Local Construction Research Articles

An investigation of the difficulty of implementing design for disassembly principles in the construction industry of Sri Lanka

Construction materials take up the highest percentage of natural resource consumption while providing a considerable amount of waste. Also, the construction industry is responsible for a substantial percentage of greenhouse gas emissions which cause global warming. Design for disassembly would provide a solution by delivering disassembly measures for a buildingcomponents, and materials could be reused keeping them in a closed loop to minimise manufacturing of new construction materials. This paper will discuss the difficulty of implementing principles of design for disassembly in Sri Lanka by considering the expert opinion collected through a questionnaire as quantified qualitative data. Samples will be based on convenience in nonprobability sampling method. Findings of the paper express, market demand for reused components and materials is the most challenging barrier for implementing Design for Disassembly in Sri Lanka, following compatibility with commercial market standards. In the local construction sector possibility of implementing design for disassembly is heavily based on the selection of materials and construction system.

Local Construction of Mn-Based Layered Cathodes through Covalency Modulation for Sodium-Ion Batteries.

P2-type Mn-based layered oxides are among the most prevalent cathodes for sodium-ion batteries (SIBs) owing to their low cost, resource abundance, and high theoretical specific capacity. However, they usually suffer from Jahn-Teller (J-T) distortion from high-spin Mn3+ and poor cycling stability, resulting in rapid degradation of their structural and electrochemical properties. Herein, a stable P2-type Mn-based layered oxide is realized through a local construction strategy by introducing high-valence Ru4+ to overcome these issues. It has been revealed that the Ru substitution in the as-constructed Na0.6Mg0.3Mn0.6Ru0.1O2 (NMMRO) renders the following favorable effects. First, the detrimental P2-OP4 phase transition is effectively inhibited owing to the robust Ru-O covalency bond. Second, the Mg/Mn ordering is disturbed and the out-of-plane displacement of Mg2+ and in-plane migration of Mn4+ are suppressed, leading to improved structural stability. Third, the redox ability of Mn is increased by weakening the covalence between Mn and O through the local Ru-O-Mn configurations, which contributes to the attenuated J-T distortion. Last, the strong Ru-O covalency bond also leads to enhanced electron delocalization between Ru and O, which decreases the oxidation of oxygen anion and thereby reduces the driving force of metal migration. Because of these advantages, the structural integrity and electrochemical properties of NMMRO are largely improved compared with the Ru-free counterpart. This work provides deeper insights into the effect of local modulation for cationic/anionic redox-active cathodes for high-performance SIBs.

Uniform yolk-shell Fe2O3@N-doped carbon nanorings with rich oxygen vacancies as anode materials for high performance Li-ion battery

Owing to the rapidly increasing demand of energy storage devices, it is necessary to create an apposite anode of lithium ion batteries (LIBs). Fe2O3-based anode materials, which possess high theoretical capacity and low cost, are one of the popular candidate anodes. However, Fe2O3-based anode suffer from large volume change and low conductivity. Herein, yolk-shell (YS) Fe2O3/N-doped carbon nanorings with abundant oxygen vacancies (YS-Fe2O3@NC-OVs) were designed and synthesized for robust lithium storage. OVs in the Fe2O3 lattices were introduced by annealing process, inducing a local construction internal electric field to accelerate the fast migration of Li+ by Coulomb force during cycling process and leading to an excellent electrochemical property for Li-ion batteries. Benefit from the yolk-shell structure and the OVs, the YS-Fe2O3@NC-OVs electrode display an outstanding cycling stability with a reversibly specific capacity of 697.4 mA h g−1 at 5 A g−1 after 500 cycles for lithium storage. And a high specific capacity of 570.3 mA h g−1 at 10 A g−1 is attained. The high reversible specific capacities and superior cycle stability of YS-Fe2O3@NC-OVs might be ascribed to the elaborate YS nanoarchitecture. The well-designed YS nanoarchitecture might be to blame for the high reversible specific capacities and remarkable cycle stability of YS-Fe2O3@NC-OVs. Additionally, the work function (WF) indicated that the enhanced lithium storage performance of YS-Fe2O3@NC-OVs might be ascribed to better Li+ diffusion kinetics and high electronic conductivity.

