摘要
再生骨料混凝土是一种新型绿色建筑材料,具有经济和环保意义。但是由于再生骨料的特性,其混凝土的长期变形(主要是收缩和徐变)较普通混凝土大大增加,这威胁到其服役期内混凝土结构的安全性,因此寻找抑制再生混凝土收缩徐变、改善其长期变形性能的有效方法十分必要。通过研究大量国内外相关文献,系统总结了各种因素(水灰比、配合比、减水剂、矿物掺和料和其他掺和物、骨料品质和取代比例、再生骨料强化手段、基体混凝土强度、再生骨料类型、生产工艺的优化)对再生混凝土长期变形性能的影响规律,探讨了优化再生混凝土长期变形性能的可行途径。
The present paper is to make a review on the research ad- vances of the optimal reduction of the deformation of the recycled con- crete in the long run. As a new kind of green building material, the recycled aggregate in structural concrete can be both economic and environment-friendly. Due to the properties of the recycled aggregate, its long-term deformation （mainly for creep and shrinkage） of recy- cled concrete is highly probable in comparison with the ordinary one, which means a serious threat to the security of the concrete users in the service period. It is therefore very necessary for the researchers to search for the effective ways to limit the shrinkage and creep by opti- mally restricting its long-term deformation properties of the recycled concrete. Covering extensive literature review of experimental cam- paigns on the related fields, we have systematically summarized the likely impacts of some factors on the shrinkage and creep of the recy- cled concrete, such as water-cement ratio, mix design, superplasti- eizer, composite fiber and mineral admixtures, quality of the recycled aggregate, replacement ratio, enhanced treatment, strength of matrix concrete, types of recycle aggregate, and the optimization of produc- tion process. Based on the analysis, we would like to present some feasible ways in hoping to improve the long-term deformation proper- ties of such kind of concrete, such as on how to reduce the water-to- cement ratio, adjust the mixing ratio, add in water-content reducing agent, mix fiber with mineral admixtures, enhance the quality of the recycled aggregate by regulating the curing condition, etc. The prac- tical.application of such methods have indeed helped to enhance the long-term deformation properties of such concrete, some of which can be made equal to or even a bit better than the ordinary one. If the shrinkage and creep of recycled concrete can be depressed better or predicted more accurately, it would be possible to put the problem of loss of prestress under control. And, if so, there will be a day when the recycled concrete may completely take the place of the ordinary one with its high performance in civil engineering projects. Thus, it can be seen that this paper is beneficial for the wide researchers to refer to if they want to understand more deeply and control the long- term deformation properties of the recycled concrete better, and do more things for the recycled use of the waste.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2013年第5期212-217,共6页
Journal of Safety and Environment
基金
国家自然科学基金项目(41102171)
浙江省科技厅科技计划项目(2008C13041-2)
关键词
工程结构
再生骨料
再生混凝土
长期变形
收缩
徐变
影响因素
engineering structure
recycled aggregate
recycledconcrete
long-term deformation
shrinkage
creep
influence factor
