Geodesign, eco-brutalist artefacts for architecture, tourism and urbanism

Geodesign project is a co-promotion project funded by the Portugal 2020 program with the aim of developing new architectural products, integrating industrial waste and by-products generated by Portuguese companies, namely in the fields of steel, smelting, power stations, metallurgy and glassmaking. The partners of the project are W2V, SA, dedicated to waste management activities, Providência Design, dedicated to product design, the CVR technology center and the Portuguese universities of Minho and Trás-os-Montes and Alto Douro. Fly ash from thermoelectric plants, aluminum anodizing sludge and glass polishing dusts, among others, offer different plastic and chromatic qualities. When chemically integrated in the form of geopolymers or calcium-based materials, they exhibit different physical qualities of mechanical strength and aging. Taking into account their physical qualities and, consequently, the diversity of chromatic, textural and economical results, several functional products for wall covering, sound barriers and exterior furniture with expressive aesthetic impact were designed. Exploring the plastic qualities of a new brutalist, recyclable and sustainable aesthetic, a generation of artifacts was born that presents competitive advantages in the range of products for hotel, tourist architecture and urban planning in general. It will be the design of this brutalist aesthetic that, communicating sustainability, will be the factor of evidence to motivate the circularity of the economy and social inversion of the unsustainability of industrial consumption. The project provides for the technological test of development of new materials containing residues, their small-scale manufacturing and pre-industrial validation, after evaluating their economic and environmental impacts.W2V, SA; Francisco M. Providência, Lda; Geodesigninfo:eu-repo/semantics/publishedVersio

Increasing the reaction kinetics of alkali-activated fly ash binders for stabilisation of a silty sand pavement sub-base

The paper addresses several options to improve the reaction kinetics of alkali-activated low-calcium fly ash binders for soil stabilisation in road platforms. For that purpose, an experimental programme was established to assess the strength evolution, with time, of different binders, based on ash, lime, sodium chloride and alkali solutions, applied in the stabilisation of a silty sand. The tests included unconfined compression strength tests, triaxial tests and seismic wave measurements performed at different curing periods. The results were compared with a binder made of Portland cement and a commercial additive specifically designed for soil stabilisation in road applications. The activated ash mixtures with lime were the most performing producing a significant increase in the reactions development and, consequently, in the strength gain rate. The sodium chloride significantly improved the lime and lime-ash mixtures, but provided only a slight improvement in the activated ash mixtures.The authors would like to acknowledge the company CJR Wind – Energy for life, for the funding which enable the presented research; the MCTES/FCT (Portuguese Science and Technology Foundation of Portuguese Ministry of Science and Technology) for their financial support through the SFRH/BPD/85863/2012 scholarship, which is co-funded by the European Social Fund by POCH program; and the Microscopy Unit of the University of Trás- os-Montes e Alto Douro. In addition, a special acknowledgment is also due to PEGOP – Energy Eléctrica, S.A. and LUSICAL – Companhia Lusitana de Cal, S.A. for providing respectively fly ash and lime for this study

Comportamento de blocos de terra comprimida estabilizados com resíduos industriais

The construction of masonry with compressed earth blocks (CEBs) is a modern earth construction technique with current growing interest, but its environmental sustainability is many times depreciated by the use of traditional chemical stabilisation techniques (lime and cement addition). This paper presents an experimental program where the possibility of manufacturing CEBs using granitic residual soils (GRS) from northern Portugal is addressed. The GRS were shown to be inadequate and their use for manufacturing CEBs requires chemical stabilisation. A composition study involving stabilisation by addition of cement and addition of geopolymeric binders resulting from the alkaline activation of fly ash or of calcinated sludge was carried out. Then, CEBs stabilised with alkaline activation of fly ash were manufactured and their mechanical properties were tested. In addition, the compressive behaviour of masonry built with these CEBs was also characterized. In general, the stabilisation with alkaline activation of fly ash revealed excellent results with respect to the improvement in strength.A construção em alvenaria de blocos de terra comprimida (BTC) é uma técnica de construção em terra moderna com um atual interesse crescente, mas a sua sustentabilidade ambiental é muitas vezes desvalorizada pelo recurso a técnicas de estabilização química tradicionais (adição de cal e cimento). Este artigo apresenta um programa experimental onde é avaliada a possibilidade de se manufaturarem BTC com solo residual granítico (SRG) do Norte de Portugal. Mostrou-se que os SRG não são adequados e que o seu uso na produção de BTC requer estabilização química. Realizou-se um estudo de composição envolvendo estabilização por adição de cimento e de ligantes geopoliméricos à base da ativação alcalina de cinza volante ou lamas calcinadas. Em seguida, manufaturam-se BTC estabilizados com ativação alcalina de cinzas volantes e testaram-se as suas propriedades mecânicas. Além disto, caraterizou-se o comportamento em compressão da alvenaria construída com estes BTC. Em geral, a estabilização com ativação alcalina de cinzas volantes revelou excelentes resultados no que diz respeito ao melhoramento da resistência

