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The paper is focused on the deterioration of industrial reinforced concrete chimneys caused by carbonation. It is considered that a chimney has to be repaired when more than 30% of its surface is affected by visible corrosion-induced cracks. An optimal maintenance strategy aims at the postponement of this state beyond the intended service life of the chimney with minimum maintenance costs.

В данной работе разработан проект промышленной дымовой трубы высотой 120 метров из высокопрочного бетона. Для объекта разработана проектная документация согласно Постановлению Правительства РФ №87 от 16.02.2008 г. «О составе разделов проектной документации и Ñ‚Ñ€ÐµÐ±Ð¾Ð²Ð°Ð½Ð¸ÑÑ Ðº Ð¸Ñ ÑÐ¾Ð´ÐµÑ€Ð¶Ð°Ð½Ð¸ÑŽÂ». Разработано новое конструктивное решение железобетонного ствола трубы из высокопрочного бетона., In the given work a project of industrial chimney made of high-strength concrete is developed. Design documentation has been developed for the object in accordance with the RF Government Decree N 87 of February 16, 2008 «On the structure of sections of project documentation and requirements for their content». A new constructive solution for a reinforced chimney core made of high-strength concrete has been developed.

This document presents a systematic analysis of the damage causes of industrial masonry chimneys, i.e. cracking patterns, materials’ degradation and structural displacements. The methodology includes an adequate geometric evaluation with identification of each observed lesion, their situation and their environmental conditions. The industrial process temperatures have been documented, hence maximum temperatures and gradients during chimney’s service life were evaluated, and any possible crack pattern because thermal loads was analyzed. In addition, chemical composition (SEM, EDS and DRX) and mechanical properties (compressive and bending strengths) were assessed. Microstructural analyses were useful to detect certain elements and compounds related to corrosion or degradation processes of mortar and steel. Analytical and FE models were made to evaluate the influence of each possible damage source, i.e. temperature gradients, corrosion and chemical reactions producing expansion in the mortar. The effect of internal pressures (because corroded steel) were successfully modelled as spring elements in vertical and horizontal cracks, which matched experimental data obtained in real structures. These results have demonstrated the relation between horizontal displacements of the crown and the position of the internal stairs (made in steel bars embedded in the masonry). Once cracked, either by corrosion or by temperature, the water entrance through the cracks produces chemical reactions with the combustion sulphurs, present in the mortar because of combustion gasses. These reactions generate an expansion inside the masonry located only in one façade. Hence, differential displacements generate the curvature and the consequent drift. This study was partially funded by Spanish Ministry of Economy, Industry and Competiveness (BIA2012-3431) and (BIA2015-69952-R) This study was partially funded by the University of Alicante VIGROB-212.

From the early 19th to the middle of the 20th century, brick chimneys formed part of the industrial landscape. As technology advanced, factories were abandoned and became absorbed by the cities growing around them but masonry brick chimneys found a new role as part of the historical heritage. A large number of these structures are now protected buildings, which means they have to be maintained in a good state of conservation. Architects and engineers who have to assess the condition or retrofit these structures therefore need to be familiar with the different types of damage that can affect brickwork chimneys, and having access to a classification of the different types of damage they are prone to would be very useful to them. This paper classifies and describes the most common defects found in these structures, compiled after a close inspection of 538 Spanish industrial chimneys. The types of damage were classified according to: a) changes in the materials used in their construction, b) damage caused by repeated actions, c) damage due to extraordinary events, and d) damage caused by living organisms.

[ES] A partir de entrevistas realizadas a distintos maestros constructores de chimeneas industriales de ladrillo, pertenecientes a las escuelas valenciana y murciana, que recurren a estilos y sistemas de ejecución muy diferentes, se ha procedido a describir los sistemas empleados en España para la construcción de estos monolitos industriales. Los sistemas abordados implementan los conocimientos de la Historia de la Construcción española, con un elemento que tuvo una corta vida, pero que fue esencial en la evolución industrial y son clave a la hora de enfrentarnos a una posible restauración del elemento., [EN] The system used in Spain for the construction of industrial brick chimneys in east and south east of Spain and those that have been its influence is described in this paper, from interviews with different master builders belonging to the Valencia and Murcia schools, with styles and systems of very different execution. The addressed systems implement the knowledge of the Spanish Construction History, of an item that had a short life though it was essential in industrial development and becomes the key for a possible restoration of the element.

