硅酸盐学报

高温对不同钢纤维掺量超高性能混凝土性能及钢纤维拔出机制的影响

PDF下载

韩方玉 ¹ , 吉旭平 ²^,³ , 刘加平 ¹ , 潘亭宏 ⁴ , 赵文昊 ²^,³ , 汤金辉 ¹ , 沙建芳 ²^,³ , 刘建忠 ²^,³

硅酸盐学报 | 研究论文 2024,52(11): 3565-3571

收起

硅酸盐学报 |研究论文 2024 , 52 (11) : 3565 -3571

高温对不同钢纤维掺量超高性能混凝土性能及钢纤维拔出机制的影响

全屏

韩方玉¹, 吉旭平²^,³, 刘加平¹, 潘亭宏⁴, 赵文昊²^,³, 汤金辉¹, 沙建芳²^,³, 刘建忠²^,³

作者信息

^1．东南大学材料科学与工程学院，南京 2111031

^2．江苏苏博特新材料股份有限公司，南京 211103

^3．高性能土木工程材料国家重点实验室，南京 211103

^4．昆明理工大学建筑工程学院，昆明 650000

通讯作者:

吉旭平（1995—），男，硕士，工程师。

刘加平（1967—），男，博士，教授。

作者简介:

韩方玉（1988—），男，博士，高级工程师。

Mechanical Properties and Pull-out Behavior of Steel Fibers of Ultra-High Performance Concrete Exposed to High Temperature

Fangyu HAN¹, Xuping JI²^,³, Jiaping LIU¹, Tinghong PAN⁴, Wenhao ZHAO²^,³, Jinhui TANG¹, Jianfang SHA²^,³, Jianzhong LIU²^,³

Affiliations

^1.Southeast University, Nanjing, 211103, China

^2.Jiangsu Sobute New Materials Co. Ltd., Nanjing 211103, China

^3.State Key Laboratory of High Performance Civil Engineering Materials, Nanjing 211103, China

^4.Kunming University of Science and Technology, Kunming 650000, China

Corresponding Author:

JI Xuping (1995-), male, Master, Engineer. E-mail: jixuping@cnjsjk.cn;

LIU Jiaping (1967-), male, Ph.D., Professor. 101011659@seu.edu.cn

HAN Fangyu (1988-), male, Ph.D., Senior Engineer. E-mail: hanfanyu@cnjsjk.cn

出版时间: 2024-11-20 doi: 10.14062/j.issn.0454-5648.20230899

文章导航

摘要

收起

为揭示高温对超高性能混凝土（UHPC）性能及钢纤维拔出机制的演变规律，研究了25~800 ℃钢纤维对UHPC力学/热工性能的影响规律，并基于纤维拔出以及SEM测试揭示了钢纤维的高温拔出机制。结果表明：钢纤维会提高UHPC的导热系数，但不改变其随温度升高而降低的基本规律，比热容则相反；UHPC的抗压强度和弹性模量随温度升高先增后减，钢纤维可改善其高温残余抗压强度，但对弹性模量影响较小；温度改变钢纤维拔出模式，25~200 ℃时，钢纤维拔出时表面光滑，UHPC抗拉强度变化不大；400 ℃时，钢纤维拔出会附带部分基体，UHPC抗拉强度开始显著下降；600 ℃及以后钢纤维表现为拔断破坏，钢纤维掺量对UHPC抗拉强度影响较小。