High Accuracy and Low Complexity Lidar Place Recognition Using Unitary Invariant Frobenius Norm

Simultaneous Localization and Mapping (SLAM) is used in solving the problems of localization, navigation, and map construction for autonomous vehicles moving in unknown environments. Place recognition is an inevitable subject in SLAM, and the current lidar-based methods have been popularized for their rising environmental robustness. Currently, the place recognition method with lidar has attracted much attention due to its high environmental robustness. However, many 3D laser point cloud methods for place recognition descriptors construction with the local or global point-cloud data omitting some intrinsic properties of the point clouds. In this article, we propose a place recognition method based on the unitary invariance of the Frobenius norm for utilizing different attributes of ground points and non-ground points. Specifically, the interpretable filtering framework and a dynamic threshold adjustment strategy are raised according to different environments and sensors with intensity and geometric information. As commissioning, the comparative experiments are conducted with CHDloop datasets and public KITTI datasets of different scales and access types. Compared to the original Scan Context (SC) and Intensity Scan Context (ISC) methods, our proposed method achieves higher efficiency while maintaining a improved recall rate and precision. This novel method has been integrated into the existing LiDAR SLAM and formed a new framework FSC_ALOAM that reduces drifts in point-cloud mapping. The entire process improves the accordance of maps at the identical position in auto-driving.

Introduction of business continuity plan for small and medium-sized local construction companies and restoration activities in Japan in the event of natural disasters

In recent years, Japan has suffered significant damage due to natural disasters such as major earthquakes and flood Construction companies are expected to play an important role during natural disasters and respond quickly and restore infrastructure. The first author runs a small local construction company in Okayama, Japan. During a flood in 2011 at Okayama, the embankment restoring site turned extremely dangerous for workers. At this juncture, the first author, in the capacity of a company manager, identified the safety and administrative issues, and in 2013, the company began to implement BCP. When there was heavy flooding in Okayama in 2017, they supported the administration in recovery operations based on their BCP. The impact of BCP is to be acknowledged as the emergency operations were safer and timelier. BCP of the company has been continuously improved, and they were invited to join infrastructure recovery activities in the disaster area of Great East Japan Earthquake in 2019. The area is not the usual business region of the company, but 1,000 km away. There is a high requirement for human resources and equipment for emergency and recovery activities immediately after a disaster. Most of the construction companies are small and locally based in Japan, and several resources available at the construction site itself for initial recovery activities. It is desirable to prepare a plan so that the affected companies themselves can respond. The main tasks are the training of personnel to provide guidance and support for BCP, and the development of systems and laws that can actively support activities. By capturing accurate information on resources of local construction companies, their capability and response speed during an emergency can be improved. It is also necessary to create a system to receive support from other companies or organizations in case self-help is difficult or insufficient.

IDENTIFICATION STUDY AND MECHANICAL CHARACTERIZATION CLAY STABILIZED BY GUMARABICSEYAL

The construction of infrastructures contributes to the development of a country, in particularthat of sustainable, economic and ecological social housing. Chad, withitsdemographic boom, isfacingthishousing and energycrisis. This experimentalstudyaims to determine the mechanicalresistance by the compression simple of local construction materials. A geotechnicalstudy of the materialwas made, including the grain size, Atterberglimits, methylene blue and normal Proctor tests.The experimentalresults of the mechanical tests show that the mechanicalstrengthgoesfrom 3.17 MPa for 100% clay to 4.04 MPa for 8% of gumarabic. Fromthisresultitcanbeconfirmedthatgumarabiccanbeused as a stabilizer for clay-based building materials.

Power, celebration and circuits of legitimation: the local use of papal letters in late twelfth-century Denmark

ABSTRACT This article explores the role of papal communication in the local construction of royal and papal authority. Taking the kingdom of Denmark as its case, it analyses letters issued by Pope Alexander III to King Valdemar I and the Danish clergy before a grand meeting at Ringsted in 1170. It is argued that to understand the function and impact of the papal letters fully it is necessary to examine not only their verbal content, but also their wider processual context: how a Scandinavian delegation obtained the letters at the papal court in Benevento; how the letters were presented to the Danish audience as part of the ritual celebrations at Ringsted; and how the events later were framed and narrated by local Scandinavian authors. As a whole, the process constituted a ‘circuit of legitimation’, a reciprocal exchange between the pope and the king of recognition and glorification.

