Buildings, Volume 8, Issue 10 (October 2018) – 17 articles

The lay-up of cross laminated timber (CLT) leads to significant differences in properties over its cross-section. Particularly the out-of-plane shear behavior of CLT is affected by the changes in shear moduli over the cross-section. Results from laboratory shear tests are used to evaluate the shear stiffness of 3- and 5-layer CLT panels in their major and minor strength direction. The results are compared to calculated shear stiffness values on evaluated single-layer properties as well as commonly used property ratios using the Timoshenko beam theory and the shear analogy method. Differences between the two calculation approaches are pointed out. The shear stiffness is highly sensitive to the ratio of the shear modulus parallel to the grain to the shear modulus perpendicular to the grain. The stiffness values determined from two test measurements are compared with the calculated results. The level of agreement is dependent on the number of layers in CLT and the property axis of the CLT panels. Full article

This paper investigates the impact of load shedding strategies on a block of multiple buildings. It particularly deals with the quantification of the factors i.e., peak shaving, occupants’ thermal comfort or CO ${}_2$ emission reduction and how to quickly quantify them. To achieve this goal, the paper focuses on a new residential district, thermally fed by heat pumps. Four modeling approaches were implemented in order to estimate buildings’ response towards load shedding. Two schemes were combined in order to study an overall load shedding. This strategy for the neighborhood has proved itself efficient for both peak shaving and thermal comfort. Most of the clipped heating load during the peak period is shifted to low-consumption periods, providing an effective peak shaving. The thermal comfort is guaranteed for at least 96% of the time. For CO ${}_2$ emissions reduction, the link between consumption reduction and CO ${}_2$ emissions savings should be realized carefully, since shifting the consumption could increase these emissions. Full article

The latest Italian seismic events have highlighted a high discrepancy between the potential destructiveness of an earthquake and the consequent economic losses due to damage to buildings. The main reason for this mismatch is the high number of vulnerable residential buildings or the low-to-medium vulnerability of buildings that are reaching the ends of their service lives. Awareness of the economic impact of seismic vulnerability should be a matter of primary interest for public administrations, private and insurance companies, banks, owners, and professionals, despite operating at different territorial levels and with different objectives. Quantification of the expected monetary consequence of seismic vulnerability, in terms of the probable cost of repairing earthquake damage, plays a key role in defining new and more effective seismic risk mitigation strategies. Retrofitting strategies based on intervention priority defined only according to the structural seismic risk level of buildings are incorrect. These strategies neglect several important issues, such as the financial losses caused by building damage. A new procedure for estimating the expected seismic direct economic losses resulting from building damage (repair/replacement measures) is proposed and applied. The fundamental roles of analytical fragility curves and cost ratio functions in the new procedure are highlighted. Full article

Since buildings account for 40% of total energy consumption and 36% of CO₂ emissions in the European Union (EU), the directive 2010/31/EU “Energy Performance of Buildings Directive (EPDB)” among other legal provisions concerning the reduction of energy consumption of buildings has been enforced. According to this legislation, all new buildings must be nearly zero energy buildings “nZEB” by 31 December 2020 (public buildings by 31 December 2018). Nonetheless, the assessment of the “high energy performance” of a building is ambiguous and a cross country comparison seems to be intricate since different national building codes and nZEB definitions employ different energy indicators and methods. This paper delves into the question of how do the ambition levels of “nZEB” definitions and the transposition of the Directive 2010/31/EU into national law differ in four selected EU Countries: Austria, Germany, Spain, and England (as part of UK). The energy performance of some exemplary buildings is assessed by means of a simplified MATLAB model that is based on the norm DIN V-18599. The results drawn from this work show how diverse are building codes scopes and national “nZEB” definitions. Only 9 of the 36 studied cases of residential buildings obtain consistently the “nZEB” compliance status in all four selected countries. The results show that climate conditions, energy requirements, primary energy factors, ambition levels, and calculation methodologies lead to the problem of an uneven cross-country comparison. Moreover, primary energy consumption [kWh/m²a] set as the main quantitative energy indicator by the directive 2010/31/EU might not be the most suitable one for an EU level comparison. Full article

