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One of the conclusions of a recent article by Egan et al. [J. Appl. Phys. 115, 084903 (2014)] was that since the melt-dispersion mechanism (MDM) of the reaction of aluminum nanoparticles was not observed in their experiments, this mechanism is very unlikely. Our main point here is to demonstrate that, in fact, these experiments do not disprove the MDM. [ABSTRACT FROM AUTHOR]

Natural bamboo fiber (BF) and bamboo charcoal (BC) resources are available in tropical and subtropical regions in which bamboo forests are widely distributed and exhibit the potential to act as sustainable local building materials. In this study, a hygrothermal properties test and a building component and enclosed space simulation were performed to determine the adaptability of applying BF and BC as construction infills in building envelopes with local climate and building conditions. Hygrothermal properties test results indicated that the relation between BF hygrothermal properties and ambient relative humidity could be generally defined with exponential equations. Both the moisture storage and transport properties of the BC increased when compared with those of uncarbonized bamboo panels. Hygrothermal performance simulation results indicated that the BC arranged in the upstream side of the moisture flow improved the hygric performance of the BF layer, weakened the moisture and heat flow through exterior walls, improved the indoor hygrothermal environment, and reduced the HVAC demand. The application of BF and BC as local building materials was beneficial for both bamboo resources utilization and the building physical performance improvements in the bamboo producing area. [ABSTRACT FROM AUTHOR]

In this study, finite element (FE) models are developed to examine the interfacial behavior of a new retrofitting system comprised small diameter carbon fiber reinforced polymer (CFRP) rods spaced apart a distance larger than the rod diameter. The CFRP rod panel (CRP) is adhesively bonded to the concrete surface. The study explores several key parameters, including bond-slip ( τ - δ ) relation, effective bond length, rod diameter ( D ), and rod spacing-to-diameter ( S / D ) ratio. The models were validated against previous double-lap CRP-concrete block tests. A bilinear ( τ - δ ) model that provides a good correlation to the failure loads of the entire range of specimens was established. The effective bond length was found for two commonly used CRPs, and was 85 mm for one with D  = 2 mm and S  = 6.35 mm, and 115 mm for that with D  = 4 mm and S  = 9.50 mm. A parametric study using 20 FE models was carried out, considering four rod dimeters (1–4 mm) and five S / D ratios (2.2–3.18). It was found that although debonding failure consistently governs; decreasing ( D ) or increasing ( S / D ) ratio increases the ultimate strength. The effect of ( S / D ) ratio is more pronounced for D = 1 mm than other diameters. The study also found that debonding load of CRP is 51% higher than that of an externally bonded conventional CFRP plate of similar cross-sectional area and mechanical properties. [ABSTRACT FROM AUTHOR]

Mechanical properties and microstructural analysis of Expanded Perlite Aggregate (EPA) concretes are presented. Using 10% EPA, the effects of using various types of fibre were investigated. For all specimens, fibrous and non-fibrous, the compressive and the splitting tensile strengths were obtained. Complete stress–strain curves for fibre-reinforced specimens were obtained. A new index for representing the toughness of fibre-reinforced Perlite concretes is introduced. The addition of fibres substantially increased the splitting tensile strength. Steel fibres with “indentations” had the best performance in this regard. Regarding the toughness, specimens with “hooked” steel fibres performed best. SEM photographs revealed that the number, shape and distribution of pores were visibly influenced by the addition of EPAs. The images showed that using steel fibres improved microstructural characteristics of Perlite concrete, in line with the results of macro studies. However, polypropylene fibres degraded the microstructure of concrete, especially at the neighbourhood of fibres. [ABSTRACT FROM AUTHOR]

