Performance of fly ash concrete with ferronickel slag fine aggregate against alkali-silica reaction and chloride diffusion

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Abstract

Ferronickel slag (FNS) is an industrial by-product of ferronickel alloy production at a high temperature which can be a promising potential to be used as fine aggregate to produce more sustainable concrete. In this study, the performance of concrete containing ferronickel slag sand and fly ash relating to alkali-silica reaction (ASR) and chloride contamination was investigated. ASR-induced expansion, chloride diffusion resistance, and chloride binding capacity of FNS concrete were determined through concrete prism tests (CPT), accelerated diffusion test, and bulk diffusion test. Thermogravimetric analysis (TGA) was conducted to measure the amount of Portlandite and Friedel's salt in concrete. Concrete with 50 wt% FNS sand as fine natural aggregate replacement and 25 wt% of cement replacement by fly ash showed a remarkable potential to be used not only as a low-carbon concrete with comparable mechanical properties to conventional concrete but also with a better performance against ASR and chloride contamination.

Introduction

Concrete is an artificial material composed of a binder, water, and aggregates and it is the second most used substance after water [1]. The demand for concrete has been significantly increased recently. Therefore, stockpiles of aggregate have been greatly enlarged to fulfill the requirements of concrete production. Natural sand has been the most used fine aggregate in conventional concrete. However, its availability has been declining due to its excessive utilization. Sand exploitation rate is now far more than its renewal rate [2,3]. Excessive mining of river sand places detrimental stress on river biodiversity, riverbed, river basins, salt-wedge intrusion, ecological communities, and food webs [[4], [5], [6], [7]]. The emerging sand scarcity has also intensified illicit sand trade, social conflicts, and political tensions between nations [[8], [9], [10]]. Sea sand has been considered but desalting related costs have to be included to eliminate any corrosion risk in reinforced structures due to its inherent chloride content [11]. Manufactured sand is one of the feasible options as natural sand substitution by using industrial by-products such as steel slag, copper slag, foundry slag, and blast furnace slag as natural sand substitution [[12], [13], [14], [15]].

Ferronickel slag is an industrial by-product of nickel production obtained by cooling with water or air [[16], [17], [18], [19], [20], [21], [22]]. In Australia and the Pacific region, over 2 Mt. (5.6 million cubic metre) of ferronickel slag (FNS) are annually produced by Société Le Nickel (SLN) in New Caledonia and the current stockpile available is over 25 Mt. Considering the volume of concrete produced in Australia of about 28.5 million cubic metres in 2016 [23] requiring about 10 million cubic metre of fine aggregate, FNS appears to be a promising candidate for natural fine aggregate replacement. It also should be noted that 150 Mt. of ferronickel slag is annually produced from the manufacturing of ferronickel alloy in the world, which represents the fourth largest amount of slag generated from smelting process after iron slag, steel slag and red mud [21,24]. In fact, the utilization rate of FNS is relatively low. 90% of FNS production is currently landfilled in open environments as “slag mountain” [21,22,25]. Ferronickel slag can present significantly different characteristics due to the divergence in laterite ore source, furnace temperature, and cooling procedure [26]. It was reported that air-cooled FNS is mainly composed of forsterite and enstatite crystalline whilst water-cooled FNS presents forsterite and high amorphous content resulting in higher expansion risk due to alkali-silica reaction (ASR) [27]. FNS from New Caledonia is water-cooled. However, in their accelerated mortar bar test (AMBT-ASTM C1567 [28]) prepared using FNS aggregate from New Caledonia [29], 30 wt% of cement replacement by fly ash effectively mitigated the ASR expansion of mortar bars. To facilitate the usage of FNS in the concrete industry, Saha and Sarker [16] reported that 50 wt% substitution rate of natural fine aggregate presented an optimum aggregate grading curve, outperforming reference OPC concrete in terms of mechanical properties. In addition, heavy metals leaching from concrete containing up to 100 wt% FNS fine sand were significantly lower than standard limits of the United States Environmental Protection Agency (US EPA) and United Kingdom Environment Agency [16]. Liu et al. [21] revealed that internal and external radiation indices of FNS were negligible (close to zero) and significantly smaller than the maximum value of 1.

Durability properties of concrete containing FNS as sand replacement are also another important factor for its industrial application. Saha and Sarker [30] showed the beneficial effect of the fly ash on FNS mortar subjected to wet-dry cycles at 23 °C and 110 °C respectively. Several previous studies indicated a reduction in the volume of the permeable void (VPV), sorptivity, chloride permeability, and negligible strength loss after accelerated weathering conditions [21,31]. Nguyen et al. [[17], [18], [19]] reported better ultrasonic pulse velocity (UPV), electrical resistivity, carbonation resistance and reduction of early age cracking due to the secondary C-S-H formation at the interfacial transition zone (ITZ) between FNS sand and paste. However, studies on durability properties of concrete with FNS sand are still limited, which can delay the adoption of FNS concrete in the construction industry.