A virtual reality-based constructability index for construction projects

Purpose This study aims to develop a constructability index (CI) that can ease the construction activities in a project based on the contractors’ experience and resources. The proposed CI is a vital decision support tool that quantifies the difficulty level for the contractor to execute certain activities with the contingency of other project elements. The virtual reality (VR) technology was used to provide additional data, communicate the contingency impact of other project elements on specific activities and provide sequential execution data to the contractors. This can minimize the risk of not being able to execute various activities on time and within the budget. Design/methodology/approach The VR-based CI was developed through two steps. Step 1 was to identify the factors affecting constructability by exploring the literature and consulting local construction experts. These factors were then organized through a hierarchy of main factors and subfactors and validated by local experts through predesigned surveys. The factors were classified into VR dependent or non-VR independent, and their relative weights were calculated using the analytical hierarchy process along with their reliability, which was determined using Cronbach’s alpha approach. Step 2 was to define the attributes for the constructability factors defined in Step 1 using the Multi Attribute Utility Theory to quantify the contractor’s compliance level of these factors by giving them the appropriate score. The utility factors for the VR-independent factors were obtained through standards, literature and local surveys, and they were quantified on a 1–10 scale. However, the VR-dependent factors were given their corresponding scores using the developed VR navigation environment generated by integrating Autodesk Revit and Navisworks software. Accordingly, the CI for each activity was evaluated, and the overall CI for the project was calculated by aggregating the CIs for all activities. Findings The developed CI quantifies the contractor’s ability to execute construction projects and addresses the lack of communication and coordination between the various construction units in the planning phase itself. Moreover, it can resolve possible hard (physical) and soft (time) construction clashes and minimize their impacts on project schedule and budget. Among the relative weights of the identified factors, prefabrication of building components was found to have the highest effect on constructability. Furthermore, applying the developed VR-CI, a real project showed that the utility values of the main factors quantified on a ten-point scale were between 6 and 9, which means routine supervisions and monitoring are required. Originality/value Though the concepts of constructability and VR have been used in different contexts, their integration to develop a comprehensive CI for the building construction industry is a unique contribution, which has not been reported previously.

Construction production trends and industry optimism in EU countries after the COVID-19 pandemic

The purpose of this study is to present the current changing situation of construction markets in selected European countries. Current trends in construction production are presented in relation to changes resulting from the coronavirus pandemic and other factors using the examples of France, the Netherlands, Belgium, Austria, Germany, Spain and Poland. The EU Construction Confidence Index (CCI) and data on the number of building permits issued in selected countries were used for inference. Additional sources of knowledge were publicly available information on ongoing and planned campaigns and government actions affecting local construction markets. The analysis presented shows a clear impact of the pandemic on construction production trends, an increase in optimism in the industry at its extinction and renewed declines in optimism due to the increasing destabilisation of economies as a result of inflation, rising energy prices and the war in Ukraine. Despite the difficulties, construction markets are slowly regaining their pre-pandemic growths, although the aforementioned factors are slowing them down. Strong mature economies, supported by additional government funding, will recover much faster than developing countries where uncertainty is greater. The negative indicators for Poland forecast a slowdown and a longer period of return to pre-pandemic COVID-19 growth.

Support local: Google Maps’ local guides platform, spatial power and constructions of “the local”

Abstract Experiences within cities are increasingly mediated by digital platforms such as Google Maps; thus, it has become imperative to establish critical frameworks to understand the spatial relationships these platforms reinforce and produce. Google draws on “local” knowledge through its Local Guides platform to add location-based data in the form of reviews and rankings to Google Maps. Through a critical technocultural discourse analysis (CTDA) of the Local Guides platform’s rhetoric and Local Guides’ reviews across varying sites in Toronto, we compare and contrast the ways the platform constructs user-mediated local participation with the actual content the platform produces. We complicate Google’s claims to supporting the local by identifying review practices and patterns that use the platform to target and harass workers. We argue that the reviews reveal who and what belongs to the platform’s construction of “the local,” while at the same time rendering hyper-visible what it constructs as not belonging.

