粗聚烯烃纤维混凝土圆板弯曲韧性和表征方法

发布时间：2018-04-12 10:08

本文选题：粗聚烯烃纤维 + 弯曲韧性　；参考：《建筑材料学报》2015年01期

【摘要】：通过圆板试件研究了新型粗聚烯烃纤维混凝土的弯曲韧性,探讨了纤维掺量、纤维长度和基体强度等对圆板能量吸收值的影响规律.试验发现:纤维掺量与圆板能量吸收值成正比;纤维长度介于38~60mm时,圆板能量吸收值随纤维长度增加而增大,当纤维长度≥48mm时,其荷载-挠度曲线下降段出现应变强化特征,荷载有2次峰值.分析了美国ASTM C1550在评价韧性方面存在的问题,提出了以圆板初裂挠度为初始参考挠度,基于能量比值法的韧性指标评定方法,该方法可表征粗纤维对混凝土板初裂后韧性的贡献,并可直接与理想弹塑性材料的韧性指标进行比较.
[Abstract]:The flexural toughness of new type coarse polyolefin fiber reinforced concrete was studied by means of circular plate specimens, and the influence of fiber content, fiber length and matrix strength on the energy absorption value of circular plate was discussed.It is found that the fiber content is proportional to the energy absorption of the circular plate, when the fiber length is between 38~60mm and the fiber length, the energy absorption of the circular plate increases with the increase of the fiber length. When the fiber length is greater than or equal to 48mm, the load-deflection curve decreases with strain strengthening.The load has two peaks.The problems in evaluating toughness of American ASTM C1550 are analyzed, and a method of evaluating toughness index based on energy ratio method is put forward, in which the initial crack deflection of circular plate is taken as the initial reference deflection.This method can characterize the contribution of coarse fiber to the toughness of concrete slab after initial crack and can be compared directly with the toughness index of ideal elastoplastic material.
【作者单位】：北京工业大学城市与重大工程安全减灾省部共建重点实验室;上海罗洋新材料科技有限公司;
【基金】：国家自然科学基金资助项目(51378032) 北京自然科学基金资助项目(8142005)
【分类号】：TU528.572

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