| 摘要: |
| 为探明石灰岩机制砂在严寒地区应用的合理性，以相对动弹性模量为评价指标，研究了混凝土强度等级、含气量和石粉含量对石灰岩机制砂混凝土抗冻性能的影响规律，采用吸水率和气泡间距系数分析了石灰岩机制砂混凝土冻融破坏原因. 结果表明：高强石灰岩机制砂混凝土具有高抗冻和破坏突发特征，提高混凝体强度等级或引入适量优质气泡是提高石灰岩机制砂混凝土抗冻性能的有效途径；当C30和C60石灰岩机制砂混凝土含气量分别为6.4%和4.4%时，混凝土的抗冻性能最佳；石灰岩石粉对混凝土性能有正、负双重效应，其含量控制在10.0%以内对混凝土抗冻性能、力学性能和工作性能有利. |
| 关键词: 机制砂 石灰岩 混凝土 抗冻性能 |
| DOI：10.3969/j.issn.1007-9629.2023.05.009 |
| 分类号:TU528.01 |
| 基金项目:国家自然科学基金资助项目（U1934206）；中国铁道科学研究院集团有限公司院基金资助项目（2020YJ049，2021WR002） |
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| Frost Resistance of Limestone Manufactured Sand Concrete |
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WANG Zhen1,2, LI Huajian1,2, HUANG Fali1,2, YI Zhonglai1,2, YANG Zhiqiang1,2
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1.Railway Engineering Research Institute， China Academy of Railway Science Corporation Limited， Beijing 100081， China;2.State Key Laboratory for Track Technology of High-Speed Railway， China Academy of Railway Science Corporation Limited， Beijing 100081， China
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| Abstract: |
| In order to determine the appliability of the utilization of limestone manufactured sand in severe cold area， taking the relative dynamic elastic modulus as the evaluation index， the effects of strength， air content and powder content on the frost resistance of limestone manufactured sand concrete were studied， and the reasons of freeze-thaw failure of manufactured sand concrete were analyzed by water absorption and bubble spacing coefficient. The results show that high strength limestone manufactured sand concrete has the characteristics of high frost resistance and sudden failure. Increasing the strength and introducing appropriate amounts of bubbles are effective ways to improve the frost resistance of limestone manufactured sand concrete. The frost resistance is the best when the air content of C30 and C60 manufactured sand concrete is 6.4% and 4.4%， respectively. The limestone powder in manufactured sand has both positive and negative effects on the performance of concrete. The content of limestone powder in manufactured sand is controlled within 10.0%， which is beneficial to frost resistance， mechanical properties and workability. |
| Key words: manufactured sand limestone concrete frost resistance |
