Constructive characteristics and degradation condition of Liceu Secondary schools in Portugal Beatriz Abreu Marques, Architect, Master in Construction and Rehabilitation from Instituto Superior Técnico, Technical University of Lisbon, Portugal. Address: Av. Rovisco Pais, 1049-001, Lisbon, Portugal. Phone: (+351) 218 419 709; Fax: (+351) 218 418 276. Email:
[email protected] Jorge de Brito, Civil Engineer, Full Professor at Instituto Superior Técnico, Technical University of Lisbon, Portugal. Address: Av. Rovisco Pais, 1049-001, Lisbon, Portugal. Phone: (+351) 218 419 709; Fax: (+351) 218 418 276. Email:
[email protected] João Ramôa Correia, Civil Engineer, Assistant Professor at Instituto Superior Técnico, Technical University of Lisbon, Portugal. Address: Av. Rovisco Pais, 1049-001, Lisbon, Portugal. Phone: (+351) 218 418 212; Fax: (+351) 218 418 276. Email:
[email protected].
Abstract: Within a full-scope modernization programme of Portuguese secondary schools, technical inspections were conducted in order (i) to identify the main degradation processes that affect different types of school buildings and (ii) to provide recommendations for the rehabilitation projects. This paper presents the constructive characteristics and a statistical analysis of the degradation condition of a particular type of Portuguese secondary schools, the Liceu, comprising a set of buildings with an invaluable historical and cultural importance and very iconic in terms of the historical period in which they were built - the Estado Novo. To that end, a database was designed in order to organize information gathered in the inspection of 15 secondary schools of Liceu typology. The aim of the database was to analyse the most frequent anomalies in this type of school buildings, taking into account the constructive solutions used and establishing statistical relationships between anomalies, probable causes and recommended rehabilitation works. Results obtained allowed concluding that the overall condition of these buildings which, in average, were 60 years old, was severe. The most frequent anomalies in both the buildings envelope and inte-
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rior are mainly due to design and execution errors, water infiltration and lack of maintenance. Although the school buildings analysed are to some extent unique, most lessons learned from this study can be extrapolated to other countries, mostly Mediterranean, where during most of the twentieth century, buildings were designed and constructed according to the same architectural and constructive principles, and were subjected to the same type of maintenance.
Keywords: Schools; Liceus; Anomalies; Causes; Database; Statistical analysis.
1. INTRODUCTION Portuguese secondary schools integrate a heterogeneous set of buildings, in terms of spatial and constructive solutions. Over the twentieth century these buildings were used as an important tool for governments’ action in order to implement their teaching policies, which are reflected in the diversity of schools built during this period. In 2007, there were about 500 public secondary schools across the country, built since the late nineteenth century (Alegre, 2010). The increase of school facilities during the last century did not take into account the necessary conservation and maintenance actions concerning the existing buildings. Given the age of most school buildings and their intensive use over the years, the absence of those important actions led to a considerable number of degraded and outdated buildings that currently offer unsuitable conditions, particularly taking into account comfort and accessibility demands and the most recent teaching and learning techniques (Heitor, 2009). Until 2007, the corrective actions aiming at maintaining and/or improving the school buildings were not sufficient nor systematically planned and led to a general need for rehabilitation actions. Therefore, a school modernization programme for secondary education was
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launched in 2007 by Parque Escolar EPE (a public company created by the Portuguese government specifically to rehabilitate and manage secondary schools infrastructure) in order to solve the problems related to school buildings degradation. About 60 secondary schools built during the twentieth century were inspected by experts of Instituto Superior Técnico, divided into three main types of secondary schools: Liceu schools, industrial schools and pavilion schools. These school buildings are located in central and southern regions of Portugal and were inspected between 2007 and 2010 (Branco et al., 2007/2010). The purpose of this expert survey was to perform mainly visual observation inspections and, based on the expert knowledge of the surveyors, to convey cognitive recommendations to the designers of the rehabilitation projects of these secondary schools. The study presented in this paper comprises the characterization of (i) the constructive and functional features and (ii) the degradation condition of 15 secondary school buildings with Liceu typology. These are very large schools (specifically, they are the biggest secondary schools in Portugal, with capacity within the thousands of students’ scale), generally comprising several building blocks per school, and they represent around 40% of all the schools of this type in the country, which is, by any statistical standard, a very representative sample. A statistical analysis was performed about the parameters that characterize these schools and their main anomalies, identified mainly through visual inspection. Relationships were established between the anomalies identified, their probable causes, recommended rehabilitation actions and other characterization parameters. It was necessary to structure and organize the information from the expert reports in a database that was designed and conceived to this end, thereby allowing establishing statistical relations between those parameters. Given the specificity and heterogeneity of these buildings, it was necessary to develop a specific methodology for the characterization of
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anomalies in school buildings, making it possible to correlate multiple characterization parameters and to classify the anomalies by assigning them severity levels. Aspects concerning structural and seismic design of the school buildings, comprising the analysis of the original projects and the development of retrofitting solutions, were thoroughly analysed by Proença et al. (2012) and Gago et al. (2012) and are outside the scope of this paper. The remainder of the paper is organized in the following way. Section 2 presents a historical overview of the development of Liceu school buildings. Section 3 describes the constructive characteristics of these buildings, in terms of functional and constructive typology, as well as their structural and non-structural materials. Section 4 presents the methodology developed to evaluate the degradation condition of school buildings. Section 5 presents the results obtained from the statistical analysis. Finally, section 6 draws the main conclusions from this study. The Liceu type of school, even though unique to Portugal, has many constructive features that are common to schools in all the other Mediterranean countries. The statistical study presented in this paper is almost unprecedented in the literature (Chamosa and Ortiz, 1984; Marteinsson, 1999; Chew, 2005) given the size of the sample and the historical and cultural value of this particular group of schools, very iconic in terms of the historical period in which they were built - the Estado Novo.
