共查询到18条相似文献,搜索用时 234 毫秒
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CFRC机敏混凝土中碳纤维的分散性研究 总被引:6,自引:0,他引:6
研究了羧甲基纤维素钠(CMC)和硅灰等分散剂对碳纤维水泥基复合材料(CFRC)中碳纤维分散性的影响。由分离出来的碳纤维质量变动系数和试件电阻率变动系数来评价碳纤维在CFRC中的分散性。结果表明,在各种CMC掺量下,硅灰均能显著改善碳纤维的分散性。随着CMC掺量的增加,碳纤维的分散性提高。当CMC掺量为0.8%、硅灰掺量为15%时,CMC和硅灰的共同作用使碳纤维质量变动系数最小,此时碳纤维在水泥基体中分散性最佳,且当CMC掺量为0.8%时,CFRC的电阻率变动系数也最小。 相似文献
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在石墨水泥基材料中掺入低电阻率且具有阻裂功能的短切碳纤维可以提高材料的导电性能.试验研究了环境温度、碳纤维长度及组合长度碳纤维等对石墨水泥基材料电阻率的影响.结果表明,碳纤维可以改善石墨水泥基材料的性能,组合长度碳纤维的掺入有利于材料导电网络的形成. 相似文献
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最近,日本的TAISET公司与东邦人造纤维公司合作,共同研制成一种新型碳纤维补强水泥(简称为CFRC)。这种水泥是由两种成分混合后组成。其一是一种特制的超细水泥,其颗粒直径为普通水泥的粒度的1/10;其二是一种聚丙睛(PAN)碳纤维,用作补强剂。碳纤维的直径是7μm,并以约10μm的间隔均匀地排列在超细水泥中。这样的组成方式使得这种CFRC水泥具有诸多的优点。其中最突出的特点是强度特别高例如按重量计掺入15%碳纤维,其强度可达到245MPa,而掺入20%,则强度高达548.8MPa。这样的强度是过去生产的CFRC强度的10-20倍。而… 相似文献
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为了进一步研究碳纤维长度对混凝土力学性能的改善效果,确定碳纤维混凝土(CFRC)中纤维的最佳长度.基于试验研究了四种不同长度的碳纤维对混凝土的增强效果,得到不同长度碳纤维对混凝土抗压强度的影响曲线,不同碳纤维长度的试块的荷载与变形曲线;在加载过程中,不同碳纤维长度试块的横向应变和纵向应变的比值随荷载的变化曲线.试验结果表明:随着纤维长度的增加,抗压强度先增加后降低,纤维长度为10mm时,其提高较为明显,并且长度为10mm的纤维可以有效地改善混凝土的脆性破坏,当长度超过30mm时,纤维对混凝土的变形改善效果不明显. 相似文献
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采用振动搅拌技术,选取碳纤维为导电相制备用于杆塔基础接地的导电混凝土,并对碳纤维导电混凝土的振动搅拌工艺参数、配合比和接地性能进行了试验研究。结果表明:采用振动搅拌技术制备碳纤维导电混凝土的最优工艺参数组合为:干拌时间10 s、湿拌时间70 s、加碳纤维搅拌时间60 s;最优配合比为:碳纤维掺量0.3%、水灰比0.46、单位用水量200 kg、砂率36%;此工艺参数和配合比下,导电混凝土的28 d抗压强度为46.3 MPa,抗折强度为5.7 MPa,28 d电阻率为2.09Ω·m,导电性能优良,满足输电线路杆塔基础接地的性能要求。 相似文献
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介绍了应用均匀设计理论设计碳纤维混凝土配方的方法,通过所得到的试验数据,运用人工神经网络(ANN)的方法预测碳纤维混凝土抗压强度和劈裂抗拉强度;阐述了采用BP算法建立碳纤维混凝土抗压强度神经网络模型的过程,仿真结果表明,BP网络可成功地建立非线性的强度模型,预测强度可达到较高精度。 相似文献
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This paper presents the results of an experimental study to investigate the flexural behavior of reinforced concrete (RC) beams that have reached their ultimate bearing capacities and then retrofitted with externally prestressed carbon fiber reinforced composite (CFRC) laminates. The effect of variation in prestressing force on CFRC laminates bonded to the RC beam is investigated in terms of the flexural strength, deflections, cracking behavior and failure modes. The results indicate that rehabilitation of significantly cracked beams by bonding CFRC laminates is structurally efficient. 相似文献
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通过对28d龄期下碳纤维混凝土抗压强度和劈拉强度的试验研究,可知碳纤维掺量对混凝土力学性能具有较大影响.结果表明:与基准混凝土相比,小掺量时碳纤维对混凝土的改性主要表现在对强度的提高上;较大掺量(体积率大于0.3%)时碳纤维可极大提高混凝土的变形性能,改善其韧性和塑性.因此,在碳纤维混凝土的路面工程应用中应根据实际需要选择合适的掺量,从而取得较好的工程效果. 相似文献
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Fatih ZALP Halit Dil&scedil ad YILMAZ Burcu AKCAY 《Frontiers of Structural and Civil Engineering》2022,16(5):615
The aim of this study is to develop concrete composites that are resistant to armor-piercing projectiles for defense structures. Different reinforcement configurations have been tested, such as short steel fibers, long steel fibers, and steel mesh reinforcement. Three different concrete mix designs were prepared as “Ultra High Performance (UHPFRC), High Performance (HPFRC) and Conventional (CFRC) Fiber Reinforced Concrete”. The content of hybrid steel fibers was approximately 5% in the UHPFRC and HPFRC mixtures, while the steel fiber content was approximately 2.5% in the CFRC mixture. In addition, a plain state of each mixture was produced. Mechanical properties of concrete were determined in experimental studies. In addition to the fracture energy and impact strength, two important indicators of ballistic performance of concrete are examined, which are the penetration depth and damage area. The results of the study show that the depth of penetration in UHPFRC was around 35% less than that in HPFRC. It was determined that the mixtures of UHPFRC and HPFRC containing 5% by volume of hybrid steel fibers showed superior performance (smaller crater diameter and the less projectile penetration depth) against armor-piercing projectiles in ballistic tests and could be used in defense structures. 相似文献