Several non-destructive (ND) techniques are presented as a tool for the evaluation of the conservation state of carbonate building materials of the 'Palazzo di Città', a historic building in the centre of Cagliari, a town in Italy. In this study, considering both the nature of the building materials and the constructive types of the investigated architectural structure, ultrasonic investigations were carried at 54 kHz. The ultrasonic measurements were performed both in the laboratory and in situ using the portable ultrasonic non-destructive digital indicating tester (PUNDIT Lab plus©) by Proceq (Schwerzenbach, Switzerland). The ultrasonic measurements were integrated by a petrographical and petrophysical study of the investigated stone materials in order to correlate their petrographical-petrophysical features with the elastic ones. A further implementation was carried out comparing elasto-mechanical and petrographical-petrophysical features of the investigated carbonate materials with surface geometric anomalies computed by means of the architectonic terrestrial laser scanner (TLS) application. In particular, we used a Leica HDS-6200 TLS to study the complex shape of some artifacts from the 'Palazzo di Città' monumental compound. A multi station approach was adopted in order to acquire more than 180 million points by performing 30 high resolution structured scans. After TLS data elaboration with JRC 3D Reconstructor software, the 3D model of the buildings together with morphological anomalies of some artifacts were computed in order to highlight the zones where the deformation was more evident. [ABSTRACT FROM AUTHOR]

In this article the results of studies of innovative materials in the field of the processes of occurrence of compliance the bolt assemblies of metal structures are presented. The main attention is focused to the shear forces in the bolt, creating a bending moment on the beam supports. Analyzing that can reveal patterns of behavior of the connection depending on the load and the number of bolts. Accounting compliance units can reduce the number of materials used. Thus, the main objective of this research was a more detailed study of compliance in the design process in order to apply the acquired knowledge into practice. [ABSTRACT FROM AUTHOR]

Drying structures using high-frequency electromagnetic radiation or microwave technology is currently gaining much more usage in the engineering practice. The goal of the method is the quickest elimination of water in construction (wall, floor structure, etc.). Microwave is a part of the electromagnetic radiation of frequency between 300 MHz and 300 GHz and wavelength between 1 mm and 1 m. The frequency of 2.45 GHz and 122 mm wavelength is used for engineering practice. Due to the effect of microwave radiation the divergent homogeneity of temperature field of different building materials can be observed. This article discusses the spread of thermal field depending on the volume of water and thereby the size of mass humidity of the given material (timber). The temperature fields will be observed by a thermo camera, always after a certain time cycles of the heating. [ABSTRACT FROM AUTHOR]

Earthen building materials bear interesting environmental advantages and are the most appropriate to conserve historical earth constructions. To improve mechanical properties, these materials are often stabilized with cement or lime, but the impact of the stabilizers on the water transport properties, which are also critical, has been very rarely evaluated. The researchers have tested four earth-based repair mortars applied on three distinct and representative rammed earth surfaces. Three mortars are based on earth collected from rammed earth buildings in south of Portugal and the fourth mortar is based on a commercial clayish earth. The main objective of the work was over the commercial earth mortar, applied stabilized and not stabilized on the three rammed earth surfaces to repair, to assess the influence of the stabilizers. The other three earth mortars (not stabilized) were applied on each type of rammed earth, representing the repair only made with local materials. The four unstabilized earth materials depicted nonlinear dependence on t1/2 during capillary suction. This behavior was probably caused by clay swelling. Stabilization with any of the four tested binders enabled the linear dependence of t1/2 expected from Washburn's equation, probably because the swelling did not take place in this case. However, the stabilizers also significantly increased the capillary suction and the capillary porosity of the materials. This means that, in addition to increasing the carbon footprint, stabilizers, like cement and lime, have functional disadvantages that discourage their use in repair mortars for raw earth construction. [ABSTRACT FROM AUTHOR]

Ballast and subballast are two layers of noncohesive, granular materials with different grain sizes filled in the track substructure to bear traffic loadings from train passages. The performance and sustainability of a track substructure depend on both of these two granular layers. This paper presents the experimental results of cyclic triaxial testing and postcyclic triaxial testing on individual ballast and subballast materials. Also, to investigate mechanical behavior at the ballast/subballast interface, cyclic tests were performed on composite specimens consisting of the upper half ballast layer and underlying half subballast layer. These cyclic tests indicated that the existence of the ballast/ subballast interface depresses the development of permanent axial or volumetric deformation at the interface zone, and this effect vanishes as the initial compaction and confining pressure increase. Postcyclic failure tests show that the ballast/subballast interface zone's strength is close to that of the ballast material but lower than that of the subballast material. [ABSTRACT FROM AUTHOR]

