变负温自然养护对混凝土强度发展的影响

INFLUENCE OF VARIED MINUS-TEMPERATURE NATURAL CURING UPON THE STRENGTH ADVANCE OF CONCRETE

冬季混凝土施工均处于变负温而非恒负温环境 ,故研究变负温养护对混凝土强度发展的影响至关重要。选用三种养护条件 :(1)自然变负温养护 ;(2)室温养护 ;(3)恒负温养护。在三种养护条件下 ,采用数据采集系统对混凝土内部、环境等进行系统测试 ,获得了不同养护条件下混凝土内、外部温度曲线及相应温度下不同龄期强度发展规律。由于变温条件增加了水泥石体系中自由能差 ,使水泥粒子和水分子有反应的能量和动力。所以变负温养护比恒负温养护条件使混凝土强度有更大幅度的增加。掺高效防冻剂和矿物混合材 ,有利于混凝土早期结构形成及强度发展。

In fact,concrete engineering in cold region doesn't belong to constant minus-temperature but varied minus-temperature.So it is important to do some research about the strength advance of concrete under varied minus-temperature.We use three kinds of way:(1)natural varied minus-temperature (2)room temperature (3)constant minus-temperature.By using data collect system,we measure the inner and outside temperature of concrete and get the strength advance of concrete under different curing temperature.After a large number of experiment,the strength advance of concrete is discovered greater under varied minus-temperature than under constant minus-temperature.Added high quality antifreezing admixture and other more materials in the early period,structure of concrete is formed and the strength development of concrete is much better.It is so approach to the practical engeering by using varied temperature to measure the preperty of minus-temperature concrete with antifreezing admixture.