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A modern, environmentally friendly urban lifestyle requires paying attention to landscaping and green areas. The scarcity of free land in cities and the high price of land require the combination of greenery with buildings—both vertically and horizontally. The developed green technology for construction brings together computer numerical control (CNC) processing of supporting structures and prefabricated solid planting blocks made of concrete composite. The timber structures are fixed together using traditional carpentry joints. The details, which will be manufactured in the factory using CNC processing at a controlled temperature and humidity corresponding to indoor conditions, can be easily assembled on the construction site. The high bending strength but good elasticity and connections of carpentry joints endow the structure with good properties in a non-controllable environment. By combining CNC-processed wooden structures with concrete technology as substrate composites, labor-intensive manual work in landscaping and gardening will be reduced in the future. The novel material-hardening substrate composite material uses only the residues as the raw materials.

Revised proof, This chapter focuses on the reinforcement of traditional timber carpentry joints according to different standards, recommendations, case studies, as well as analytical, numerical and experimental research works. The aim of the review is to present the state-of-the-art methodologies that can be at the disposal of carpenters, architects and engineers. In order to understand how traditional carpentry joints, work and their failure mechanisms, such as compressive crushing, shear and tensile cracks, six geometrical typologies of such joints are discussed. Finally, for the above typologies, several reinforcement strategies are presented by defining their objectives, methodologies, traditional and contemporary techniques, performance criteria and applicability areas. When assessing and reinforcing traditional carpentry joints, some challenges may come up, namely their design, based on the ratios of stiffness and load-bearing capacities. These challenges should thus be a focal point for further research in the near future., (undefined)

Dissertação de Mestrado Integrado em Engenharia Civil apresentada à Faculdade de Ciências e Tecnologia Este trabalho tem como objetivo principal, a partir de ensaios experimentais e pesquisa, avaliar a repartição de cargas dos dentes, bem como a resistência ao corte nas ligações de dente duplo e estudar as superfícies de corte na rotura das mesmas.Historicamente, o dimensionamento manual das ligações de carpintaria tem sido feito com base em regras empíricas e conhecimento prático. Nas ligações de carpintaria tipo step-joint de dente duplo, embora existam procedimentos de cálculo para a determinação da repartição de carga entre os dois dentes e para a avaliação das cargas e modos de rotura, estes baseiam-se na adaptação das regras usadas para ligações de dente simples e, tanto quanto é do conhecimento do autor, não foram ainda comprovados por trabalho experimental. O estudo consistiu, inicialmente, na realização de ensaios destrutivos de ligações do tipo step-joint de dente simples e de dente duplo, para a determinação da carga de colapso da estrutura, tendo sido usado o protocolo de carga definido na norma EN 26 891. Posteriormente, foram realizados ensaios de caracterização, com peças retiradas dos provetes utilizados, para estimar os valores da resistência à flexão e ao corte, para além de módulo de elasticidade, massa volúmica e teor de água.Para entender o funcionamento mecânico da ligação, foram avaliados a carga de rotura e o mecanismo de colapso em cada ensaio e foram comparados com os já estimados, levando em conta a hipótese de distribuição de carga, regida pela resistência dos entalhes e métodos de dimensionamento propóstos pelo Professor Doutor João Henrique Negrão. This work has as its main objective, by means of experimental tests and researches, evaluate the load division between notches, as well as the shear resistance in double-step joint and study the shear surface in their failure.Historically, the manual design of carpentry joints has been made based on practical experience. In double-step carpentry joint, although there are calculation procedures to determine the load division between two notches as well as to evaluation of loads and modes of failure, they are based on using rules of both front and rear single step-joint. At first, the study consists of destructive tests of step-joint and double-step joint to determine the structure collapse load, considering the load protocol agreed in the EN 26 891 standard. Secondly, characterizations tests, with pieces of the used provets, were carried out, to estimate the values of bending and shear resistence, beyond the elasticity modulus, volumic mass, and moisture content.To understand the mechanical function of the joint, the failure load and the collapse mechanism in each test were evaluated. Then, they were compared with the previously estimated, regarding the load division between the two notches governed by the notch resistence and design methods proposed by PhD João Henrique Negrão.The lack of theoretical knowledge about the functioning of wood connections can lead to very conservative projects. In this sense, this dissertation has as general objective, starting from experimental studies and researches, to try evaluate existing load sharing rules in double-step joint carpentry connections and to study the shearing surfaces in their failure

This paper summarises the current state of knowledge related to scarf and splice carpentry joints in flexural elements, also providing some examples of tensile joints. Descriptions and characteristics of these types of joints found in historical buildings are presented. In addition, issues related to forming carpentry joints in historic and heritage structures are discussed. Next, analyses and studies of flexural elements as well as selected examples of tensile joints described in the literature are presented. It is worth noting that authors of vast majority of the publications cited draw attention to the need for further research in this area. They acknowledge that existing descriptions are incomplete and insufficient for bringing about precise understanding and correct description of the static behaviour of these joints. Knowledge about designing and assessing static behaviour of existing carpentry joints is an important issue and is necessary to properly design and strengthen existing joints in historical timber structures.