Compressed earth blocks, a form of earthen construction, is a growing field of natural building. It is a low-cost, locally available material that provides high thermal capacity with low environmental impact. Earthen blocks have been primarily used in warmer climates; however, there is increasing interest in using the blocks in cold climates. Limited research has been done on long-term durability in cold climates. In this study, combinations of cement and lime stabilizers were tested with metakaolin and Plasticure, a water repellant, to determine freeze-thaw durability. Blocks were exposed to up to twelve 48-hour freeze-thaw cycles. Prisms were tested in compression to failure in both the wet and dry condition as a measure of deterioration. Freeze-thaw damage occurred when water was readily available via capillary action. Blocks with 7.5% cement content provided optimum strength retention; however, 10% cement provided higher strengths. The addition of lime, metakaolin, and Plasticure to a 5% cement-stabilized block increased dry strength retention by 75 to 146%, but there was no significant difference when wet. Plasticure reduced variability in strength reduction from as high as 91 to 24%, and increased strength retention by up to 75%. Reductions in both strength and water strength coefficients were observed in different combinations. [ABSTRACT FROM AUTHOR]

The drinking of coffee forms a deep-rooted pastime in many communities worldwide. However, the culture of coffee drinking generates vast quantities of organic waste that ends up in landfills. Current research trends are inclined towards recycling of waste materials into alternative construction materials, hence the need to research sustainable uses for spent coffee grounds. Coffee grounds (CG) are highly organic with a very high percentage of biodegradable material. The objective of this research was to study the strength development of CG when used as a geopolymer stabilized embankment structural fill material aiming for a better understanding of geopolymer stabilization of highly organic material. Fly ash (FA), being a silica and alumina rich material, was used as a precursor. A liquid alkaline activator, L, being a sodium hydroxide-sodium silicate solution was used for alkali activation of FA in the CG-FA geopolymer. Factors found to affect strength development of the CG-FA geopolymer were: (1) the ratio of sodium hydroxide and sodium silicate in the activator liquid; (2) the curing time; (3) the replacement ratio of FA in the CG; (4) the alkalinity of the activator liquid used; and (5) the curing temperature. Optimally, FA can constitute up to 30% of the CG-FA mix for efficient geopolymerization to occur. The concentration of sodium hydroxide can be increased up to 12 mol before the strength development-to-alkalinity ratio decreases. The highest strength was found to occur when the curing temperature was 50°C. By introducing 30% of FA into CG, an efficient geopolymer can be synthesized with a L=FA ratio of 1.8 and a Na2SiO3:NaOH ratio of 50:50, which provides the maximum 7-day strength. California Bearing Ratio tests conducted on the CG-FA geopolymer, confirm that it is possible to use geopolymer stabilized CG as an embankment structural fill or subgrade material. Geopolymerization products will further encapsulate and bind the organics in CG, eliminating their potential to biodegrade, which attest to the efficacy of geopolymers as an alternative stabilization agent for highly organic soils. [ABSTRACT FROM AUTHOR]

This paper presents the experimental investigation on the compressive behavior of cold-formed high-strength steel tubular stub columns. In this paper, the nominal 0.2% proof stress of the high-strength steel was 700, 900, and 1,100 MPa. A total of 25 stub column tests on circular, rectangular, and square hollow structural sections were conducted. Geometric imperfections and load-deformation histories were reported and assessed. The experimental results were compared against the design values calculated from the Australian, European, and North American codes, and the corresponding compactness criteria were assessed. A finite-element model, which incorporated the varying material properties, was described, and the influence of geometric and material imperfections was also evaluated. The finite-element results successfully captured the experimental observations and can be adopted for future parametric studies. [ABSTRACT FROM AUTHOR]