Rammed earth construction with granitic residual soils: the case study of northern Portugal

Building in unstabilised rammed earth results in low environmental impact. However, northern Portugal has not historical tradition with this technique, and thus the suitability of the local granitic residual soils is unknown. This paper presents an experimental investigation, where this possibility is assessed. The results showed that these soils are unsuitable, and that rammed earth construction is only feasible if these soils go through a stabilising process. The alkaline activation of fly ash was investigated as an environmentally friendly stabilisation technique, and it proved to be capable of improving the performance of rammed earth

CEBs stabilised with geopolymeric binders: mechanical performance of dry-stack masonry

The sustainability in the building industry is currently a sounding topic, seeking the development of more environmental friendly building materials. The incorporation of industrial wastes and the reuse of construction and demolition waste (CDW) in the production of building materials are methods being used to solve this problem. Furthermore, these methods contribute to fulfilling the targets defined by European Union for the valorisation of non-hazard waste. The construction with compressed earth blocks (CEBs) stabilised with geopolymeric binders is a solution that can contribute to this objective by incorporating both CDW (excavation soil) and industrial wastes. Despite some recent research done on this topic, it still deserves further investigation. This paper intends to contribute to the development of this topic by presenting an experimental program, continuing previous research. The experimental program is addressed to the mechanical characterisation of a dry-stack CEB (stabilised with geopolymer obtained from alkaline activation of fly ash) masonry system, and includes the evolution of the strength of the CEBs with the curing time. In general, the evolution of the strength of the CEBs cured under ambient condition was shown to be a slow process, which can have implications on the production process.Portuguese Science and Technology Foundation (FCT) through the project FCOMP-01-0124-FEDER-028864 (FCT-PTDC/ECM-EST/2396/2012)

Mechanical characterization of dry-stack masonry made of CEBs stabilised with alkaline activation

The increasing interest on earth construction as a sustainable building solution led to the development of modern earth construction techniques, in particular of masonry made of compressed earth blocks (CEBs). The traditional chemical stabilisation of the soil is a frequently used improvement process. However, such process increases significantly the embodied energy of the CEBs. This paper presents an alternative technique for the stabilisation of CEBs, based on alkali activation of fly ash. The mechanical behaviour of the CEBs and of the respective dry stack masonry is comprehensively investigated through an experimental program, during which this technique proved to be highly effective.The authors wish to express their gratitude to Mr. Pedro Esteves for his support in the experimental work and to Eng. Jorge Henriques, on behalf of the company PEGOP – Energia Eléctrica SA, for providing the fly ash. The financial support provided by the Portuguese Science and Technology Foundation through the project FCOMP-01-0124-FEDER-028864 (FCT-PTDC/ECM-EST/2396/2012) is also gratefully acknowledged.Fundação para a Ciência e a Tecnologia (FCT

Mechanical performance of masonry made with CEB stabilised by alkali activated fly ashes

