后续养护方式缓解蒸汽养护混凝土性能缺陷的试验研究

Test Study on Alleviating Performance Defects of Steam Cured Concrete Through Subsequent Maintenance

为研究后续养护缓解蒸汽养护造成的永久损伤,以蒸汽养护混凝土为例,设计了4种后续养护方式,测试不同后续养护方法对混凝土抗压强度、吸附系数、氯离子扩散系数和透气性等性能参数的影响。结果表明,后续养护方式对混凝土试件28 d强度增长贡献率由大到小为标准养护、饱和石灰水养护、水养护和空气养护;混凝土毛细吸附性、氯离子扩散性和透气性曲线均呈近似“L”形,即随养护时间增加而降低,且前期(龄期3 d前)下降显著,后期趋于平缓;蒸汽养护混凝土预制构件均应及时进行适当加湿养护,但不建议长时间浸泡于水环境中养护。

To study the alleviation of permanent damage caused by steam curing in subsequent curing,four subsequent curing methods were designed for steam cured concrete.The effects of different subsequent curing methods on the compressive strength,adsorption coefficient,chloride ion diffusion coefficient,and permeability of concrete were tested.The results show that the contribution rate of subsequent curing methods to the 28 d strength growth of concrete specimens from large to small is listed as:standard curing,saturated lime water curing,water curing,and air curing;The capillary adsorption,chloride ion diffusion,and permeability curves of concrete all show an approximate"L"shape,which decreases with increasing curing time,and the decrease is significant in the early stage(before the age of 3 days),and tends to be gentle in the later stage;Steam cured precast concrete components should be promptly and appropriately humidified for curing,but it is not recommended to soak them in water for a long time for curing.