2. HISTORICAL OVERVIEW The word Liceu comes from the Latin Lyceum and has its roots in the Greek word Lykeion that means the place where Aristotle taught his disciples in ancient Greece. The Liceu buildings and the concept of compulsory, secular and public education emerged in Portugal within the scope of the liberal reforms of the nineteenth century, under the influ-
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ence of the Republican model that emerged in France in the same period. In Portugal, the initial occupation of extinct convents and monasteries was directly linked with the extinction of religious orders that took place in 1834. Therefore, the first Portuguese secondary schools were installed in convent buildings, given the lack of economic resources for the construction of new school buildings and the availability of these spaces, after the extinction of the religious orders in Portugal (Fig. 1). Given the age of these buildings and the deficient health conditions they offered, the installation of schools in convents proved to be unsuitable for the education needs and requirements brought by the reforms. The first initiatives to build new secondary schools occurred in this context driven by the educational reforms of the period. International experiences introduced new concepts and the deployment of a formal language in the design of this public equipment, following a rational approach to the composition and organization of spaces. These concepts are also reflected in the concerns about the schools sanitary and health conditions, as these spaces were seen as privileged places for the transformation of society and urban environments. These new buildings also envisaged meeting the demands of the educational reforms, by creating spaces for gymnastics, enhancing the outdoors, and other spaces dedicated to scientific education. An example of the implementation of these ideals is the Pedro Nunes secondary school (Fig. 2), where a more open structure towards the surroundings can be observed (Alegre, 2009). The construction of the new Liceu school buildings is definitely launched in the beginning of the twentieth century, under the influence of the École de Beaux-Arts in Paris and the French Lycée building models (Fig. 3). The first step towards the implementation of the new educational principles was the choice of the construction site, seeking the suitability of the buildings for a long period of time.
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The educational reforms of the nineteenth and early twentieth centuries are a milestone in the design of schools in Portugal, which remained until the establishment of the military regime in 1926, withstanding the political transition from Monarchy into Republic. The political consciousness of the role of Liceu schools influenced the development of school buildings throughout the twentieth century. Following this political change, significant changes took place regarding the building policy for new secondary schools. The cultural symbolism associated to these educational spaces was intentionally used by governments as a communication vehicle of the patriotic values to the Portuguese Society, influencing the educational system and the construction characteristics of the buildings. The Loan administration department for secondary schools (JAEES), created in 1928, had the role of administrating and controlling the fund application for the construction and repair of secondary schools in Portugal. This board defined the tenders for new school buildings and promoted architectural competitions for their design (Moniz, 2007). These tenders allowed greater freedom of architectural expression connected to the functional organization of school buildings and were the first opportunity to develop a program considering the hygienic and constructive requirements that could be regarded as "modernist" (Fig. 4). Emerging in this period of the twentieth century in Europe, the Modern Movement ideals were moved by a greater rationalism, in terms of functional organization of spaces and the choice of new construction techniques, while the use of new materials - such as reinforced concrete - allowed the establishment of a formal sobriety (Fig. 5). Despite the initiatives to build new secondary schools in the 1930’s, the shortage of schools had not yet been resolved. The need for new schools remained and, therefore, new programmes were developed to increase their number in Portugal. The Liceu buildings designed in Portugal in this period reflect the Portuguese political
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circumstances, namely the onset of the Estado Novo regime. Therefore, the schools design reproduced nationalistic symbols, which led to the abandonment of foreign influences in the school projects (Fig. 6). In 1938, the initiative to build and repair schools that had taken place during the 1930’s is continued through a different path. The “Buildings, extensions and improvements plan for Liceu schools” by the Department of Construction for Technical and Secondary Education (JCETS) that followed JAEES, also known as Plan of 38, promoted the construction of 10 new Liceu schools, with four additional schools having been added during the implementation of this plan between 1944 and 1945. This program centralized the design of these school projects, which resulted in the homogeneity of Liceu buildings and the exclusion of new architectural designs. The “General program for the development of Liceu projects” in 1940-1943 established the spatial and functional characteristics of the schools to be designed. The definition of areas and sizes, sun exposure, lighting and ventilation conditions and coating materials to be applied led to common characteristics, making the projects more uniform (Fig. 7). The monumental design of these buildings, using a historical and nationalist lexis, emphasized the social importance of the secondary schools and defined multiple characteristics that reminded traditional construction and architectural solutions. Between 1952 and 1958 the construction of Liceu schools slowed down due to the priority given to the design and development of projects focused on technical and vocational schools. Within the implementation of the so called Marshall Plan and the consequent promotion of industrialization, a law on the reform of technical, industrial and commercial education buildings was passed in 1947. Besides the definition of these school regulations, this law further defined the construction, extent or adaptation of school buildings that were intended for these levels of education. These school projects
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presented new demands and requirements, particularly the need of a larger teaching area and a different organization of the school layout. For such schools, a preliminary draft project was created, which promoted systematization of the architectural and construction solutions. Despite these efforts, the construction of new school buildings was not enough to meet the objectives, due to the increase of pre-university preparation needs in this period. In 1958 a new plan, known as the Plan of 58, was approved to build 16 Liceu schools across the country. This plan sought to develop standardized projects for school buildings, based on the experience acquired in the previous years. In addition, this initiative allowed returning to a modernist constructive language and to other international influences in the development of school buildings, now presented as a social space open to the community (Fig. 8).
