Weathering’s beneficial effect on waste-stabilised rammed earth: a chemical and microstructural investigation

Arrigoni, Alessandro; Pelosato, Renato; Dotelli, Giovanni; Beckett, Chris; Ciancio, Daniela

doi:10.1016/j.conbuildmat.2017.02.009

Cited by 45 publications

(26 citation statements)

References 52 publications

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“…Wetting-drying cycles have a double effect on stabilised soils: i) the swelling and shrinking behaviour of clays has a detrimental effect on expansive soils, leading to a destruction of the hydrated gel; ii) the availability of water and the relatively high temperatures (71°C) in the drying cycles triggers the hydration of unreacted stabilisers present in the mixture, forming new cementitious products [54]. Renewed inundation of large pores by cementitious gel, formed by the activation of large quantities of unreacted FA during wet and dry cycles, has previously been demonstrated by the authors [29] and contributes to hysteresis via the ink-bottle effect, where moisture becomes trapped inside large pores whose entrances are restricted [42,55,56]. Given the far higher FA and calcium hydroxide content of CCR-stabilised material, opportunities for renewed hydration reactions were more likely in CCR-FA ELS.…”

Section: Discussionmentioning

confidence: 99%

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Reduction of rammed earth's hygroscopic performance under stabilisation: an experimental investigation

Arrigoni

Grillet

Pelosato

et al. 2017

Building and Environment

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a b s t r a c tOne of the acknowledged qualities of rammed earth (RE) is its moisture buffering capacity. Recently, stabilisation of RE has become a common practice to improve the mechanical resistance but very little is known about the effect that stabilisation has on hygroscopic properties. The present study aims to fill this gap by understanding the role that stabilisation plays in the buffering and sorption capacity of RE. The use of alternative stabilisers such as fly ash and calcium carbide residue and a comparison with traditional unstabilised RE (URE) have also been investigated. Moreover, the effect of weathering, simulated by cyclic wetting-drying, on hygroscopic performance has been analysed. Moisture Buffer Value (MBV) testing, moisture and nitrogen adsorption-desorption isotherms and mercury intrusion porosimetry were performed on stabilised samples to examine microstructural phenomena responsible for behavioural changes. URE was confirmed to be a good-to-excellent passive air conditioner according to the MBV scale but its performance seemed to be highly influenced by the soil particle size distribution and mineralogy. Based on the experimental outcomes of the mixtures investigated, stabilisation had a detrimental effect on the moisture buffer capacity of rammed earth, likely due to the inhibition of the physico-chemical interactivity between moisture and clays. Weathering had a variable effect on the buffering capacity, depending on the availability of unreacted particles in the matrix.

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Section: Discussionmentioning

confidence: 99%

“…8d and e). The higher surface area of CEM-FA ELS (S) compared to CCR-FA ELS (S) could be explained by the higher degree of hydration of the stabilisers used in the former case under standard curing conditions [29].…”

Section: Nitrogen Adsorption-desorption Isothermsmentioning

confidence: 99%

Reduction of rammed earth's hygroscopic performance under stabilisation: an experimental investigation

Arrigoni

Grillet

Pelosato

et al. 2017

Building and Environment

Self Cite

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“…A summary of all mixes is given in Table 1. Extensive microstructural investigations of Mixes 4, 5 and 6 were presented by the authors in [14,15]. CL, RCA and ELS particle size distributions (PSDs) are presented in Fig.…”

Section: Methodsmentioning

confidence: 99%

“…The height of the samples used in this work (200 mm) and the number of compacted layers (5) differ from those proposed in ASTM D559M (116 mm and only one layer). These dimensions were chosen to permit UCS testing of specimens post-WBT [14]. The test is deemed successful if the weight loss is lower than 5%, according to Fitzmaurice [24].…”

Section: Wire Brush Testmentioning

confidence: 99%

Life cycle analysis of environmental impact vs. durability of stabilised rammed earth

Arrigoni

Beckett

Ciancio

et al. 2017

Construction and Building Materials

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Rammed earth (RE) has enjoyed a revival in recent decades due to the increasing awareness of environmental issues surrounding the building industry. Although RE in its traditional form is deemed a highly environmentally-friendly material, the same cannot be said for its modern stabilised counterpart. Comprehensive experimental procedures exist to estimate mechanical strength properties of stabilised RE (SRE). However, tests for material durability are far less common. Engineers and practitioners therefore assume that strength and durability are interchangeable properties, i.e. the stronger the material, the more durable. Inflated strengths are recommended to ensure adequate durability, leading to high environmental costs through excessive use of stabilisers. This paper rates the relevance of two acknowledged durability tests (accelerated erosion due to sprayed water and mass loss due to wire brushing) and relates outcomes to the strength and the environmental impact of several SRE mixes. The environmental impact of each mix was estimated using attributional and consequential life cycle assessment (LCA) approaches as well as an assessment of cumulative energy demand. Results demonstrated that it is possible to have durable SRE mixes without paying the cost of using environmentally-expensive stabilisers

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“…For this reason, raw earth is often chemically stabilised by addition of hydraulic binders such as cement or lime (Walker, 1995;Bui et al, 2009;Reddy, 2012), which improve water durability but also introduce undesirable collateral effects on stiffness, strength and moisture buffering capacity. A number of studies have analysed the effect of stabilisation by hydraulic binders on stiffness and strength (Walker, 1995;Jayasinghe and Kamaladasa, 2007;Morel et al, 2007;Ciancio and Gibbings, 2012;Bui et al, 2014;Ciancio et al, 2014;Kariyawasam and Jayasinghe, 2016;Arrigoni et al, 2017a) but also on moisture buffering capacity (Liuzzi et al, 2013;McGregor et al, 2014;Arrigoni et al, 2017b). These investigations have shown that stabilisation by hydraulic binders generally improves the mechanical properties of raw earth but considerably reduces the ability of the material to store and release moisture.…”

Section: Introductionmentioning

confidence: 99%

Effect of stabilisation on mechanical properties, moisture buffering and water durability of hypercompacted earth

Bruno

Gallipoli

Perlot

et al. 2017

Construction and Building Materials

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This paper investigates the effect of stabilisation by alkaline activation and silicon based admixture on the mechanical properties, moisture buffering capacity and durability of an earthen material for building construction. The stiffness and strength of both unstabilised and stabilised cylindrical samples were measured, under different humidity conditions, by means of unconfined compression tests. The effect of stabilisation on moisture buffering capacity was instead explored by subjecting samples to cyclic variations of relative humidity at constant temperature, according to the experimental procedures prescribed by the norm ISO 24353 (2008). Finally, durability against water erosion was assessed by performing immersion, suction and liquid contact tests on both unstabilised and stabilised samples according to the norm DIN 18945 (2013). Results from this extensive experimental campaign highlighted that the chosen stabilisation methods improved the durability of the material while maintaining a relatively good mechanical performance and a good to excellent moisture buffering capacity.

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Weathering’s beneficial effect on waste-stabilised rammed earth: a chemical and microstructural investigation

Cited by 45 publications

References 52 publications

Reduction of rammed earth's hygroscopic performance under stabilisation: an experimental investigation

Reduction of rammed earth's hygroscopic performance under stabilisation: an experimental investigation

Life cycle analysis of environmental impact vs. durability of stabilised rammed earth

Effect of stabilisation on mechanical properties, moisture buffering and water durability of hypercompacted earth

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