This study aims to investigate the performance of concrete containing FNS as sand substitution against aggressive environments including ASR-favourable and chloride contaminated environments. 50% FNS replacement by mass of natural fine aggregate was considered to achieve suitable mechanical properties based on recommendations of the previous studies [16,17,32]. 25% fly ash by mass of binder was used to mitigate ASR risk and reduce the embodied carbon of concrete. Reliable test protocols such as the concrete prism test (CPT) for ASR and bulk diffusion test for chloride diffusion were conducted. The specimens extracted from concrete prisms after 637 days were analysed using scanning electron microscopy – energy dispersive X-ray spectroscopy (SEM-EDS). Accelerated experiments by applying external voltage including rapid chloride permeability test (RCPT) and chloride migration test (CMT) were also carried out to compare the chloride diffusion performance of FNS fly ash concrete with that of reference OPC concrete. Total and free chloride contents from bulk diffusion test and Friedel's salt contributing to chloride binding capacity of FNS concrete were determined by titration and thermogravimetric analysis (TGA) respectively.

Section snippets

Materials and mix design

Three different kinds of aggregate were used in this study. 10 mm nominal size Basalt and Sydney sand were employed as natural coarse and fine aggregate, respectively. FNS as manufactured fine aggregate was obtained from Société Le Nickel (SLN) in New Caledonia. Physical characteristics of all aggregate including apparent relative density, water absorption, and fineness modulus are shown in Table 1. The chemical composition of FNS was analysed using X-ray fluorescence analysis (XRF) and

ASR concrete prism test

CPT was conducted in the mixes of FNS_100GP and FNS_25FA with the addition of sodium hydroxide in the mixing water (Section 2). The variation of FNS_100GP and FNS_25FA concrete prisms length was measured on 3 duplicate samples for each mix design by utilizing the differences between initial comparator reading and subsequent comparator readings for up to 637 days according to ASTM C1293 and Australian Standard AS 1114.60.2 [37,38]. 24 ± 2 h after concrete casting, the initial comparator reading

Expansion of concrete prism due to ASR

Expansion due to ASR and weight variation of concrete specimens until 637 days are shown in Fig. 2. The expansion limitations after 1 year from ASTM C1293 and AS 1141.60.2 (0.04% and 0.03% respectively) are also integrated to Fig. 2(a) to identify the aggregate classification. Previous crystallographic study using the same FNS sand [29] reported that FNS used contains 44% of amorphous silica and cryptocrystalline silica structures. However, as shown in Fig. 2(a), the ASR expansions of FNS_100GP

Conclusions

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    Regarding ASR risk, the expansion of concrete prisms containing ferronickel slag was below the limits recommended in ASTM C1293 and AS 1411.60.2 after 637 days of exposure. SEM images presented no significant damage for both GP cement and fly ash blended concretes. The non-reactive characteristic of FNS sand could be attributed to the secondary C-S-H formation instead of Portlandite to strengthen the ITZ between FNS sand and cement paste.

  • -

    Chloride diffusion accelerated tests with externally

CRediT authorship contribution statement

Quang Dieu Nguyen: Conceptualization, Methodology, Software, Validation, Formal analysis, Investigation, Data Curation, Writing - Original Draft, Visualization

Arnaud Castel: Methodology, Validation, Resources, Writing - Review & Editing, Supervision, Project administration, Funding acquisition

Taehwan Kim: Methodology, Validation, Resources, Writing - Review & Editing, Supervision

Mohammad S.H. Khan: Methodology, Investigation, Writing - Review & Editing, Supervision

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgement

This research was funded by Société Le Nickel (SLN), New Caledonia. The authors gratefully acknowledge the contribution and continuous support from SLN.

References (98)

  • Y.-c. Gu et al.

    Immobilization of hazardous ferronickel slag treated using ternary limestone calcined clay cement

    Constr. Build. Mater.

    (2020)
  • B. Xi et al.

    Constraints and opportunities for the recycling of growing ferronickel slag in China

    Resour. Conserv. Recycl.

    (2018)
  • F. Gu et al.

    Selective recovery of chromium from ferronickel slag via alkaline roasting followed by water leaching

    J. Hazard. Mater.

    (2019)
  • A.K. Saha et al.

    Value added utilization of by-product electric furnace ferronickel slag as construction materials: a review

    Resour. Conserv. Recycl.

    (2018)
  • Y.C. Choi et al.

    Alkali–silica reactivity of cementitious materials using ferro-nickel slag fine aggregates produced in different cooling conditions

    Constr. Build. Mater.

    (2015)
  • A.K. Saha et al.

    Expansion due to alkali-silica reaction of ferronickel slag fine aggregate in OPC and blended cement mortars

    Constr. Build. Mater.

    (2016)
  • A.K. Saha et al.

    Compressive strength of mortar containing ferronickel slag as replacement of natural sand

    Procedia Engineer

    (2017)
  • Q.D. Nguyen et al.

    Reinforcement corrosion in limestone flash calcined clay cement-based concrete

    Cem. Concr. Res.