Calcined titanium gypsum was investigated by the ways of XRD (powder X-ray diffraction), XRF (X-ray fluorescence) and TG-DTA (thermogravimetric–differential thermal analyses). It was employed as raw material for making lightweight materials. The influence of cement, amount of water/solid (W/S) ratio, water-reducing agent, citric acid content and the hydration age on the gypsum blocks was investigated. The results showed that the optimum W/S ratio, cement content and water-reducing agent are 0.9, 10% and 2 wt% for the calcined gypsum from titanium gypsum, respectively. The 5.96 MPa was attained after 7 days of ageing. It was also found that the citric acid is inappropriate to be used in the production of gypsum blocks from TiO2production by-products. [ABSTRACT FROM PUBLISHER]

Describing the moment rotation (M/ϑ) behavior of reinforced concrete (RC) hinges is essential in predicting the behavior of RC structures under severe loadings, such as under cyclic earthquake motions and blast loading. The behavior of RC hinges is defined by localized slip or partial interaction (PI) behaviors in both the tension and compression region. In the tension region, slip between the reinforcement and the concrete defines crack spacing, crack opening and closing, and tension stiffening. While in the compression region, slip along concrete to concrete interfaces defines the formation and failure of concrete softening wedges. Being strain-based, commonly-applied analysis techniques, such as the moment curvature approach, cannot directly simulate these PI behaviors because they are localized and displacement based. Therefore, strain-based approaches must resort to empirical factors to define behaviors, such as tension stiffening and concrete softening hinge lengths. In this paper, a displacement-based segmental moment rotation approach, which directly simulates the partial interaction behaviors in both compression and tension, is developed for predicting the M/ϑ response of an RC beam hinge under cyclic loading. Significantly, in order to develop the segmental approach, a partial interaction model to predict the tension stiffening load slip relationship between the reinforcement and the concrete is developed. [ABSTRACT FROM AUTHOR]

In this study, the setting and tensile strength development of ultra-high-performance concrete (UHPC) at a very early age was investigated by performing the penetration resistance test (ASTM C403), as well as the direct tensile test using the newly developed test apparatus, and taking ultrasonic pulse velocity (UPV) measurements. In order to determine the optimum surface treatment method for preventing rapid surface drying of UHPC, four different methods were examined: plastic sheet, curing cover, membrane-forming compound, and paraffin oil. Based on the test results, the use of paraffin oil was found to be the best choice for measuring the penetration resistance and the UPV, and attaching the plastic sheet to the exposed surface was considered to be a simple method for preventing the rapid surface drying of UHPC elements. An S-shaped tensile strength development at a very early age (before 24 h) was experimentally obtained, and it was predicted by a power function of UPV. Lastly, the addition of shrinkage-reducing and expansive admixtures resulted in more rapid development of penetration resistance and UPV of UHPC. [ABSTRACT FROM AUTHOR]

Although concrete is one of the most widely used construction materials, it is characterized by substantially low tensile strength in comparison to its compression strength, and the occurrence of cracks is unavoidable. In addition, cracks progress due to environmental conditions including damage by freezing, neutralization, and salt, etc. Moreover, detrimental damage can occur in concrete structures due to the permeation of deteriorating elements such as Cl- and CO2. Meanwhile, under an environment in which moisture is being supplied and if the width of the crack is small, a phenomenon of self-healing, in which a portion of the crack is filled in due to the rehydration of the cement particles and precipitation of CaCO3, is been confirmed. In this study, cracks in cementitious composite materials are effectively dispersed using synthetic fibers, and for cracks with a width of more than 0.1 mm, a review of the optimal self-healing conditions is conducted along with the review of a diverse range of self-healing performance factors. As a result, it was confirmed that the effective restoration of watertightness through the production of the majority of self-healing products was achieved by CaCO3 and the use of synthetic fibers with polarity, along with the effect of inducing a multiple number of hairline cracks. In addition, it was confirmed that the self-healing conditions of saturated Ca(OH)2 solution, which supplied CO2 micro-bubbles, displayed the most effective self-healing performance in the surface and internal sections of the cracks. [ABSTRACT FROM AUTHOR]

