预吸水空心玻璃微珠的内养护作用研究

Internal Curing Effect of Water-Saturated Hollow Glass Microspheres

本文采用预吸水空心玻璃微珠制备内养护砂浆,研究了预吸水空心玻璃微珠的释水特性及减缩效果,探明了内养护水在水泥水化进程中的作用,阐明了预吸水空心玻璃微珠的内养护作用机制。结果表明,空心玻璃微珠表面开孔孔径尺寸为1~20μm。在相对湿度为97.5%的环境中,预吸水空心玻璃微珠的释水百分比大于95%。将预吸水空心玻璃微珠引入内养护水后,随着内养护水胶比增加,内养护砂浆的自收缩逐渐减小。内养护水可以提高水泥浆体内部的相对湿度和水泥的水化程度,显著延长水泥浆体的湿度饱和期,从而减小混凝土/砂浆的早期自收缩。

The internal curing mortar was prepared by water-saturated hollow glass microspheres in this paper.The water release characteristics and shrinkage retardation effects of water-saturated hollow glass microspheres were studied.The role of internal curing water in cement hydration process was investigated,and the internal curing mechanism of water-saturated hollow glass microspheres was illustrated.The results show that the pore size on the surface of hollow glass microspheres is 1~20μm.When the relative humidity is 97.5%,the water release percentage of water-saturated hollow glass microspheres is greater than 95%.When the internal curing water is introduced through water-saturated hollow glass microspheres,autogenous shrinkage of internal curing mortar decreases gradually with the increase of internal curing water-binder ratio.The internal curing water can improve the relative humidity inside cement paste and the hydration degree of cement,and significantly extend the humidity saturation period of cement paste,so as to reduce the early autogenous shrinkage of concrete or mortar.