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Old masonry buildings, which are frequently part of the cities-built heritage, are vulnerable to seismic actions. Thus, it is important to conduct efficient seismic strengthening interventions that allow maintenance of the existing building to minimize the environmental and economic impact. The use of reinforced renders is a simple and effective solution for seismic strengthening of this type of constructions. In this paper, several compositions of reinforced renders are analyzed, consisting of mortars with air lime, hydraulic lime, or cement binders, reinforced with steel mesh, fiberglass mesh and a natural fiber mesh. Additionally, the results of diagonal compression tests on three small wall specimens are presented, one of which is non-reinforced and the other two are strengthened with reinforced renders. The results of all tested walls are presented and compared, allowing us to evaluate the efficiency of the reinforced render on the wall shear strength.

The goal of this study is to propose a method for the architectural design of wood houses in Portugal. Construction and manufacturing companies were interviewed to understand the wood house market. A case study was developed by simulating four variations of a project, including different wood construction systems (wood frame, post and beam, logs, and cross-laminated timber). Based on the identified problems, a design method was defined by using decision support tables, lists of procedures and optimization strategies. A multi-criteria decision support process was proposed to assist in the assessment and selection of the “best” solution among the potential options. During the program phase, the use of a catalogue of architectural typologies with construction and formal systems promotes the process’ optimization. In the sketch design phase, the adoption of an assessment process, specific design procedures and pre-set strategies (durability, construction integrity, economy) aims to assure construction quality., Se presenta un método para el diseño arquitectónico de casas de madera. Se entrevistó a empresas de construcción y fabricación y se desarrolló un caso de estudio simulando cuatro variaciones de un proyecto, incluidos diferentes sistemas de madera (entramados ligeros, poste y viga, troncos, y madera contralaminada encolada). Sobre la base de los problemas identificados, se definió un método de diseño utilizando tablas de apoyo a las decisiones, listas de procedimientos y estrategias de optimización. Un proceso de apoyo a la decisión de criterios múltiples fue propuesto como una ayuda en la evaluación y selección de la mejor solución. Durante la fase del programa, el uso de un catálogo de tipologías con sistemas de construcción y sistemas formales promueve la optimización del proceso. En la fase de anteproyecto, la adopción de un proceso de evaluación, procedimientos de diseño específicos y estrategias preestablecidas (durabilidad, integridad de la construcción, economía) tienen como objetivo garantizar la calidad de la construcción.

The in-plane seismic performance of old unreinforced brick masonry walls strengthened with stainless-steel twisted bars and conventional steel bars (usually used in concrete reinforcing) was investigated in the present study. For this purpose, a total of seventeen masonry wallettes reproducing masonry walls of traditional Lisbon buildings from the 1930s–1950s (known as “placa” buildings) were constructed. The specimens were assembled using original bricks from demolished old buildings and a sand-cement bedding mortar with the same proportions as reported in building design documents of the time. Out of the fourteen wallettes tested in diagonal compression, three were unreinforced, and eleven were strengthened in different layouts. Additionally, axial compression tests were performed on the other three unreinforced masonry wallettes. The tested specimens were reproduced with numerical models calibrated based on the experimental results. The experimental and numerical results of the reinforced specimens were compared to the unreinforced specimens to draw conclusions on the effectiveness of the strengthening solutions when applied to masonry walls of the typology under study. The most important result of the strengthening was an important increase in the ductility of the specimens that were originally brittle. In addition, in some cases a slight increase of shear strength was also observed.

This paper presents part of the results of an experimental study undertaken to develop a structural strengthening technique for old masonry buildings. The technique consisted of external reinforcement with a CFRP (Carbon Fibre Reinforced Polymer) reinforced render. CFRP reinforced render is an innovative seismic structural strengthening material for the structural masonry walls of old buildings. It consists of a non-cementitious mortar reinforced with a carbon fibre mesh and is applied to one or both wall faces (preferably by shotcreting). The reinforced render material was developed to improve the mechanical capabilities of masonry walls subjected to “in-plane” and “out-of-plane” seismic loads. Similarly to other widely known composite materials (e.g., reinforced concrete) the composite behaviour of the reinforced masonry relies on both the anchoring as well as on the adhesion of the reinforcing material to the masonry substrate. These aspects are the main objectives of the presented experimental work. The tests carried out in this study included the mechanical characterisation of all the materials involved, specifically of the mechanical behaviour of the reinforced composite render material, and finally focused on the bonding characteristics between CFRP reinforced render strips and masonry substrates, as well as the anchoring solution for the ends of the strips. The present experimental work is part of a research project to develop an innovative seismic strengthening technique for load-bearing masonry wall buildings.

