聚丙烯纤维混凝土的力学性能研究-资料分享下载-无忧分享网

摘要

本文首先研究了高温循环作用后混凝土力学性能的变化规律，其次针对聚丙

烯纤维混凝土展开了试验研究，分析了高温、水浸泡作用后聚丙烯纤维混凝土力

学性能的变化规律和劣化机理，探讨了加载速率对聚丙烯纤维混凝土单轴抗压性

能的影响，研究了含不同宏观裂纹聚丙烯纤维混凝土的单轴压缩破坏方式，并提

出了一种关于计算混凝土剪切强度的试验方法。具体如下：

(1) 首先进行了高温循环作用后混凝土的力学性能研究，分析了经受不同高

温不同循环次数作用后混凝土力学性能的变化，探讨了高温循环作用后混凝土峰

值应力、峰值应变、弹性模量和应力-应变曲线随高温循环次数的变化规律，为进

行混凝土建筑结构在火灾后的损伤评估和稳定性分析时提供一些试验数据及理论

基础。

(2) 考虑不同温度、不同纤维掺量对聚丙烯纤维混凝土力学性能的影响，分析

了不同纤维掺量对混凝土峰值应力、峰值应变、弹性模量和应力-应变关系的影响

变化，探讨了高温作用后聚丙烯纤维混凝土力学性能的劣化机理，总结了高温作

用后聚丙烯纤维混凝土单轴压缩试验过程中的破坏规律。

(3) 聚丙烯纤维混凝土由于其优越的抗渗性和抗裂性广泛应用于长期在水环

境中工作的混凝土结构，本文研究了水饱和状态下纤维掺量对聚丙烯纤维混凝土

力学性能的影响；根据普通混凝土的应力-应变曲线方程，结合试验数据通过 origin

软件拟合得到了水饱和与干燥条件下聚丙烯纤维混凝土的应力-应变曲线方程；基

于普通混凝土损伤本构模型，结合试验数据计算得到了聚丙烯纤维混凝土的损伤

本构模型及损伤演化曲线。

(4) 利用液压伺服试验系统对聚丙烯纤维混凝土进行了 0.5MPa/s、1MPa/s、

1.5MPa/s 加载速率下的单轴压缩试验，系统分析了加载速率与纤维掺量对聚丙烯

纤维混凝土峰值应力、峰值应变、弹性模量和应力-应变关系的影响，探讨了聚丙

烯纤维混凝土抗压强度、破坏方式与加载速率的关系。

(5) 对高温作用后含宏观裂纹的聚丙烯纤维混凝土进行了单轴压缩试验，研究

了含宏观裂纹聚丙烯纤维混凝土的抗压强度、破坏方式及剪切强度随温度和裂纹

宽度的变化规律，并提出了一种通过制作含宏观裂纹试件进行单轴压缩试验来测

量混凝土剪切强度的试验方法。

最后依据试验研究结果，总结了高温、水浸泡、不同加载速率作用下聚丙烯

纤维混凝土的力学性能变化和单轴压缩破坏规律，提出了一种通过制作含宏观裂

纹试件进行单轴抗压试验来测量混凝土剪切强度的试验方法。本文关于聚丙烯纤

维混凝土的研究对聚丙烯纤维在实际混凝土结构中的广泛应用具有重要指导作用。

关键词：聚丙烯纤维混凝土高温水饱和加载速率峰值应力剪切

强度高温循环

ABSTRACT

In this thesis, an experimental investigation is conducted to study mechanical of

concrete under different high temperature cycles and polypropylene-fiber reinforced

concrete. It discusses the mechanical properties deterioration mechanism and law of

concrete under different high temperature and polypropylene-fiber reinforced concrete

under the influence of high temperature and water-saturated, and analyzes the effect of

the mechanical properties of uniaxial compression under different loading rates. The

destruction mechanism of uniaxial compression of polypropylene-fiber reinforced

concrete containing different cracks is analyzed and a new method about measuring the

shear strength of concrete is attained, this paper focuses on the following aspects

primarily:

(1) The mechanical properties of concrete after high temperature cycles are

studied. The influence of the different numbers of high temperature cycles on peak

stress, peak strain, elastic modulus, stress-strain curve of concrete is analyzed. Some

experimental data and theoretical basis for the fire value and stability assessment of the

concrete structure after fire are attained.

(2) Considering the effect of high temperature and different fiber dosage, the

experiment studies the mechanical properties of polypropylene-fiber reinforced concrete.

The influence of the different high-temperature and different fiber dosage on peak stress,

elastic modulus, stress-strain curve of polypropylene-fiber reinforced concrete is

analyzed. The regularity and mechanism of compressive strength, elastic modulus,

stress-strain curve of polypropylene-fiber concrete affected by different temperature and

different fiber dosage is studied. The physical and chemical changes, damage process

and the micro-mechanisms of surface elements of polypropylene-fiber concrete are

summarized.

(3) The polypropylene-fiber concrete with superior penetration-proof quality and

crack resistance is widely used in the concrete structure soaking in water. Therefore, the

thesis studies the mechanical properties of polypropylene-fiber reinforced concrete after

water soaking; the uniform numerical stress-strain relationship is put forward according

to the good similarity on the stress-strain curve of saturated and dry polypropylene-fiber

concrete with the experiments data and software of origin. Based on the basic principles

of damage mechanics, the damage evolution curve of the polypropylene-fiber concrete

is attained.

