泡沫混凝土(foam concrete, FC)与传统混凝土相比具备优良的保温隔热、隔音、耐火及抗震性能,同时显著降低了建筑自重,更契合现代建筑绿色发展理念。夹芯保温墙板在长期经历昼夜温差变化、冷热交替和冻融循环后会改变保温材料内部结构,使其粘结强度逐渐下降,导致保温层与结构层之间的粘结不牢固,从而引发空鼓和脱落等质量问题,因此对夹芯保温墙板进行抗冻性能的研究非常有必要。Compared with traditional concrete, foam concrete (FC) has excellent thermal insulation, sound insulation, fire resistance and seismic resistance, and at the same time significantly reduces the weight of the building, which is more in line with the green development concept of modern buildings. After experiencing the temperature difference between day and night, alternating between cold and hot and freeze-thaw cycles for a long time, the internal structure of the insulation material will be changed, and the bonding strength will gradually decrease, resulting in the infirm bond between the insulation layer and the structural layer, which will cause quality problems such as hollowing and falling off, so it is very necessary to study the frost resistance of the sandwich insulation wallboard.
在工程项目中应用再生混凝土,既保护了生态环境,又提高了废弃混凝土的利用率,满足了可持续发展的要求。但是,再生混凝土在力学性能上可能不及普通混凝土。为了提高再生混凝土的性能,增加其在工程领域中的普及和应用,在使用钢纤维、植物纤维和矿物纤维材料方面取得了显著进展。这些材料掺入到再生混凝土中以改善其机械性能。研究表明:1) 钢纤维提高了再生混凝土的强度、韧性和弹性模量;2) 植物纤维混凝土具有轻质、环保、韧性高、保温性能好等优点,但在碱性环境中会发生腐蚀,同时植物纤维吸水能力强,导致湿胀干缩现象;3) 玄武岩纤维的制作成本相对较低,掺入适量的玄武岩纤维可以改善再生混凝土的力学性能。Applying recycled concrete for engineered projects not only protects the ecological environment but also improves the utilization rate of waste concrete to satisfy sustainable development requirements. However, the mechanical properties of recycled concrete are not as good as those of ordinary concrete. To enhance the former’s performance and increase its popularity and application in engineering fields, notable advances have been made by using steel, synthetic, plant, and mineral fiber materials. These materials are added to recycled concrete to improve its mechanical properties. Studies have shown that 1) steel fibers have a distinct reinforcing effect and improve the strength, toughness, and elastic modulus of recycled concrete;2) plant fiber concrete is lightweight and environmentally friendly and provides high toughness and good thermal insulation, but the fibers corrode in alkaline environments;in addition, plant fibers have high water absorption capacity, which leads to wet expansion and dry shrinkage phenomena, 3) the cost of basalt fiber, a mineral fiber, is relatively low, and a suitable basalt content can improve the mechanical properties of recycled concrete to a certain extent.
随着国家对于碳排放领域的重视以及混杂纤维混凝土在建筑领域中的广泛应用,植物纤维与人造纤维混合增强混凝土性能的研究成为重要课题。混杂纤维的加入有效地改善了混凝土易开裂,抗拉强度低,脆性破坏等缺点,同时还提高了混凝土的耐久性。本文结合国内外学者的研究,综述了植物纤维与人造纤维混杂对于混凝土静态力学性能,动态力学性能的改善以及增强机理,分析了混杂纤维对于混凝土吸水性、渗透性、耐酸腐蚀性的影响以及混杂纤维混凝土在高温环境下的抗剥落机理,残余力学性能。最后提出目前关于植物纤维与人造纤维混合增强混凝土所存在的一些问题,为今后进一步研究混杂纤维增强混凝土提出参考建议。With the attention of the country to the field of carbon emission and the wide application of hybrid fiber concrete in the construction field, the research on the performance of reinforced concrete mixed with plant fiber and man-made fiber has become an important topic. The addition of hybrid fiber can effectively improve the shortcomings of concrete such as easy cracking, low tensile strength, brittle damage, and improve the durability of concrete. Based on the research of domestic and foreign scholars, this paper summarizes the improvement and enhancement mechanism of the hybrid of plant fiber and man-made fiber on the static and dynamic mechanical properties of concrete, and analyzes the influence of hybrid fiber on the water absorption, permeability and acid corrosion resistance of concrete, as well as the anti-spalling mechanism and residual mechanical properties of hybrid fiber concrete under high temperature environment. Finally, some problems existing in the hybrid reinforced concrete of plant fiber and man-made fiber are put forward, and some suggestions are put forward for further study of hybrid fiber reinforced concrete.
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