关键词

超高性能混凝土 / 高温 / 钢纤维 / 力学性能 / 热工参数 / 拔出机制

Abstract

收起

Introduction

Ultra-high performance concrete (UHPC), as an advanced cementitious fiber-reinforced composite material, is often widely used as a load-bearing member in the critical parts of various types of large-span and high-rise structures. However, the increasingly frequent fire disasters have posed a great challenge to the safe serviceability of UHPC. Steel fiber, as an important factor for UHPC to achieve ultra-high toughness, the cracking mechanism of steel fibers exposed to high-temperature will directly affect the high-temperature residual properties of UHPC. Although some scholars have carried out studies on the residual properties of UHPC after high temperature, there are less systematic studies on the influence of steel fibers on the mechanical and thermal properties of UHPC, especially on the deterioration mechanism of steel fibers exposed to high temperature. In view of this, this work systematically investigates the influence of steel fiber on the mechanical and thermal properties of UHPC exposed to high temperature. The mathematical model between steel fiber dosage-temperature-mechanical properties/thermal properties was established. In addition, the changes in the pull-out behavior of steel fibers from the UHPC matrix at different temperatures were investigated for the first time, and the deterioration mechanism of steel fibers exposed to high temperature was elucidated based on SEM tests.

Methods

The Onoda P.II 52.5 cement and the blending material produced by Jiangsu Sobute New Material Co. were used, respectively. At the same time, an appropriate amount of polypropylene fiber was mixed to reduce the risk of explosive spalling of UHPC. UHPC with 0%, 1.0%, 2.0% and 2.5% steel fiber volume mixing were prepared. The concrete molding size was 100 mm×100 mm×100 mm, and 28 d standard curing was carried out after the casting was completed. Then the mechanical and thermal properties were tested after high temperature. The changes in the pull-out mechanism of steel fibers after high temperature were also investigated.

Results and discussion

The compressive strength of UHPC after high temperature with different steel fiber dosage increases and then decreases with temperature. The addition of steel fibers can improve its overall compressive strength to different degrees. The tensile strength of UHPC shows almost monotonically decreasing with the increase of temperature, and the degree of loss rate is greater. Among them, the enhancement of steel fiber addition can obviously improve the tensile strength of UHPC at room temperature as well as at 200 ℃, but the degree of its enhancement with the increase in temperature gradually weakened. The elasticity modulus of UHPC with the increase in temperature first increased and then decreased, and the overall rule of change is similar to the compressive strength. The thermal conductivity of UHPC shows a monotonically decreasing law with temperature, which is mainly because the high temperature makes the organic fiber in UHPC melt, free water continues to evaporate, and the hydration products continue to decompose and so on to reduce the apparent density of the system. The addition of the steel fibers effectively improves the thermal conductivity of UHPC. The specific heat capacity showed the opposite law to the thermal conductivity. In addition, the maximum pull-out load, pull-out work and bond strength of steel fibers at 200 ℃ increased to varying degrees, compared to room temperature. At 400 ℃, relevant parameters began to have a substantial decline. When the temperature reached 600 ℃, the failure mode of steel fibers changed from pull-out to pull-off mode.

Conclusions

The compressive strength of UHPC increases at the beginning and then decreases with the increase of temperature, and reaches the peak value at 200 ℃. The addition of steel fiber does not affect the trend of UHPC residual compressive strength exposed to high temperature, but improve absolute value of its residual strength. Temperature changes pull-out mode of steel fiber. At 25-200 ℃, the surface of the steel fibers was smooth when they were pulled out, and the tensile strength of UHPC did not change much. At 400 ℃, steel fibers were attached to part of the matrix when they were pulled-out, UHPC tensile strength began to drop significantly. At 600 ℃, the failure mode of steel fibers changed from pull-out to pull-off mode. The tensile strength of UHPC with different steel fibers continues to decline, and the difference gradually narrowed. The elasticity modulus of UHPC reached its peak at 200 ℃ and began to decline rapidly, and its sensitivity to high temperature is much greater than the compressive and tensile strength changes, the value of the proposal can be used as an important indicator for the assessment of the safety of the relevant building after the fire, and the incorporation of steel fibers does not affect the overall development of its law. Steel fiber can significantly increase the thermal conductivity of UHPC, but will not change the overall trend of thermal conductivity with the increase in temperature. The thermal conductivity of UHPC decrease with the increase of temperature and the gradual decrease in the overall trend of change; specific heat capacity shows the opposite development law with the thermal conductivity. Copper-plated steel fiber as UHPC commonly used metal fiber, can maintain good mechanical properties and play a toughening crack resistance before 400 ℃. When the temperature reached at 600 ℃ and later, the degree of deterioration of copper-plated steel fiber itself is greater than the fiber-matrix interface transition zone, which leads to UHPC tensile and compressive drop in coordination, it is recommended that the steel fiber's own high-temperature performance enhancement should be focused on under this condition.