3. CONSTRUCTIVE CHARACTERIZATION In the first Liceu school buildings, of the beginning of the XX century, the structural material used in the bearing walls was irregular stone masonry. Its coating was chosen to meet the hygienist requirements, to ensure easy cleaning and greater sanitation quality of the interior spaces, and ranged from limestone panels or cementitious renders with water-based paint (in the exterior) to hydraulic or ceramic tiles. The original pavements and stair structures were in timber and were progressively replaced or added in some specific areas by reinforced concrete slabs built some decades after the initial construction, within restoration actions. In the 1930s, the first modern school projects aimed at complying with the conditions described by JAEES. The programme defined for these schools was organized by functional centres that led to the construction of some independent buildings, such as the gymnasium. These functional buildings were constructed using a structural material that
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was new then - reinforced concrete - which allowed the use of terraces, wider openings in the façade and a different geometric organization of plans (Fig. 9). This constructive option led to an aesthetic aspect of these buildings towards a new modern architectural lexis that reflected the more rigorous and pure geometry of their volumetric proportions. The Liceu schools designed according to the so-called Plan of 38 are characterized by the uniformity of solutions, rejecting the design principles of the modern period and recovering some national traditional architecture elements (Fig. 10a). In terms of functional organization of these buildings, the Liceu schools of this period were characterized by symmetric organization with the entrance as the focal element, and the remaining school premises distributed around it (Fig. 10b). In terms of constructive solutions adopted, pitched roofs were used, along with a strong decorative sobriety of the walls decoration. Decorative stonework was used only on the facades of the main buildings marking the entrance. The structural material used in the bearing walls was irregular stone masonry, as in the early XX century, complemented with reinforced concrete elements. The floors’ structure was also in reinforced concrete, very often comprising joist-beam slabs with vault bricks. In the second half of the XX century the design of Liceu buildings is marked by the influence of experiences in school architecture from northern Europe and the support received from international work groups, such as the research of innovative solutions based on cost control and planning and standardization of construction elements to speed construction (Fig. 11). These issues allowed further exploiting the potential of reinforced concrete. The evolution of the Liceu schools typology was marked by distinct phases, which resulted in a wide range of constructive solutions that went through important transition periods and experimentation of new building materials. The introduction of these innovative materials and new constructive and design solutions, without a thorough empirical knowledge of their characteristics and degradation mechanisms, is important to un-
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derstand the current degradation condition of these Liceu buildings. The evolution of Liceu school buildings in the XX century, the natural aging of materials and construction elements, as well as the lack of maintenance and rehabilitation actions, resulted in a general state of severe building degradation. The intensive use over the years increased the degradation process since these buildings have not been used according to the expectations of the original design (Riveiro et al., 2011). Most of these school buildings are an important element of Portuguese architectural heritage, linked to their unique characteristics or to their cultural and social symbolic value. In fact, some of these school buildings witnessed experiments with innovative solutions concerning space organization and construction materials that were not complemented by a controlled maintenance plan or the necessary functional adaptations for new learning and pedagogical policies. Therefore, these schools should be object of actions of cataloguing and database implementation such as the ones preconized by Azzalin (2005) and Meyer et al. (2007).
4. METHODOLOGY FOR CHARACTERIZATION OF ANOMALIES The patrimonial value of Liceu buildings combined with their degradation condition and the lack of space in urban areas for the construction of new school buildings, as well as budgetary constraints, led to the implementation by Parque Escolar EPE of a large scale modernization program for the existing secondary schools. The main goal was to rehabilitate school buildings and adapt them to new educational requirements (Heitor, 2009). Given the necessary interventions for the schools rehabilitation, it became mandatory to assess their conservation condition in order to define the scope of the interventions needed in the buildings and to promote the enhancement of the entire school complex. Detailed inspections were carried out to characterize the buildings and identify their main defects, both structural and related to the presence of moisture and water. Even
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though these inspections were based on visual observation, which is naturally prone to some degree of subjectivity, the findings were cross-checked within the inspection team (6 members) that collectively has several decades of experience in this type of surveys. Subsequently, a methodology was developed for the characterization of the anomalies identified in the expert reports, allowing studying the degradation processes that led to the pathological phenomena observed in the school buildings, considering the multiple factors that may affect the degradation process of the construction elements (CIB, 1993). The aim of this methodology was to study the most frequent degradation phenomena from the identification and characterization of the school buildings, its surrounding urban environment and the characterization of the anomalies identified in the reports, considering their location within the building and the construction elements, the type of pathological phenomenon, their causes and most frequent recommendations. This statistical analysis involves a huge amount of information since each of the schools analysed, very large by any standards, includes several building blocks and provides tens of thousands of data items that were treated consistently and individually. In order to organize the information gathered in the expert reports and allow its statistical analysis, a specific database was designed, comprising information on the school buildings and the various criteria used for the anomalies characterization. The database was created with three main sections: (i) information on constructive characterization, (ii) building location, and (iii) anomalies characterization. The first two sections of the database concern the identification and characterization of the school building, describing the school building in terms of constructive and functional characteristics (Fig. 12) and also its territorial context (district, city, street and building surroundings). The third section concerns the characterization of the degradation state of the school
