The Concrete Structure Of Sulfate Attack Of Diseases Of Cementitious Repair Materials Research

The structures which serve in sulfate envornment always present serious damaged characteristics with cracks and spallings. How to effectivelly repair the strctures attacked by sulfate has become one of the most important issues all over the world. In view of the representative sulfate attacked concrete structures as well as domestic and foreign technical status, cementitious repairing materials which is suitable for recovering the sulfate attacked concrete structures was studied systematically in this article. A cementitious repairing mortar that can effectivelly resist sulfate attack was successfully developed.In this article, the effect of cementitious repairing mortar with different cement, mineral admixtures, polymers and other raw materials on workability, bond strength and volume deformation properties was studied by macro test. Then, weight changes, compressive strength losses and length changes ratio was used to evaluate the properties of resisting sulfate attack of cementitious repairing mortar with different components, which was based on the laboratory simulation experiment by fully immersion, partially immersion and wet-dry-cycle methods. Finally a optimal cmponent of the cementitious repairing mortar was obtained. The results of the research shows that:sulphoaluminate cementitious repairing mortars present earlier strength, larger bonding strength, lower dry shrinkage superiority, but its resistance to high concerntrations of sulfate physical or chemiscal attack and changeable temperature in wet-dry-cycle is lower; Adding composite mineral admixtures and good-ductility polymer components, can observably improve the resistance of the cementitious repairing mortar to sulfate chemical attack and physical crystallization destructive attack, which is good in comprehensive technical and economic effect.