Behavior of fresh and hardened concretes with antifreeze admixtures in deep-freeze low temperatures and exterior winter conditions

Karagöl, Fatma; Demirboğa, Ramazan; Khushefati, Waleed H.

doi:10.1016/j.conbuildmat.2014.12.011

Cited by 101 publications

(31 citation statements)

References 9 publications

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“…The performance of hardened Portland cement (e.g., mechanical behavior, and durability) is linked tightly with early age chemical hydration and hardening, while the relationships between hydration processes, hydrates produced, microstructures, and mechanical behaviors have been proved in previous studies [2][3][4][5]. In service life of infrastructures, cement-based materials have to be faced with severe environmental conditions, such as super-low temperatures [6][7][8]. In these conditions mechanical behaviors (e.g., compressive strength, flexural strength, elastic modulus, and Poisson ratio) of hardened Portland cement concrete will be enhanced by the super-low temperature, for example, −70∼ −10 ∘ C [7].…”

Section: Introductionmentioning

confidence: 99%

Portland Cement Hydration Behavior at Low Temperatures: Views from Calculation and Experimental Study

Liu

Jiao

Sha

et al. 2017

Advances in Materials Science and Engineering

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Environmental condition affects the property of construction materials. This study gives an initial understanding of Portland cement hydration under low temperatures from the views of laboratory experiments (including electrical resistivity, degree of hydration (DoH), and maturity) as well as thermodynamic calculation. The hydrates of Portland cement at the given period were detected with X-ray diffraction (XRD), and their microstructure was observed by scanning electron microscope (SEM). Experiment result (i.e., DoH and electrical resistivity) indicated that the hydration of Portland cement was delayed by low temperature without hydration stopping at −5 ∘ C. Based on a basic kinetics model, the thermodynamic calculation predicted that the final hydrate differs in dependence on environmental temperatures. The mechanical behavior trend of Portland cement paste affected by low temperatures potentially is linked to the appearing of aluminate compounds and reduction of portlandite.

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Section: Introductionmentioning

confidence: 99%

Portland Cement Hydration Behavior at Low Temperatures: Views from Calculation and Experimental Study

Liu

Jiao

Sha

et al. 2017

Advances in Materials Science and Engineering

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“…Another study examined the effects of the combination of both admixtures of urea and calcium nitrate. An equal amount of 4.5 wt% was used in each concrete sample, and they were exposed to different curing regimes, i.e., [36]. There are mainly three aspects for strength development: 1) urea accelerates the hydration process by the rapid solubilization of C 3 S and C 2 S; 2) calcium nitrate, having similar ions to C 3 S and C 2 S nucleate and intensify the hydration process by rapidly forming crystallization products and 3) the eutectic point of urea and calcium nitrate ranges between −6.3 • C to −7.4 • C and −7.6 • C to −11.5 • C, respectively.…”

Section: Opc-based Concretesmentioning

confidence: 99%

A Review of the Mechanical Properties and Durability of Ecological Concretes in a Cold Climate in Comparison to Standard Ordinary Portland Cement-Based Concrete

et al. 2020

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Most of the currently used concretes are based on ordinary Portland cement (OPC) which results in a high carbon dioxide footprint and thus has a negative environmental impact. Replacing OPCs, partially or fully by ecological binders, i.e., supplementary cementitious materials (SCMs) or alternative binders, aims to decrease the carbon dioxide footprint. Both solutions introduced a number of technological problems, including their performance, when exposed to low, subfreezing temperatures during casting operations and the hardening stage. This review indicates that the present knowledge enables the production of OPC-based concretes at temperatures as low as −10 °C, without the need of any additional measures such as, e.g., heating. Conversely, composite cements containing SCMs or alkali-activated binders (AACs) showed mixed performances, ranging from inferior to superior in comparison with OPC. Most concretes based on composite cements require pre/post heat curing or only a short exposure to sub-zero temperatures. At the same time, certain alkali-activated systems performed very well even at −20 °C without the need for additional curing. Chemical admixtures developed for OPC do not always perform well in other binder systems. This review showed that there is only a limited knowledge on how chemical admixtures work in ecological concretes at low temperatures and how to accelerate the hydration rate of composite cements containing high amounts of SCMs or AACs, when these are cured at subfreezing temperatures.

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“…3). With the assumption that the lowest temperature in fresh concrete is at 5 degrees, the regions where the average daily air temperature is below 5 degrees for 3 days and the temperature is below 10 degrees during the half day within the 3 days is defined as cold weather zones in terms of concrete casting in the literature [9]. When the average annual temperatures of the Erzurum, which is the application area of isolators examined in this study, are evaluated.…”

Section: Isolation Anchorage To Concrete: Via Steel Plates or Directlymentioning

confidence: 99%

“…During concrete pouring in cold weather and after achieving the standard strength of concrete, some problems can occur. While concrete pours in cold weather, the volume of concrete changes due to the water freezing in the concrete or due to the moisture movements in the hardened concrete [9], and additional stresses occur due to this.…”

Section: Isolation Anchorage To Concrete: Via Steel Plates or Directlymentioning

confidence: 99%

Installation and Maintenance Principles of Seismic Isolators: Erzurum Health Campus

Sagiroglu¹,

Maali²,

Aydın³

2018

TOCIEJ

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Background:The objective of isolation is to reduce the seismic forces transmitted through the structure using active and/or passive insulation systems.Seismic isolators, which are passive insulation systems and are placed between the foundation of the structure and the structure, are discussed throughout this study. Isolators consist of rubber layers that have horizontal flexibility, steel layers that increase rigidity and a lead or ball core, which increases vertical stiffness. Installation and maintenance of seismic isolators require great care in order not to exceed the displacements/section forces envisaged at the design of the structure during the earthquake.Objective:Installation and maintenance principles of the friction pendulum type isolators used in Erzurum Health Campus (hospital) are presented throughout this study. While the seismic isolators are anchoraged to directly concrete in the general application, they are placed between two steel plates of type S355J2 in this application, because of cold-weather conditions. To evaluate this condition, it is investigated the models with and without steel plate and compared to each other.Methodology:The models with and without steel plate were formed using finite-element method to compare the stress distributions on the isolator.Conclusion:The results demonstrated that the model with steel plates occur the uniform stress through surface and keep under control deformation of cross-section in the reinforced concrete.

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Behavior of fresh and hardened concretes with antifreeze admixtures in deep-freeze low temperatures and exterior winter conditions

Cited by 101 publications

References 9 publications

Portland Cement Hydration Behavior at Low Temperatures: Views from Calculation and Experimental Study

Portland Cement Hydration Behavior at Low Temperatures: Views from Calculation and Experimental Study

A Review of the Mechanical Properties and Durability of Ecological Concretes in a Cold Climate in Comparison to Standard Ordinary Portland Cement-Based Concrete

Installation and Maintenance Principles of Seismic Isolators: Erzurum Health Campus

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