Timber frame structures have a long and rich tradition. In addition to their functional and structural value, they are important elements of the cultural landscape. At the turn of the 21st century, concern for nature, resulting from the threat of environmental degradation, contributed to a growing interest in wooden constructions. For these reasons, we have observed the erection of buildings with wooden frame structures in many countries around the world. This trend contributed to the rapid development of wooden structures, new technologies, and innovative architectural solutions. The conducted research mainly focused on the joints used in their construction, as well as their perception. From among many examples, some original and innovative solutions were selected and analyzed. Their creators are famous architects: Renzo Piano, Imre Makovecz, Jürgen Meyer, Kengo Kuma, and Shigeru Ban. The objects presented in this article are distinguished by the originality of their form and by the fact that they are clearly inspired by vernacular architecture. Crucial elements of these objects, such as wooden, steel, and hybrid connections, are analyzed in this article. Because they are intentionally exposed, they play an important aesthetic role in addition to a structural one.

Joints play a major role in the structural behavior of old timber frames (Descamps et al., 2014) [1] . Current standards mainly focus on modern dowel-type joints and usually provide little guidance (with the exception of German and Swiss NAs) to designers regarding traditional joints. With few exceptions, see e.g. [2–4] , most of the research undertaken today is focused on the reinforcement of dowel-type connections. When considering old carpentry joints, it is neither realistic nor useful to try to describe the behavior of each and every type of joint. The discussion here is not an extra attempt to classify or compare joint configurations (Gerner, 2012) [5,6] , (Seike, 1977) [7] . Despite the existence of some classification rules which define different types of carpentry joints, their applicability becomes difficult. This is due to the differences in the way joints are fashioned depending, on the geographical location and their age. In view of this, it is mandatory to check the relevance of the calculations as a first step. A limited number of carpentry joints, along with some calculation rules and possible strengthening techniques are presented here.

In European seismic areas timber structures are found as building frames, in combination with masonry infills, in bridges, but most frequently in roof structures and floor slabs of traditional buildings. Seismic strengthening of existing structures should provide a well-defined and simple path to seismic forces, maintain timber members elastic, and develop as much as possible the post-elastic behaviour of joints. Provisions must be adopted to avoid sudden loss of capacity and brittle failure, and to foster ductility. Different criteria for seismic strengthening of floor slabs and of carpentry joints are presented.

The paper presents the results of an experimental investigation of stop-splayed scarf joints, which was carried out as part of a research programme at the Wroclaw University of Science and Technology. A brief description and the characteristics of scarf and splice joints appearing in historical buildings are provided, with special reference to stop-splayed scarf joints (so-called &lsquo, Bolt of lightning&rsquo, ) which were widely used, for example, in Italian renaissance architecture. Analyses and studies of scarf and splice joints in bent elements presented in the literature are reviewed, along with selected examples of analyses and research on tensile joints. It is worth noting that the authors in practically all the cited literature draw attention to the need for further research in this area. Next, the results of the authors&rsquo, own research on beams with stop-splayed scarf joints, strengthened using various methods, e.g., by means of drawbolts (metal screws), steel clamps and steel clamps with wooden pegs, which were subjected to four-point bending tests are presented. Load-deflection plots were obtained for load-bearing to bending of each beam in relation to the load-bearing of a continuous reference beam. A comparative analysis of the results obtained for each beam series is presented, along with conclusions and directions for further research.

