共查询到20条相似文献,搜索用时 15 毫秒
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通过18个中心拉拔试件试验,研究在基体中加入不同纤维(聚丙烯长纤维(PPA)、聚丙烯短纤维(PPB)、钢纤维(SF)以及混杂纤维)对玻璃纤维增强聚合物(GFRP)筋与混凝土基体粘结性能的影响,旨在寻找改善GFRP筋与混凝土基体粘结性能的有效途径。参照德国纤维混凝土标准DBV和国际材料与结构研究试验联合会标准RILEM弯曲韧性评价方法,采用等效抗弯强度和变形能来评价粘结韧性。试验结果表明:与素混凝土(NC)基体相比,GFRP筋与掺入混杂钢纤维与聚丙烯长纤维以及各自单掺基体的粘结强度可提高13%~35%,还可改善粘结韧性;同时,GFRP筋与基体的粘结强度随钢纤维掺量增大而提高。根据试验结果拟合得出粘结滑移曲线上升段的模型参数,计算结果与试验结果吻合良好。图11表6参13 相似文献
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自密实混凝土的力学性能研究 总被引:1,自引:0,他引:1
对自密实混凝土的力学性能进行了研究,探讨了自密实混凝土的抗压强度、抗压尺寸效应、劈拉强度、养护龄期、抗折强度以及各强度指标之间的关系. 相似文献
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H. Mazaheripour S. Ghanbarpour S.H. Mirmoradi I. Hosseinpour 《Construction and Building Materials》2011,25(1):351-358
This paper evaluates the LECA Lightweight Self-Compacting Concrete (LLSCC) manufactured by Nan-Su, of which the Packing Factor (PF) of its design mixing method has been modified and improved.The study analyzes the impact of polypropylene fibers on LLSCC performance at its fresh condition as well as its mechanical properties at the hardened condition.The evaluation of Fiber Reinforced LLSCC (FR-LLSCC) fluidity has been conducted per the standard of second class rating of JSCE, by three categories of flowability, segregation resistance ability and filling ability of fresh concrete.For the mechanical properties of LLSCC, the study has been conducted as follows: compressive strength with elapsed age, splitting tensile strength, elastic modulus and flexural strength, all of which were measured after the sample being cured for 28 days.When self-compacting concretes were lightened to 75% of their normal weight, their fresh properties are affected immensely.Applying 0.3% volume fractions of polypropylene fiber to the LLSCC resulted in 40% reduction in the slump flow (from 720 mm to 430 mm). In general, the rate of slump flow over Super Plasticizer (SP) volume percentage reduced with the use of polypropylene fibers in the FR-LLSC.Polypropylene fibers did not influence the compressive strength and elastic modulus of LLSCC, however applying these fibers at their maximum percentage volume determined through this study, increased the tensile strength by 14.4% in the splitting tensile strength test, and 10.7% in the flexural strength. 相似文献
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Miao Liu 《Construction and Building Materials》2011,25(2):919-925
This research investigated the feasibility of using ground glass in self-compacting concrete (SCC). The ground glass was used as a partial replacement for both the cement and fine aggregate.The results show that to keep the filling ability constant, the inclusion of ground glass would require an increase in water/powder ratio and a reduction in superplasticizer dosage. These did not change the passing ability, but degraded the consistence retention and hardened properties such as strength but not to a prohibitive extent. This research concludes that SCC with satisfactory fresh properties can be produced by incorporating up to 104 kg/m3 ground glass, replacing about 10% cement and 10% sand, without the need for viscosity modifying agent (VMA).The successful completion of this study can lead to the application of ground glass in SCC, thus widening the types of additions available for SCC, saving landfill and reducing CO2 emissions by the use of less cement and sand. 相似文献
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通过掺入外加剂,改变胶结材料和粗细骨料的含量及种类,改善混凝土的配合比,使混凝土的自重力大于混凝土的屈服应力,混凝土的流动性增大,又具有足够的黏度和塑性.能自由流淌并充填模板内的空间,它不需要外加振动力,而依靠自重力作用即可获得密实且均匀的胶凝结构. 相似文献
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基于自密实混凝土是高性能混凝土的一个重要发展方向,简要介绍了国内外混凝土材料的发展现状,论述了高性能自密实混凝土的研究现状和发展趋势,并指出在我国推广自密实混凝土的应用与研究具有积极意义。 相似文献
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自密实混凝土研究与应用初探 总被引:1,自引:1,他引:1
介绍了自密实混凝土的定义,阐明了其制备原理及试验技术路线,分析了其应用方向,说明了其质量控制要点,进行了综合效益分析,得出了该技术前景可观的结论。 相似文献
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结合高性能混凝土发展的情况,介绍了高流态自密实混凝土在工程实践中的应用,阐述了高流态自密实混凝土的施工工艺,指出采用该工艺具有良好的经济与环保效益。 相似文献
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简单介绍了自密实混凝土的特点、原理,分别阐述了配制自密实混凝土过程中水泥、粗骨料、细骨料及外加剂的选择,并通过配合比试验确定了自密实混凝土的最佳配合比,结合其优点,指出自密实混凝土具有良好的社会经济效益。 相似文献
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掺生物胶自密实混凝土流动性的试验研究 总被引:2,自引:0,他引:2
增稠剂已成为自密实混凝土(SCC)中的重要组分.采用两种生物胶,即黄原胶和文莱胶,作为混凝土增稠剂,对掺有两种增稠剂的自密实混凝土进行流动性试验研究,结果表明:黄原胶和文莱胶可改善新拌混凝土的流动性,黄原胶尤为明显;随黄原胶和文莱胶掺量的增加,新拌混凝土的初始流动性逐渐降低;掺有较高掺量(0.03%~0.05%)黄原胶的新拌混凝土初始流动性较小,但随时间的延长流动性逐渐增加;而文莱胶(0.03%~0.05%)则随时间延长,流动性变化不大或减小. 相似文献
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自密实混凝土即拌合物具有很高流动性而不离析、不泌水 ,能不经振捣或少振捣而自动流平并充满模型和包裹钢筋的混凝土。钢管混凝土柱的核心混凝土采用泵送顶升工艺施工的关键是配制自密实混凝土。 相似文献
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主要介绍了C20自密实混凝土在堆石混凝土中的应用,然后通过试验研究,初步验证了自密实混凝土的抗压强度、抗渗性和抗冻性以及堆石混凝土芯样抗压强度。 相似文献
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