Improving hydraulic properties of lime–rice husk ash (RHA) binders with metakaolin (MK)

To improve long-term hydraulic properties of binders from RHA and lime, 25–75% MK was added to RHA. Binders were formulated and properties were compared to that containing RHA or MK as only pozzolans. The lime–pozzolan ratio was 1:3. The properties tested after 7, 28 and 56 days were: absolute density and fineness of the binders, initial setting time, chemical and mineralogical composition of hydrated binders, flexural and compressive strengths and water absorption of mortars. The micrographs of the hardened binder pastes at 56 days permitted to evaluate the densification of different matrixes and the development of pores. From the results obtained, it was concluded that, MK increased the density of mixtures and decreased their grindability. The presence of MK decreased the SiO₂ content of binders and increases their Al₂O₃ and Fe₂O₃ contents. Calcium-silicate hydrates (CSH) gel and gehlenite (C₂ASH₈) were the main phases formed during the pozzolanic reaction in the presence of MK. No reduction in flexural and compressive strengths was observed after 28 days for binders containing MK. The mixture of 25% MK and 75% RHA which is recommended gave flexural and compressive strengths higher than binder with RHA or MK as the only pozzolan. Water absorption of mortars was less than 20%.     

Energy and emergy based cost–benefit evaluation of building envelopes relative to geographical location and climate

This paper presents an environmental evaluation of building envelopes, made of three different technologies: a traditional air-cavity wall, a plus-insulated wall (with an external cork covering), and a ventilated wall (with external brick panels fixed on extruded frames). An environmental accounting method, namely Emergy Evaluation (EE), was performed for assessing environmental resource use (energy and material flows), both directly and indirectly, for the construction of a façade (1000 m²). Then, energy use during the building lifetime was assessed as a constant inflow to the building depending on the thermal skills of building envelopes, besides thermal efficiency of air-conditioning system. In particular, this energy inflow is needed for maintaining constant indoor climate conditions (18 °C) and has to balance heat dissipation through envelopes (heat loss in winter and heat gain in summer). Outcomes were compared with an Energy Analysis (EA) based on an embodied energy accounting. Finally, costs for manufacturing walls (with enhanced performance) and benefits (energy saving) were compared in a unique balance, through both EA and EE. Moreover, outcomes were obtained for three scenarios corresponding to three geographic locations (Berlin in northern Europe, Barcelona on the Mediterranean coast and Palermo in the south of Italy). Results highlighted that performances of building envelopes depend on technologies relative to external climate conditions. Different environmental accounting methods, such as EE and EA, provided outcomes with some difference that are not contradictory to each other but complementary.     

The effect of the proportion of thin film transistor–liquid crystal display (TFT–LCD) optical waste glass as a partial substitute for cement in cement mortar

In the high-tech industry in Taiwan, the use of LCD glass products have increased significantly in recent years, which produces a large amount of waste LCD glass during the manufacturing process. This study is based on the 0.485 w/b and 10%, 20%, 30%, 40%, and 50% substitution amount to discuss the effect of glass powder proportions on cement in cement mortar. The research found that of cement mortar by the waste liquid crystal glass powder substitution cement, along with the substitution quantity increase, the set time decreases progressively also the compressive strength gradually reduces. A 10% substitution amount is considered the best in durability tests involving sodium hydroxide, sodium sulfate, and concentrated sulfuric acid resistance. According to the microstructure, the internal structure of the mortar body appears rather dense on the 28th day. Thus, this compound can be used as a substitute for cement and achieve goals of resource development and utilization as well as environmental protection.     

Characteristics of municipal solid wastes incineration (MSWI) fly ash–cement matrices and effect of mineral admixtures on composite system

An experimental work was carried out to investigate the feasibility of application of MSWI fly ash as an auxiliary cementitious material. The water demand for normal consistency, setting time, volume stability, flexural and compressive strength of MSWI fly ash–cement compound matrices were tested. And, the composite effect and the influence of mechanical properties and heavy metals solidification are studied by mixing MSWI fly ash–cement matrices with common mineral admixtures. The results show that the MSWI fly ash has some cementitious activity, but the reactivity is relatively lower and its addition to cement may lead to retardation of cement hydration. After incorporation of common mineral admixtures, the strength of solidified body was enhanced, and the effect of the heavy metals-immobilizing may be reinforced.     