Structural and Mechanical Properties of Modified Hot and Warm Mix Asphalt Concrete

Statement of the problem. The problem of improving the structural and mechanical properties of hot and warm mix asphalt concrete based on mineral materials, produced by Ltd. «PavlovskNerud», Voronezh region, is considered, using the method of polymer-dispersed reinforcement. The effect of the modifier RTEP-M on the resistance of rutting for hot and warm mix asphalt concrete has been studied. Results. By studying hot and warm mixes asphalt with RTEP-M modifier in the amount of 0.3 and 0.6 % by weight in the mineral part, respectively, and the control composition, a significant improvement in structural and mechanical properties was achieved. It is shown that it is possible to increase the resistance of rutting for hot and warm asphalt concrete prepared on local road construction materials by increasing its viscous-elastic properties by using the method of dispersed reinforcement using the Russian additive RTEP-M. Conclusions. The efficiency of using the method of polymer-dispersed reinforcement to improve the structural and mechanical properties of hot and warm asphalt concrete based on local mineral materials has been proven. It is shown that the addition of the RTEP-M modifier to the mineral part of hot and warm asphalt concrete mix in the amount of 0.3 and 0.6 % by weight, respectively, improves the rutting resistance of the road surface. It has been proved that by applying the method of polymer-dispersed reinforcement, it is possible to optimize the properties of warm asphalt concrete for its use in hot climatic conditions for the introduction of warm technologies instead of hot ones in the construction and repair of road surfaces.

Natural quasirandomness properties

AbstractThe theory of quasirandomness has greatly expanded from its inaugural graph theoretical setting to several different combinatorial objects such as hypergraphs, tournaments, permutations and so forth. However, these quasirandomness variants have been done in an ad‐hoc case‐by‐case manner. In this article, we propose three new hierarchies of quasirandomness properties that can be naturally defined for arbitrary combinatorial objects. Our properties are also “natural” in more formal sense: they are preserved by local combinatorial constructions. Similarly to hypergraph quasirandomness properties, we show that our quasirandomness properties have several different but equivalent characterizations. We also prove several implications and separations comparing them to each other and to what has been known for hypergraphs. The main notion explored is that of unique coupleability: two limit objects are uniquely coupleable if there is only one way to align (i.e., couple) them.

Physical and mechanical characterization of mallotus oppositifolius wood for use as reinforcement in bent parts

Faced with the lack of patents for the characterization of local construction materials, it is therefore important and topical to study the behavior of these local substitute materials that can reduce the overexploitation of materials from natural deposits in order to develop environmentally friendly materials. The present research is therefore rightly devoted to the physical and mechanical characterization of mallotus oppositifolius wood for use as reinforcement in flexed parts. For this reason, standardized specimens have been extracted based on the relevant standard. At the end of the work, we note that mallotus oppositifolius has very interesting physical and mechanical characteristics, although always inferior to those observed for the runnier (Borassus aethiopum Mart). A physico-botanical characterization allowed us to classify it as a semi-heavy foliage with a density at 12 % moisture of 855.94 Kg/m3. An analysis of its mechanical characterization gives us a ductile behavior of the wood developing a large plastic domain with an elastic compressive stress parallel to the fibers σc = 71.60 MPa with a modulus elasticity Ec = 17397.733 MPa and a brittle rupture of the oppositifolius mallotus in tension parallel to the fibers with an elastic stress σT = 83.76 MPa; a modulus elasticity ET = 15942.20 MPa and a fish coefficient per v = 0.007 %. In view of these mechanical performances, we note the possibility of using oppositifolius mallotus as reinforcement of flexed parts with engineer constants E = 15942.20 MPa (Young's modulus) for a Poisson coefficient v = 0.007.

Integration, urban citizenship, and spatial aspects of (new) mobilities: Greek migrants' constructions of integration in European cities.

