defects often have the characteristics of large internal area, complex structure, over-water or high pressure, using underwater undispersed concrete, chemical grouting material or other materials for repair and sealing, or because of insufficient material performance or because of construction equipment and Construction scene restrictions, it is difficult to play a good effect, and the use of conventional cement slurry repair and sealing, cement slurry due to poor consistency, will be washed away by water erosion and dispersion, leading to failure to play the role of closure.
Hydroxypropyl Methyl Cellulose(HPMC) as a cement slurry thickener, the cement slurry is underwater anti-dispersed cement mortar or cement paste, characterized by its use of hydroxypropyl methyl cellulose as an anti-dispersed cement slurry thickener , Wherein hydroxypropyl methyl cellulose is prepared by the etherification method or the step-etherification method.
Simply adding hydroxypropyl methylcellulose as a thickener to the cement slurry is not enough because the thickener can significantly increase the consistency of the cement slurry but there is no guarantee that it will have good fluidity and fluidity, So at the same time polycarboxylate superplasticizer also need to add in the cement slurry.
Adding the thickener hydroxypropyl methyl cellulose underwater anti-dispersion cement slurry underwater cave or cavity sealing of other parts will play a good effect, because the cement slurry has high fluidity, Water dispersibility, high strength and high frost resistance, impermeability, it can effectively fill the underwater cavity defects and small internal cracks, also to ensure that the slurry the compressive strength and antifreeze, impermeability into the water.