Moisture balance assessment at room scale for four cases based on numerical simulations of heat–air–moisture transfers for a realistic occupancy scenario

The moisture balance at room scale is influenced by the air change rate, moisture production and vapour transfer with the envelope. However, results may differ strongly from one study to another depending on the sizing of the ventilation system, the boundary conditions and the modelling of vapour transfer in the walls. This paper aims to provide a realistic comparison of usual construction techniques based on energy consumption, indoor comfort and durability. To achieve this objective, an existing whole-building heat–air–moisture simulation tool was selected to compute coupled transfer at room scale over an entire year. Moisture production due to occupancy was modelled using a stochastic approach. Four cases were selected to emphasize the differences of both a vapour-permeable wall assembly and a relative humidity sensitive ventilation system compared to common practices.     

Thermal analysis for a double glazing unit with and without a solar control film (SnS–CuxS) for using in hot climates

In this paper the thermal analysis by natural convection of a double glazing unit (DGU) is presented. One of the sheet glasses may or may not have a solar control film (SnS–Cu_xS) on its surface. Solar radiation falls on the outside surface of the DGU at 32 °C, the opposite sheet glass interacts with the inside environment at 24 °C. The governing equations of mass, momentum and energy of the air enclosed between the two sheet glasses are solved, as well as the heat conduction equation for both sheet glasses. The effect of varying the separation distance between the glasses (1.0 ≤ b (cm) ≤ 10.0) and the incident solar radiation is analyzed (500.0 ≤ G (W/m²) ≤ 800.0). From the results, it was found that in order to reduce heat gains towards the inside environment, the optimal separation distance between the sheet glasses was b ≥ 6.0 cm. It was also observed that, the use of a solar control film in this type of system (double glazing unit) is highly recommended; due to energy gain was reduced by 55% compared to the traditional DGU without solar control film.     

Introducing a method of human health risk evaluation for planning and soil quality management of heavy metal-polluted soils—An example from Grugliasco (Italy)

European governmental institutions, as well as local communities, have recently become aware of the threats arising from soil pollution for the welfare of the population. Humans contact with soils is more likely in urban than in rural areas, and is strongly dependent on land use. Spatial planning and land management may have important impacts on the potential transfer of pollutants from contaminated soils to humans. In the present study, we propose a land use-based method for the evaluation of human health risks arising from heavy metal-contaminated urban soils, addressing in particular the influence of planning measures and land use changes on such risks. The method accounts for the role of the bioavailability of soil metals as a key factor in health risk assessment. In order to increase method applicability, a step-by-step procedure and a calculation tool were elaborated. The method can be used to identify areas in which the current or planned land use is associated with unacceptable health risks and to optimise the allocation of a certain land use to areas that are well suited and where the risks are minimal. A risk index is calculated for the area, taking the land use into consideration, as the sum of the risks from different exposure pathways and different heavy metals. For those areas where risk is identified as unacceptable, alternative planning or management options should be defined to achieve a maximal risk reduction in a cost-effective way. The method is illustrated using the Italian municipality, Grugliasco.     

The Ten‐Year Plan for the port of Antwerp (1956–1965): a linear city along the river

The Ten‐Year Plan for the port of Antwerp (1956–1965) funded the expansion of the port’s infrastructure over a 10‐year period. Strictly, a national government‐funded infrastructure programme for the construction of a set of canal docks, the programme laid the basis for a broader urbanization of the north‐eastern Antwerp metropolitan region. The importance of the operation lies primarily in its role as an instrument of urbanization rather than in the improvement of the transport and transshipment capacity of the port because it opened up a large territory to industrial settlement. The linear layout of the project along the Scheldt River led planners to conceive the further urbanization of the adjacent region on a linear city model, with satellite communities attached to the industrial and infrastructural strip. Compared with the contemporary Europoort plan for the port of Rotterdam, where several planning agencies implemented conflicting plans for functionally distinct infrastructures and the construction of a new town, the success of the Antwerp approach resides in the flexible and strategic implementation of the project as a co‐production between various authorities and private parties.     