The rheological properties of the cement pastes have been determined using a rotational viscometer under a special testing routine by increasing and retaining a steady rotation speed of the viscometer cylinder up to certain values and for a certain time. These tests, using rotational viscometer, have been conducted by making the assessment of cement paste flow curves, using Bingham rheological model. Rheological properties of cement pastes were tested at different times after pastes mixing: 0 min, 30 min, 60 min, 90 min, 120 min and 180 min. Cement pastes with same W/C ratio equal to 0.35 were tested. The content of admixture was used 0%, 0.5%, 1%, 2%, 3% and 5%. The admixture of Ca(NO3)2can be used in cement pastes and concretes without a reduction in consistency during 120 min in the dosage of up to 2%. Dosages of Ca(NO3)2 from 3% are not recommended for cement pastes and concrete, they significantly increase the viscosity of mixtures immediately after mixing The admixture of calcium nitrate changes thixotropy of cement pastes. In this case, a bigger dosage of calcium nitrate increases the thixotropy of pastes. [ABSTRACT FROM PUBLISHER]

This research work deals with a study of a residential building located in climatic context of Karachi with the objective of being the study of thermal performance based upon passive design techniques. The study helps in reducing the electricity consumption by improving indoor temperatures. The existing residential buildings in Karachi were studied with reference to their planning and design, analyzed and evaluated. Different construction's compositions of buildings were identified, surveyed and analyzed in making of the effective building envelops. Autodesk® Ecotect, 2011 was used to determine indoor comfort conditions and HVAC (Heating, Ventilation, Air-Conditioning and Cooling) loads. The result of the research depicted significant energy savings of 38.5% in HVAC loads with proposed building envelop of locally available materials and glazing. [ABSTRACT FROM AUTHOR]

Upon accession to the European Union, economic growth became accelerated in Poland, resulting in a boost in infrastructure development. This led to a marked growth in demand for natural sand-gravel aggregates and other raw materials used in road construction. To meet the demand for suitable raw materials, the Ministry of Environment commissioned the Polish Geological Institute-National Research Institute to start a re-evaluation of earlier raw material prognoses assessments in order to delineate prognostic areas for development of new resources. The re-evaluation has been conducted by the PGI-NRI within the frame of the compilation of the Geoenvironmental Map of Poland at the scale of 1:50 000, making it possible to identify potential conflicts with land-use plans as well as already established NATURA 2000 and other natural heritage conservation designations and more or less continuous built up areas which preclude or at least impede exploitation of mineral raw materials. The analyses also covered economic factors related to costs of transport and the current economic criteria of mineral resources and reserves. At the first stage of the project (between 2008 and 2012) the re-evaluation was conducted in 432 prognostic areas with a total area of over 33 thousands of hectares. According to the current economic criteria of sand-gravel aggregate deposits there were estimated resources of over 5 mld tons, of which around 3 mld tons of aggregates were suitable for road investments and over 2 mld tons of aggregates were suitable for construction. The work has made it possible to re-evaluate the occurrences of natural aggregates in the vicinities of urban centers and along corridors delineated for selected planned motorways and expressways as well as those under construction. The study was compiled especially for business entities involved in construction projects or the exploitation of mineral resources and state administrative units as a tool to support land-use planning and management at the level of individual communes, counties (poviats) and voivodeships. Re-evaluated prognostic areas data are gathered in spatial database and are available through WMS service on the Geoenvironmental Map of Poland portal (). [ABSTRACT FROM AUTHOR]

This study presents the results of the mathematical modelling for the micropiles foundation of an investment objective located in Slanic, Prahova county. Three computing models were created and analyzed with software, based on Finite Element Method. With Plaxis 2D model was analyzed the isolated micropile and the three-dimensional analysis was made with Plaxis 3D model, for group of micropiles. For the micropiles foundation was used Midas GTS-NX model. The mathematical models were calibrated based with the in-situ tests results for axially loaded micropiles, embedded in salt rock. The paper presents the results obtained with the three software, the calibration and validation models. [ABSTRACT FROM AUTHOR]

