Unified Damage Constitutive Model for Fiber-Reinforced Concrete at High Temperature

The marked brittleness of concrete could be overcome by the addition of fibers. This paper experimentally investigated the mechanical properties and constitutive relationship of different fiber reinforced concrete. It is shown from the results that the compressive strength and peak strain of concrete with fiber have little improvement, but the ultimate strain, deformation capacity, toughness and energy dissipation capacity are improved greatly. The damage constitutive model recommended by the emendatory code for design of concrete structure (appendix C) (GB50010-2002) is applied for calculations and analyses according to the test results. The damage constitutive model and non-elastic constitutive model of different fiber reinforced concrete are established based on the test results. It is indicated from the analyses that the constitutive models established in this paper are in accordance with the characteristic of the fiber reinforced concrete in loading process. The damage constitutive model in appendix C in code could be applied directly in some low precision calculation and engineering application.

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Uniaxial Compressive Test of High Ductile Fiber-Reinforced Concrete and Damage Constitutive Model

Advances in Civil Engineering ◽

10.1155/2018/4308084 ◽

2018 ◽

Vol 2018 ◽

pp. 1-12 ◽

Cited By ~ 1

Author(s):

Mingke Deng ◽

Jiaojiao Pan ◽

Xingwen Liang

Keyword(s):

Reinforced Concrete ◽

Constitutive Model ◽

Damage Model ◽

Engineering Application ◽

Strain Curve ◽

Damage Threshold ◽

Fiber Reinforced Concrete ◽

Fiber Reinforced ◽

Uniaxial Compressive Test ◽

Damage Constitutive Model

It has been widely recognized that the constitutive model plays an essential role in engineering application of high ductile fiber-reinforced concrete (HDC). In this research, uniaxial compressive tests were conducted on nine groups of HDC specimens with different mixture ratios and one group of mortar matrix specimens as comparison, discussing the effect of fiber content, water-cement ratio, fly ash content, and sand-binder ratio. According to the characteristics of stress-strain curve of HDC under uniaxial compression, a damage constitutive model was proposed by introducing two damage threshold parameters and then was compared with other existing models. Results indicated that the damage model curves suggested in this paper were best consistent with experimental curves and substantially demonstrate the damage evolution process as well as the cracking resistance effect of fiber bridging stress.

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The Statistical Damage Constitutive Model of the Mechanical Properties of Alkali-Resistant Glass Fiber Reinforced Concrete

Symmetry ◽

10.3390/sym12071139 ◽

2020 ◽

Vol 12 (7) ◽

pp. 1139

Author(s):

Xianzeng Shi ◽

Cong Zhang ◽

Xingde Zhou

Keyword(s):

Reinforced Concrete ◽

Constitutive Model ◽

Strain Curve ◽

Fiber Reinforced Concrete ◽

Fiber Reinforced ◽

Statistical Parameters ◽

Glass Fiber Reinforced ◽

Damage Constitutive Model ◽

Statistical Damage Constitutive Model ◽

Statistical Damage

Alkali-resistant glass fiber reinforced concrete (AR-GFRC) has greatly improved in terms of tensile strength, toughness, durability, and reduction of cracking, which has been proven by testing. However, the constitutive relationship of fiber reinforced concrete under complicated stress represents a complex theoretical problem. In order to investigate the microscopic damage evolution and failure mechanism of AR-GFRC, the meso-statistical damage theory, microcontinuum theory, and composite material theory were considered, and uniaxial tensile tests of two types of AR-GFRC were conducted. A new damage variable expression of the AR-GFRC was proposed, and the stress-strain curve was redefined by considering the residual strength based on experimental fitting parameters and statistical parameters. A Weibull distribution was assumed and a statistical damage constitutive model was developed of the deformation process of the AR-GFRC while considering the residual strength effect; detailed calculation methods to determine the mechanical and statistical parameters of the concrete were developed. The validation results show that the theoretical stress-strain curve of the constitutive model is in good agreement with the experimental curve and the trend is consistent.

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