双膨胀水泥混凝土自生体积变形的试验研究

通过改变低热微膨胀水泥中MgO的掺量和掺入方式、改变水泥组成、调整膨胀源组分等方法制备了不同膨胀性质的双膨胀水泥,对低热微膨胀水泥和这几种双膨胀水泥在不同试验温度、不同养护制度下的混凝土自生体积变形进行全面试验研究,阐明了温度、湿度变化及水泥质量组成对混凝土自生体积变形的影响。试验结果表明:在低热微膨胀水泥中掺入MgO能减少其回缩,增大膨胀量,稳定膨胀变形;G13型水泥膨胀量最大;优化复合型水泥组分掺MgO可能获得理想的膨胀过程曲线。

Experimental study on autogenous volume deformation of double-swelling cement concrete

By changing the amount of MgO mixed into the low-heat micro-exponsive cement, the mixing mode, the composition of cement, and the components of expansive sources, several kinds of double-swelling cement with different swelling properties were produced. An experimental study was performed on autogenous volume deformation of the low-heat micro-expansive cement and these kinds of double-swelling cement at different temperatures and curing conditions, and the influences of variations of temperature and humidity and the composition of cement on the autogenous volume deformation of the concretes were expounded. Test results show that the mixing of MgO into the low-heat micro-expansive cement can effectively decrease the back-shrinkage, increase the volume expansion and stabilize the expansion-induced deformation, and that the expansion of cement G13 is the greatest. As a result, the optimization of the components of cement with MgO mixed is helpful to obtain satisfactory expansion deformation curve.