In the scope of COST IE0601-WoodCulther (http://www.woodculther.org) it was agreed to produce Guidelines for the Assessment of Historic Timber Structures, covering the principles and possible approaches for the safety assessment of old timber structures of historical relevance, that could be used as the basis for possible European Standards, as discussed with CEN/TC346 (Conservation of cultural heritage). This was targeted at all those concerned with the conservation of heritage buildings. It should also help decision-making regarding the need for immediate safety measures. Its aim is to guarantee that inspection and assessment measures provide the necessary data for historical analysis, structural safety assessment and planning of intervention works, while having minimal impact on the building fabric (the original materials, structural systems and techniques). This paper provides information on the criteria to be used in the assessment of load bearing timber structures in heritage buildings. It covers the preliminary assessment (desk survey, preliminary visual survey, measured survey, structural analysis and preliminary report), as well as the detailed survey of timbers (with a special emphasis on visual strength grading on site) and carpentry joints. The subsequent diagnostic report and the detailed design of repairs are outside its scope., This paper originates from a document with the same name prepared by the Task Group “Assessment of Timber Structures” set within COST Action IE0601 – Wood Science for Conservation of Cultural Heritage (WoodCultHer) and presented to its final meeting in November 2011. Therefore, the authors thank to COST for sponsoring two Task Group meetings, CIS-Madeira (SP) and LNEC (P) for hosting them and Dr. Philipe Galimard, Dr. Emmanuel Maurin, Dr. Ladislav Reinprecht and Dr. Artur Feio for their suggestions. They also acknowledge the work done by all the Committees working on the same subject in the past, namely ICOMOS/ISCARSAH, CIB/Commission W023, CEN/TC250, ISO/TC98, UNI - CT Normal - GL20 and COST Action E55, which produced the valuable standards, guidelines and other background documents referenced in the text and listed under Bibliography.

Carpentry joints have been dimensioned in the past with global statics considerations. New design requirements impose considering the response to exceptional as well as to ordinary loading and require a more detailed knowledge of the mechanical behavior. A typical double-step joint, common in the rafter to tie-beam node of large-span trusses, has been studied numerically for monotonically increasing axial compression in the rafter and for cyclic rafter rotation up to ultimate conditions. The stress distribution at the contact surfaces as well as the rotational stiffness and ultimate moment for different levels of axial force have been evaluated. Results, compared with other joint types, show a good degree of interlocking and confirm a better performance of this joint in sliding shear.

In the field of Built Heritage Restoration, engineers have to work with old structures made of poorly preserved timber elements. The assessment of timber elements and connections is a major issue for engineers involved in a restoration project. Before thinking about any intervention techniques, engineers have to properly understand how the carpentry connections fail, which parameters influence the failure modes (e.g. geometry of the joint, mechanical properties of the wood) and how the internal forces are distributed into the joint to finally figure out how to design the traditional carpentry connections. The present paper aims at raising those questions focusing on the Single Step Joint (SSJ) design. Even if this common joint between the rafter and the tie beam is geometrically simple, one may pick up three SSJ families from the past till today: the Geometrical Configuration Ideal Design, the Geometrical Configuration Perpendicular to the Tie Beam and the Geometrical Configuration Perpendicular to the Rafter. The first one is more recent because its geometry requires accurate timber cutting, using new technologies (e.g. Computer Numerical Control). For each one, some general design rules about the SSJ geometrical parameters are defined by some European standards (e.g. Eurocode 5 in Design of timber structures-part 1-1: general-common rules and rules for buildings. CEN, European Standardisation Institute, Brussels, 8) or authors (e.g. Siem and Jorissen in Shatis' 15: 3rd international conference on structural health assessment of timber structure, vol 1. Wroclaw, Poland, 9-11 Sept 2015, 11), but no detail is available on how to design this connection in order to prevent the shear crack at the heel depth in the tie beam, or the compressive crushing at the front-notch surface. Hence the design rules and the emergence of failure modes must be defined according to the SSJ geometrical parameters. In order to check the design equations and the failure modes, lab tests on the three SSJ families have been carried out, mo, This work was financed by FEDER funds through the Competitivity Factors Operational Programme-COMPETE and by national funds through FCT-Foundation for Science and Technology within the scope of the project PTDC/EPH-PAT/2401/2014. This work was partly financed in the framework of the Portuguese Public Procurement Code, LOTE 3ES2-Escola Secundaria de Loule e Olhao., info:eu-repo/semantics/publishedVersion

This paper describes, in detail with the aid of pictures and annotated drawings, the solution for the pedestrian wooden bridge in the old town centre of Trogir in Croatia. The bridge made completely of natural solid oak wood consists of two-hinged arches of 25m span and all the bridge elements are made of the same wood connected by traditional carpentry joints. Design and calculations are in accordance with the appropriate Euro codes (1-4) and details of the woods preparation and preservation are given along with the techniques employed. Details of the foundations under the arch footing are given and the treatment of the soil under the reinforced concrete blocks is explained.