This paper presents the results of an experimental study carried out with the following main purposes: (i) evaluate the effect of different types of delamination of straight glulam beams on their structural behavior up to failure; (ii) evaluate the effectiveness of repairing those beams after bending failure through the use of self-drilling screws and plywood sheets; (iii) evaluate the effectiveness of a preventive repair of those beams (applied before loading them to failure) through the use of self-drilling screws. The tested elements comprised (i) reference beams, without delamination; beams with delamination at the ends involving the overall cross-section width, in (ii) moderate lengths and in (iii) significant lengths; and (iv) beams with delamination along all length at the outer thirds of the cross-section width. The results of the bending tests of the unrepaired beams showed that (i) the end delamination causes a decrease in the strength and stiffness of the beams, more markedly for longer delamination length and that (ii) the longitudinal delamination, not involving the entire cross-section width, does not significantly affect the behavior of the beams. The results of the beams repaired after failure showed that the intervention technique used is adequate and that its degree of effectiveness depends on the type of delamination and on the level of damage occurred at failure. The results of the preventively repaired beams showed that the intervention method used confers significant improvements in resistance and stiffness to unrepaired beams, although it does not allow achieving the performance of healthy beams.

The following paper presents the most recent results of a research programme carried out to, among other purposes, develop an innovative anchoring system for old masonry buildings. Despite the recognized importance of connections and anchoring systems, there is little experimental information about their strength and stiffness when installed in the masonry walls of old buildings. Therefore, one of the important goals of the research programme mentioned was the experimental characterization of the proposed anchoring system. The main characteristic of the proposed system, which makes it different from others, is an internal spherical steel element where the rod is connected. This steel eleme nt, called hinge, allows no orthogonality between the steel anchor plate and the tie rod, which makes it suitable for uneven connections between orthogonal walls and/or walls and floors. Besides this particular characteristic, the proposed system demonstrates all the capabilities of the traditional anchoring systems, namely, it can be used to strengthen the connection between orthogonal masonry walls or to ensure the connection of constructive elements (floors, roofs, stairs, etc.) to masonry walls. Moreover, numerical simulations with non-linear finite elements models were performed, aimed at reproducing the experimental tests for other load conditions or different wall thicknesses. The prime objective of the experimental and numerical studies was to assess the actual behaviour of the anchoring system and to establish appropriate design rules, which are also presented in this paper.

Sustainability is a pressing concern of the 21st century. Social development in most countries is raising awareness of the needs of future generations and legislation to protect the present and future quality of life. These needs are compelling various sectors, including construction, to find sustainable solutions. This paper investigates the feasibility of incorporating high-quality recycled concrete aggregates in new concrete, providing a recycling option for precast rejects. The massification of recycled aggregate incorporation would decrease the environmental impacts of the concrete industry, for instance due to reduced landfill disposals, less quarry mining and shortened transport distances. The study presented in this paper concerns the material, mechanical, durability and short-term structural behaviour of concrete specimens and structures made with recycled aggregates sourced from high-quality concrete elements. This paper intends to provide a holistic view of the study, from the procurement and crushing process that generated the aggregates to the conclusions of the different experiments performed. The results of this experimental campaign are benchmarked with other investigations and the importance of the quality of the RA is evaluated. This paper concerns the first full-scale experiments made on recycled aggregates concrete structures. Also, some of the tests performed were the first of their type made on recycled aggregates concrete.

