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

Hempcrete is a natural building material that, in recent years, has known an increased popularity in a number of European countries. Hempcrete-based construction materials are used in non-bearing walls, as finishing plasters and floor/roof insulators. In the present work, the environmental performances of a non-load-bearing wall made of hempcrete blocks were assessed via Life Cycle Assessment (LCA). The analysis encompassed the whole life cycle but the end of life, due to the lack of reliable data for this stage. The production phase of the raw materials was identified as the main source of environmental impacts, but the transport distance of raw materials, as well as the amount and composition of the binder mixture, can considerably affect the results. An experimental assessment (via X-ray Powder Diffraction analysis) of the carbonation process taking place within the binder during the use phase of the wall showed that the carbonation rate may be smaller than assumed in previous works: after 240 d, only the outermost layers of the blocks showed significant levels of carbonation, while the innermost layers experienced only a negligible increase in the amount of carbonates. Nevertheless, the overall emission balance is very favourable: thanks to biogenic CO2 uptake during hemp growth and to CO2 uptake by carbonation, hempcrete blocks have a negative carbon footprint and act therefore as effective carbon sinks

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.

We distinguish between social capital theory and social capital political discourse in order to reflect upon their relation with one another and neoliberalism. We claim this analytical distinction is useful to understand the existence of a feedback effect between theory and political discourse. During the 1990s, the connection between social capital theory and neoliberalism has been transposed from academia to political discourse, thus contributing to popularise social capital within the public sphere. Over time, however, rising economic inequalities (exacerbated by the recent economic crises) have demonstrated that the neoliberal political agenda is incompatible with the aim to generate social capital. Focusing on the critical case of Britain, we argue that the rapid demise of the Big Society idea might signal a corresponding decline of social capital theory within academia.

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