聚烯烃粗合成纤维混凝土抗弯韧性试验

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发布时间：2021-09-28

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聚烯烃粗合成纤维混凝土抗弯韧性试验
邓宗才，师亚军，曹炜
(北京工业大学城市与工程防灾减灾省部共建教育部重点实验室，北京 100124)
摘要：为了解新型粗合成纤维对改善混凝土抗弯韧性的效果，试验研究了纤维掺量、基体强度、纤维
直径等因素对混凝土抗弯韧性的影响规律。结果表明：单掺或混掺不同几何尺寸粗合成纤维后，试
件具有很好的韧性，呈延性破坏；抗弯韧性指数随纤维掺量的增加而增大；基体强度提高时，抗弯韧
性指数略有上升；纤维直径不同时，抗弯韧性指数变化不明显；3种合成纤维与钢纤维混掺后，其抗
弯韧性指标大于单掺钢纤维或 3种合成纤维混掺的试件；混掺粗合成纤维可有效改善梁裂后行为，
即峰值荷载后仍保持较高荷载；而单掺钢纤维梁在峰值荷载后，荷载下降较快；新的抗弯韧性评价
方法能够准确地反映粗合成纤维混凝土裂后阻裂能力高、变形大的特点。
关键词：粗合成纤维；抗弯韧性；剩余强度；混凝土；配合比；纤维掺量
中图分类号：TU528．58 文献标志码：A
Experim ent on Flexural Toughness of Polyolefin M acro-fiber
Reinforced Concrete
DENG Zong—cai，SHI Ya—j un，CAO W ei
(Key Laboratory of Urban Security and Disaster Engineering of M inistry of Education，
Beijing University of Technology，Beijing 100124，China)
Abstract：In order to grip the flexural toughness im pact of new type synthetic m acro—fiber on
reinforced concrete，the effects of the fiber content，the matrix strength of reinforced concrete
and the diam eter of fiber on the flexural toughness were studied． The results show that the
addition of synthetic m acro—fiber changes the failure mode of reinforced concrete from brittleness
to ductility． The flexural toughness index increases with the fiber content，it also increases when
the matrix strength increases；and it has’t evidently changed when the diameter of fiber changes．
The flexural toughness of reinforced concrete with steel fiber and three synthetic macro—fiber is
higher than those of steel fiber or three synthetic macro—fiber， and synthetic macro—fiber can
increase the toughness of reinforced concrete． The synthetic m acro—fiber reinforced concrete can
have a higher load after the peak load，but the load of concrete with steel fiber decreases quickly
after the peak load， the characteristic of reinforced concrete with synthetic macro—fiber can be
proved by the new toughness evaluation method．
Key words： synthetic macro—fiber； flexural toughness； residual strength； reinforced concrete；