Massive self-compacting concrete pumped in steel tube columns has been used more and more widely in super high-rise buildings and bridge engineering at present. The early-age expansion and shrinkage performance of its core mass concrete is an important index to ensure the stress state of triaxial compression and structural safety. However, no relevant reports have been found. In view of the actual building with the height of 265.15 meters, the early-age expansion and shrinkage tests of the massive self-compacting concrete pumped in full-scale columns with the height of 12.54 m and 12.24 m and diameter of 1.3 m and 1.6 m were carried out by means of strain gauges embedded in concrete-filled steel tubes (CFSTs). The early-age variation regularity of the vertical and horizontal expansion and shrinkage strains for the core concrete with the diameter of steel tube, development time, temperature, the pouring pressure, expansion stress, and so on is given. The calculation model of its early-age deformation strains is presented in this paper, which is in good agreement with the experimental results. It provides the basis of experimental and theoretical analyses for shrinkage compensation of massive self-compacting concrete pumped in steel tube columns.

中文翻译：

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钢管柱中大体积自密实混凝土的早期胀缩模型研究

目前，在钢管柱中泵送的大体积自密实混凝土在超高层建筑和桥梁工程中的应用越来越广泛。核心大体积混凝土的早期膨胀和收缩性能是确保三轴压缩应力状态和结构安全的重要指标。但是，没有找到相关的报告。鉴于实际建筑物的高度为265.15米，在高度分别为12.54 m和12.24 m且直径为1.3 m和1.6的全尺寸柱中泵送的大型自密实混凝土的早期膨胀和收缩试验m是通过嵌入在钢管混凝土（CFST）中的应变仪进行的。给出了芯混凝土的纵横向伸缩应变随钢管直径，发育时间，温度，浇筑压力，膨胀应力等的早期变化规律。提出了其早期变形应变的计算模型，与实验结果吻合良好。它为钢管柱中泵送的大体积自密实混凝土的收缩补偿提供了实验和理论分析的基础。