Cross-laminated timber (CLT) possesses both good shape stability and possible two-way force transfer ability due to its crosswise lamination. However, the transverse layers in CLT are prone to rolling shear failure under an out-of-plane load. An innovative multi-layer composite laminated panel (CLP) was developed by combining structural composite lumber (SCL) and dimension lumber to overcome the rolling shear failure while maintaining the high mechanical performance and aesthetic appearance of natural wood. The mechanical properties of 5-layer CLP that consisted of laminated strand lumber (LSL) and dimension lumber with different layups were evaluated by both static and modal tests. The results showed that the shear resistance, bending stiffness, and moment resistance of CLP were up to 143%, 43%, and 87% higher than their counterparts of regular CLT, respectively. The failure modes observed in both shear and bending tests indicated that the use of LSL in transverse layers could eliminate the potential rolling shear failure in CLT. With the lamination properties from components tests as inputs, the validity of shear analogy method was assessed by test results. The mechanical properties can be well predicted by shear analogy method except for the bending moment resistance of CLP and CLT with either rolling failure in the cross layer or tension failure in the bottom layer. Full article

This paper reports on the dynamic characterisation of a Reinforced Concrete (RC) stadium grandstand module for the Sporting Stadium in Lisbon. To this aim, a three-dimensional (3D) Finite-Element (FE) numerical model, implemented according to the technical drawings of the structure, is first presented to provide preliminary estimates of the expected modal characteristics for the examined structural system. Ambient vibration tests are then carried out on the same grandstand, and used to extract the natural frequencies and vibration modes of the system, according to conventional state-of-the-art output-only modal parameter identification techniques. A sensitivity investigation and FE model updating study is hence presented for the grandstand, giving evidence of the major influencing parameters and key input data for the numerical fitting of the experimental modal testing results. Full article

Europe’s cultural heritage is a rich and diverse legacy that shows evolution through many centuries of history. The Mediterranean landscape is the result of a long process of human activity in the physical environment, which makes the cultural landscape concept remarkable. Despite its growing interest, most cases are still exposed to different types of threats that can compromise their permanence. Given cultural variety, its consideration requires a multidisciplinary approach to provide scientific knowledge and to assess its values from different points of view (e.g., territorial, historical, technical, artistic, etc.). The valleys of Marina Alta are a most interesting example of different periods of history, from prehistory to recent rural life. Mountain conditions have favoured the survival of rural heritage, which is not that affected by the threat of better communicated areas and can be consider a place of exceptional value. In this context, our paper focuses on houses and hamlets of a Muslim origin that date back to at least the 13th century according to archival documents. Scattered in valleys, they are essential to understand historic transformations. They are directly related to the natural environment, are located in and have adapted to mountains to obtain small farming areas with small irrigated areas. Given their present state of ruin, an architectural assessment is needed to recognise the values and threats, and to make proposals for their conservation as a specific contribution to be considered part of an interdisciplinary vision. Full article

Green roofs are one of the most extensively investigated roofing technologies. Most of the bibliographical studies show results of researches focused on the analysis of different configurations of green roofs, but only few researches deal with the calculation of the growing media thermal resistance using laboratory tests. From 2009 to 2013, ITC-CNR, the Construction Technologies Institute of the National Research Council of Italy, carried out a first laboratory experimental campaign focused on the definition of thermal performances curves of growing media for green roofs as a function of both density and percentage of internal moisture. During this campaign, the experimental results underlined some existing gaps, such as the absence of specific standards concerning the sample laboratory preparation, the absence of shared references concerning the compaction level reached by samples in real working conditions and the evaluation of the internal moisture content of growing media exposed to atmospheric agents. For this reason, the ITC-CNR has set up a second experimental campaign focused on the solution of the gaps underlined by the first phase concerning the preparation of samples for the laboratory calculation of the thermal resistance of growing media for green roofs. This paper proposes and presents methodological approaches, methods and new test devices implemented to solve these gaps, and the results obtained. Full article

