在高强度自压缩混凝土 (SCC) 中印入的宏观合成聚烯纤维的性能评估
Chen Yaqin1, Saud Ul Haq2, Shahid Iqbal3
1School of Civil Engineering and Architecture, Xi'an University of Technology, Xi'an, 710048, China.
Scientific reports
|September 6, 2024
概括
添加新的宏聚烯 (PP) 纤维显著提高了混凝土的机械性能. 这些改进的PP纤维增强了强度和性,在高强度混凝土应用中提供了更好的抗裂性能.
科学领域:
- 材料科学 材料科学 材料科学
- 土木工程 土木工程是指土木工程.
- 建筑材料 建筑材料
背景情况:
- 混凝土的脆弱性限制了它的应用.
- 传统的微型聚烯 (PP) 纤维的粘合和凝结问题很差.
- 建议使用具有增强表面固性的新型宏观PP纤维.
研究的目的:
- 研究宏观PP纤维对高强度混凝土的影响.
- 评估混凝土的新鲜性和机械性质,其中含有不同宏观PP纤维含量.
- 为了评估强度,性和抗裂的改进.
主要方法:
- 在混凝土混合物 (40-50MPa) 中加入宏观PP纤维 (0-1.5%v/f).
- 根据ASTM标准测试新鲜混凝土的性能 (可加工性,空气含量,密度).
- 根据ASTM和RILEM标准评估硬化混凝土的机械性能 (裂纹拉力,粘合力,屈曲强度) 和性.
主要成果:
- 可加工性下降,空气含量增加,但密度保持稳定.
- 在分裂拉伸强度 (+34.5%),结合强度 (+35%) 和屈曲强度 (+100%) 中观察到显著增加.
- 应变硬化行为和显著的屈曲性增加 (2.2至47.1),纤维含量为1-1.5%.
结论:
- 宏观PP纤维有效地提高了高强度混凝土的机械性能.
- 增强的纤维设计克服了传统微型PP纤维的局限性.
- 宏观PP纤维增强了混凝土对裂开始和传播的抵抗力.
相关概念视频
01:22Fiber Reinforced Concrete
71
Fiber-reinforced concrete significantly enhances the structural and nonstructural properties of traditional concrete by incorporating fibers like steel, glass, and polymers. These fibers, varying from natural ones such as sisal and cellulose to manufactured ones like polypropylene and Kevlar, are mixed into hydraulic cement with aggregates. Steel fibers, often preferred for their robustness, contribute to improved ductility, toughness, and post-cracking performance. The concrete is classified...
71
01:23Abrasion Resistance of Concrete
114
Abrasion resistance is an essential characteristic of concrete that determines its durability and longevity under various wear conditions. Concrete surfaces are vulnerable to different types of abrasion. For instance, surfaces may wear down due to the constant movement of vehicles or be eroded by solids carried in water, as seen in concrete canal linings. Specific tests are conducted to measure the abrasion resistance of concrete.
One such test is the revolving disc test, where three plates...
One such test is the revolving disc test, where three plates...
114
01:20Microcracking in Concrete
111
Microcracking in concrete refers to the tiny cracks that can form within the material even before any external load is applied. These microcracks typically occur at the interface between the coarse aggregate and the hydrated cement paste, often as a result of differential volume changes prompted by variations in stress-strain behavior, as well as thermal and moisture movement. Initially, these microcracks remain stable and do not grow substantially until the concrete is stressed to about 30...
111
01:22Fatigue Strength of Concrete
178
Fatigue, in the context of materials science and engineering, refers to the weakening or failure of a material caused by repeatedly applied loads, even if these loads are below the strength limit of the material. Fatigue strength in concrete is a critical property that influences its durability and longevity. Concrete can fail in two ways due to fatigue. Static fatigue or creep rupture occurs under a constant load or one that increases slowly. The other failure mode is due to cyclical or...
178
01:12Bonding and Strength of Aggregate
143
The bond between aggregate particles and the cement matrix is significantly influenced by the shape and surface texture of the aggregates. High-strength concretes benefit from a rougher texture, which leads to stronger bonding due to greater adhesion. Angular aggregates with larger surface areas also enhance this bond. The bonding quality, however, is complex to assess as no universally accepted test exists. Good bonding is indicated when a crushed concrete specimen shows some aggregate...
143
01:20Strength of Cement
127
Strength tests for cement are not performed directly on neat cement paste due to difficulty in obtaining consistent, reliable specimens. Instead, cement is typically tested in the form of cement-sand mortar.
For compressive strength tests, ASTM C 109-05 standards prescribe a cement-sand mix ratio of 1:2.75 and a water/cement ratio of 0.485 for making 2-inch cubes. These cubes are mixed, cast, and cured in saturated lime water at 23°C until testing. Flexural strength testing, outlined in...
For compressive strength tests, ASTM C 109-05 standards prescribe a cement-sand mix ratio of 1:2.75 and a water/cement ratio of 0.485 for making 2-inch cubes. These cubes are mixed, cast, and cured in saturated lime water at 23°C until testing. Flexural strength testing, outlined in...
127