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building. All anomalies identified in the inspection reports are characterized in terms of the following specific parameters: (i) anomaly identification/characterization; (ii) location in the school/building (Fig. 13), in terms of functional spaces and sun orientation; (iii) most probable causes; and (iv) main rehabilitation recommendations. In order to support the consistent identification of the type of anomalies and their matching description, a comprehensive list of anomalies was prepared (Fig. 13) with small descriptions and illustrations. For a pathological phenomenon to develop at least one degradation agent must be activated, often referred to as the most probable cause of the anomaly observed. It is frequent to have several causes/origins of the same defect, either combined or sequential (Josephson, 1999). In the database developed there are six groups that gather an extensive list of probable causes, according to their origin: C1 Structural cause; C2 Environmental cause; C3 Temporal cause; C4 design or execution error; C5 Human or animal cause; C6 Accidental cause. Each of these groups comprises individual causes (a total of 45 were considered). As an example, group C3 Temporal causes includes the following individual causes: (i) natural ageing; (ii) carbonation; and (iii) loss of resistance against penetration of external aggressive agents. Furthermore, anomalies may change over time without any modification of the causes behind them. This change may lead to new anomalies that add or overlap existing ones. With this respect, one can consider that there is a chain of preceding and subsequent anomalies, which should also be identified when filling in the database. The degradation condition of the construction elements was also evaluated through the development of a system that allows assigning a severity level to each defect: 1 (the less severe), 2 or 3 (the most severe). The definition of this global severity level for a given defect took into account three parameters: (i) the type of Element Subject to Maintenance (ESM) affected; (ii) the type of defect; and (iii) an immediate perception of the severity of
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the defect, based on visual observation. The ESM weighting took into account that various building elements have different significance for the school buildings performance. Defects in structural elements and roof claddings have a greater relevance compared to defects limited to internal cladding elements, since the degradation processes of the former have more serious consequences to the durability and safety conditions of the building. The various types of anomalies also have different relevance for the overall condition of the building. Anomalies that can rapidly compromise the durability and the structural performance of construction elements are more relevant to the degradation state of the building. To define the severity levels of each type of defect, the methodology developed proposes a comparative visual evaluation, as depicted in Fig. 14. This analysis is based on the use of images of the same type of anomaly from which a comparison is made and also on the definition of appropriate numerical criteria, when appropriate. The three above mentioned parameters allow characterizing the level of degradation of the elements, while reducing the level of subjectivity of the classification of severity levels and, consequently, the evaluation of the buildings condition (Gaspar and de Brito, 2005). In terms of rehabilitation recommendations, the database is organized according to the following eight groups: R1 Cleaning; R2 Superficial treatment or finishing; R3 Replacement; R4 Fastening or strengthening; R5 Application or execution; R6 Removal; R7 Reconstitution; R8 Maintenance. Each of these groups comprises individual potential interventions (a total of 96 were considered).
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5. RESULTS AND DISCUSSION 5.1. School buildings characterization The historic overview allows concluding that a large part of the Portuguese Liceu school buildings was built in the middle of the XX century (Fig. 15), mainly in the 1940’s and 1950’s. Therefore, the average age of these school buildings is about 60 years. In terms of vertical structural elements, most buildings (62%, corresponding to the most recent) are made exclusively of reinforced concrete, 17% are made of irregular masonry (the oldest), whereas 21% combine vertical elements made of those two structural materials. In what concerns floors, in the vast majority of school buildings they are made of reinforced concrete. Only in a very limited number of case studies there are floors and/or stairs made of timber, but always coexisting with other floors made of reinforced concrete. Throughout the twentieth century these school buildings underwent some remodelling actions that frequently consisted of replacing the timber structural elements with reinforced concrete ones. The vast majority of Liceu buildings with reinforced concrete structure (71%) do not have expansion joints - these construction elements, important to avoid thermo-hygrothermal cracking, were first used in the most recent schools, built in the decades of 1950’s and 1960’s. The roofs of main buildings are pitched, covered with ceramic tiles and the supporting structure is made of timber (47%), steel (29%) or reinforced concrete (24%) - these results stem from the relatively old age of these buildings. In several buildings, timber structures were replaced by steel or reinforced concrete ones. 5.2. Defects Given their age, the Liceu school buildings have difficulty in complying with modern performance requirements. In fact, natural aging due to exposure to weather conditions combined with intensive use and lack of maintenance actions led to a significant decrease of the buildings conditions.
