The change of latex powder content has obvious influence on the flexural strength of polymer mortar. When the content of latex powder is 3%, 6% and 10%, the flexural strength of fly ash-metakaolin geopolymer mortar can be increased by 1.8, 1.9 and 2.9 times respectively. The ability of fly ash-metakaolin geopolymer mortar to resist deformation increases with the increase of latex powder content. When the content of latex powder is 3%, 6% and 10%, the flexural toughness of fly ash-metakaolin geopolymer increases by 0.6, 1.5 and 2.2 times, respectively.
Latex powder significantly improves the flexural and bonding tensile strength of cement mortar, thereby improving the flexibility of cement mortar and increasing the bonding tensile strength of the interface area of cement mortar-concrete and cement mortar-EPS board systems.
When the poly-ash ratio is 0.3-0.4, the elongation at break of the polymer-modified cement mortar jumps from less than 0.5% to nearly 20%, so that the material undergoes a transition from rigidity to flexibility, and further increasing the amount of polymer can obtain More excellent flexibility.
Increasing the amount of latex powder in the mortar can improve the flexibility. When the polymer content is about 15%, the flexibility of the mortar changes significantly. When the content is higher than this content, the flexibility of the mortar increases significantly with the increase of the latex powder content.
Through bridging crack ability and transverse deformation tests, it was found that with the increase of latex powder content (from 10% to 16%), the flexibility of mortar gradually increased, and the dynamic bridging crack ability (7d) increased from 0.19mm to 0.67 mm, while the lateral deformation (28d) increased from 2.5mm to 6.3mm. At the same time, it was also found that the increase of latex powder content can slightly increase the anti-seepage pressure of the back surface of the mortar, and can reduce the water absorption of the mortar. With the increase of latex powder content, the long-term water resistance of mortar gradually decreased. When the content of latex powder is adjusted to 10%-16%, the modified cement-based slurry can not only obtain good flexibility, but also have excellent long-term water resistance.
With the increase of the latex powder content, the cohesion and water retention of the mortar are obviously improved, and the working performance is optimized. When the amount of latex powder reaches 2.5%, the working performance of the mortar can fully meet the construction requirements. The amount of latex powder does not need to be too high, which not only makes the EPS insulation mortar too viscous and has low fluidity, which is not conducive to construction, but also increases the cost of mortar.