The materials used in construction, such as those used in windows, currently require different procedures when making a choice that go beyond the aspect of functionality and take into account the need for efficient use guided the prerogatives of sustainability. Among other requirements, design specification guidelines, in this regard, indicate material selection based on criteria related to the consumption of raw materials, waste generation and its management. The purpose of this research was to define the sustainability index of the materials used or with a potential for use in windows in multifamily residential buildings located in Vitória, Espírito Santo, Brazil, using ISMAS – Instrument for the Selection of More Sustainable Materials – as a tool. The study consisted of two steps, one in the field and the other in analyzing the sustainability index of the materials. Among the 23 types of identified windows, it was found that the most commonly used materials are aluminum, wood, PVC, and glass. The results demonstrate that materials with different compositions and properties can achieve the same sustainability index when assessed using the ISMAS approach, giving the designer different options when making a selection. The research also showed that the functional, aesthetic, and economic criteria traditionally adopted by architects and designers are not sufficient to improve a building’s performance when the issue of sustainability is introduced into the process. [ABSTRACT FROM AUTHOR]

The implementation of active and responsive materials in architecture and construction allows for the replacement of digitally controlled mechanisms with material-based systems that can be designed and programmed with the capacity to compute and execute a behavioral response. The programming of such systems with increasingly specific response requires a material-driven computational design and fabrication strategy. This research presents techniques and technologies for significantly upscaling hygroscopically actuated timber-based systems for use as self-constructing building surfaces. The timber's integrated hygroscopic characteristics combined with computational design techniques and existing digital fabrication methods allow for a designed processing and reassembly of discrete wood elements into large-scale multi element bilayer surfaces. This material assembly methodology enables the design and control of the encoded direction and magnitude of humidity-actuated responsive curvature at an expanded scale. Design, simulation, and material assembly tests are presented together with formal and functional configurations that incorporate self-constructing and self-rigidizing surface strategies. The presented research and prototypes initiate a shift toward a large-scale, self-construction methodology. [ABSTRACT FROM AUTHOR]

This article presents a contextual analysis of stone materials from northwestern Argentina, produced at a time when sedentary life was unfolding throughout the region. It examines the circulation and use practices of everyday obsidian tools, as well as the technical and semantic relationships they established within the wider field of materials and artefacts that characterized the period. Arguing for a sensitive approach to the classificatory logic of past societies, it is proposed here that a particular hierarchy of stone artefacts of regional significance emerged during this period. After discussing anthropological value perspectives and their relevance to Andean archaeology, the article explores Andean conceptualizations of stone that can provide a culturally specific framework for understanding ancient stone materials. The final sections examine the technical and contextual practices involving with domestic stone tools, as well as how these were embedded in a wider landscape of physical and semantic relationships. It is hoped that this article will contribute to ongoing discussions on non-Western models of value and their relevance for understanding social interaction and complexity, both in the south-central Andes and beyond. [ABSTRACT FROM PUBLISHER]

Sanliurfa limestones have been used as building materials from antiquity to current day (e.g., Gobeklitepe temple B.P. 14,000, Bazda underground quarries B.P. 3000, Harran castle B.P. 3000, etc.). These antique structures are listed within the United Nations Educational, Scientific and Cultural Organization (UNESCO)'s World Heritage List. However, the stones were used in these structures without any protection, and atmospheric conditions (precipitation, acid rain, temperature changes, etc.) cause damage to these stones over time, such as strength loss, abrasion, and discoloring. The damage can lead to the collapse of precious historical structures, or may require costly restoration. In this study, Sanliurfa limestone was investigated with respect to conservation using polish insulation (polysiloxane, lithium silicate, and varnish), appearance performance by polishing, and potential usage in the marble industry. The results revealed that conservatives could maintain up to 92 % of the unconfined compressive strength (UCS) of the natural stone and reduced acid abrasion to 0.5 % of the original weight. The stone gained a bright appearance after polishing, especially by lithium silicate. Thus, it can be stated that it is possible to recover or prolong the lifetime of the monuments that were constructed using Sanliurfa limestone, and this limestone may have great industrial potential as marble stone. [ABSTRACT FROM AUTHOR]