The system used in Spain for the construction of industrial brick chimneys in east and south east of Spain and those that have been its influence is described in this paper, from interviews with different master builders belonging to the Valencia and Murcia schools, with styles and systems of very different execution. The addressed systems implement the knowledge of the Spanish Construction History, of an item that had a short life though it was essential in industrial development and becomes the key for a possible restoration of the element. A partir de entrevistas realizadas a distintos maestros constructores de chimeneas industriales de ladrillo, pertenecientes a las escuelas valenciana y murciana, que recurren a estilos y sistemas de ejecución muy diferentes, se ha procedido a describir los sistemas empleados en España para la construcción de estos monolitos industriales. Los sistemas abordados implementan los conocimientos de la Historia de la Construcción española, con un elemento que tuvo una corta vida, pero que fue esencial en la evolución industrial y son clave a la hora de enfrentarnos a una posible restauración del elemento.

Estruturas como torres e chaminés industriais são bastante vulneráveis ao fenômeno de desprendimento de vórtices, devido à sua esbeltez e forma rombuda. Além disso, devido ao baixo amortecimento estrutural que possuem, essas estruturas também têm maiores chances de atingir grandes amplitudes de deslocamento, o que é causado pelo efeito de captura. Apesar de esse tipo de estrutura ser considerado simples dos pontos de vista estrutural e aerodinâmico, o estudo das vibrações transversais nessas estruturas é bastante complicado, pois envolve a interação entre tópicos complexos da mecânica dos fluidos e estrutural, tornando a determinação confiável da resposta estrutural um dos problemas mais difíceis da Engenharia do Vento. Ao longo das últimas cinco décadas, diversos pesquisadores vêm estudando esse fenômeno, buscando uma abordagem que consiga considerar todos os tópicos que envolvem o mecanismo de vibração por desprendimento de vórtices. Entretanto, apesar dos esforços, os modelos existentes para a verificação da resposta da estrutura são de caráter empírico, sendo os dois mais aceitos pela comunidade científica o modelo de comprimento de correlação de Ruscheweyh e o modelo matemático espectral de Vickery e Clark, o qual foi posteriormente aprimorado por Vickery e Basu. Primeiramente, são estudados em detalhe esses dois modelos e seus métodos derivados, os quais são apresentados em normas e códigos. Após isso, é feita uma proposta de cálculo de dimensionamento do deslocamento do topo de tais estruturas baseada no modelo de Vickery e Basu e adaptada às necessidades da NBR- 6123. E finalmente, são apresentados dados de 42 estruturas, as quais atingiram grandes amplitudes de vibração em seu topo. Essas estruturas foram dimensionadas segundo as diretrizes de cada um dos métodos estudados neste trabalho, o que demonstrou o bom desempenho do Método II do Eurocódigo, do Método do CICIND e da Proposta III-B para a NBR-6123. Structures like towers and industrial chimneys are quite vulnerable to the vortex shedding phenomenon, due to their slenderness and non-aerodynamic form. Furthermore, due to their low structural damping, these structures are also more likely to reach large displacement amplitudes, which is caused by the lock-in effect. Although these structures are considered as simple from structural and aerodynamic points of view, the study of cross-wind vibrations in these structures is quite complicated, as it involves the interaction of complex topics of fluid and structural mechanics, turning a reliable determination of the structural response into one of the most complicated problems in Wind Engineering. Over the past five decades, several researchers have been studying this phenomenon, seeking an approach that could consider all topics involving the vibrating mechanism by vortex shedding. However, despite the efforts, the existing models for predicting the response of the structure are empirical, with the two most accepted by the scientific community being the Ruscheweyh’s correlation length model and the Vickery & Clark’s spectral mathematical model, which was further enhanced by Vickery & Basu. Firstly, these two models and their derivative methods, which are reported in standards and codes, are studied in detail. After, a calculation proposal for predicting the top displacement of such structures is presented, which is based on the Vickery & Basu model and adapted to the needs of NBR-6123. Finally, data for 42 real structures which have reached large vibration amplitudes at their tops is presented. These structures were designed according to the guidelines for each of the methods studied in this work, which demonstrated the good performance of the Eurocode II Method, of the CICIND Method and of the NBR-6123 III-B Proposal.