This research involves the study of two models of green facades and a model of bare wall. A house miniature was used as thermal lab. The aim of the project is evaluating the performance of energy transfer based on the various leaves densities on the green facade. Heat calculation was used to calculate heat transfer on the wall surface. There are two kinds of leaves densities, 50% and 90%. The data measurement show that the green facade has a significant cooling effect and more visible for the facade with higher leaves densities. Respectively, from experiment I to experiment III, the average of heat fluxes are 22.35 W/m², 8.76 W/m², and 0.60 W/m² where in experiment III, the negative heat flux occurred during day time due to interior surface temperature is higher than exterior surface temperature. Lastly, higher leaves densities possibility can create a better cooling effect but also has the risk of creating higher relative humidity, especially for the interior air layer. Full article

Several studies investigated the influence of infills on the response of reinforced concrete (RC) frames. However, possible shear brittle failures are generally neglected. The interaction between the infill panels and the surrounding frames can lead to anticipated brittle-type failures that should be considered in code-based assessment of lateral seismic capacity. This paper investigates, by means of simplified pushover analyses, on the effect of infills on the lateral seismic capacity explicitly considering possible brittle failures in unconfined beam-column joints or in columns. Archetype buildings representative of existing gravity load designed (GLD) RC frames of three different height ranges are obtained with a simulated design process and a sensitivity analysis is performed to investigate on the effect of infill consistency on the capacity. Moreover, possible alternative local retrofit interventions devoted to avoiding brittle failures are considered, evaluating their relative efficacy in case of different infill typologies. It is seen that for the considered existing GLD buildings, the attainment of life safety limit state is premature and happens before the damage limitation limit state. The capacity can be increased with application of local retrofit interventions. However, the retrofit efficacy varies depending on the infills consistency if the horizontal action transferred from the infills to the surrounding frame is not absorbed by the retrofit solution. Full article

The purpose of this study has been to conduct an energy diagnosis research of the third level. An energy diagnosis is a tool aimed to seek improvements related to measures of energy efficiency and saving, and environmental conservation as well. These improvements would prove to be relevant for any kind of building. The diagnosis was carried out in 36 university buildings (Renewable Energy Institute—REI) through survey and census; that in order (to identify and) to characterize current patterns of energy consumption and demand, as well as for generating specific strategies towards energy efficiency and saving, for instance the identification of systemic indicators and corrective proposals, and non-financial investment. The results promote the achievement of grand energy efficiency. The task on energy conservation entails the supporting participation of each person who either studies or works in the entity, whereas some other activities require economic stimulus for being implemented. Annual per capita energy consumption in the REI is 40 kWh/person: that is greater than the country’s average consumption rate. The main energy consumption corresponds to Building 3.1 (49% of total energy consumption). This is due to its large concentration of laboratories specialized in renewable energy research and innovation. Full article

The first part of the title of this article purposefully recalls Walter Benjamin’s interpretation of ‘love at last sight’ in connection with Charles Baudelaire’s famous poem entitled ‘To a Passerby’ in his famous book ‘The Flowers of Evil’. The poem was written about a lost chance of love. Within the title of this article it is used in relation to the concept of peace. The other part of the title contains Andrew Herscher’s concept of ‘warchitecture’, which is used to describe destroyed or semi destroyed pieces of architecture in political conflict zones. The paper intendeds to represent another face of warchitecture, which has nothing to do with physical destruction. By making value judgements regarding examples of architectural aesthetics, which exist within a long-term conflict zone—Jerusalem; Mosche Safdie’s David Village and Santiago Calatrava’s Bridge of Strings will be discussed. Peacefully they may stand in their appearance, they express a ‘nonbeing peace’ when analyzed in relation to their context. Accordingly, this paper questions both buildings’ attempts to peace and harmony when discrimination is taking place against Palestinians in Jerusalem. By articulating the relationship between the representation of ‘nonbeing’ and the destruction of buildings’ ‘warchitecture’ during wars, the paper shows that neglect can be another tool of destruction towards Palestinians and their culture. Full article

The hybrid steel trussed concrete beams examined in the present study are comprised of two principal components, i.e., a steel joist with inclined rebars, realized in industry, which is welded to a smooth steel plate and then embedded within the concrete cast in situ. The paper presents first the state of the art on laboratory tests and analytical modeling of the steel-to-concrete stress transfer mechanism investigated by push-out tests. Next, the most relevant scientific contributions currently available in the technical literature regarding experimental investigation on actual shear behavior are summarized and discussed. Lastly codes and analytical models are reviewed. Full article

