Advanced Materials Research Vol. 778

Abstract: The new observation tower on the Pyramidenkogel (Keutschach, Austria) has a spatial frame structure, with three main components:

Abstract: This paper describes the goals, work plan, organization and results of the COST Action FP 1001 Assessment, Reinforcement and Monitoring of Timber Structures. 21 European countries with over 100 experts participate in the COST Action that started in 2012. The work of the COST FP 1101 is coordinated with the COST FP1004 "Enhance Mechanical properties of Timber, Engineered Wood Products and Timber Structures." This conference is one of the results of the COST action.

Abstract: The paper reports on the activities of the RILEM technical committee Reinforcement of Timber Elements in Existing Structures. The main objective of the committee is to coordinate the efforts to improve the reinforcement practice of timber structural elements. Recent developments related to structural reinforcements can be grouped into three categories: (i) addition of new structural systems to support the existing structure; (ii) configuration of a composite system; and (iii) incorporation of elements to increase strength and stiffness. The paper specifically deals with research carried out at the Bern University of Applied Sciences Switzerland (BFH), the University of Minho Portugal (UniMinho), and the University of Trento Italy (UNITN). Research at BFH was devoted to improve the structural performance of rounded dovetail joints by means of different reinforcement methods: i) self-tapping screws, ii) adhesive layer, and iii) a combination of self-tapping screws and adhesive layer. Research at UNITN targeted the use of dry connections for timber-to-timber composites, specifically reversible reinforcement techniques aimed at increasing the load-bearing capacity and the bending stiffness of existing timber floors. At UniMinho, double span continuous glulam slabs were strengthened with fibre-reinforced-polymers. All three examples demonstrate the improved structural performance of timber elements after reinforcing them.

Abstract: Structural engineers and architects must make decisions about the ability of lumber and structural timber (wood members) to resist the design loads in existing or historic buildings. Unfortunately, they do so often without the necessary knowledge to properly assess the ability of the timber to provide reliable, long-term, safe performance. Due to uncertainties about the allowable design stresses that can be assigned to structural timbers, very conservative decisions to replace or reinforce these members are often made, even though the timbers are working, i.e. they have and will continue to safely carry the loads imposed upon them. Too many decisions result in the replacement of historic material that could, in fact, remain in service without compromising structural integrity. This paper presents engineers and architects with the justification to retain more structural timber in existing buildings through a better understanding of visual grading.

Abstract: A group of databases making a total of ca. 9.000 beams from coniferous trees from Spain, tested according EN 384 and visually graded according Spanish standards were analyzed. The main goal was to reach a detailed comprehension about the true state of nature of the three reference structural material properties (density, MOR and MOE), in the conditions it reaches the real market. Provided the existing beams (reasonably) came from the same populations, the use of reliability updating technics is a meaningful approach to the problem of conjecturing its resistant behavior. Distribution parameters for the target species have been proposed. Spanish softwood (with the exception of p. radiata) has proved to be extremely dense and quite stiff related to its resistance, compared with usual North American, Central or North European coniferous trees. Hence, the basic information of these last species should not be used when dealing with Spanish historical timbers, as it leads to rather uneconomical conjectures (as deformation and joints use to be design governing factors). Also therere significant differences related to the current Probabilistic Model Code suggestion on the topic (as the Code itself warns of).

Abstract: The paper deals with the application of the Italian method for assessing on-site and diagnosing timber elements to a distinctive Spanish type of horizontal structure called “revoltón” i.e. jack arch floor. As in Spain does not exist a specific regulation for the on-site diagnosis of timber elements, this analysis was performed according to the Italian standard UNI 11119. Due to the peculiar features of the jack arch floor some modifications were applied to the method.During spring 2012 the authors had the opportunity to carry out a pilot project by making a diagnostic analysis on a whole three stories building. The building, “Palacio del Marqués de Benicarló”, located in Spain in the town of Benicarló, between Barcelona and Valencia, was erected during the second half of the XVIII century. It maintains the original internal distribution and structure, and it is characterized by precious ceramic decorations on walls and floors. All the horizontal structures studied inside the palace were jack arch floor except the roof structure that was also made of timber.The results of the project described in the paper clarify the specific problems of the horizontal structures and the roof surveyed during the fieldwork. These results are accompanied by several plans that represent the information recovered on-site and lead to a complete assessment of the structures. The plans include the grading based on wood defects, the local moisture content of wood, the superficial and inner decay due to insects and rot and the deformation of the joists. In this way it was possible to locate the areas of the palace where more problems were concentrated, and better understand the causes and origin of the damages.