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As mentioned, the school buildings survey campaign was carried out in order to detect anomalies related to structural problems and to the degradation of the materials due to the presence of water and moisture. The results obtained by the statistical analyses point to a recurrent occurrence of this type of anomalies, as illustrated in Fig. 16. The statistical analysis depicted in Fig. 16 shows that the most frequent anomalies are A3 (discoloration and/or stains), A5 (cracking) and A21 (water infiltration), illustrated in Fig. 17. The discoloration and/or stains and water infiltrations are the most typical defects identified in cases with moisture problems, since they are natural symptoms of this kind of anomalies. In terms of cracking, Fig. 16 shows that this anomaly frequently affects, in some cases simultaneously, different layers of the construction elements: the substrate, the coating and the finishing layer. The column identified as A5 is the union (and not the sum) of the occurrence of oriented/linear cracks in these three layers, while the columns identified as A5a and A5b stand for oriented/linear cracking of the coating and of the finishing layer, respectively. One can see that in most cases, these last two types of cracking occur simultaneously, i.e. cracking of the coating causes the cracking of the finishing layer. These results are consistent with other surveys specifically addressing the pathology of various coating materials (Flores-Colen et al., 2008; Silvestre and de Brito, 2011; Gaião et al., 2012; Neto and de Brito, 2012; Palha et al., 2012; Garcez et al., 2012; Amaro et al., 2013; Sá et al., 2013). Anomaly A8 (spalling, peeling or flacking) was also very frequently observed. In finishing materials it stems from the above mentioned defects, while in structural materials, namely in reinforced concrete, it is generally due to reinforcement corrosion. Results presented in Fig. 16 show also that there are more defects in the interior of the school buildings in comparison with the envelope. This is due to the higher number of interior construction elements, the more intensive use of these spaces and the evident
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decay of the indoor living conditions. In interior spaces, the most common anomalies are stains (A3), cracks (A5) and water infiltrations (A21), resulting from lack or loss of waterproofing capacity of the building envelope and deficient sealing elements, compromising the performance and durability of interior elements. In the building envelope, there is also higher incidence of other types of defects, such as corrosion (A12), biological colonisation (A23), vegetation growth (A24) and debris accumulation (A28), and this is due to the higher exposure to environmental agents, incorrect constructive detailing (e.g., eave protection) and insufficient maintenance. 5.3. Most affected construction elements Fig. 18 provides data on the construction elements most affected by defects. The ESMs most frequently affected are ESM 10 (wall coatings, 24%), ESM 03 (concrete elements, 16%) and ESM 06 (masonry walls, 12%). This is partly due to the higher frequency of these elements in the buildings inspected and also to their higher exposure to degradation. Fig. 19 shows the distribution of anomalies identified in these ESMs: concrete elements, walls and wall coatings. The most frequent anomalies in concrete elements are oriented cracking (A5), spalling (A8), corrosion (A12) and water infiltration (A21). These defects are more often observed in columns, slabs and exterior platbands and eaves. The most frequent causes of these defects, discussed in section 5.4, are related with insufficient cover, deficient drainage/waterproofing (spalling, corrosion and water infiltration) and, in a reduced number of cases, lack/malfunctioning of expansion joints (cracking). In masonry walls, the most frequent anomalies are by far cracking (A5) and water infiltration (A21), followed by discoloration and/or stains (A3). In wall coatings, the most frequent anomalies are basically related with the presence of water - discoloration and/or stains (A3), peeling or flaking (A8), water infiltration (A21) and blistering (A31) - and their consequences on the mechanical performance of the coating material - oriented cracking (A5).
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5.4. Probable causes The identification of the most probable causes presented in Fig. 20 provides information on the origin of the pathological processes, allowing acting on the resolution of anomalies and preventing future occurrences. The overall statistical results about the most probable causes point out a higher frequency of causes related to the environmental factors (C2, 24%) and to the execution and/or design errors of the construction elements (C4, 29%). Environmental actions are related with lack of regular maintenance and with the buildings’ exposure to environmental degradation agents over the years (Gaspar and de Brito, 2008a). Consequently, this exposure makes 60-year old (on average) buildings more vulnerable to outdoor defects, some of which have consequences on indoor elements. However, none of these schools was exposed to obviously uncommonly aggressive outer environments. The other most frequent causes of the defects are related to design and/or execution errors as acknowledged in previous studies (Chamosa and Ortiz, 1984; Silvestre and de Brito, 2010; Garcez et al., 2013). For instance, reinforced concrete was used in these school buildings when this material was being introduced in construction and there was insufficient knowledge and practical experience about its use, including the parameters that affect its durability, most particularly the rebars cover. The age of these buildings together with intensive use and lack of regular conservation actions resulted in defects that negatively affected the durability and performance of the schools. Furthermore, some elements are located in areas where conservation and maintenance actions are more difficult and expensive to perform. A very striking finding was that none of the pitched roofs was easily accessible and some were impossible to inspect without external mechanical means, therefore precluding any maintenance actions of the roofs drainage system and claddings. These potential problems were not taken into account at the
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design and execution stages, which explains the frequency of such anomalies in these buildings. Other relevant design and/or execution problems, mostly in terms of waterrelated anomalies, include deficient tail-ends, inadequate drainage design (e.g. the vast majority of building pitched roofs did not include gutters, causing water draining on the surface of the walls and/or splashing the wall socles), deficient ventilation and lack of watertightness, especially in the pitched roofs, but also in traditional single-glass wooden window frames. Nonetheless, the level of execution of the traditional construction methods used in these Liceu schools was far better compared to more modern schools inspected in the same program (Barrelas et al. 2013). As a consequence of these mostly outdoor- and envelope-related problems, the main probable causes of anomalies in interior spaces are also related to the environmental degradation agents, due to lack of drainage and waterproofing capacity, as well as design and/or execution errors. However, in interior spaces, a higher frequency of causes related to humans or animals’ action is found when compared to other locations, and again this is related to intensive use and lack of maintenance. In fact, the main problems detected in interior areas are mostly a direct consequence of the defects presented in the coating elements, which highlights the essential role of these elements to ensure the durability and the performance of the whole building. 5.5. Overall degradation condition and rehabilitation needs As mentioned, the methodology proposed includes a rating procedure of the anomalies identified. The visual comparison of the anomalies and the weighting system, considering the type of ESM affected, the type of defect identified and the assignment of a level of severity to each occurrence, are important tools to analyse the degradation, to evaluate the general state of conservation and to estimate the service life of construction elements (Gaspar and de Brito, 2008b; Bordalo et al., 2011; Silva et al., 2011).
