hpmc in gypsum plaster based mortar

With the increase of the content of hydroxypropyl methylcellulose, the water retention rate of sprayed gypsum mortar gradually increased. When the content of hydroxypropyl methylcellulose ether was 0.20%, the water retention rate of the mortar reached 90%. Considering the actual use conditions of sprayed gypsum mortar, the tensile bond strength of sprayed gypsum mortar with concrete slabs and aerated concrete blocks was tested respectively. When the content of hydroxypropyl methyl cellulose ether reaches more than 0.15%, the tensile bond strength with the concrete slab is higher, and the change of the tensile bond strength is small with the increase of the content of cellulose ether; Concrete blocks have high water absorption, and the content of cellulose ether needs to reach more than 0.20% in order to achieve the effect that the tensile bond strength changes less with the increase of the content of cellulose ether. Considering that with the increase of the content of cellulose ether, the water consumption of mortar increases, and the flexural and compressive strength decreases, so the content of cellulose ether is determined to be 0.20%.