(4) The uniaxial loading tests of polypropylene-fiber reinforced concrete after three

different kinds of loading rates of 0.5MPa/s, 1MPa/s, 1.5MPa/s are conducted on a

micro-controlled electro-hydraulic uniaxial loading system. The influence of the

different loading rates and different fiber dosage on peak stress, elastic modulus,

stress-strain curve of polypropylene-fiber concrete is analyzed. The relationship

between compressive strength and loading rates of polypropylene-fiber concrete is

summarized.

(5) The thesis studies the mechanical properties of polypropylene-fiber reinforced

concrete with macroscopic cracks after different high-temperature. The regularity and

mechanism of compressive strength, failure mode, shear strength of polypropylene-fiber

reinforced concrete affected by different temperature and the crack width is studied, and

a new experimental method by making samples with cracks to measure the shear

strength by uniaxial loading tests is attained.

Based on the experiment results, the thesis sums up the deterioration and

destructive regularity of polypropylene-fiber reinforced concrete after high temperature,

water and different kinds of loading rates, and a new experimental methods by making

samples with cracks to measure the shear strength by uniaxial loading tests is attained.

In this thesis, the studies on polypropylene-fiber reinforced concrete has an important

guiding role to the widely use of polypropylene-fiber in practical engineering.

Key Word: polypropylene-fiber, concrete, high temperature,

water-saturated, loading rates, peak stress，shear strength, high

temperature cycles

中文摘要

ABSTRACT

第一章绪论 .............................................................................................................. 1

1.1 研究背景............................................................................................................. 1

1.2 研究意义............................................................................................................. 1

1.3 聚丙烯纤维混凝土的研究概况......................................................................... 1

1.3.1 聚丙烯纤维混凝土的基本特性 .................................................................. 1

1.3.2 聚丙烯纤维混凝土的施工应用 .................................................................. 2

1.3.3 聚丙烯纤维在混凝土中的作用机理 .......................................................... 2

1.4 水饱和混凝土力学性能研究概况..................................................................... 5

1.5 高温作用后混凝土及聚丙烯纤维混凝土性能研究概况................................. 5

1.6 混凝土本构模型研究概况................................................................................. 7

1.6.1 混凝土损伤本构模型 .................................................................................. 7

1.6.2 纤维混凝土损伤本构模型 .......................................................................... 7

1.7 论文的主要研究内容......................................................................................... 7

1.7.1 论文的创新点 .............................................................................................. 8

1.7.2 论文的主要内容 .......................................................................................... 8

第二章高温循环作用后混凝土的力学性能研究 .................................................. 10

2.1 引言................................................................................................................... 10

2.2 试验概况........................................................................................................... 10

2.2.1 试件制作 .................................................................................................... 10

2.2.2 混凝土高温循环试验 .................................................................................11

2.2.3 单轴压缩试验 ............................................................................................ 12

2.3 试验结果分析................................................................................................... 12

2.3.1 应力-应变曲线与温度及循环次数的关系 ............................................... 12

2.3.2 峰值应力与加热温度及循环次数的关系 ................................................ 13

2.3.3 峰值应变变化规律 .................................................................................... 15

2.3.4 弹性模量变化规律 .................................................................................... 16

2.4 本章小结........................................................................................................... 18

第三章高温作用后聚丙烯纤维混凝土的力学性能研究 ...................................... 19

3.1 引言................................................................................................................... 19

3.2 试验概况........................................................................................................... 19

3.2.1 试件制作 .................................................................................................... 19

3.2.2 高温试验 .................................................................................................... 20

3.2.3 单轴抗压试验 ............................................................................................ 21

3.3 试验结果与分析............................................................................................... 21

3.3.1 试验现象及机理分析 ................................................................................ 21

3.3.2 应力-应变曲线与温度关系 ....................................................................... 24

3.3.3 应力-应变曲线与聚丙烯纤维掺量的关系 ............................................... 25

3.3.4 峰值应力与温度及纤维掺量的关系 ........................................................ 27

3.3.5 弹性模量与温度及纤维掺量的关系 ........................................................ 28

3.4 本章小结........................................................................................................... 29

第四章水饱和聚丙烯纤维混凝土力学性能研究 .................................................. 31

4.1 引言................................................................................................................... 31

4.2 试验概况........................................................................................................... 31

4.2.1 试件制作 .................................................................................................... 31

4.2.2 试验设备 .................................................................................................... 32

4.3 试验结果与分析............................................................................................... 32

4.3.1 试验现象及机理分析 ................................................................................ 32

4.3.2 应力-应变曲线与聚丙烯纤维掺量及水饱和状态的关系 ....................... 34

4.3.3 水饱和与干燥条件下聚丙烯纤维混凝土应力-应变曲线方程 ............... 35

4.3.4 峰值应力与聚丙烯纤维掺量及水饱和状态的关系 ................................ 37

4.3.5 峰值应变与聚丙烯纤维掺量及水饱和状态的关系 ................................ 38

4.3.6 弹性模量与聚丙烯纤维掺量及水饱和状态的关系 ................................ 39

4.4 聚丙烯纤维混凝土单轴受压本构模型的建立............................................... 40

4.4.1 损伤本构模型 ............................................................................................ 40

4.4.2 聚丙烯纤维混凝土单轴压缩损伤本构关系及损伤演化曲线 ................ 43

4.5 本章小结........................................................................................................... 44

第五章加载速率对聚丙烯纤维混凝土力学性能的影响研究 .............................. 46

5.1 引言................................................................................................................... 46

5.2 不同加载速率下聚丙烯纤维混凝土力学性能试验....................................... 46

5.2.1 试件制作 .................................................................................................... 46

5.2.2 试验方法 .................................................................................................... 46

5.3 试验结果与分析............................................................................................... 47

5.3.1 试件破坏形态 ............................................................................................ 47

聚丙烯纤维混凝土的力学性能研究

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