Studies About The Degradation Of Concrete Frost Resistance Subjected To Deicing Salt And Improvement Measures

In winter, The people who lived in north using deicing salt to remove snows, the capability of concrete chloride-frost resistance is becoming more and more importance. Under the environment of chloride solution and freezing-thawing cycles, freezing-thawing damage and chloride influence destroy concrete rapidly. So doing researches of the damage under this situation, effective measures of improvements will be absolutely meaningful to actual projects.This thesis compared with different W/C ratio under the environment of 5% concentration of MgCl2, some conclusions are obtained:(1) The relationship of W/C ratio with chloride-frost resistance,low W/C ratio indicate higher frost resistance capability;(2) Different coarse aggregate concrete damaged in different way.Through orthogonal exprimental method to figure out how different amount of fly ash, slag, air contained and different type of coarse aggregate works in concrete frost resistance, Some interest conclusion obtained:(1)Fly ash does harm to concrete frost resistance, especially for pebble concrete;(2)10%~30% amount of slag mixed have no obvious influence on concrete frost resistance;(3)Wthin 6% air contained, more air indicate stronger frost resistance, approaching linear relation;(4) Under the same condition, gravel concrete indicate around twice as pebble in frost capability;(5)There’s no complicated interactions between Fly ash, slag, and air-entraining, just a principle of simple superposition on concrete frost resistance;(6) Building the model of concrete damage under 5% MgCl2, based on different type of aggregate.Through doing experiment with different type of coating concrete, It is obvious that the epoxy coating system can effectively protect concrete in the chloride-frost environment, just polyurethane top coating have weak protection, organosilicon coating does not work apparently.