Key words

ultra-high performance concrete / high temperature / steel fiber / mechanical property / thermal property / pull-out

引用本文

韩方玉, 吉旭平, 刘加平, 潘亭宏, 赵文昊, 汤金辉, 沙建芳, 刘建忠. 高温对不同钢纤维掺量超高性能混凝土性能及钢纤维拔出机制的影响. 硅酸盐学报, 2024 , 52 (11) : 3565 -3571 . DOI: 10.14062/j.issn.0454-5648.20230899

Fangyu HAN, Xuping JI, Jiaping LIU, Tinghong PAN, Wenhao ZHAO, Jinhui TANG, Jianfang SHA, Jianzhong LIU. Mechanical Properties and Pull-out Behavior of Steel Fibers of Ultra-High Performance Concrete Exposed to High Temperature[J]. Journal of the Chinese Ceramic Society, 2024 , 52 (11) : 3565 -3571 . DOI: 10.14062/j.issn.0454-5648.20230899

基金

收起

国家重点研发计划(2021YFB2601002)
江苏省基础研究计划自然科学基金-前沿引领技术基础研究专项(BK20222004)
中交科技研发项目(K22096-2)
工程咨询项目(8512008540)

参考文献

收起

文献

收起

参考文献引证文献

排序方式：

2024年第52卷第11期

PDF下载

引用本文

BibTeX

文章信息

doi: 10.14062/j.issn.0454-5648.20230899

接收时间：2023-11-22
首发时间：2026-10-22
出版时间：2024-11-20

补充材料

相关文章

文章信息

作者

出版历史

收稿日期：2023-11-22
修回日期：2024-02-18

基金

国家重点研发计划(2021YFB2601002)

江苏省基础研究计划自然科学基金-前沿引领技术基础研究专项(BK20222004)

中交科技研发项目(K22096-2)

工程咨询项目(8512008540)

作者信息

^1．东南大学材料科学与工程学院，南京 2111031

^2．江苏苏博特新材料股份有限公司，南京 211103

^3．高性能土木工程材料国家重点实验室，南京 211103

^4．昆明理工大学建筑工程学院，昆明 650000

通讯作者:

吉旭平（1995—），男，硕士，工程师。

刘加平（1967—），男，博士，教授。

参考文献

分享链接

https://castjournals.cast.org.cn/joweb/gsyxb/CN/10.14062/j.issn.0454-5648.20230899

分享至

全文二维码

扫描看全文

引用本文

BibTeX

本文的引用情况

2种不同金属材料的力学参数

科 Family	属数 Number of genus	种数 Number of species	占总种数比例 Percentage of total species (%)	属 Genus	种数 Number of species	占总种数比例 Percentage of total species (%)
鹅膏菌科Amanitaceae	2	11	5.26	鹅膏菌属 Amanita	10	4.78
小菇科 Mycenaceae	2	12	5.74	丝盖伞属 Inocybe	5	2.39
多孔菌科 Polyporaceae	8	14	6.70	蜡蘑属 Laccaria	5	2.39
红菇科 Russulaceae	3	23	11.00	小皮伞属 Marasmius	6	2.87
				小菇属 Mycena	11	5.26
				光柄菇属 Pluteus	5	2.39
				红菇属 Russula	17	8.13
				栓菌属 Trametes	5	2.39

关闭全屏

BibTeX
EndNote
RefWorks
TxT