Compressive stress-strain relationship for fly ash concrete under thermal steady state

Fan, Kunjie; Li, Dawang; Damrongwiriyanupap, Nattapong; Li, Long-yuan

doi:10.1016/j.cemconcomp.2019.103371

Cited by 25 publications

(11 citation statements)

References 24 publications

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“…On the other hand, after comparing the stress-strain relationship subjected to FE results of a concrete cube containing 20% FA, numerically obtained in the current study, to other examined constitutive models for compression state of concrete based on Popovics formulations and Eurocode standards, it is proved that the numerical results of the current study have a relatively high approximation with the proposed constitutive models which were found through other empirical functions, especially Eurocode and Popovic relations [22][23][24][25][26][27]. The value of the 'n' parameter for the constitutive model presented by Fan et al [19] in the range of 3-4 is strongly recommended for this concrete type with a low calcium amount. It is necessary to point out that the experimental data achieved in the present study (compressive strength for 20% FA, and concrete density) were utilized for defining material properties in the FE model of GPC.…”

Section: Validation Of the Developed Constitutive Model For Gpc Concretesupporting

confidence: 62%

“…As shown in Figure 1, 'n' is attributed to the peak stress value. Additionally, Fan et al [19] demonstrated that the parameter 'n' at different temperatures can play an effective role in the nonlinear behavior of concrete in the descending region at the collapse moment. It was proved that 'n' has a significant effect on the nonlinear behavior of concrete resulting in less plastic strain in the concrete specimens containing FA compared to those with conventional paste such as OPC.…”

Section: Determination Of Basic Equations For the Stress-strain Curve...mentioning

confidence: 99%

“…Popovics [24] Fan et al [19] Popovics [25] and Mander et al [26] Modified Popovics Formula 2 (Halahla [23]) From Figures 2 and 3, it can be observed that the predictions of constitutive models by Isojeh et al [22] and EN1992-1-1 [27] are the closest to the numerical results of the present study, while the equations presented by Popovics [25] andMander et al [26] and Fan et al [19], Halahla [23] yield lower and higher values, respectively, than the current study. Hence, the developed constitutive concrete model using the modified Popovics model recommended by Isojeh et al [22] using Equation (2) for calculating Ec was chosen as the basic equation for concrete specimens involving 20% FA content at age of 28 days, to assess the nonlinear (cracking and crushing) behavior of this concrete type for the next stages of this study.…”

Section: Validation Of the Developed Constitutive Model For Gpc Concretementioning

confidence: 99%

“…Popovics [24] Fan et al [19] Popovics [25] and Mander et al [26] Modified Popovics Formula 2 (Halahla [23])…”

Section: Validation Of the Developed Constitutive Model For Gpc Concretementioning

confidence: 99%

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Static and Seismic Responses of Eco-Friendly Buried Concrete Pipes with Various Dosages of Fly Ash

Mostofizadeh

Tee

2021

Applied Sciences

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In this paper, an evaluation based on the detailed failure has been conducted for underground sewage Geopolymer concrete (GPC) pipes under static and seismic loadings with consideration of the optimal time steps in the time-dependent process related to nonlinear behavior of GPC pipes in static and dynamic analyses. The ANSYS platform is employed for improving an advanced FE model for a GPC pipe which can simulate the performance of underground GPC pipes containing various percentages of fly ash (FA) as a Portland cement (PC) replacement. Subsequently, the time-dependent model is used to assess the efficacy of this concrete admixture (FA) in the structural response of the unreinforced GPC pipe in FEM. Indeed, the generated GPC pipe with the three-dimensional model has the potential to capture the nonlinear behavior of concrete which depicts the patterns of tensile cracking and compressive crushing that occur over the applied static loads in the FE model. The main issue in this paper is the assessment of the GPC pipe response typically based on the displacement due to static and seismic loadings. The numerical results demonstrated that the optimal displacement was obtained when the structural response had typically the lowest value for GPC pipes containing 10–30% FA and 20% FA under static and seismic loadings, respectively. Indeed, a reduction by 25% for the vertical displacement of a GPC pipe containing 20% FA was observed compared to that without FA under time-history analysis.