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The statistical results obtained in this part of the study show that the distribution of the severity levels of the anomalies observed is as follows: 23% in level 1, 45% in level 2 and 32% in level 3. A significant number of occurrences correspond to the maximum severity level, indicating an advanced state of deterioration of the construction elements and, consequently, of the buildings inspected. These occurrences were mostly felt in the pitched roofs’ timber trussed structure and claddings, as well as in some original timber floor or staircase structures and claddings affected by water leakage and biological attack (Fig. 21). These results show that the degradation condition of Liceu school buildings was a matter of concern. Identifying and characterizing the anomalies and their probable causes also allows gathering statistical information concerning the most frequently recommendations prescribed, as illustrated in Fig. 22. It must be stressed that at this stage there were no studies (even preliminary) on what the rehabilitation design of each school would be. Therefore, the measures proposed at this stage were merely indicative of the aspects that should be taken into account to reinstate the original functional requirements, avoiding design, execution and maintenance mistakes that were recurrently identified. These measures must be regarded as the solutions deemed most adequate by the inspectors for each specific circumstance. As a consequence of the lack of maintenance actions and the overall state of degradation, the most frequent recommendations are elements reconstitution (R7, 21%) and cleaning (R1, 20%), followed closely by removal (R6, 18%) and superficial treatment or finishing (R2, 15%), similarly to other studies (Silvestre and de Brito, 2010). These types of actions (except for elements reconstitution and removal) could be included in a periodic maintenance plan, which would prevent or delay buildings degradation (Flores-Colen and de Brito 2010). The high frequency of the “elements reconstitution” and “removal” recommendations has to with the factors already mentioned, namely the age of the schools. The “cleaning” and “superficial treatment or finishing” recommendations, naturally associated
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with minor severity anomalies, are mostly linked to the lack of maintenance of the buildings coatings, located both indoor and on the envelope. Fig. 23 shows the distribution of rehabilitation needs of the three ESMs with the highest number of defects: reinforced concrete, masonry and wall coatings. In reinforced concrete, the most frequent recommendations - superficial treatment or finishing (R2, 22%) and reconstitution (R7, 20%) - are most often concerned with the repair of members with reinforcement corrosion and concrete spalling. Reinforced concrete elements tended to have extreme levels of severity, i.e. those that were indoor or in other ways well protected (e.g. painted) had no severe degradation, thus requiring only superficial treatment or finishing; conversely, badly executed or designed elements directly exposed to aggressive environmental actions had severe damage, sometimes with major structural implications, thus requiring reconstitution measures. In masonry elements and wall coatings, cleaning (R1, 21-24%), removal (R6, 22-23%) and reconstitution (R7, 25-28%) are the interventions most often prescribed. They aim at solving the most frequent anomalies observed in these elements: stains, oriented cracking and water infiltration in masonry; and discoloration/stains, peeling/flaking, water infiltration, flaking and oriented cracking in wall coatings.
6. CONCLUDING REMARKS The high historical and patrimonial value of the Liceu schools, comprising a great variety of functional and constructive solutions, and their degradation condition justified the need to implement a large scale inspection and rehabilitation programme of school buildings in Portugal. The maintenance, preservation and rehabilitation actions to be implemented must safeguard the quality and durability of school spaces. These actions are a fundamental part of the process of heritage conservation and must be organised with systematic research, inspection, control, monitoring and testing (Charter of Krakow, 2000).
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The proposed methodology proved to be an effective tool for the statistical characterization of the overall state of degradation of school buildings. The anomalies identified in Portuguese Liceu schools show important functional problems and a poor state of conservation of the buildings, due to the deficient drainage and waterproofing conditions and lack of maintenance, all affecting the durability of the construction elements. The buildings of this period were not designed planning the maintenance and repair actions of their components, which promoted the action of the main degradation agents and accelerated the end of their service life. Apart from the lack of planning of maintenance actions, these buildings suffer from some design and/or execution errors, associated with inadequate performance of elements detailing that can be associated with the deficient application and lack of knowledge and experience with the use of materials which at that time were innovative, such as reinforced concrete. The structural problems in reinforced concrete members are linked to their design and execution stages, since designers and contractors were still relatively unfamiliar with this new building material, as well as with the pathological phenomena leading to its degradation. In the future, adequate maintenance plans, such as those prescribed by Flores-Colen and de Brito (2010), must be developed for these school buildings, regarding the degradation agents to which they are more frequently exposed. This continuous action plan would allow extending the already long service life of these buildings. The conclusions from this study, unique in the literature in terms of the scale and type of school buildings, can however be extrapolated to other countries, mostly Mediterranean, where for the most part of the XX century, buildings in general were designed and constructed following the same architectural and constructive principles, and were subjected to the same lack of maintenance measures. Therefore, most lessons learned from this study apply to a much larger set of constructions.
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7. ACKNOWLEDGMENTS The authors acknowledge the support of ICIST (Instituto de Engenharia de Estruturas, Território e Construção), IST (Instituto Superior Técnico) and FCT (Fundação para a Ciência e Tecnologia).
