石灰石粉水泥基材料自干燥与自收缩研究

Research on Autogenous Shrinkage and Self-dessication of Cement-based Material with Ground Limestone

研究了石灰石粉对水泥基材料自收缩性能和自干燥效应的影响,探讨了硬化浆体自干燥效应与自收缩的关系。研究发现:硬化浆体的自收缩随石灰石粉掺量的增加呈现先增加后降低的趋势,石灰石粉掺量为10%时达到最大值。同时发现,当石灰石粉掺量超过15%时,硬化浆体的自收缩开始低于基准组,随着掺量增加,自收缩进一步降低。石灰石粉对硬化浆体自干燥效应的影响规律与石灰石粉对硬化浆体自收缩的影响规律一致。硬化浆体的自干燥体积与自收缩变形具有良好的正相关性,硬化浆体的自干燥效应能够在一定程度上体现硬化浆体的自收缩变形。

Effects of the ground limestone on the autogenous shrinkage and the self-dessication volume of the cement-based materials are studied,and the relationship between the self-dessication effect and the autogenous shrinkage is discussed.The results show that the autogenous shrinkage of the hardened pastes increases at first and decreases later with the ground limestone content increasing,which reaches the maximum when ground limestone is 10%.At the same time,it is found that the autogenous shrinkage of the paste containing more than 15% ground limestone starts to be lower than that of the pure ones,and the increasing ground limestone content leads to the further increase of the autogenous shrinkage.The influence law of the ground limestone on the self-dessication effect is consistent with the influence law of the ground limestone on the autogenous shrinkage of the pastes.It is known that there is a significant positive correlation between the self-dessication volume and the autogenous shrinkage of the pastes through the research of the relationship between the self-dessication effect and the autogenous shrinkage of the samples,therefore,the self-dessication effect can reflect the autogenous shrinkage of the pastes in a certain extent.