摘要
为增强机场水泥混凝土的韧性,提升道面结构的抗开裂能力,制备了聚酯纤维(FC)、聚乙烯醇纤维(PVA)和聚丙烯粗纤维(PP)混凝土。以砂率、FC纤维掺量和减水剂掺量为影响因素,28 d抗折强度为响应值,采用响应面法确定了FC纤维混凝土的最佳配比。采用三点弯曲韧性试验和三点弯曲断裂试验,分析了纤维的增韧阻裂机理。结果表明:砂率、FC纤维掺量和减水剂掺量之间存在交互作用,三者对混凝土28 d抗折强度的影响程度排序为FC纤维掺量>减水剂掺量>砂率,最佳配比为砂率34%、FC纤维掺量1.4 kg/m^(3)、减水剂掺量2%。三种纤维P-δ曲线拐点处的荷载峰值和挠度显著提高,拐点尖锐程度下降。相较于素混凝土,FC、PVA和PP纤维混凝土的断裂韧性分别提高了125.8%、118.4%和87.1%,起裂韧度分别提升了38.7%、33.9%和25.2%,断裂韧度分别提升了87.1%、73.2%和55.6%。此外,FC、PVA和PP纤维混凝土开裂过程中所需的断裂能分别提升了216.2%、193.2%和162.9%。结合能量平衡理论,纤维通过能量传递的方式在混凝土中起到增韧阻裂作用,FC纤维的增韧阻裂效果相对显著。
In order to enhance the toughness and fracture performance of airport cement concrete,fiber reinforced concrete was prepared by using modified polyester fiber(FC),polyvinyl alcohol fiber(PVA)and polypropylene crude fiber(PP)as reinforcing materials.The optimum mixture ratio of FC fiber reinforced concrete was determined by response surface method with sand ratio,amount of FC fiber and water reducer as the influencing factors and 28 d flexural strength as the response value.The flexural toughness and fracture performance of three kinds of fiber reinforced concrete were studied by three-point bending toughness test and three-point bending fracture test,and the mechanism of fiber toughening and crack resistance was analyzed.The results show that there is an interaction between three factors:sand ratio,FC fiber content and water reducer content.The degree of influence of the three factors on the 28 d flexural strength of FC fiber concrete is ranked as:FC fiber content>water reducer content>sand ratio.The optimum mixture ratio of FC fiber concrete is:sand ratio is 34%,FC fiber content is 1.4 kg/m^(3),water reducer content is 2%.The peak load and deflection at the inflection points of the P-δcurves of the three fibers were significantly higher,and the sharpness of the inflection points decreased.Compared to plain concrete,the fracture toughness of FC fiber,PVA fiber and PP fiber concrete increased by 125.8%、118.4%and 87.1%,respectively,the starting toughness increased by 38.7%、33.9%and 25.2%,respectively,the fracture toughness increased by 87.1%、73.2%and 55.6%,respectively,and the fracture energy increased by 216.2%、193.2%and 162.9%,respectively.Combined with the energy balance theory analysis,the fibers play a role in toughening and fracture resistance in concrete by means of energy transfer.All three kinds of fibers can improve the toughness and fracture properties of concrete,and FC fibers have a relatively significant effect on the toughness and fracture property enhancement of concrete.
作者
赵胜前
游庆龙
李京洲
尹杰
黄之懿
ZHAO Shengqian;YOU Qinglong;LI Jingzhou;YIN Jie;HUANG Zhiyi(School of Highway,Chang’an University,Xi’an 710064,China;Tianjin Municipal Engineering Design and Research Institute,Tianjin 300000,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2024年第13期302-309,共8页
Materials Reports
基金
国家自然科学基金(51308064)
首都机场集团公司科技项目(XJC[2019]-KY-033)。
关键词
水泥混凝土道面
纤维混凝土
改性聚酯纤维
响应面法
弯曲韧性
断裂性能
cement concrete pavement
fiber reinforced concrete
modified polyester fiber
response surface method
flexural toughness
fracture properties
