| 摘要: |
| 利用微量热仪法研究了细度对水泥水化热及水化放热速率的影响规律，利用非接触式激光位移传感器和集中约束平板法测试了不同细度水泥混凝土的早期收缩变形与开裂.结果显示：随着细度的增加，水泥水化热与水化放热速率增加，水化放热峰值时间明显提前；水泥比表面积提高，混凝土早期收缩增大，早期单位裂缝面积增加，但混凝土水分蒸发速率与最大裂缝宽度减小.建议混凝土工程中应限制水泥过细. |
| 关键词: 水泥细度 水泥水化 早期收缩 早期开裂 |
| DOI：10.3969/j.issn.1007 9629.2013.05.020 |
| 分类号: |
| 基金项目:西部交通建设科技项目（2009318000033） |
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| Influence of Cement Fineness on Hydration of Cement andEarly Age Cracking of Concrete |
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WANG Chong1, ZHANG Hong bo1, YANG Chang hui1, QIAN Jue shi1, ZHONG Ming quan2, LI Hao ju1
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1.College of Materials Science and Engineering, Chongqing University, Chongqing 400045, China;2.Chongqing Institute of Communications Planning Surveying and Designing, Chongqing 401121, China
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| Abstract: |
| Cement fineness, cement hydration and concrete cracking are closely related. Influence of cement fineness on hydration heat and hydration rate of cement was investigated using microcalorimetry. Early age shrinkage and early age cracking of concrete prepared with different fineness cement were determined using non contact laser displacement sensor and centralized constrained plate method, respectively. The test results show that with increase of cement fineness, hydration heat and hydration rate are increased, and time to peak of hydration is reduced. Increasing the specific surface area of cement causes higher shrinkage and unit crack area at early age, but reduces rate of water evaporation and maximum crack width of concrete. According to the research results, it is suggested to set an upper limit value of the cement fineness in concrete engineering. |
| Key words: cement fineness hydration of cement early age shrinkage early age cracking |