In order to study the behaviour of concrete structures made with coarse crushed concrete aggregates recycled from discarded elements from the precasting industry, extensive testing was performed in four full-scale structures with varying recycled aggregate (RA) ratios. This paper describes and analyses the results of vertical load tests on each slab of these double-floor structures. The Young’s modulus ( E ) of the concrete mixes was estimated by finite element model calibration using deflection data from the tests. The response pattern of the various structures was the same and the aggregates used had a small influence on E , even smaller than the execution conditions. One of the concrete mixes included a superplasticizer (SP) and this product more than offset the loss of stiffness due to RA use. To the authors’ best knowledge this is the first study ever concerning the behaviour of full-scale recycled aggregate concrete (RAC) structures subjected to vertical loading and the behaviour of slabs with significant replacement of conventional aggregates by RA.

The analysis and control of deformability of wall coating mortars contributes to minimize crack development and propagation, one of the most common anomalies in building facades. Many of these cracks appear due to internal stresses in the coating mortar, because of imposed deformations or of imposed restrictions by the substrate. These deformability studies should include one or more experimental methods to determine the modulus of elasticity (E) of the coating mortars in question. There are two approaches to experimentally determine E for mortar specimens: static and dynamic experimental methodologies. For civil engineering applications, the results obtained from static methodologies are more adequate than those obtained with dynamic methodologies. However, since static E results are scarce due to a lack of an established static methodology for mortars, mainly due to their lower mechanical resistance, friable behaviour and higher frailty when compared to concrete, engineers are led to use the established dynamic methodologies. This paper proposes an experimental methodology to determine the static E for moulded mortars specimens. The methodology was adapted from the standard procedure used for concrete specimens, to accommodate the specific characteristics of mortar specimens, namely: provide reliable displacement and applied load data; solve issue related to specific mechanical characteristics of mortar specimens, such as low strength and friable behaviour. This methodology was applied to standard moulded mortar specimens made from multiple mineral binders (cement, hydraulic lime and air lime). In order to validate it, the obtained results were compared with two, well-established, dynamic experimental methodologies (Resonance Frequency and Ultrasonic methodologies) as well as with reference values from relevant bibliography. Using the previous data, this paper also includes a preliminary analysis on the ratios between static and dynamic E values for the studied mortars, representing another objective of this study.

Aiming at characterizing the behaviour of concrete structures made with coarse aggregates recycled from crushing concrete elements from the precast industry, extensive testing was performed in four full-scale recycled concrete structures, made with various recycled aggregate ratios. This paper concerns the in situ concrete characterization tests carried out. The purpose was to study the use of the coarse fraction of the recycled aggregates (RCA) at different replacement ratios and the possibility of including a superplastizer (SP) in concrete mixes, as a means of replicating the properties of a conventional concrete (RC) mix. The results showed that the behaviour of the concrete mixes produced with these aggregates, originated from the precasting industry, i.e. with high quality, is almost unaffected by their incorporation. Only the results of the ultrasonic pulse velocity (UPV) tests were affected by RCA incorporation, but the loss was lower than the one reported in the literature. This study concluded that these RCA have, in fact, high quality and are suitable for the production of recycled aggregate concrete to be used in structural elements. The SP more than offset the effects of RCA incorporation on the concrete mixes. To the authors’ best knowledge this is the first investigation concerning the in situ concrete properties of full-scale recycled aggregate concrete structures.

This paper presents the results of an experimental campaign developed with the aim of evaluating the effect of the incorporation in concrete of recycled aggregates from crushed elements produced by the precasting concrete industry. The specific purpose was to study the use of the coarse fraction of these aggregates. This was done by studying various replacement ratios of the coarse fraction of the aggregates. The possibility/need to correct the composition of concrete mixes with recycled aggregates was also investigated, by testing various contents of a superplasticizer, intending to replicate the characteristics of a reference concrete, i.e. a mix with an analogous composition but where all aggregates are natural. An extensive set of tests was performed to evaluate the mechanical and durability properties of all concrete mixes. The results prove that the concrete mixes with recycled aggregates have an equivalent performance to that of the reference concrete in most of the properties. In the others, where a performance loss was registered, that loss was lower than the one reported in the literature review performed. This was expected since the quality of the coarse aggregates recycled from precast elements is very good and totally fit for the production of new concrete, originating concrete compositions with good quality, namely in terms of hardened state properties. As expected the use of a superplasticizer is beneficial for concrete performance in all properties analysed.