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Section: Validation Of the Developed Constitutive Model For Gpc Concretesupporting

confidence: 62%

Section: Determination Of Basic Equations For the Stress-strain Curve...mentioning

confidence: 99%

Section: Validation Of the Developed Constitutive Model For Gpc Concretementioning

confidence: 99%

“…Popovics [24] Fan et al [19] Popovics [25] and Mander et al [26] Modified Popovics Formula 2 (Halahla [23])…”

Section: Validation Of the Developed Constitutive Model For Gpc Concretementioning

confidence: 99%

See 2 more Smart Citations

Static and Seismic Responses of Eco-Friendly Buried Concrete Pipes with Various Dosages of Fly Ash

Mostofizadeh

Tee

2021

Applied Sciences

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“…Coal fly ash is a type of ultrafine particle produced by coal carbon combustion in power plants. As an industrial byproduct, coal fly ash has been broadly utilized for concrete in recent decades, and its recovery has brought significant economic and environmental benefits [ 26 , 27 , 28 ]. When coal fly ash is used as an SCM to prepare concrete, the loss on ignition is a problem that must be considered.…”

Section: Introductionmentioning

confidence: 99%

Effect of Nano Silica Particles on Impact Resistance and Durability of Concrete Containing Coal Fly Ash

Zhang

Sha

et al. 2021

Nanomaterials

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In this study, the effect of adding nano-silica (NS) particles on the properties of concrete containing coal fly ash were explored, including the mechanical properties, impact resistance, chloride penetration resistance, and freezing–thawing resistance. The NS particles were added into the concrete at 1%, 2%, 3%, 4%, and 5% of the binder weight. The behavior under an impact load was measured using a drop weight impact method, and the number of blows and impact energy difference was used to assess the impact resistance of the specimens. The durability of the concrete includes its chloride penetration and freezing–thawing resistance; these were calculated based on the chloride diffusion coefficient and relative dynamic elastic modulus (RDEM) of the samples after the freezing–thawing cycles, respectively. The experimental results showed that the addition of NS can considerably improve the mechanical properties of concrete, along with its freezing–thawing resistance and chloride penetration resistance. When NS particles were added at different replacement levels, the compressive, flexural, and splitting tensile strengths of the specimens were increased by 15.5%, 27.3%, and 19%, respectively, as compared with a control concrete. The addition of NS enhanced the impact resistance of the concrete, although the brittleness characteristics of the concrete did not change. When the content of the NS particles was 2%, the number of first crack impacts reached a maximum of 37, 23.3% higher compared with the control concrete. Simultaneously, the chloride penetration resistance and freezing–thawing resistance of the samples increased dramatically. The optimal level of cement replacement by NS in concrete for achieving the best impact resistance and durability was 2–3 wt%. It was found that when the percentage of the NS in the cement paste was excessively high, the improvement from adding NS to the properties of the concrete were reduced, and could even lead to negative impacts on the impact resistance and durability of the concrete.

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Residual mechanical properties of concrete containing lightweight expanded clay aggregate (LECA) after exposure to elevated temperatures

Dabbaghi

Dehestani

Yousefpour

2021

Structural Concrete

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The mechanical properties of light-weight concrete (LWC) in fire are known to be better than those of normal-strength concrete (NSC), both at high temperature (hot properties) and after cooling (residual properties). The objective of this paper is to increase the knowledge of LWC's residual properties by testing a number of mixes containing expanded clay as light-weight coarse aggregate.An experimental program was carried out, in which one normal-weight concrete mix and two lightweight aggregate mixes containing different amounts of LECA were used to fabricate 72 concrete cylinders and 36 concrete prisms. All mixes contained silica fume as a supplementary cementitious material. The specimens were tested at the ambient temperature and after exposure to temperatures of 250, 500, and 750 C to obtain their compressive and tensile strength, modulus of elasticity, and stress-strain response. Results indicate that exposure to temperatures up to 250 C has no significant effect on the mechanical properties of concrete containing LECA just as in normal weight concrete.However, with increasing the temperature, increasing the lightweight aggregate content of the mix resulted in better strength retention after exposure to elevated temperatures. The experimental data are also used to develop equations to evaluate the residual mechanical properties of concrete.

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Compressive stress-strain relationship for fly ash concrete under thermal steady state

Cited by 25 publications

References 24 publications

Static and Seismic Responses of Eco-Friendly Buried Concrete Pipes with Various Dosages of Fly Ash

Static and Seismic Responses of Eco-Friendly Buried Concrete Pipes with Various Dosages of Fly Ash

Effect of Nano Silica Particles on Impact Resistance and Durability of Concrete Containing Coal Fly Ash

Residual mechanical properties of concrete containing lightweight expanded clay aggregate (LECA) after exposure to elevated temperatures

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