Ao longo dos últimos anos foi possível observar uma crescente preocupação ao nível da sustentabilidade e da preservação do meio ambiente. Este trabalho tem como principal objetivo prestar um contributo nesse sentido, nomeadamente através do desenvolvimento de ummaterial mais sustentável, com menor impacto ambiental, recorrendo a uma técnica que permite encarar os resíduos industriais como matérias-primas. A terra, como material de construção, tem já uma utilização milenar, comprovada pelos importantes monumentos que chegaram até aos nossos dias. A ativação alcalina, enquanto técnica para a produção de ligantes alternativos, tem demonstrado um grande potencial, evidenciado ao longo dos últimos anos. Através da utilização de solo e da ativação alcalina de cinzas volantes foi possível desenvolver um material para fabrico de blocos de terra compactada (BTC) com desempenho mecânico, quer a nível individual quer ao nível da própria alvenaria resultante, adequado ao funcionamento deste tipo de estrutura.Over the last years it was possible to observe an increasing concern in terms of sustainability and environmental preservation. This work aims to make a contribution in this direction, particularly through the development of a more sustainable material, with lower environmental impact, employing a technique that allows to face the industrial waste as raw materials. The earth as building material has a millenary use, proven by the important monuments that have survived till nowadays. The alkaline activation, while technique for the production of alternative binders, has shown a great potential, evidenced over the last years. Through the use of the soil and alkali activated fly ashes was possible to develop a material for the manufacture of compressed earth blocks (CEB) with mechanical performance, either individually or at the level of the masonry itself, suitable for use in this type of structure.FCT (Fundação para a Ciência e Ta ecnologia), através do ISISE, com o projeto IUD/ECI/04029/201

Shear behaviour characterization of dry-stack masonry made of compressed earth blocks

Como material de construção não normalizado, a terra é ainda associada à construção de subsistência dos países em desenvolvimento. Porém, as vantagens da construção em terra têm sido cada vez mais reconhecidas, nomeadamente a sua sustentabilidade. Esta mudança de paradigma tem levado ao desenvolvimento de técnicas modernas de construção em terra, particularmente a alvenaria de blocos de terra comprimida (BTC). A estabilização química tradicional do solo é um processo de melhoramento frequentemente utilizado, mas que também aumenta significativamente a energia incorporada dos BTC. Este artigo apresenta uma solução de estabilização alternativa para BTC, baseada na ativação alcalina de cinza volante. O comportamento mecânico dos BTC e da respetiva alvenaria de junta seca é estudado através de um programa experimental, que inclui a caraterização do comportamento ao corte da alvenaria.Raw earth, as a non-standard building material, is still associated to the poor construction from the developing countries. However, the advantages of earth construction have been increasingly recognized, namely its sustainability. This change of paradigm have been led to the development of modern earth construction techniques, in particular of the masonry made of compressed earth blocks (CEBs). The traditional chemical stabilization of the soil is an improvement process used frequently, but which increases significantly the embodied energy of the CEBs. This paper presents an alternative stabilisation technique for CEBs, based on the alkaline activation of fly ash. The mechanical behaviour of the CEBs and of the respective dry-stack masonry is investigated through an experimental program, which includes the characterization of the shear behaviour of the masonryFundação para a Ciência e a Tecnologia (FCT

Soil stabilisation using alkaline activation of fly ash for self-compacting rammed earth construction

This paper studies the effectiveness of alkaline activation of low-calcium fly ash on the improvement of residual granitic soils to be used on rammed-earth construction. Different liquid:solid ratios, alkali concentrations and Na2O : ash ratios were tested. Effect of calcium hidroxide, sodium chloride and concrete superplasticiser is also reported. Compressive strength up to 7 days at 60ºC was determined. Results show that, in terms of mechanical strength, there is an optimum value for the activator:solids ratio and the alkali concentration, and that a decrease in the Na2O:ash ratio results in strength increase. No improvement was observed with the sodium chloride or the superplasticiser, while the calcium produced only a short term increase in strength. SEM/EDS analysis were used to analyse microstructural development, showing that strength is fairly related to the Si:Al and Na:Si ratios

Influence of fibre reinforcement on the post-cracking behaviour of a cement-stabilised sandy-clay subjected to indirect tensile stress

An experimental campaign was carried out to determine the influence of polypropylene fibre content and length on the post-cracking response of a sandy-clay stabilised with different cement contents. Three main sets of specimens were prepared: cement-stabilised specimens with two cement contents (5% and 10%); fibre-reinforced specimens with three fibre contents (0.1%, 0.2% and 0.3%) and cement-fibre-reinforced specimens combining the mentioned fibre and cement contents. Tensile tests on the fibres and indirect tensile tests and triaxial compression tests on the prepared specimens were conducted. Results show that the post-cracking behaviour is strongly affected by the combination of fibre and cement content as well as fibre length. Pull-out was the governing failure mode. Post-peak tension loss rate increased with fibre content, as a result of the loss of influence of the fibres on the post-peak behaviour. On the contrary, an increase in fibre content resulted in higher pre-peak strength gain rates and higher peak stresses.info:eu-repo/semantics/publishedVersio