The Comparison Of Carbonization Resistance Of Common Cement Used In China And France

Steel corrosion has been one of the biggest problems around the reinforced concrete building structure safety,the rebar in reinforced concrete with a layer of passivation film can prevent corrosion,but wrapped reinforced concrete carbonation if lost after alkaline,will cause the steel surface passivation membrane damage,so that the steel corrosion.Steel corrosion is mainly due to concrete carbonation,chloride induced steel depassivation and acidic medium caused,and whether the concrete carbonation key to chloride ions and acidic medium into,so research on carbonation of concrete is very important.In order to study the reason of concrete carbonation,cement is the most easily formed component of concrete,so it is the key to solve the problem that the carbonation of cement block is the key to solve the problem.This paper studies the anti carbonation properties of Chinese and France cement,the purpose is to understand the influence on the durability of reinforced concrete for construction engineering construction of cement,and the effects of water cement ratio,CO₂ concentration,with or without water proofing agent,pretreatment（carbonization test before）and effect of cement ingredients on the carbonation of cement test block.Draw the following conclusions:1)Experiments were carried out on the 0.45,0.50 and 0.55 groups of water cement ratio of the test results were compared,the experimental results show that with the increase of the water cement ratio,the degree of carbonation increased.2)The experimental results show that the concentration of CO₂ is 10% and 20%.The results show that the higher the concentration of CO₂,the faster the carbonization.3)The selection of a group of test block adding surface organosilicon waterproofing agent and a group of specimens without adding waterproof agent to compare the carbonation degree,found that adding waterproof agent 7 days before the carbonation rate is significantly less than the specimens without waterproof agent,and carbonationdepth lower the total..4)The pretreatment process is that a group of test blocks is formed and dried in a drying oven with a temperature of 60℃,and another group of test blocks is dried in a drying chamber of a temperature of 45℃ after being formed for a period of 14 days,so as to accelerate the formation of 48 h.The results show that the former is slower than the latter.5)China and France commonly used cement composition is different,China’s commonly used cement carbonation speed than the common cement carbonization speed.Because of the cement used in France,the CaO content of the composition is relatively more,more alkaline substances after hydration,the unit volume consumption of more CO₂,so the carbonation rate is slower.