Blockhaus structural systems are obtained by assembling multiple timber logs able to interact with each other by means of simple mechanisms (e.g. contacts, tongues and grooves, and carpentry joints, also referred to as ‘corner’ joints). Although these systems have ancient origins, the structural behaviour of Blockhaus systems under well-defined loading and boundary conditions is still complex to predict. The paper focuses on the assessment of the typical buckling behaviour and resistance of in-plane compressed timber log-walls. The effects of various mechanical and geometrical aspects such as in-plane rigid inter-storey floors, load eccentricities, different types of lateral restraints, openings (e.g. doors or windows) or additional metal stiffeners, are investigated by means of full-scale buckling experiments. Results are then critically discussed and preliminarily assessed via analytical formulations taken from classical theory of plate buckling and column buckling. Although further advanced studies are required for the development of a generalized buckling design method, it is shown that several mechanical and geometrical aspects should be properly taken into account to correctly predict the structural capacity of Blockhaus systems under in-plane compression.

The force distribution inside a dovetail joint is complex. Wood is simultaneously loaded in different directions in the several connected surfaces. The analytical solutions available for the analysis of the behavior of those carpentry joints rely on the mechanical properties of wood. In particular, the stiffness properties of wood under compression are crucial for the forces equilibrium. Simulations showed that the stiffness values considered in each of the springs normally assumed in the analytical models, have great influence in the bearing capacity and stiffness of the dovetail joints, with important consequence on the stress distribution over the overall structure. In a wide experimental campaign, the properties under compression of the most common wood species of existing timber structures have been determined. Then, a solved example of a dovetail joint is presented assuming different wood species and the corresponding strength and stiffness properties values obtained in the tests., Financial support of Ministry of Culture of the Czech Republic project NAKI - DF12P01OVV004 - Design and Assessment of Timber Joints of Historical Structures. Moreover the financial support of experimental campaign by STSM COST project FP1101 (COST-STSM-FP1101-1679

Příspěvek se zaměřuje na tradiční strukturální principy historických staveb éry 18. - 19. století v regionu Znojma, které jsou mimo jiné zahrnuty v rámci projektu NAKI „Identifikace a interpretace vzniku, podoby a proměny barokní kulturní krajiny jihomoravského pohraničí“. Předmětem práce je popis tradičních krovových systému vybraných historických objektů dané lokality. Cílem popisu je nalezení vhodného konstrukčního principu užitého v tradičním stavitelství, jenž by byl možno využít pro struktury dočasného charakteru. Dočasné konstrukce jsou spojeny s přechodnou funkční náplní, která je jednou z možných fází při plánované obnově opuštěných památek. Existence mnoha příkladů na mezinárodním poli dokládá úspěšnou obnovu chátrajících objektů za využití přechodného stavebního a provozního programu. Provedenou analýzou tradičního stavitelství byl nalezen vhodný konstrukční spoj pro návrh designu, který bude sloužit jako modulární prvek pro stavby dočasného charakteru. Jeho charakteristikou je nízkonákladová výroba a jednoduchá konstrukce, kterou je možno opětovně složit na jiných místech a přizpůsobit dalšímu využití. Význam práce spočívá v návrhu řešení elementárních konstrukcí objektů přechodné povahy, které jsou založeny na tradičních stavebních principech historických památek a doplňují zachovalou strukturu dané architektury. The paper focuses on traditional structural principles of historical buildings of the era 18 to 19 century in the Znojmo region, which are also included in the project „Identification and interpretation of origins, forms and transformations of Baroque cultural landscape of the South Moravian Borderland“. The aim of this work is to describe traditional roof frames of selected historical buildings of the area. The goal of the work is to find a suitable construction detail applied in the traditional roof frames, which would be used for a structure of temporary character. Temporary structures are associated with transient functional use, which can be one of the possible phases in the planned restoration of abandoned sites. The existence of many examples at the international level demonstrates successful redesign of dilapidated buildings by the use of temporary programme. The analysis of traditional structures proposed a suitable structural joint for a design of a modular element for the construction of temporary architecture. Its characteristic is the low-cost production and simple construction, which can be relocated to other places and adapted for further use. The significance of the work lies in the design of elementary structures of objects of a transitory nature, which are based on the traditional building principles of historical monuments and try to preserve structural uniqueness of the architecture.

