（1 内蒙古科技大学土木工程学院， 包头 014000； 2 中南大学土木工程学院， 长沙 410000）

［摘要］为了研究0，50，100，150次冻融循环作用后，塑钢纤维掺量对轻骨料混凝土弯曲韧性、冲击韧性的影响规律，对塑钢纤维掺量分别为0，3，6，9kg/m3的高强轻骨料混凝土分别进行弯曲韧性试验和抗冲击性能试验，实测了轻骨料混凝土的荷载挠度关系、初裂冲击次数、破坏冲击次数，并计算了初裂耗能和破坏耗能。结果表明：冻融环境下，掺入塑钢纤维能显著提高轻骨料凝土弯曲韧性及抗冲击性能；冻融150次后，塑钢纤维掺量为9kg/m3轻骨料混凝土的累积耗能为素轻骨料混凝土的115倍。

［关键词］冻融循环； 塑钢纤维； 轻骨料混凝土； 弯曲韧性； 抗冲击性能

中图分类号：TU528-5文献标识码：A文章编号：1002-848X(2019)10-0085-04

Effect of plastic-steel fiber on toughness of lightweight aggregate concrete to freeze-thaw environment

Niu Jiangang1， Zuo Fuliang1， Wang Jialei2

(1 College of Civil Engineering， Inner Mongolia University of Science and Technology， Baotou 014000， China;2 College of Civil Engineering， Central South University， Changsha 410000， China)

Abstract:In order to study the influence of plastic-steel fiber content on flexural toughness and impact toughness of lightweight aggregate concrete after 0，50，100，150 freeze-thaw cycles． Bending toughness test and impact resistance test for high strength lightweight aggregate concrete with plastic-steel fiber content of 0, 3, 6,  9kg/m3 respectively were carried out．The load-deflection relationship of the lightweight aggregate concrete, the number of initial cracking impacts, the number of damages, and the energy consumption of the initial cracking and the energy of the failure were calculated. The results show that in the freeze-thaw environment, the incorporation of plastic-steel fiber can significantly improve the bending toughness and impact resistance of lightweight aggregate concrete. After 150 freeze-thaw cycles, the cumulative energy consumption of  lightweight aggregate concrete with plastic-steel  fiber content 9kg/m3 is 115 times that of plain lightweight aggregate concrete.

Keywords:freeze-thaw cycle; plastic-steel fiber; lightweight aggregate concrete; bending toughness; impact resistance

*国家自然科学基金项目（51368042）。

作者简介：牛建刚，博士，教授，Email：niujiangang@imust.edu.cn。