The World Green Building Council (WGBC) advocates improvements in employee health, wellbeing, and productivity in buildings as people are about 90% of an organisation’s expense and well exceed building costs and energy costs. It was reported that earlier research on workplace design primarily focused on physical arrangement of employees’ immediate work area, and ambient environmental qualities of the work area. Building organisation, exterior amenities, and site-planning have been given less attention. Therefore, we examine more closely the health relevance of both proximal and remote aspects of workplace design. Occupational stress is a complex phenomenon that is dynamic and evolving over time. This investigation reviews the existing fundamental conceptual models of occupational stress, workplace design, and connection to nature. It aims to develop an improved model relevant to work place design and occupational stress linked with connection to nature. The proposed improved model is presented with an appropriate causal loop diagram to assist in visualizing how different variables in a system are interrelated. The developed model highlights how connection to nature in workspaces can function as a work resource with a dual effect of improving physical wellbeing and psychological wellbeing. Full article

The development of environmentally-friendly methods as alternatives to chemical fumigation for controlling insect pests has attracted public attention. Among these methods, heat treatment is based on the use of fan heaters that are positioned by operators who typically establish their number and position within buildings to be treated. The aim of this research was to improve heat treatment effectiveness by applying a validated computational fluid dynamics (CFD) model for planning fan heater positions within the building environment. Based on a CFD model, which was built and validated according to experimental data acquired during heat treatment of a flour mill, simulations were carried out by changing the position and/or rotation of fan heaters with the aim of enhancing temperature distribution inside the building. The results showed that in some simulations the percentage of internal wall surfaces having a temperature value lower than that required for heat treatment efficacy was considerably reduced, by up to 56.7%. Therefore, the CFD approach proposed in this study could be used as a decision support system for improving heat treatment efficacy. Full article

This paper presents the full-scale experimental assessment of a log-house timber wall with partial thermal insulation under in-plane compression and exposed to fire on one side. A key aspect of the current design application for log-house systems is represented by geometrical details, like cross-sectional properties of logs (typically characterised by high depth-to-width ratios) and outriggers. The latter provides restraint condition for the examined walls and hence markedly affects their overall load-carrying capacity. As a result, careful consideration should be given to the choice of these details, compared to fully monolithic timber walls (i.e., made from cross-laminated timber), due to the possible occurrence of local structural and/or thermo-mechanical mechanisms. This is the case of exceptional loading conditions like fire load, as the fire resistance of these systems could be affected by a multitude of variables, including the presence (even though limited to few surfaces only) of thermal insulation panels. To this aim, the results of a full-scale furnace test are discussed in the paper for a log-wall with partial thermal insulation, namely thermal insulation applied on the outriggers only, under the effects of EN/ISO standard fire conditions. The results of Finite Element (FE) numerical studies are also reported, to further explore the load-carrying performance of the reference log-house specimen and compare it with the experimental observations. Several thermal insulation configurations are finally numerically investigated, showing their effects on the overall fire resistance of the assembly. In accordance with literature, the test shows that the log house’s timber wall is suitable to obtain a fire resistance of about 60 min under relevant loading. The FE results are in rather close agreement with the temperature measurements within the section of logs, as well as a qualitative correlation with respect to the mechanical behaviour observed in the full-scale furnace experiment. The key role of outriggers and their thermo-mechanical boundaries, finally, is emphasised. Full article

The priorities in the design of more sustainable buildings are quite dependent on the specific social context. In developing countries, the sustainability concept and priorities in the residential buildings sector are quite different from the ones of the developed countries, since there are still basic needs to answer. Therefore, this research is aimed at contributing to a better understanding of the concept of social sustainability in the residential building sector of the developing countries. A methodology to define and prioritise the social sustainability indicators is proposed and applied in the context of Palestine. The presented methodology is based on the sustainability indicators of international standards, on the most well know building sustainability assessment methods and in the analysis of their application to a specific context. It includes a methodology to prioritise the list of social indicators, by considering the expectations of two groups of building stakeholders: designers and building users. At the end, this research proposes a framework of social aspects to consider in the design of more sustainable residential buildings in West Bank, Palestine that is composed of twenty-one indicators, distributed among six sustainability categories and ranked according to their weight in the overall of sustainability level. Full article