Uporaba lesa kot materiala za nosilne konstrukcijske elemente je pri stanovanjskih, javnih ter gospodarskih objektih najbolj pogosta pri strešnih konstrukcijah. Podali smo zgodovinski pregled razvoja lesenih strešnih konstrukcij. Prikazali smo najpomembnejše izume, ki so omogočili izdelavo zahtevnejših konstrukcij večjega razpona (lok, paličje, sestavljeni nosilci, lepljeni lamelirani nosilci). Vloga strešne konstrukcije se je skozi čas spreminjala in vse pomembnejša je postajala izkoriščenost prostora. Streha je sestavljena iz krova (nosi kritino) ter ostrešja (nosi obremenitve, vključno s težo krova in lastno težo). Sistematično smo pregledali različne tipe strešnih konstrukcij in opisali njihove sestavne dele. Za sodobne lesene strešne konstrukcije je značilna uporaba veznih sredstev. Ugotovili smo, da se z izbiro pravilne lesne zveze mehanska odpornost in stabilnost lesene strešne konstrukcije lahko bistveno poveča. Na kratko smo opisali tradicionalne in sodobne lesne zveze. Preučili in prikazali smo sodobno izdelane lesene strešne konstrukcije - od načrtovanja do postavitve. Obiskali smo podjetje Kregar, kjer z uporabo sodobne računalniško vodene linije za obdelavo lesa izdelujejo tudi zahtevnejša tesarska dela. Med drugim so naredili najvičji samostoječi leseni objekt v Sloveniji - razgledni stolp na Planini nad Vrhniko. In roof constructions, using wood as a material for load-bearing structural elements in housing, public and other buildings is most common. A historical overview of the development of wooden roof structures is presented, so as the most important inventions that have enabled the manufacturing of a demanding wider range of structures (arch construction, stick construction, assembled constructions, and laminated carriers). The role of the roof structure has changed over time, and is becoming increasingly important for space utilization. The roof consists of a deck and a roof timber (to bear the burden, including the weight of the deck and its own weight). We systematically reviewed the various types of roof structures and described their components. The use of advanced fasteners is characteristic for modern wooden roof constructions. We have found that by selecting the correct timber joints mechanical resistance and stability of wooden roof structures can be significantly increased. We briefly described the traditional and modern wood carpentry joints. We examined and demonstrated a contemporary designed wooden roof structure - from planning to the final assembling. We visited the Kregar firm, where the usage of modern computer-controlled woodworking lines also produces sophisticated carpentry. Among other things, they made the highest standing wooden building in Slovenia - the lookout tower on Planina above Vrhnika.

Joints in traditional timber structures usually present notches where stresses are transferred by compression and, to some extent, by friction between the contact surfaces. There are many structures still in service today which employ a wide range of traditional notched joints with and without different metal parts, some introduced during construction and others added later as reinforcement, which can be reduced to a few common typologies. These traditional timber connections, even without any strengthening device, usually exhibit some moment-resisting capability, but common design methods are mainly focused in the transmission of compression internal forces and do not account for the presence of metal parts. Thus the common employment of steel stirrups, internal bolts or clamping devices in traditional connections can have unexpected consequences in the global performance of timber a structure, because while enhancing the joints’ strength they also modify their stiffness, failure mode and overall behaviour. As the assessment of ancient timber structures implies the evaluation of the mechanical properties of elements and joints, and since other research projects are narrowing the uncertainties around the determination of the members’ properties, the real behaviour of traditional timber joints has also to be addressed. The proposed presentation will discuss the relevant conclusions achieved in a research program, aimed at investigating the monotonic and cyclic behaviour of traditional timber joints, regarding their structural assessment, by identifying the effect of some key parameters, like geometry, detailing, damage and timber moisture content, and evaluating the effect of some strengthening techniques. These results allow understanding and predicting more accurately the behaviour of timber structures, which is crucial in every restoration or strengthening intervention. 19 9p DE/NEM 2009 21 a 22 de Maio

An experimental campaign on traditional diagonal front notched timber joints was carried out in order to assess their rotational behaviour. This campaign included ten different test conditions, comprising some of the most frequently observed configurations of the rafter and tie beam joint in Portuguese roof structures. The joints' mechanical behaviour was appraised with regard to their geometric parameters, presence of metal fastening devices and moisture content of timber. The experimental results show that the joint's response is different when opening or closing the skew angle and that specific load bearing mechanisms dictate the different performances exhibited by each typology. The authors wish to thank the Portuguese Science and Technology Foundation (Project POCI/ECM/56552/2004) for the financial support towards this research. Thanks also go to the LNEC Scientific Instrumentation Centre (Paulo Morais and Fernando Oliveira) for their most valuable contribution in the design and set up of the test equipment. 22 6p DE/NEM 2010 20 a 24 de Junho