防裂剂和纤维对面板混凝土性能的影响研究

The influence of anti-cracking agent and fibers on the properties of face slab concrete

摘要

研究了防裂剂与PVA纤维、玄武岩纤维单掺或复掺对面板混凝土抗压性能、抗拉性能、干缩变形性能和早期抗裂性能的影响。结果表明：掺加12%防裂剂导致面板混凝土各龄期抗压强度、抗压弹模、轴拉强度、极限拉伸值降低，但有利于减小干缩变形，面板混凝土180 d干缩变形减小了22×10^-6,并且在平板开裂试验中无裂纹产生。掺加PVA纤维(0.9 kg/m³)或玄武岩纤维(2.5 kg/m³)有利于面板混凝土的各项性能提升，其中28 d轴拉强度分别提高了7.0%和9.2%,平板开裂试验中开裂时间延迟、裂纹数量减少、裂纹面积减小。防裂剂与PVA纤维或玄武岩纤维复掺时，二者对面板混凝土抗压和抗拉性能的影响相互补偿，对干缩变形和早期抗裂性能具有协同改善作用，面板混凝土180 d干缩变形可减小约30×10^-6,平板开裂试验中无裂纹产生。

Abstract

The influence of anti-cracking agent, PVA fibers and basalt fibers single or composite doping on the compressive, tensile, dry shrinkage deformation and early crack resistance of face slab concrete was investigated.The result showed that the addition of 12% anti-cracking agent result ed in a decrease in the compressive strength, compressive modulus, axial tensile strength and ultimate tensile value of the face slab concrete at various ages, but it was beneficial for reducing the dry shrinkage deformation. The dry shrinkage deformation of the face slab concrete after 180 days was reduced by 22×10^-6. And no cracks were found in the flat plate cracking test. Adding PVA fibers(0.9 kg/m³) or basalt fibers(2.5 kg/m³) is beneficial for improving the properties of face slab concrete, with a 7.0% and 9.2% increase in 28 day axial tensile strength, respectively. Meanwhile, in the plate cracking test, the cracking time is delayed, the number of cracks is reduced, and the crack area is reduced. When the anti-cracking agent is mixed with PVA fibers or basalt fibers, their effects on the compressive and tensile properties of the face slab concrete compensate for each other, but they have a synergistic effect on improving the dry shrinkage deformation and early crack resistance performance. The dry shrinkage deformation of the face slab concrete after 180 days can be reduced by about 30×10^-6. And no cracks were found in the flat cracking test.

关键词

面板混凝土 / 防裂剂 / PVA纤维 / 玄武岩纤维 / 混凝土性能

Key words

face slab concrete / anti-cracking agent / PVA fibers / basalt fibers / concrete properties

基金资助

新疆和田玉龙喀什水利枢纽工程专项科研试验项目(YLKS-SW-2022-017)

中央级公益性科研院所基本科研业务费项目(CKSF2024348/ CL)

湖北省自然科学基金三峡创新发展联合基金(2022CFD026)