8. REFERENCES http://www.lyc-lakanal-sceaux.ac-versailles.fr - Website of the Academic Centre of Lakanal in Paris, France. http://www.igespar.pt - Website of Portuguese Institute for the Management of Architectural and Archaeological Heritage. http://www.culture.gouv.fr - Website of the French Ministry of Culture and Communication. Alegre, A. (2009). School Architecture. The Liceu building in Portugal (1882-1978). PhD Dissertation in Architecture, Instituto Superior Técnico, Technical Institute of Lisbon. Lisbon, Portugal (in Portuguese). Alegre, A., Heitor, T., Cotrim, H., Vaz, D., Silva, J. C., Silva, J. F. (2010). Liceus, technical and secondary schools. Lisbon, Portugal: Parque Escolar / Argumentum (in Portuguese). Amaro, B., Saraiva, D., de Brito, J., Flores-Colen, I. (2013). Statistical survey of the pathology, diagnosis and rehabilitation of ETICS in walls, Journal of Civil Engineering and Management, accepted for publication. Azzalin, M. (2005). Building pathology database and maintenance approach in a welldefined context: Calabrian historical centres, 10th DBMC International Conference on Durability of Building Materials and Components. Lyon, France, pp. 988-994. Barrelas, J., de Brito, J., Correia, J.R. (2013). Analysis of the degradation condition of secondary schools. Case study: pavilions and prefabricated buildings, Journal of Civil Engineering and Management, accepted for publication. Bordalo, R., de Brito, J., Gaspar, P., Silva, A. (2011). Service life prediction modelling of adhesive ceramic tiling systems, Building Research and Information, 39(1): 66-78. Branco, F., Brito, J. de, Ferreira, J., Correia, J., Roriz, L., Paulo, P., Flores-Colen, I. (2007/2010). Reports on the construction defects of secondary schools. ICIST Reports
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(15 individual reports). Lisbon, Portugal: ICIST (in Portuguese). Chamosa, J. V., and J. R. Ortiz. (1984). Building pathology in Spain: Statistical approach, Informes de la Construcción. Madrid, Spain (in Spanish). Charter of Krakow. (2000). Principles for conservation and restoration of building heritage. Krakow, Poland. Chew, M.Y.L. (2005). Defect analysis in wet areas of buildings, Construction and Building Materials, 19(3): pp. 156-173. CIB. (1993). Building Pathology. A State-of-the-art report. In CIB Report Publication 155. International Council for Research and Innovation in Building and Construction (CIB), Rotterdam, Holland: CIB. Flores-Colen, I., de Brito, J., Freitas, V. (2008). Stains in facades rendering - Diagnosis and maintenance techniques’ classification, Construction and Building Materials, 22(3): pp. 211-221. Flores-Colen, I., de Brito, J. (2010). A systematic approach to maintenance budgeting of building façades based on predictive and preventive strategies, Construction and Building Materials, 24(9): 1718-1729. Gago, A.S., Proença, J.M., M. Villar (2012). Seismic strengthening of masonry buildings with reinforced concrete floor slabs: the schools D. João de Castro and Sá da Bandeira – Portugal, Proceedings of the 15th World Conference on Earthquake Engineering (15WCEE), Lisbon. Gaião, C., de Brito, J., Silvestre, J. (2012). Technical note: Gypsum plasterboard walls: inspection, pathological characterization and statistical survey using an expert system, Materiales de Construcción, 62(306): 285-297. Garcez, N., Lopes, N., de Brito, J., Sá, G. (2012). Pathology, diagnosis and repair of pitched roofs with ceramic tiles: Statistical characterisation and lessons learned from inspections, Construction and Building Materials, 36: 807-819. Garcez, N., Lopes, N., de Brito, J., Sá, G., Silvestre, J. (2013). The influence of design on the service life of the cladding of pitched roofs, Journal of Performance of Constructed Facilities, accepted for publication. Gaspar, P., de Brito, J.. (2005). Mapping defect sensitivity in external mortar renders.
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Construction and Building Materials, 19(8): 571-578. Gaspar, P., de Brito, J. (2008a). Quantifying environmental effects on cement-rendered façades, Building and Environment, 43(11): 1818-1828. Gaspar, P., de Brito, J. (2008b). Service life estimation of cement-rendered facades, Building Research and Information, 36(1): 44-55. Heitor, T. V. (2009). Modernisation of secondary schools. In Escolas Secundárias ‐ Reabilitação. Lisbon, Portugal: Caleidoscópio.
Josephson, P.-E., Hammarlund, Y. (1999). The causes and costs of defects in construction: A study of seven building projects. Automation in Construction, 8(6): 681-687. Marteinsson, J. (1999). Overall survey of buildings – performance and maintenance. 8h DBMC International Conference on Durability of Building Materials and Components. Vancouver, Canada, pp. 425-436. Meyer, E., Grussenmeyer, P., Perrin, J. P., Durand, A., and Drap, P. (2007). A web information system for the management and dissemination of cultural heritage data. Journal of Cultural Heritage, 8(9): 396-411. Moniz, G. C. (2007). Architecture and education: the modern Liceu project 1836-1936. Coimbra, Portugal: Editorial of the Department of Architecture FCTUC (in Portuguese). Neto, N., de Brito, J. (2012). Validation of an inspection and diagnosis system for anomalies in natural stone cladding (NSC), Construction and Building Materials, 30(1): 224-236. Palha, F., Pereira, A., de Brito, J., Silvestre, J. (2012). Effect of water on the degradation of gypsum plaster coatings: Inspection, diagnosis and repair, Journal of Performance of Constructed Facilities, 26(4): 424-432. Proença, J.M., Gago, A.S., Heitor, T. (2012). Overview of Seismic Strengthening Interventions buildings in Portugal, Proceedings of the 15th World Conference on Earthquake Engineering (15WCEE), Lisbon. Riveiro, B., Arias, P., Armesto, J., and Ordoñez, C. (2011). A methodology for the inventory of historical infrastructures: Documentation, current state, and influencing factors, International Journal of Architectural Heritage, 5(6): 629-646. Sá, G., Sá, J., de Brito, J., Amaro, B. (2013). Statistical survey on inspection, diagnosis and repair of wall renderings, Journal of Civil Engineering and Management, accepted
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for publication. Silva, A., de Brito, J., Gaspar, P. (2011). Service life prediction model applied to natural stone wall claddings (directly adhered to the substrate), Construction and Building Materials, 25(9): 3674-3684. Silvestre, J., de Brito, J. (2010). Inspection and repair of ceramic tiling within a building management system, Journal of Materials in Civil Engineering, 22(1): 39-48. Silvestre, J., de Brito, J. (2011). Ceramic tiling in building facades: Inspection and pathological characterization using an expert system, Construction and Building Materials, 25(4): 1560-1571.
