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混凝土结构物在工程中的重要性以及混凝土材料应用的普遍性,使其耐久性能的评价逐渐成为本行业的迫切要求。混凝土的早期抗裂性能是耐久性能评价的一个指标,众所周知,混凝土的早期开裂对其整体性能、力学性能和耐久性能会产生一定的影响,早期裂缝的研究也就成为当前混凝土材料界和工程界的热点问题。早期裂缝指的是混凝土结构在尚未完全硬化之前就出现的裂缝,即塑性收缩裂缝。根据形状有表面型的和贯穿型的,根据变动形态则可以分为愈合、闭合、稳定和不稳定等形式。据以往的理论观点,混凝土结构的早期裂缝主要由混凝土拌合物硬化过程中失水引起,一般发生在混凝土初凝到终凝时间段,故多采取加强养护的方式来作为主要的防裂方法,但始终未能根治混凝土的裂缝问题。是否存在新的方法和观点来对待早期裂缝的问题?一般对于混凝土生产企业来说,如何在最大程度上避免此类裂缝的发生?在施工过程中,又有哪些措施可以避免?另外针对发生的此类裂缝,一般施工单位和混凝土生产企业如何进行处理?众多问题都成为了目前混凝土早期裂缝问题关注的焦点。本期将针对这些问题征求各位专家的意见,以期给一些从事混凝土生产和施工的技术人员予以参考借鉴。
The importance of concrete structures in engineering and the universality of the application of concrete materials make the evaluation of the durability performance an urgent requirement in the industry. The early crack resistance of concrete is an indicator of durability evaluation. It is well known that the early cracking of concrete has certain influence on its overall performance, mechanical properties and durability. The study of early cracks has also become the current concrete material and engineering The hot issue. Early cracks refer to cracks in concrete structures that have not fully hardened before, ie, plastic shrinkage cracks. According to the shape of the surface and through the type, according to changes in shape can be divided into healing, closed, stable and unstable forms. According to the previous theoretical point of view, the early cracks in concrete structures are mainly caused by water loss during the hardening process of concrete mixes, which usually takes place during the initial setting to the final setting of concrete. Therefore, the way of strengthening the curing is taken as the main method of anti-cracking , But has failed to cure the concrete crack problem. Are there any new ways and ideas to deal with the problem of early cracks? How to prevent such cracks from occurring to the greatest extent for concrete manufacturers? What measures can be avoided in the process of construction? Such cracks, general construction units and concrete manufacturing enterprises how to deal with? Many problems have become the focus of the early concrete cracks in the focus of attention. This issue will seek the views of experts on these issues, with a view to some of the technical personnel engaged in concrete production and construction for reference.