    (2020)
  • S.C. Paul et al.

    Chloride ingress in cracked and uncracked SHCC under cyclic wetting-drying exposure

    Constr. Build. Mater.

    (2016)
  • R. Talero et al.

    Comparative and semi-quantitative XRD analysis of Friedel’s salt originating from pozzolan and Portland cement

    Constr. Build. Mater.

    (2011)
  • M. Gbozee et al.

    The influence of aluminum from metakaolin on chemical binding of chloride ions in hydrated cement pastes

    Appl. Clay Sci.

    (2018)
  • Z.G. Shi et al.

    Role of calcium on chloride binding in hydrated Portland cement-metakaolin-limestone blends

    Cem. Concr. Res.

    (2017)
  • G. Paul et al.

    Friedel’s salt formation in sulfoaluminate cements: a combined XRD and 27 Al MAS NMR study

    Cem. Concr. Res.

    (2015)
  • Z.G. Shi et al.

    Friedel's salt profiles from thermogravimetric analysis and thermodynamic modelling of Portland cement-based mortars exposed to sodium chloride solution

    Cement Concrete Comp

    (2017)
  • R.O. Grishchenko et al.

    Thermodynamic properties and thermal behavior of Friedel’s salt

    Thermochim. Acta

    (2013)
  • F. Golmakani et al.

    Impact of pore solution concentration on the accelerated mortar bar alkali-silica reactivity test

    Cem. Concr. Res.

    (2019)
  • Y. Shimada et al.

    Thermal stability of ettringite in alkaline solutions at 80 degrees C

    Cem. Concr. Res.

    (2004)
  • D.Y. Lu et al.

    Evaluation of accelerated test methods for determining alkali-silica reactivity of concrete aggregates

    Cement Concrete Comp

    (2006)
  • M. Thomas et al.

    Test methods for evaluating preventive measures for controlling expansion due to alkali-silica reaction in concrete

    Cem. Concr. Res.

    (2006)
  • J. Lindgård et al.

    Alkali–silica reactions (ASR): literature review on parameters influencing laboratory performance testing

    Cem. Concr. Res.

    (2012)
  • A.A. Ramezanianpour et al.

    Influence of metakaolin as supplementary cementing material on strength and durability of concretes

    Constr. Build. Mater.

    (2012)
  • A.A. Ramezanianpour et al.

    Effects of calcined perlite powder as a SCM on the strength and permeability of concrete

    Constr. Build. Mater.

    (2014)
  • H.J. Du et al.

    Properties of high volume glass powder concrete

    Cement Concrete Comp

    (2017)
  • H.J. Du et al.

    Durability performances of concrete with nano-silica

    Constr. Build. Mater.

    (2014)
  • L. Evangelista et al.

    Durability performance of concrete made with fine recycled concrete aggregates

    Cement Concrete Comp

    (2010)
  • A. Noushini et al.

    The effect of heat-curing on transport properties of low-calcium fly ash-based geopolymer concrete

    Constr. Build. Mater.

    (2016)
  • C.C. Yang et al.

    The relationship between charge passed and the chloride-ion concentration in concrete using steady-state chloride migration test

    Cem. Concr. Res.

    (2002)
  • P. Chindaprasirt et al.

    Resistance to chloride penetration of blended Portland cement mortar containing palm oil fuel ash, rice husk ash and fly ash

    Constr. Build. Mater.

    (2008)
  • A. Noushini et al.

    Chloride diffusion resistance and chloride binding capacity of fly ash-based geopolymer concrete

    Cem. Concr. Compos.

    (2020)
  • Q. Yuan et al.

    Chloride binding of cement-based materials subjected to external chloride environment - a review

    Constr. Build. Mater.

    (2009)
  • A. Delagrave et al.

    Chloride binding capacity of various hydrated cement paste systems

    Adv. Cem. Based Mater.

    (1997)
  • R. Loser et al.

    Chloride resistance of concrete and its binding capacity - comparison between experimental results and thermodynamic modeling

    Cement Concrete Comp

    (2010)
  • T. Luping et al.

    Chloride binding capacity and binding isotherms of OPC pastes and mortars

    Cem. Concr. Res.

    (1993)
  • M.D. Gavriletea, Environmental impacts of sand exploitation. Analysis of Sand Market, Sustainability, 9 (2017)...
  • A. Torres et al.

    A looming tragedy of the sand commons

    Science

    (2017)
  • D. Padmalal et al.

    Environmental effects of river sand mining: a case from the river catchments of Vembanad lake

    Southwest coast of India, Environmental Geology

    (2008)
  • J. de Leeuw et al.

    Strategic assessment of the magnitude and impacts of sand mining in Poyang Lake

    China, Regional Environmental Change

    (2009)
  • M. Mingist et al.

    Could sand mining be a major threat for the declining endemic Labeobarbus species of Lake Tana, Ethiopia?

    Singap. J. Trop. Geogr.

    (2016)
  • C. Milton

    The Sand Smugglers

    (2010)
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