Abstract: The wooden structures are most common on the roofs of historical buildings. The ancient building techniques that were employed such as the use of notched joints are no longer known today. This lack, affects the project and implementation of restoration of these structures, and demonstrates, therefore, the importance of its preservation as a legacy to future generations. As result, the decision to restore heritage structures is the key to safeguarding the cultural heritage. The designer should be aware of the consequences of choosing some intervention techniques on preserving the cultural value of the monument. The technique may harm or benefit such as the patrimonial as the technical issue, preserving its historical and cultural value, durability and safety. Although there are important technical manuals and books that refer to the restoration of ancient roof structures published by Brazilian governmental agencies, there are not references about the consequences of certain technique´s application on the patrimonial value. Thus, this work analysed, critically and reflectively, the technical solutions most commonly adopted by Brazilian designers on the restoration of the structural roofs in ancient wooden structures. This analysis will be based on principles and recommendations of the key documents and the charters of heritage preservation. After the evaluation of restoration techniques most commonly applied to restoration of roofs with wooden structures, general procedures are recommended in order to ensure the safeguarding of the heritage.

Abstract: Beside seismic activity climate changes, reflecting in extreme events such as heat and cold waves, storms and floods, presents the main natural hazards. Although predicting events perimeter is not trivial, the vulnerabilities of society emphasizing built environment should be at least critically estimated and re-estimated, especially after the occurrence of such event. Many strong thunderstorms causing huge damage to agriculture and to build environment occurred in recent summers. Meteorologists concluded that summer storms especially those ones in July and August 2008 were very intense and affected many Slovenian regions. Extensive damage to buildings rose up questions about possible causes: bad construction practice, use of inappropriate materials, deficient maintenance and inadequate building regulation relating to loads. Some experts also claimed that additional material and product characteristics should be tested /defined to prevent extensive damage, like hail resistance for example. Slovenian National Building and Civil Engineering Institute (ZAG) tried to answer to these questions in a special research project, financed by Slovenian Ministry for Environment and Spatial Planning (MOP).

Abstract: Criteria for assigning class values to different vulnerability indicators in a procedure for assessing the seismic vulnerability of timber roof structures are discussed here. The main issues concern grading the structural typology, the quality of the carpentry joints, the effectiveness of supports, the effect of strengthening interventions, if present, and the resulting global behavior.

Abstract: Brazil still has a diversity of architectural structures that represent various historical periods experienced. However, much of this cultural heritage is not properly maintained and this work aims to contribute to the conservation of the wooden structure of a historic site in the state of São Paulo. Problems related to the health/physical normality of wood present in historical building structures are commonly found, therefore, assessment measures and maintenance should be performed to secure the structural integrity of these parts, so that these architectural references are not lost over time. The farm Santa do Maria Monjolinho, located in São Carlos, the central region of the state of São Paulo, Brazil, declared cultural heritage in 2007 by the department of state assets - CONDEPHAAT - stands out for the richness of its architectural set which was built in the nineteenth century, under the dominance of the coffee economy. Its facilities include the main house, yard coffee, granary and machine room, aqueduct and water wheel, chapel, mill, barn, settler houses and the building of the former slave quarters, fully preserved by the family Malta Campos. The old slave quarters, the object of our study, was built in the mid nineteenth century: today is the building that has the highest level of degradation. Originally consisted of two large environments, called wards, one female and the other male, with the function of house the farms slaves. After abolition, italian colonists adapted the building turning it into five houses with party walls of clay and wattle-and-daub. The roof, which consists in a wood structure and clay tiles, is bulging and has loads of broken tiles and the timber (rafters, beams and purlins) structurally compromised due to moisture attack and wood decay agents. The roof structure is supported by brickwork pillars and fresh mainstays, and some of them exhibit some level of degradation. To evaluate the health of these mainstays were used wood samples from other similar structures in the same property, built at the same era of the slave quarters. Tests of shear, compression parallel to the fibers and density that were developed made possible to make an analogy to the strength and condition of the wooden structures that support the roof of the slave quarters. The results as such tests show the reduction of the mechanical resistance of the pieces evaluated, leading to the need to reassess the conditions of service of the structures considered. Seeking an evaluation and diagnosis of health and structural conditions of the roof of the slave quarters, we intend to perform nondestructive tests on some parts of the wood of the structure itself. To do so, the following equipment could be used: Stress Wave Timer, Pylodin and Resistograph, offered by USP. Thus, using data obtained by the tests will be possible to determine the percentage of deterioration of structural components and the indication of restoration suitable for conservation of the structure, while cultural heritage of regional significance.