The cyclic behavior of a composite timber-masonry wall was evaluated in quasi-static conditions. The wall was conceived to replicate a traditional partition wall of the downtown area of Lisbon, rebuilt after the 1755 earthquake. The wall presented an almost linear behavior for small displacements, followed by a plastic deformation zone where significant inelastic behavior was observed. On a second stage, superelastic dampers based on the hysteretic behavior of NiTi wires were also installed to strengthen the wall. Good cyclic behavior was observed in these devices, although the difference in stiffness of the wall compared to the NiTi wires did not lead to significant increase in the overall area of the hysteresis of the force–displacement diagram. Nevertheless, the technique proved to be promising in reinforcing old building walls regarding their seismic behavior.

When designing structures to the wind action, the variation of the mean wind velocity and turbulence parameters with the height above the ground must be taken into account. This paper presents the numerical simulation results of atmospheric boundary layer (ABL) airflows, in a numerical domain with no obstacles and with a cubic building. The results of the flow characterization, obtained with the FLUENT CFD code were performed using the k turbulence model with the MMK modification. The mean velocity and turbulence intensity profiles in the inflow boundary were defined in accordance with the Eurocode 1.4, for different conditions of aerodynamic roughness. The maintenance of the velocity and turbulence characteristics along the domain were evaluated in an empty domain for uniform incident flow and the ABL Eurocode velocity profiles. The pressure coefficients on a cubic building were calculated using these inflow conditions.

Glass fiber-reinforced concrete (GRC) is a material made of a cementitious matrix composed of cement, sand, water, and admixtures, in which short-length glass fibers are dispersed. It has been widely used in the construction industry for nonstructural elements, especially facade panels. Based on the recent results of a research project, this material was applied to the fabrication of structural elements, namely, 30-m-high telecommunication towers and pedestrian bridges. In these structures, the effects of cyclic loads, like wind, earthquakes, or pedestrian circulation, are important, and the corresponding GRC behavior has to be considered in their structural design. This paper focuses on the experimental evaluation and numerical modeling of GRC mechanical behavior. Based on the results of experimental tests on material samples, a numerical model was developed to reproduce the cyclic and monotonic behavior of GRC. This numerical model was then used to assess the structural behavior of GRC telecommunication...

Glass-fiber reinforced concrete (GRC) is a material made of a cementitious matrix composed of cement, sand, water and admixtures, in which short length glass fibers are dispersed. It has been widely used in the construction industry for non-structural elements, like facade panels, piping and channels. In this paper, the results of a research project are presented where this material was applied to the fabrication of structural elements, namely 30 m high telecommunication towers. Here, the lightness and tensile strength advantages of the GRC were associated with carbon and stainless steel reinforcement, leading to an innovative material with high durability.

Glass fibre-reinforced concrete (GRC) has been used for more than 30 years in the construction industry, especially in facade panels. In this paper, a rehabilitation case study is presented, of a building where cracking and excessive deformations were detected in the sandwich GRC facade panels due to thermal effects. The structural behaviour of the panels was simulated with a finite element method (FEM) model, validated by experimental tests performed on the facade, and then used to assess the efficiency of a repair technique, based on external insulation, which showed a good efficiency.

This paper presents the results of an experimental study on the low cycle fatigue strength of cruciform welded joints. Tests were performed on 22 specimens of three different categories, namely full-penetration, partial-penetration and fillet welded cruciform joints. These tests consisted basically of imposing on each specimen a constant amplitude cyclic displacement history in the plastic range of the material behaviour. The experimental testing procedure is described and the results are presented. The unified approach for low and high cycle fatigue strength assessment proposed by Ballio and Castiglioni [1] is applied to the test results. Such approach leads to the conclusion that the same set of Wohler ( S – N ) lines [2] usually given in recommendations [3] for high cycle fatigue can be also applicable in the low cycle fatigue range. It is demonstrated that the proposed damage model allows prediction of the number of cycles to failure for the specimens, at each given cycle amplitude, with a notable accuracy.