Influence of Metakaolin on Performances of Polymer Modified PC-CSA-FGD Anti-corrosion Mortar
XU Huijie
ZHANG Guofang
LUO Shun
ZHANG Zhenlei
Abstract：The effects of metakaolin on the setting time,mechanical properties,resistance to sulfate and chloride attack,hydration products,and pore structure of polymer modified anti-corrosion mortar(anti-corrosion mortar)with Portland cement-calcium sulphoaluminate cement-flue gas desulfurization gypsum(PC-CSA-FGD)ternary binder systems were investigated.The results show that with its content increase,metakaolin can reduce the setting time of anti-corrosion mortar,with the maximum reduction of the initial and final setting time to be 28 and 47 minutes at 30%of metakaolin content.At low content,metakaolin can improve the mechanical properties including flexural strength,compressive strength and tensile bond strength,the sulfate resistance and the chloride penetration resistance of the anti-corrosion mortar.At 90 d,the flexural and compressive strengths reach 13.6 MPa and 73.4 MPa respectively,and the chloride diffusion coefficient is only 0.30×10-12 m2/s at 10%of metakaolin content.It is mainly due to that metakaolin can optimize the pore structure,decrease the content of portlandite and ettringite,and increase the content of hydrate calcium silicate and hydrated calcium aluminosilicate gels.Comprehensively,the content of metakaolin in the anti-corrosion mortar should not exceed 20%,with the optimal content to be 10%.
Keywords：anti-corrosion mortarPortland cement-calcium sulphoaluminate cement-flue gas desulfurization gypsum(PC-CSA-FGD)ternary binder systemmetakaolinphysical and mechanical propertysulfate resistancechloride penetration resistance
Publication Date：2025-04-30
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：9( 358-366 )