This study aims at casting light on the ways in which spatial aspects of mobility and belonging serve as social-psychological discursive resources used by Intra-European Greek immigrants in order to account for integration. For the purposes of the study, 17 virtual interviews with Greek migrants in European cities were analysed. Interview discussion was facilitated by photographs of participants' meaningful places. In the analysis, accounts of belonging to the community 'in general' were juxtaposed to accounts of bonding with specific places. Participants, using spatial discursive resources and constituting complex relationships between political participation, citizenship and place, developed competing arguments and positioned themselves as integrated or excluded from local, national or supranational communities. Accounts of attachment to private and public places mobilized constructions of citizenship based on place appropriation and people-environment relations and constructed spatial or symbolic boundaries. The conclusions underscore the benefits of understanding migrant integration through multilevel (local, national and supranational) constructions of political participation and urban and localized perspectives of citizenship.

Appropriate Strengthening Technologies for the Mitigation of Seismic Vulnerability of Bhutanese Vernacular Stone Masonry Architecture

ABSTRACT Bhutanese vernacular stone masonry architecture proved highly vulnerable to the recent seismic events affecting Bhutan since 2009. The isolation of rural communities, due to the site geomorphology, the precarious roads networks condition, the local labour limited skills, and the scarce resources availability, largely influence the applicability of strengthening technologies for traditional stone masonry architecture’s seismic vulnerability mitigation. Following up the collaboration with the Royal Government of Bhutan, within an international research project, the paper aims to analyse the appropriateness and suitability of strengthening intervention strategies to the local context. The identified strategies have been associated with the analysis of the stresses causing the failure mechanisms occurred during the 2009 earthquake and tailored to local construction technologies. A full-scale static test carried-out on a stone masonry-building mock-up, allowed to evaluate its behaviour under static loads. As a final result, the suitability of the interventions has been evaluated through qualitative indicators.

Restitution process in conservation: Exploring the historical adventure of Derik Former Government Building

Derik Old Government Building, with its architectural structure, is one of the leading examples of civil architecture that reflects the local architecture and construction technique of Derik district of Mardin. The building was registered as the 1st Group in 2006 and is not used today. It has been used in different functions by the local people until today and has taken its current form with the additions made in different periods. In the archive records scanning, no information or document was found that the restoration project was drawn. In this context, it is necessary to reveal the historical evolution of the building in order to ensure the sustainability of the building and to maintain its historical identity. The aim of the restitution research of the historical building is to determine the changes that the building has undergone until today, to find its original state based on scientific data, to find the periods it went through and to lay the groundwork for the restoration work. As a method in the study, comparative studies were made with examples of similar periods, and determinations were made about the structure in line with the existing traces in the building. In addition, oral interviews were conducted with the people living in the region in order to better understand the historical process of the building. In the results of the study, it was determined that there were two periods related to the structure. It is understood that the upper floor was built later, since the traces from the building, the door and window alignments, the construction technique and the wall alignments of the lower and upper floors are not in the same direction. It is not known exactly when the ground floor was built, but according to the inscription on the mosque next to it, it was built before 1846. It is estimated that the first floor was built at the end of the 19th century.

Horse domestication as a multi-centered, multi-stage process: Botai and the role of specialized Eneolithic horse pastoralism in the development of human-equine relationships

For over a decade there has been general, but not universal, consensus that the earliest known evidence for horse husbandry was at Eneolithic Botai, Kazakhstan, circa 3,500 BCE. Recent ancient genomic analyses, however, indicate that Botai is not the source of modern domestic horse stock (DOM2 lineage), but is instead related to the Przewalski clade of horses. DOM2 appears to instead to have emerged in early Bronze Age (mid 3rd Mill. BCE) in the Pontic-Caspian steppe, and spread quickly replacing other horse lineages after approximately 2,000 BCE. Whilst the specific evidence for earlier husbandry at Botai is not diminished by this evidence, it has broken the consensus regarding the early stages of horse domestication, with some now viewing it as a later event. This paper argues that domestication is rarely an event, but instead a process that is ongoing. The case is made for a “prey pathway” initial phase of domestication in multiple localities during the Eneolithic, which was based around local subsistence pastoralist niche construction. This took different forms due to the presence or absence of ruminant domestic stock in the Eastern European or Central Asian steppes, respectively. Whilst “push” factors likely played a part in the development of horse specialist pastoralism at Botai, it is suggested that “pull” factors accelerated the spread of DOM2 lineages, replacing others, in the later Bronze Age. The DOM2 spread was principally driven, not by local subsistence needs, but wider social, economic and military desirability of equestrianism. The long-term process of horse domestication continues in modernity with major breed changes caused first by the post-medieval agricultural revolution and, more currently, the desire for sporting achievement.

