膨胀剂对自密实钢管核心混凝土变形的影响

发布时间：2018-07-27 19:41

【摘要】：为满足工程中钢管混凝土施工技术和经济效益的需要,将绿色高性能的自密实混凝土取代普通混凝土应用到钢管混凝土中。钢管中核心混凝土的收缩关系到整体的受力性能,为研究钢管混凝土中核心混凝土的收缩特性,制作了8个圆钢管自密实混凝土试件来进行收缩试验,探讨分析了膨胀剂掺量对试件收缩的影响。研究结果表明:钢管自密实混凝土中核心混凝土的收缩变形要远小于普通混凝土的收缩变形;掺入膨胀剂可以减小钢管混凝土的早期纵横向变形;适量掺入膨胀剂可以减小核心混凝土的收缩变形和钢管壁的环向变形,但过量掺入膨胀剂会增大钢管壁的环向膨胀率;对于钢管自密实混凝土,膨胀剂的最佳掺量在5%~10%之间,而膨胀剂的掺入量与收缩之间的关系十分敏感,建议实际应用中最佳掺量尽量精确到1%。
[Abstract]:In order to meet the need of construction technology and economic benefit of concrete-filled steel tube (CFST) in engineering, the self-compacting concrete with green and high performance is applied to the concrete filled steel tube (CFST) instead of ordinary concrete. The shrinkage of the core concrete in the steel tube is related to the mechanical properties of the whole. In order to study the shrinkage characteristics of the core concrete in the concrete filled steel tube, eight self-compacting concrete specimens of circular steel tube are made to carry out the shrinkage test. The effect of the amount of expansion agent on the shrinkage of the specimen was discussed and analyzed. The results show that the shrinkage deformation of the core concrete in the self-compacting concrete filled steel tube is much smaller than that of the ordinary concrete, and the early longitudinal and transverse deformation of the concrete filled with steel tube can be reduced by the addition of expansion agent. The shrinkage deformation of the core concrete and the circumferential deformation of the steel tube wall can be reduced by adding an appropriate amount of expansive agent, but the circumferential expansion rate of the steel tube wall can be increased by excessive addition of the expansive agent, and for the self-compacting concrete of the steel tube, the optimum amount of the expansive agent is between 510% and 10%. However, the relationship between the dosage of dilatant and the shrinkage is very sensitive. It is suggested that the best dosage in practical application should be as accurate as possible.
【作者单位】：南京工业大学土木工程学院;江苏省绿色建筑工程技术研究中心;扬州科技学院;
【基金】：国家自然科学基金项目(51178218)
【分类号】：TU528

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