Pattern recognition techniques for the evaluation of spatial and temporal variations in water quality. A case study: Suquía River Basin (Cordoba-Argentina)

We report a comparative study using three different chemometric techniques to evaluate both spatial and temporal changes in Suquía River water quality, with a special emphasis on the improvement obtained using discriminant analysis for such evaluation. We have monitored 22 parameters at different stations from the upper, middle, and beginning of the lower river basin during at least two years including 232 different samples. We obtained a complex data matrix, which was treated using the pattern recognition techniques of cluster analysis (CA), factor analysis/principal components (FA/PCA). and discriminant analysis (DA). CA renders good results as a first exploratory method to evaluate both spatial and temporal differences, however it fails to show details of these differences. FA/PCA needs 13 parameters to point out 71% of both temporal and spatial changes, consequently data reduction from FA/PCA in this case is not as considerable as expected. However, FA/PCA allows to group the selected parameters according to common features as well as to evaluate the incidence of each group on the overall change in water quality, specially during the analysis of temporal changes. DA technique shows the best results for data reduction and pattern recognition during both temporal and spatial analysis. DA renders an important data reduction using 6 parameters to afford 87% right assignations during temporal analysis. Besides, it uses only 5 parameters to yield 75% right assignations during the spatial analysis of four different basin areas. DA allowed us to greatly reduce the dimensionality of the starting data matrix, pointing out to a few parameters that indicate the biggest changes in water quality as well as variation patterns associated with seasonal variations, urban run-off, and pollution sources, presenting a novel approach for water quality assessments.     

From Greater London to Greater Valencia: a case of British influence on regional planning and neighbourhood units in Spain (1939–1952)

Starting in 1945, Pedro Bidagor, the National Chief of Urban Planning in Spain, attempted to replicate the British regional urban model based on Abercrombie’s proposals of the County of London Plan and the Greater London Plan. The Greater Valencia Administrative Corporation, with its supramunicipal approach, was the principal representative of this urbanistic transposition. This article analyses the transmission of British planning ideas and practices in the years following the Spanish post-war period, and the important role that the architect Pedro Muguruza – key figure in early Francoism – played in it. The study also demonstrates the influence that the contemporary British urban models based on neighbourhood units had for the satellite town centres projected in Valencia (Burjasot and Manises, 1952).     

Multistage treatment system for raw leachate from sanitary landfill combining biological nitrification–denitrification/solar photo-Fenton/biological processes,at a scale close to industrial – Biodegradability enhancement and evolution profile of trace pollutants

A multistage treatment system, at a scale close to the industrial, was designed for the treatment of a mature raw landfill leachate, including: a) an activated sludge biological oxidation (ASBO), under aerobic and anoxic conditions; b) a solar photo-Fenton process, enhancing the bio-treated leachate biodegradability, with and without sludge removal after acidification; and c) a final polishing step, with further ASBO.     

The prospects for a production management body of knowledge in business schools: response to Koskela (2017) “Why is management research irrelevant?”

This article is a response to Lauri Koskela’s recent piece in Construction Management and Economics (“Why is management research irrelevant?” 35(1–2): 4–23) which reflects on the relationship between academic research and management practice in business schools. In particular, Koskela asks why production management research and teaching has disappeared from the business school agenda and why management research has failed to produce a consistent body of knowledge that is of use to management practice. In this article, I try to provide some alternative perspectives on the present and past contexts of management theory and production research. I argue that production research, if not teaching, is alive and well and the site of theory generation, problem-focused research and innovation. I also question the veracity and wisdom of a creating “body of knowledge” in relation to management research and practice-even if it were possible, which I believe it is not. My assessment of the state of research in business schools, at least in the U.K. and the U.S. and notwithstanding a lack of consensus over how to approach management research, is that it is eclectic and vibrant and of much more use to practicing managers in that state.