Morphismes de périodes et cohomologie syntomique

We give the geometric version of a construction of Colmez-Niziol which establishes a comparison theorem between arithmetic p-adic nearby cycles and syntomic sheaves. The local construction of the period isomorphism uses $(\phi,\Gamma)$-modules theory and is obtained by reducing the period isomorphism to a comparison theorem between cohomologies of Lie algebras. By applying the method of "more general coordinates" used by Bhatt-Morrow-Scholze, we construct a global isomorphism. In particular, we deduce the semi-stable conjecture of Fontaine-Jannsen. This result was also proved by (among others) Tsuji, via the Fontaine-Messing map, and by Cesnavicius and Koshikawa, which generalized the proof of the crystalline conjecture by Bhatt, Morrow and Scholze. We use the previous map to show that the period morphism of Tsuji and the one of Cesnavicius-Koshikawa are the same.

Temporal and Spatial Distribution Characteristics of Microplastics and Their Influencing Factors in the Lincheng River, Zhoushan City, China

Microplastics (MPs), a new type of pollutant, pose a significant threat to the environment at high concentrations. One of the primary sources of MPs in the ocean is river runoff, highlighting the need to investigate the spatial and temporal variations of MPs in rivers that flow into the sea, as well as their contributing factors. In this study, we analyzed MPs distribution and their influence factors in the Lincheng River, China. The Lincheng is the second largest river in Zhoushan island that directly flows into the ocean. MPs in the river water and sediments were detected during the wet season (July 2021), the dry season (November 2021) and the typhoon season (September 2021), and MPs were present in all reaches of the river. The abundance of MPs in the river was moderate compared to other studies, with the river water exhibiting a concentration of 15 ± 2.64 n/L and the sediment containing 318.24 ± 49.53 n/kg of MPs. In surface water, the most commonly found MP was blue man-made cellulose (CE), while the sediment contained mostly fragments of polypropylene (PP) and polypropylene polyethylene blends (PP + PE) in blue and green colors. The abundance of MPs showed significant seasonal differences, with higher abundance during the wet season compared to the dry season and typhoon period. Furthermore, local construction activities may contribute to higher MP abundance. To explore the influence factors of MPs, the Basin Development Index (BDI) was proposed, and a positive correlation between BDI and MP abundance was founded. This correlation indicates that the increase in land use for construction highly contributes to the MP pollution. In conclusion, future long-term monitoring of the abundance of MPs in the Lincheng River is necessary.

On-site construction of a point-of-care low-field MRI system in Africa.

To describe the construction and testing of a portable point-of-care low-field MRI system on site in Africa. All of the components to assemble a 50 mT Halbach magnet-based system, together with the necessary tools, were air-freighted from the Netherlands to Uganda. The construction steps included individual magnet sorting, filling of each ring of the magnet assembly, fine-tuning the inter-ring separations of the 23-ring magnet assembly, gradient coil construction, integration of gradient coils and magnet assembly, construction of the portable aluminum trolley and finally testing of the entire system with an open source MR spectrometer. With four instructors and six untrained personnel, the complete project from delivery to first image took approximately 11 days. An important step in translating scientific developments in the western world from high-income industrialized countries to low- and middle-income countries (LMICs) is to produce technology that can be assembled and ultimately constructed locally. Local assembly and construction are associated with skill development, low costs and jobs. Point-of-care systems have a large potential to increase the accessibility and sustainability of MRI in LMICs, and this work demonstrates that technology and knowledge transfer can be performed relatively seamlessly.