It is recognized that there is often a discrepancy between the measured fabric thermal performance of dwellings as built and the predicted performance of the same dwellings and that the magnitude of this difference in performance can be quite large. This paper presents the results of a number of in-depth building fabric thermal performance tests undertaken on three case study dwellings located on two separate Passivhaus developments in the UK: one masonry cavity and the other two timber-frame. The results from the tests revealed that all the case study dwellings performed very close to that predicted. This is in contrast with other work that has been undertaken regarding the performance of the building fabric, which indicates that a very wide range of performance exists in new-build dwellings in the UK, and that the difference between the measured and predicted fabric performance can be greater than 100%. Despite the small non-random size of the sample, the results suggest that careful design coupled with the implementation of appropriate quality control systems, such as those required to attain Passivhaus Certification, may be conducive to delivering dwellings that begin to ‘bridge the gap’ between measured and predicted fabric performance. [ABSTRACT FROM PUBLISHER]

The recast of the European Union's Energy Performance of Buildings Directive introduced the concept of nearly zero-energy buildings, requiring its adoption from 2021 by all new buildings and existing ones submitted to major renovations. European Union member states must also ensure minimum energy requirements for buildings in order to achieve cost-optimal levels during their life cycle. Cost optimality and nearly zero-energy buildings are important concepts in European Union energy policies. These concepts are related, but one is more focused on costs, while the other is more concerned with low energy consumption and on site-renewable energy harvesting. If these approaches result in major differences in the selection of the best package of retrofit measures, then the transition from the cost-optimal concept to nearly zero-energy buildings might be problematic. To assess the most cost-effective solutions to achieve net-zero, a building in Porto, Portugal, was analysed. This determined not only the most cost-effective retrofit solutions but also compared these net-zero solutions with those resulting from the cost-optimal calculation. Both approaches lead to similar results, indicating that the transition between ‘cost optimality’ to ‘nearly zero-energy buildings’ could occur in Portugal. [ABSTRACT FROM PUBLISHER]

Frequent site energy consumption auditing is a potential strategy to mitigate greenhouse gas (GHG) emissions from existing buildings. Such a strategy has been practised in Australia for nearly 15 years. This paper documents and analyses the effect of repetitive audits on measured site energy consumption. Using a self-constructed database of over 3500 audited disclosures representing over 800 unique office buildings, empirical models demonstrate that measured site energy consumption declines, on average, over the first five re-certification periods. The results also suggest a market average post-certification equilibrium in Australia of approximately 430 MJ/m2/year (120 kWh/m2/year) within approximately six years, if all else – including green management strategy – is held constant. Since GHG emissions from buildings in Australia are highly correlated with site energy consumption, such a result is comparable with meeting 50-year GHG mitigation targets reliant on the implementation of existing technologies. This suggests that repetitive auditing is a successful approach for motivating owners to invest in existing energy efficiency technologies. [ABSTRACT FROM PUBLISHER]

This article reviews current challenges for the masonry industry from a regulatory perspective. First, the CJEU judgment and its consequences will be discussed. The judgment of 16 October 2014 will make fundamental changes in the German regulatory system necessary. How these will be implemented is not yet clear so that this article can only give an overview of the present situation (September 2015) in the discussions. What is clear is that the changes in the regulatory system will have repercussions in the field of standardisation. These repercussions will be outlined - in general and specifically for the masonry sector - in the second part of this article. Finally, the paper will look at the progress in the implementation of Eurocode 6 (Design of masonry structures). [ABSTRACT FROM AUTHOR]

