Benefits of slag and fly ash

Bijen, J.M.J.M.

doi:10.1016/0950-0618(95)00014-3

Cited by 314 publications

(247 citation statements)

References 2 publications

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“…Geopolymeric systems are reported to demonstrate similar or 34 superior mechanical and durability properties compared to OPC-based concretes (Bijen 1996; Fernández-35 Jiménez et al 2007;Bernal et al 2012). Geopolymers based on coal fly ash are of particular interest 36 because of the potential utilization of a waste material that is available in large quantities as well as the 37 beneficial properties of the resulting binder (Provis et al 2007).…”

Section: Introduction 24mentioning

confidence: 99%

Observations on the rheological response of alkali activated fly ash suspensions: the role of activator type and concentration

et al. 2014

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5This paper reports the influence of activator type and concentration on the rheological properties of alkali 6 activated fly ash suspensions. A thorough investigation of the rheological influences (yield stress and 7 plastic viscosity) of several activator parameters, including: (i) the cation type and concentration of alkali 8 hydroxide, and (ii) the alkali-to-binder ratio (n) and silica modulus (Ms), and (iii) the volume of the 9 activation solution, on the suspension rheology is presented. The results indicate a strong dependence on 10 the cation and its concentration in the activation solution. The viscosity of the activation solution and the 11 volumetric solution-to-powder ratio are shown to most strongly influence the plastic viscosity of the 12 suspension. The suspension yield stress is predominantly influenced by the changes in fly ash particle 13 surface charge and the ionic species in the activator. A shift from non-Newtonian to Newtonian flow 14 behavior is noted in the case of silicate-based suspensions for Ms ≤ 1.5. This behavior, which is not 15 observed at higher MS values, or when the fly ash is dispersed in hydroxide solutions or pure water, is 16 hypothesized to be caused by colloidal siliceous species present in this system, or surface charge effects 17 on the fly ash particles. Comparisons of the rheological response of alkali activated suspensions to that of 18 portland cement-water suspensions are also reported. Page 2 NOMENCLATURE 22 n ratio of Na2O in the activator to the total fly ash content Ms ratio of SiO2-to-Na2O in the activator (as/p)v Activation solution-to-powder ratio, by volume (Refer to the definition of activation solution in 2.1 (as/b)v Activation solution-to-binder ratio, by volume; binder implying fly ash here (w/s)m Water-to-solids ratio, mass-based (Refer to the definition of solids in 2.1) w/c Water-to-cement ratio, mass-based, for OPC systems  Shear stress, Pa y Yield stress, Pa p Plastic viscosity, Pa.s a Apparent viscosity, Pa.s ̇ Shear rate, s -1 23Page 3 INTRODUCTION 24Ordinary portland cement (OPC) based concrete is one of the most widely used materials globally, and 25 production of OPC has been shown to require a significant quantity of energy and release significant 26 quantities of CO2. One of the sustainable alternatives to OPC that has been gaining attention is the use of 27 geopolymeric or alkali activated materials, where alumino-siliceous wastes/by-products such as fly ash or 28 slag can be activated using alkalis to create a binding medium that is X-ray amorphous and has a three-29 dimensional network structure (Palomo et al. 1999;Puertas and Fernández-Jiménez 2003; Škvára et al. 30 2009). The formation of the binding gel is a complex process including the dissolution process where Si 31and Al from the source materials are dissolved into a highly alkaline solution, precipitation of 32 aluminosilicate gel, and further polymerization and condensation to develop the final microstructure 33 (Davidovits 1999;Davidovits 2005). Geopolymeric...

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Section: Introduction 24mentioning

confidence: 99%

Observations on the rheological response of alkali activated fly ash suspensions: the role of activator type and concentration

et al. 2014

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“…The addition of slag in concrete, especially at high rates, can have the disadvantage of low strength at early ages [5]. In addition, the use of GGBFS in concrete improves compressive strength at latter age, reduces heat of hydration and reduces permeability [6]. However, the effectiveness of slag depends on its hydraulic reactivity, which is mainly influenced by the reactive glass content and composition, chemical composition and fineness [7,8].…”

Section: Introductionmentioning

confidence: 99%

Durability of mortar and concretes containing slag with low hydraulic activity

Hadjsadok

Kenaï

Courard

et al. 2012

Cement and Concrete Composites

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a b s t r a c tGranulated blast furnace slag has been widely used as a partial substitute for Portland cement in many applications because of advantages which include cost reduction, reduction in heat evolution and improvement of durability properties. However, the effectiveness of slag depends on its hydraulic reactivity. In this paper, the results of an experimental study on the effect of slag with low hydraulicity on the mechanical and durability properties of concrete and the performance of mortar under sulfate attack are discussed. Special attention is given to gas permeability and water absorption of slag concrete. The durability of slag concrete is improved at long term at low Water/Binder ratio. Sulfate resistance of mortar is improved by slag replacement up to 30%.

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“…One disadvantages of using cements with fly ash from steelmaking slag is their susceptibility for carbonation when compared with CPO [4,22]. It is therefore necessary to define the maximum allowed addition without affecting the final durability.…”

Section: Introductionmentioning

confidence: 99%

“…The attack that is produced by the ingress of chloride ions into concrete can locally break the passive oxide layer of the steel surface, when sufficient chloride concentration reaches the reinforcement surface [4][5][6][7]. The critical chloride concentration needed to break the passive state is not constant, but it depends on several factors, such as the cation type of the chloride salt.…”

Section: Introductionmentioning

confidence: 99%

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Improving Sustainability through Corrosion Resistance of Reinforced Concrete by Using a Manufactured Blended Cement and Fly Ash

et al. 2018

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Abstract:The objective of this paper is to report the improvement of sustainability through the increase of reinforced concrete corrosion resistance by using a blended cement and fly ash. Different reinforced concrete mixtures were prepared with partial substitution of a manufactured blended cement with fly ash from a thermal power plant in Andorra (Teruel, Spain). These mixtures were manufactured using three different water/cement ratios (0.46, 0.59, and 0.70) and three substitution percentages of cement by fly ash (0%, 25%, and 50%). The test cylinders underwent an accelerated carbonation process and exposure to different chloride levels, with the aim of characterizing the corrosion level of the different mixtures. The addition of local FA matched or even improved the resistance of the control mixture against carbonation and chlorides.

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Benefits of slag and fly ash

Cited by 314 publications

References 2 publications

Observations on the rheological response of alkali activated fly ash suspensions: the role of activator type and concentration

Observations on the rheological response of alkali activated fly ash suspensions: the role of activator type and concentration

Durability of mortar and concretes containing slag with low hydraulic activity

Improving Sustainability through Corrosion Resistance of Reinforced Concrete by Using a Manufactured Blended Cement and Fly Ash

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