Enhancing behavior of large volume underground concrete structure using expansive agents

Liu, Fang; Shen, Shui‐Long; Hou, Dongwei; Arulrajah, Arul; Horpibulsuk, Suksun

doi:10.1016/j.conbuildmat.2016.03.075

Cited by 54 publications

(22 citation statements)

References 34 publications

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“…The waterproong of underground or underwater concrete structures is of great signicance to ensure desired performance and durability, which oen relies on hydrophobic surface coatings that consist of organic ingredients, such as rubber, asphalt binder or other organic materials. [1][2][3] For example, asphalt membranes and polyurethane waterproong paint have been used as coating materials for underground garages and tunnels for decades. 4,5 However, the origin of the hydrophobicity of most surface coatings lies in their own hydrophobic characteristics or simply physical adsorption with the concrete surface.…”

Section: Introductionmentioning

confidence: 99%

A cement paste–tail sealant interface modified with a silane coupling agent for enhancing waterproofing performance in a concrete lining system

Yang

Tao

et al. 2019

RSC Adv.

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Although hydrophobic surface coating of concrete is currently used to enhance waterproofing performance of underground structures, the chemical and mechanical incompatibility between an inorganic cement and organic coating makes it a challenge to ensure long-term waterproofing properties of underground facilities, especially for tunnel lining systems. This study explores the feasibility of using a silane coupling agent to improve compatibility between the cement and tail sealant interface, which aims to reduce the water leakage risk of lining systems. The enhanced waterproofing performance of the cement-tail sealant interface modified with the silane agent was confirmed by its hydrophobicity (i.e. reduced wetting ability) and reduced permeability, which was evaluated by static water-contact angle and impermeability pressure measurements. The processes underlying the enhanced waterproofing performance of the cement-tail sealant interface were revealed by chemical bonding, microstructure and porosity characterization. Fourier transform infrared spectroscopy (FTIR) results of the cement-tail sealant interface confirm the reactions between the silane agent and cement hydration products, while both microstructure and porosity results reveal that the cement-tail sealant interface is denser and less porous, relative to the control cement grout.Conventional tail sealant was used as the base material in this study, which is composed of hydraulic uid, polyisobutylene, cotton ber and active calcium carbonate. Among these ingredients, hydraulic uid and polyisobutylene act as base oil and Fig. 1 (a) Schematic illustration of how a tail shield is applied on the surface of linings, (b) a sketch map of transverse section of a tunnel lining system and (c) a picture of a typical cross-section of a tunnel lining system. 7166 | RSC Adv., 2019, 9, 7165-7175 This journal is

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Section: Introductionmentioning

confidence: 99%

A cement paste–tail sealant interface modified with a silane coupling agent for enhancing waterproofing performance in a concrete lining system

Yang

Tao

et al. 2019

RSC Adv.

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“…Yet, the main disadvantage of mass concrete is that it exhibits high brittleness, low tensile strength and high cracking risk caused by concrete shrinkage, which limits its use in large construction projects under extreme environmental conditions [6,7]. The addition of expansive agents in cementitious binders during the industrial process is a practical strategy for enhancing the strength and anti-cracking performance of cement-based materials [8,9]. For instance, expansive agents could compensate for shrinkage of underground concrete structures in order to avoid water leakage [8].…”

Section: Introductionsmentioning

confidence: 99%

“…The addition of expansive agents in cementitious binders during the industrial process is a practical strategy for enhancing the strength and anti-cracking performance of cement-based materials [8,9]. For instance, expansive agents could compensate for shrinkage of underground concrete structures in order to avoid water leakage [8]. Typical commercial expansive agents are anhydrous calcium sulfoaluminate (3CaO•3Al 2 O 3 •CaSO 4 ), calcium oxide (CaO), and magnesia (MgO), and the mixtures of 3CaO•3Al 2 O 3 •CaSO 4 , CaO, and MgO [8,9].…”

Section: Introductionsmentioning

confidence: 99%

Effects of Expansive Agents on the Early Hydration Kinetics of Cementitious Binders

et al. 2019

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The addition of expansive agents could overcome the main disadvantages of raw concrete including high brittleness and low tensile strength. Few studies have investigated the early hydration kinetics of expansive cementitious binders, though the findings from the early hydration kinetics are helpful for understanding their technical performances. In this study, mixtures of 3CaO•3Al2O3•CaSO4 and CaSO4 (i.e., ZY-type™ expansive agent) with different proportions of mineral admixtures (e.g., fly ash and slag) were added into cement pastes to investigate the early hydration kinetics mechanism of expansive cementitious binders. Early hydration heat evolution rate and cumulative hydration heat were measured by isothermal calorimeter. Kinetic parameters were estimated based on the Krstulovic–Dabic model and Knudsen equations. Mechanical performances of expansive cementitious binders were tested in order to evaluate if they met the basic requirements of shrinkage-compensating materials in technical use. The early hydration heat released from cementitious binders containing ZY-type™ expansive agent was much greater than that released by pure cement, supporting the idea that addition of the expansive agent would improve the reaction of cement. The early hydration kinetic rates were decreased due to the reactions of the mineral admixture (e.g., fly ash or slag) and the ZY-type™ expansive agent in the cement system. The hydration reaction of cementitious binders containing ZY-type™ expansive agent obeyed the Krstulovic–Dabic model well. Three processes are involved in the hydration reaction of cementitious binders containing ZY-type™ expansive agent. These are nucleation and crystal growth (NG), interactions at phase boundaries (I), and diffusion (D). The 14-day expansion rates of cementitious binders containing ZY-type™ expansive agent are in the range of 2.0 × 10−4 to 3.5 × 10−4, which could meet the basic requirements of anti-cracking performances in technical use according to Chinese industry standard JGJ/T 178-2009. This study could provide an insight into understanding the effects of expansive agents on the hydration and mechanical performances of cementitious binders.

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“…A comprehensive literature review shows that the introduction of expansive agents into cement is able to compensate the concrete shrinkage fairly well, and even prestress the outer formwork during the curing time [13][14][15]. Inspired by this, some attempts therefore were made to replace the conventional concrete with self-stressing concrete [16], and the experimental results from Chang et al [17,18] suggested that the self-stressing CFST was a promising alternative because of its constructive capacity in reducing the unfavorable effects caused by debonding.…”

Section: Introductionmentioning

confidence: 99%

Performance of the High-Strength Self-Stressing and Self-Compacting Concrete-Filled Steel Tube Columns Subjected to the Uniaxial Compression

Penghua

Chi

et al. 2017

Int J Civ Eng

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Enhancing behavior of large volume underground concrete structure using expansive agents

Cited by 54 publications

References 34 publications

A cement paste–tail sealant interface modified with a silane coupling agent for enhancing waterproofing performance in a concrete lining system

A cement paste–tail sealant interface modified with a silane coupling agent for enhancing waterproofing performance in a concrete lining system

Effects of Expansive Agents on the Early Hydration Kinetics of Cementitious Binders

Performance of the High-Strength Self-Stressing and Self-Compacting Concrete-Filled Steel Tube Columns Subjected to the Uniaxial Compression

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