In the study presented in this article we investigated the feasibility and the reliability of a transducer design for the nondestructive evaluation (NDE) of the stiffness of structural materials. The NDE method is based on the propagation of highly nonlinear solitary waves (HNSWs) along a one-dimensional chain of spherical particles that is in contact with the material to be assessed. The chain is part of a built-in system designed and assembled to excite and detect HNSWs, and to exploit the dynamic interaction between the particles and the material to be inspected. This interaction influences the time-of-flight and the amplitude of the solitary pulses reflected at the transducer/material interface. The results of this study show that certain features of the waves are dependent on the modulus of elasticity of the material and that the built-in system is reliable. In the future the proposed NDE method may provide a cost-effective tool for the rapid assessment of materials' modulus. [ABSTRACT FROM AUTHOR]

A series of reinforced concrete (RC) components with high-strength materials were tested under pure flexural monotonic and cyclic quasi-static loading protocols. The specimen materials included high-strength concrete (HSC), ultra-high-strength steel (UHSS), and steel fibers to create high-strength fiber-reinforced concrete (HSFRC) specimens. The replacement of conventional steel with UHSS increased the specimen's ultimate flexural capacity more than 60%, but reduced its ductility. The addition of steel fibers to HSC specimens increased the peak strength by an additional 10%, and greatly reduced cracking and spalling of HSC specimens. However, the energy dissipation capacity of the specimens did not increase due to the presence of fibers. [ABSTRACT FROM AUTHOR]

This paper presents the results of a systematic experimental campaign consisting of 13 symmetric punching tests on interior slab-column connections. The study focuses on the influence of varying the size of the supported area and the slenderness of the slab. Other investigated parameters are the flexural reinforcement ratio and the presence of shear reinforcement. The results of the present campaign and of previous tests are compared to the predictions of different codes of practice and to the critical shear crack theory (CSCT). The comparison shows that the CSCT and fib Model Code 2010 give the most consistent predictions, whereas the results of Eurocode 2 for small support sizes have a large scatter. The predictions of ACI 318 are observed as overall conservative in the investigated range. This study shows that slenderness has an important influence on the punching strength of slabs with shear reinforcement, despite the fact that it is neglected in many codes of practice. [ABSTRACT FROM AUTHOR]

The article deals with the algorithm of investigating the structure of building material on the basis of its photomicrographs by means of statistical analysis of point images. The obtained values allow defining the basic characteristics of the material structure. [ABSTRACT FROM AUTHOR]

A prerequisite of the efficient recycling of demolition waste and its evaluation in terms of the material specific recycling rates is information on the composition of the building material stock (as the source of future demolition waste). A practical method is presented that characterizes the material composition of buildings prior to their demolition. The characterization method is based on the analysis of available construction documents and different approaches of on-site investigation. The method is tested in different buildings and the results from four case studies indicate that the documents are useful to quantify bulk materials (e.g.bricks, concrete, sand/gravel, iron/steel and timber). However, on-site investigations are necessary to locate and determine the trace materials such as metals (e.g.copper and aluminium), or different types of plastics. The overall material intensity of the investigated buildings ranges from 270 to 470 kg/m³ gross volume. With ongoing surveys about the composition of different buildings, the collected data will be used to establish a building-specific database about the amount of materials contained in Vienna's building stock. [ABSTRACT FROM PUBLISHER]

Bridge design and construction has gone through several phases in Southern Africa. The first phase was dominated by steel. During this phase, revolutionary steel bridges were constructed. This happened despite the fact that steel was not manufactured in this region. The use of structural steel in these bridges exploited its advantageous properties of economically carrying heavy loads over long spans with minimum dead weight. After this phase, the choice of material used in bridges changed to concrete. During the past 20 years, steel has staged a strong comeback. The aim of this paper is to explain why the bridge industry has experienced different phases in construction. Selected case studies of vehicle and foot steel bridges are presented and discussed to substantiate the competitiveness of steel as a bridge construction material. [ABSTRACT FROM AUTHOR]

The article discusses an activity of research and development at the University of Petrosani, Romania called scientific research conducted in accordance with the Chart of the University of Petrosani, regulations about scientific research and the Ethics Code. It cites research centres that were locally accredited at University which include engineering of rocks, useful mineral substances and construction materials, evaluation of risks in industry and mining engineering.