The industrial chimney has been the symbol of the Industrial Revolution par excellence. Transcending both regionalism and traditional forms of construction, some specimens found in Spain, dating mainly from the early twentieth century, follow unique schools of construction with regard to the mastery with which the brick is handled. All this was achieved without being endorsed by famous architects; rather they were the product of master masons, skilled in their craft and relishing the opportunity to give to the best of their ability. Currently unimaginable in today s construction climate, their work shows signs of enduring, despite their obsolescence and disappearance of their original function. One of the most beautiful and spectacular types of chimney, whatever cross section it has, is the helical chimney. The paper reviews the origin of these chimneys and illustrates their various types of construction using both historical photographs of lost chimneys and photographs of some spectacular ones that have survived. In an interview with the author, one of the last great chimney builders explained how to erect a helical chimney using the tool he invented for the purpose. The paper ends by noting that heritage legislation in Spain is gradually including industrial heritage and that, in Valencia, industrial brick chimneys of merit, constructed before 1940, are now protected.

International audience; Coal power stations as well as waste incinerators produce humid acid gases which may condense in industrial chimneys. These condensates can cause corrosion of chimney internal cladding which is made of stainless steel, nickel base alloys or non metallic materials. In the aim of polluting emission reduction and material optimal choice, it is necessary to determine and characterize all the phenomena which occur throughout the chimney and more especially condensation and dissolution of acid gases (in this particular case, sulfur dioxide SO2).

National audience; Coal power stations as well as waste incinerators produce humid acid gases which condensate in industrial chimneys. These condensates may cause corrosion of the internal cladding made of stainless steels, nickel base alloys or non metallic materials. In the aim of polluting emission reduction and material optimal choice, it is necessary to determine all the phenomena which occur throughout the chimney such as condensation and dissolution of acid gases (in this particular case, sulphur dioxide SO2). The production of energy from fossil fuels (coal, petroleum, natural gas, etc.) brings about the emission of gas containing sulphur compounds (SO2, SO3) as well as chlorine and fluorine compounds. To avoid this atmospheric pollution and its harmful effects (acid rains, impact on the health) due to hydrochloric, sulphuric and hydrofluoric acids produced in the presence of air, it is necessary to steam these flue gases. Nevertheless, a considerable quantity of residual acid gases remains in the gas discharge which also contains large amounts of water vapour. Thus, condensation may occur and by the way an acid attack of the internal cladding of the chimney. This results in high costs of maintenance and a reduction of their structural stability. The knowledge of the phenomena of heat and mass transfer during the condensation of these acid gases in chimney is essential for their conception and materials choice.

Different plastic/failure are applied to a masonry structure showing the difficulties to deal with masonry material and the results obtained for a masonry chimney under erathquake loading when two different criteria are used. Generalitat Valenciana GV05/085.

The practical use of the specialised computer package BETHEV44 is illustrated with the analysis of a 150 m tall chimney of a thermo-electric plant. The package is based on finite element non-linear modelling for the analysis of reinforced concrete structures under both static and transient (thermal and mechanical) loading conditions. The material model is prepared to simulate the dominant non-linear behaviour of concrete (e.g. tensile cracking, non-linear multiaxial compressive behaviour, etc.) and reinforcement. Steel reinforcing bars or meshes are modelled by special bar or membrane elements embedded in concrete elements. Using the software described, the reinforced concrete chimney, built over 25 years ago, is analysed simulating the various working and ambient conditions in order to determine the cause of the structural cracking as well as to provide a reliable base for a structural repair. Selected results of the analysis are presented and briefly described showing the merit of applying BETHEV44.

This paper deals with the seismic behaviour of an unreinforced masonry chimney representative of the large number of chimneys currently in existence in many European areas which were built during the period of the industrial revolution. Maximum seismic intensity value that can be resisted in terms of peak ground acceleration and failure mode are the main goals. A 3D finite element model capable of reproducing cracking and crushing phenomena have been used in a non-linear analysis in order to obtain lateral displacements, crack pattern and failure mode for this type of construction. Earthquakes artificially generated for a low to moderate seismic intensity area from the response spectrum proposed by the codes have been tested on the structure obtaining failure mode, maximum stresses and displacements. Subsequently, the accelerograms generated were scaled until non-failure earthquakes were obtained.