The Study Of The Influence Of Capillary Crystalline Waterproofing Agent On Concrete On Frost Resistance

Impermeability of concrete have an important influence on its frost resistance.To improve the impermeability we usually coat water repellent,such as infiltration crystalline material over concrete.As for the free water breaking through coating,appropriate protections are yet to be developed.The corporation of capillary crystalline waterproofing agent will largely improve the impermeability of concrete,heightening its frost resistance,enhancing concrete waterproof.This study focused on the effects homemade capillary crystalline waterproofing agent generated on performance and frost resistance of concrete by measuring compressive strength and mass losses rate,testing microstructure characteristics of concrete specimens by XRD and SEM.Homemade have a significant influence on cement's flowability and setting time:as the waterproof agent content increases,the flowability gets low and the initial and final setting time gets prolonged.With water-ash ratio of 0.5,8%of waterproofing agent content will increase initial setting time by 0.5 hour and final setting hour by 5 hours.Compressive strength of cement mortar hardly changes when the agent content is low,say 4%.It declined with a high content,and it declined faster with higher content.While the corporation of barely affects flexural strength.The corporation of capillary crystalline waterproofing agent has great influence on frost resistance of concrete:with proper content the frost resistance can be improved,and the compressive strength and mass losses decrease as the content increases.In this study,the loss rate of compressive and mass get smallest at the content of 8%,while exorbitant content and corporation of fly ash can generate negative effect on frost resistance of concrete.As the compressive strength decreasing by the addition of 0.05%air-entraining agents(8%air content),the corporation of capillary crystalline waterproofing agent(4%or 8%)has insignificant influence on the compressive strength,but improves the frost resistance a great deal.According to X-ray(XRD)and scanning electron microscopy(SEM)studies,capillary crystalline waterproofing agent promotes hydration of cementitious materials by filling in the gap with hydration products,making the concrete structure more compact.While the water-ash ratio makes little impact on hydration products.The proper amount of capillary crystalline waterproofing agent can reduce the volume of ettringite crystals,reducing pore size,refining the pores,compacting structure,improving the frost resistance,while the exorbitant amount can damage frost resistance because it will make bigger pore size and coarse ettringite crystals.At certain amount homemade capillary crystalline waterproofing agent can improve frost resistance of concrete.With adjusting by admixture,the performance of cement mortar can meet the actual application requirements,enhancing durability of concrete.In this study.8%content of capillary crystalline waterproofing agent makes smallest loss of compressive and mass.