| 一年龄期内超高泵送SCC力学性能时变研究 |
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| 引用本文： | 周济,陈宗平,唐际宇,陈宇良.一年龄期内超高泵送SCC力学性能时变研究[J].西南交通大学学报,2022,57(6):1175-1183. |
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| 作者姓名： | 周济 陈宗平 唐际宇 陈宇良 |
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| 作者单位： | 1.广西大学土木建筑工程学院，广西 南宁 5300042.南宁学院土木与建筑工程学院，广西 南宁 5302003.中建八局广西分公司，广西 南宁 5300044.广西科技大学土木建筑工程学院，广西 柳州 545006 |
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| 基金项目： | 国家自然科学基金（51578163）；八桂学者专项研究经费项目（[2019]79号）；广西科技基地与人才专项（桂科AD21075031）；中央引导地方科技发展资金项目（桂科ZY21195010）；南宁市科学研究与技术开发计划重大专项（20223024） |
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| 摘 要： | 为揭示施工龄期内超高层建筑泵送自密实混凝土（SCC）轴心抗压强度、弹性模量以及劈裂抗拉强度等力学性能的时变规律，提供超高层建筑施工阶段力学性能分析的基础依据，依托某一超400 m高层建筑泵送SCC制作了120个试件，包括96个圆柱体件和24个立方体试件，并对其进行了不同时间龄期的力学性能测试，获取了超高层建筑泵送SCC的应力-应变曲线，提出了各力学性能指标时变及关系计算公式. 研究结果表明:超高层建筑泵送SCC在免振条件下具有良好的密实性；随着龄期的增长，超高层建筑泵送SCC的峰值应力增大，且其峰值应变显著大于普通混凝土的；早期14 d内为各项性能增长的关键阶段，弹性模量在90 d后趋于稳定，而轴心抗压强度和劈裂抗拉强度在28 d后仍有大幅增长；龄期T ≤ 60 d时，超高层建筑泵送SCC的轴压刚度随龄期增长呈增大趋势，而相对韧性则呈减小趋势，龄期T > 60 d时，二者均变化较小趋于稳定；超高层建筑泵送SCC强度的提高能增快早期性能的发展，且能增大轴压刚度和相对韧性；提出的各力学性能指标时变计算公式能为超高层建筑泵送SCC的力学性能预测与评估提供可靠依据.
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| 关 键 词： | 超400 m高层建筑 自密实混凝土 施工龄期 力学性能 时变规律 |
| 收稿时间： | 2020-11-03 |
Time Variation of Mechanical Properties of Ultra-High Pumped Self-Compacting Concrete Within One Year of Age |
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| ZHOU Ji,CHEN Zongping,TANG Jiyu,CHEN Yuliang.Time Variation of Mechanical Properties of Ultra-High Pumped Self-Compacting Concrete Within One Year of Age[J].Journal of Southwest Jiaotong University,2022,57(6):1175-1183. |
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| Authors: | ZHOU Ji CHEN Zongping TANG Jiyu CHEN Yuliang |
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| Affiliation: | 1.College of Civil Engineering and Architecture, Guangxi University, Nanning 530004, China2.College of Architecture and Civil Engineering, Nanning University, Nanning 530200, China3.China Construction Eighth Engineering Division Co., Guangxi Branch, Nanning 530004, China4.College of Civil Engineering and Architecture, Guangxi University of Science and Technology, Liuzhou 545006, China |
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| Abstract: | In order to reveal the time-varying laws of the axial compressive strength, elastic modulus and splitting tensile strength of the pumped self-compacting concrete (SCC) in super high-rise buildings during the construction period, and to provide a basis for mechanical performance analysis of super high-rise buildings in construction stage, 120 specimens, including 96 cylindrical specimens and 24 cube specimens, were fabricated by pumping the SCC of a high-rise building over 400 m, their mechanical properties were tested at different ages, and the stress-strain curves of the ultra-high pumped SCC were obtained. Based on the tested results, formulas for calculating the time-varying relationship of the mechanical properties were proposed. The results show that the ultra-high pumped SCC has good compactness under vibration-free conditions. With the increase of age, the peak stress of the ultra-high pumped SCC increases, and the peak strain is significantly greater than that of ordinary concrete. The period of early 14 d is the key stage for the growth of various properties; the elastic modulus tends to stabilize after 90 d, while the axial compressive strength and split tensile strength still increase significantly after 28 d. When the age T ≤ 60 d, the axial compressive stiffness of the ultra-high pumped SCC increases with time, while the relative toughness decreases. When T > 60 d, both of them change little and tend to be stable. The improvement of strength of the pumped SCC in super high-rise buildings can accelerate the development of its early performance, and increase the axial compressive stiffness and relative toughness. The proposed calculation formulas of time-varying mechanical properties can provide a reliable basis for prediction and evaluation of mechanical performance of the pumped SCC in super high-rise buildings. |
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