Experimental Investigation of Neutralisation of Concrete with Fly Ash as Fine Aggregate in Freeze-Thaw Environment

Zhang, Dongsheng; Mao, Mingjie; Yang, Qiuning; Zhang, Wenbo; Han, Pengfei

doi:10.1155/2019/6860293

Cited by 5 publications

(4 citation statements)

References 44 publications

(54 reference statements)

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“…rough freeze-thaw and carbonation cycle tests, Zhang et al [12] discussed the change characteristics of carbonation depth and relative dynamic elastic modulus of fly ash fine aggregate concrete under the alternating action of freeze-thaw cycles and carbonation. Xiang et al [13] designed cement-fly ash mortar and adopted the orthogonal design method, mainly studying the influence of carbonation on the compressive strength and antifreeze strength of the cube under freeze-thaw conditions.…”

Section: Introductionmentioning

confidence: 99%

Experimental Study on the Effect of Freeze-Thaw Cycles on Axial Tension and Compression Performance of Concrete after Complete Carbonization

Cao

Liu

Zhou

et al. 2021

Advances in Civil Engineering

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The effect of freeze-thaw cycles on the axial tension and axial compression properties of completely carbonized concrete are investigated in this study. Three grade concrete specimens (C30, C40, and C45) were fabricated. The freeze-thaw cycle test was carried out on the completely carbonized specimens, followed by axial tension and axial compression tests. The results show that completed carbonization increases the axial tensile peak stress of C30, C40, and C45 concrete specimens by 8.7%, 9.7%, and, 12.1%, respectively. The peak axial tension strain increased by 1.9%, 7.2%, and 9.6%, respectively. The peak axial compressive stress increased by 10.5%, 19.1%, and 24.1%, respectively. The peak axial compressive strain decreased by 13.7%, 14.1%, and 14.3%, respectively. With the increase of freeze-thaw cycles, the peak stress of tensile stress, peak strain, and compressive stress of concrete decrease continuously. The peak strain of compressive strain increases. The lower the strength grade of concrete, the faster the decline rate of stress and strain. According to the data changes of peak stress and peak strain at different times of freeze thaw after carbonization, the stress-strain curve fitting formula for concrete under freeze-thaw cycles after complete carbonization is put forward, which has a good coincidence with the experimental result.

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Section: Introductionmentioning

confidence: 99%

Experimental Study on the Effect of Freeze-Thaw Cycles on Axial Tension and Compression Performance of Concrete after Complete Carbonization

Cao

Liu

Zhou

et al. 2021

Advances in Civil Engineering

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“…Contemporary research regarding concrete with fly ash as the fine aggregate (CFA) has focused on the concrete's mechanical properties [12][13][14][15], broadly confirming that the compressive and flexural strengths of CFA are superior to ordinary concrete. Few studies have considered the durability of CFA [15][16][17]. is lack of knowledge regarding CFA durability, and, in particular, its volume stability, limits its practical engineering applications.…”

Section: Introductionmentioning

confidence: 99%

Shrinkage Effects of Using Fly Ash instead of Fine Aggregate in Concrete Mixtures

Zhang

Han

Yang

et al. 2020

Advances in Materials Science and Engineering

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China is the world’s largest emitter of fly ash, an industrial by-product of coal combustion. Motivated towards greener development, China’s engineering industries must determine how to effectively utilize this by-product, while ensuring environmental and public safety protections. This study investigated the use of fly ash instead of fine aggregate in concrete mixtures with a focus on concrete shrinkage. A series of experiments were performed in which fly ash substitution levels, water-binder ratios, and ambient humidities were each respectively and exclusively varied to determine changes in the concrete’s drying and autogenous shrinkages. Experimental results indicated that the substitution of fly ash consistently decreased the drying shrinkage relative to ordinary concrete; a substitution level of 25% optimally reduced the drying shrinkage by 20.81%. A substitution level of 15% decreased the autogenous shrinkage relative to ordinary concrete, whereas higher levels (25, 35, and 45%) increased it. Ambient humidities also affected the concrete shrinkage, but the water-to-binder ratio effects were negligible. Drying shrinkage largely occurred before 28 d, whereas autogenous shrinkage continued after 28 d. Based on these experimental results, we evaluated common theoretical shrinkage models and subsequently developed a modified shrinkage model for application to concrete containing fly ash as fine aggregate.

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“…Some researchers studied the durability of fly ash concrete under the coupling conditions of freeze-thaw and carbonization. For example, Mao et al analyzed the degradation mechanism of the alternate effects of freeze-thaw and carbonization, and discussed the carbonization depth, the relative dynamic modulus of elasticity, and the mass loss changes; and the mathematical expression of the damage coefficient of composite material k(F) pointed out that the damage of concrete caused by the coupling effect is more serious than that by a single factor [10][11][12][13]; Li et al [14] pointed out that carbonization can improve the frost resistance of concrete to a certain extent within a reasonable range. Rao et al used computer tomography (CT) and scanning electron microscope (SEM) to study the microscopic characteristics of fly ash concrete under the alternating effects of freeze-thaw and carbonization [15,16].…”

Section: Introductionmentioning

confidence: 99%

Carbonization Law of Fly Ash Concrete under Freeze-Thaw Cycles Based on Image-Pro Plus

Yuan¹,

Zhao²,

Wang³

et al. 2020

ACSM

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To understand the influence of freeze-thaw on the carbonization performance of concrete in severe cold areas, this paper conducted experiments to explore the carbonization law of fly ash concrete under freeze-thaw cycles. First, carbonization tests were conducted under different freeze-thaw cycles and fly ash contents; then PS (Photoshop) and IPP (Image-Pro Plus) were adopted to measure the carbonized area and calculate the ratio of carbonized area (RCA). The experimental results showed that, when the fly ash content was between 10% and 30%, RCA increased slowly; when the fly ash content was 20%, the convergence point showed up; when the fly ash content was 0, the air-entrained fly ash concrete had the best resistance to carbonation. With the help of PS and IPP, this paper calculated the RCA more accurately and found that, the freeze-thaw cycles can aggravate carbonization, and there is a linear relationship between carbonization depth and RCA. The research findings in this paper can provide a reference for the durability evaluation and design of concrete structures in severe cold areas.

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Experimental Investigation of Neutralisation of Concrete with Fly Ash as Fine Aggregate in Freeze-Thaw Environment

Cited by 5 publications

References 44 publications

Experimental Study on the Effect of Freeze-Thaw Cycles on Axial Tension and Compression Performance of Concrete after Complete Carbonization

Experimental Study on the Effect of Freeze-Thaw Cycles on Axial Tension and Compression Performance of Concrete after Complete Carbonization

Shrinkage Effects of Using Fly Ash instead of Fine Aggregate in Concrete Mixtures

Carbonization Law of Fly Ash Concrete under Freeze-Thaw Cycles Based on Image-Pro Plus

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