Frost-heaving mechanical model for concrete face slabs of earthen dams in cold regions

Qin, Zipeng; Lai, Yuanming; Tian, Yan; Yu, Fan

doi:10.1016/j.coldregions.2019.03.009

Cited by 34 publications

(13 citation statements)

References 26 publications

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“…It is well know that the concrete face slab is the main impervious structure of the CFRD, the structural integrity of the concrete slab is essential to ensure the normal operation and safety of CFRD 1,4,5,7 . In northern and northwestern China, air temperatures as low as -20 °C are common during winter months, face slab concrete frequently suffers from serious frost damage in these regions, which brings great challenges to the operation and safety of water conservancy projects during freezing periods 8,9 . Therefore, how to improve the frost resistance of face slab concrete in cold regions is one of the important issues in CFRD design and construction in China.…”

Section: Introductionmentioning

confidence: 99%

Comparison of Fly Ash, Pva Fiber, Mgo and Shrinkage-Reducing Admixture on the Frost Resistance of Face Slab Concrete via Pore Structural and Fractal Analysis

et al. 2021

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Face slab concrete suffers from serious frost damage in cold regions in China, how to improve the frost resistance of face slab concrete in cold regions is one of the important issues in concrete faced rockfill dam (CFRD) design and construction. The results in this paper indicate that the frost resistance of concrete can be improved by adding fly ash, fiber, MgO and shrinkage-reducing admixtures (SRA), and the efficiency is in the sequence: (fly ash + fiber) > fiber > fly ash > MgO > SRA. The incorporation of 0.8 kg/m 3 PVA fiber and 20 wt% fly ash together enhances the compressive strength and tensile capacity of concrete by 6-7 % at late age, whereas the addition of 6 wt% MgO or 1 wt% SRA reduces the compressive strength and tensile capacity by about 4-10 % at various ages. The Ds of concrete added with fly ash, fiber, MgO and SRA is within the range of 2.619-2.796. The frost resistance of concrete correlates linearly with the air void parameters, pore structures and Ds. The utilization of fly ash and/or PVA fiber refines and optimizes the pore structure, thus increasing Ds and improving the frost resistance. On the contrary, MgO and SRA in this study are less effective in refining the pores than PVA fiber and fly ash, thereby producing smaller Ds and relatively weaker frost resistance.

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Section: Introductionmentioning

confidence: 99%

Comparison of Fly Ash, Pva Fiber, Mgo and Shrinkage-Reducing Admixture on the Frost Resistance of Face Slab Concrete via Pore Structural and Fractal Analysis

et al. 2021

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“…Infrastructure built in cold regions, such as roads [1], railways [2], pipelines [3], buildings [4] and dams [5], is always subject to frost heaves, resulting in great damage. To address this engineering problem, frost heaves should be considered in the building design phase; thus, the prediction of frost heaves is necessary.…”

Section: Introductionmentioning

confidence: 99%

Application of the Segregation Potential Model to Freezing Soil in a Closed System

Zhang

Sheng

Huang

et al. 2020

Water

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Previous studies have shown that an accurate prediction of frost heaves largely depends on the pore water pressure and hydraulic conductivity of frozen fringes, which are difficult to determine. The segregation potential model can avoid this problem; however, the conventional segregation potential is considered to be approximately unchanged at a steady state and only valid in an open system without dehydration in the unfrozen zone. Based on Darcy’s law and the conventional segregation potential, the segregation potential was expressed as a function of the pore water pressure at the base of the ice lens, the pore water pressure at the freezing front, the freezing temperature, the segregation freezing temperature and the hydraulic conductivity of the frozen fringe. This expression indicates that the segregation potential under quasi-steady-state conditions is not a constant in a closed system, since the pore water pressure at the freezing front varies with the freezing time owing to the dehydration of the unfrozen zone, and that when the pore water pressure at the freezing front is equal to that at the base of the ice lens, the water migration and frost heave will be terminated. To analyze the possibility of applying the segregation potential model in a closed system, a series of one-sided frost heave tests under external pressure in a closed system were carried out in a laboratory, and the existing frost heaving test data from the literature were also analyzed. The results indicate that the calculated frost heave was close to the tested data, which shows the applicability of the model in a closed system. In addition, the results show the rationality of calculating the segregation potential from the frost heaving test by comparing the potential with that calculated from the numerical simulation results. This study attempted to extend the segregation potential model to freezing soil in a closed system and is significant to the study of frost heaves.

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“…Gong [5] analyzed the mechanisms of frost damage to concrete pore structures using ultrasonic nondestructive testing, image analysis, and scanning electron microscopy. Qin [6] investigated the types of damage to slabs under the effect of static ice pressure, and clarified the mechanism of frost-heave damage using a theoretical model. It is generally acknowledged that the frost-heave force produced by the water-ice phase transition causes cracks to propagate [7].…”

Section: Introductionmentioning

confidence: 99%

Experimental and Theoretical Determination of the Frost-Heave Cracking Law and the Crack Propagation Criterion of Slab Track with Water in the Crack

et al. 2019

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Crack propagation produced by frost heave affects the durability of slab-track structures in high-humidity and cold regions in China. This work is intended to reveal the evolution laws of frost-heave crack propagation, establish evaluation criteria for crack propagation, and investigate factors involved in frost-heave crack propagation. Firstly, by preparing slab-track specimens with initial cracks, an experiment of frost-heave crack propagation was designed. The process of frost-heave crack propagation was carried out by means of digital image correlation (DIC) technology and acoustic emission (AE) technology, respectively. These experiments revealed the evolution laws of generalized strain and AE events’ location during crack initiation and propagation, respectively, and the key parameters of micro-crack initiation strain and unstable propagation strain were obtained. By using theoretical and experimental analysis, a double-strain criterion for frost-heave crack propagation was proposed. Finally, factors involved in frost-heave crack propagation were investigated. The results show that crack initiation can be reflected by the crack-tip strain. The average micro-crack initiation strain and unstable propagation strain were found to be 224 με and 243 με, respectively. Moreover, it was found that the frost-heave crack propagation was caused by an ice plug which formed at the crack opening. When the crack width is larger than 2.7 mm and the external temperature is lower than −6.6 °C, cracks propagate easily under the frost-heave force.

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Frost-heaving mechanical model for concrete face slabs of earthen dams in cold regions

Cited by 34 publications

References 26 publications

Comparison of Fly Ash, Pva Fiber, Mgo and Shrinkage-Reducing Admixture on the Frost Resistance of Face Slab Concrete via Pore Structural and Fractal Analysis

Comparison of Fly Ash, Pva Fiber, Mgo and Shrinkage-Reducing Admixture on the Frost Resistance of Face Slab Concrete via Pore Structural and Fractal Analysis

Application of the Segregation Potential Model to Freezing Soil in a Closed System

Experimental and Theoretical Determination of the Frost-Heave Cracking Law and the Crack Propagation Criterion of Slab Track with Water in the Crack

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