25
FIGURES
Fig. 1 - Aerial view of Colégio das Artes, in Coimbra.
Fig. 2 - Aerial view of Pedro Nunes Secondary School, in Lisbon.
a)
b)
Fig. 3 - Lycée Lakanal in Paris: a) view of a façade; b) aerial view (http://www.lyclakanal-sceaux.ac-versailles.fr).
b)
a)
Fig. 4 - Diogo de Gouveia Secondary School, in Beja: a) view of a façade; b) isoparametric perspective (http://www.igespar.pt).
26
Fig. 5 - Exterior views of Groupe Scolaire Karl Marx, in Paris (adapted from http://www.culture.gouv.fr).
Fig. 6 - Main entrance for Gil Vicente Secondary School, in Lisbon (Branco, 2007/2010).
a)
Fig. 7 - Main entrance of João de Deus Secondary School, in Faro (Branco, 2007/2010).
b)
Fig. 8 - Rainha D. Leonor Secondary School, in Lisbon: a) main entrance; b) general view.
27
Fig. 9 - Plans of Filipa de Lencastre Secondary School, in Lisbon (Branco, 2007/2010).
a)
b)
Fig. 10 - Sá da Bandeira Secondary School, in Santarém: a) main entrance; b) isoparametric perspective.
28
Fig. 11 - Plan (top) and section (bottom) of Rainha D. Leonor Secondary School, in Lisbon.
Fig. 12 - Parameters and input fields of the database, included in the constructive characterization sections.
29
Fig. 13 - Parameters and input fields of the database, including the lists of the elements subject to maintenance (ESM) and the list of the anomalies, included in the anomalies characterization section.
30
b)
a)
c)
Fig. 14 - Comparative visual evaluation for the A3 defect (discolorations or stains) in wall and ceiling coatings: a) level 1 (Diogo de Gouveia Secondary School, in Beja); b) level 2 (João de Deus Secondary School, in Faro); and c) level 3 (Sebastião e Silva Secondary School, Oeiras).
5 4
2
2 1
1 0 1910
1920
1930
1940
1950
1960
1970
Fig. 15 - Schools by decade of construction.
1
200 180 160 140 120 100 80 60 40 20 0
A1
A2
A3
ENVELOPE
1
26
40
A4 A4.b A5 A5.a A5.b A7 5
5
72
53
60
26
70
1
3
54
8
11
0
3
52
4
36
28
20
2
17
2
11
7
INTERIOR
4
22
135
5
3
121 103
98
21
86
5
25
11
6
13
8
17
24
0
148
23
0
3
2
21
5
60
EXTERIOR
0
0
5
1
0
0
11
4
0
2
6
4
3
1
0
1
0
1
1
11
0
0
5
1
0
4
0
A8
A9 A10 A12 A14 A16 A17 A18 A19 A20 A21 A23 A24 A25 A28 A29 A30 A31
A1 Differential dirt| A2 Uniform dirt | A3 Discoloration and/or stains | A4 Mapped cracking | A4b Mapped cracking in the finishing layer | A5 Oriented/linear cracking | A5a Oriented/linear cracking in coating | A5b Oriented/linear cracking in the finishing layer | A7 Fracture/broken element(s) | A8 Spalling, peeling or flacking | A9 Alveolization or pits | A10 Deep cavities | A12 Corrosion | A14 Loose element(s) | A16 Lack of element(s) | A17 Localized wear | A18 Uniform wear | A19 Deficient functioning | A20 No functioning| A21 Water infiltration | A23 Biological colonisation | A24 Vegetation growth | A25 Animal waste | A28 Debris accumulation | A29 Differential settlements| A30 Graffiti | A31 Blistering
Fig. 16 - Absolute frequency of the anomalies identified in the survey, according to their specific location.
a)
b)
c)
Fig. 17 - Examples of the most frequent anomalies: a) stains; b) cracking; and c) water infiltrations.
2
450 23.6%
400 350 300 15.7%
250 11.5%
200
11.1% 8.8%
150
5.8%
5.2%
100
4.1%
3.8%
50
2.0% 1.9%
1.8% 1.9% 0.8%
0.4%
0.0%
0.4% 0.2% 0.3% 0.0%
0.0%
0.8%
0 01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
Fig. 18 - Absolute frequency of the anomalies identified in the survey by ESM (relative frequency above the columns; cf. Fig. 13 for ESM list).
160 ESM 03 ESM 06 ESM 10
140 120 100 80 60 40 20 0
A1 A2 A3 A4 A4b A5 A5a A5b A7 A8 A9 A10 A12 A14 A16 A17 A18 A19 A20 A21 A23 A24 A25 A28 A29 A30 A31
Fig. 19 - Absolute frequency of the different types of anomalies identified in concrete elements (ESM 03), masonry walls (ESM 06) and wall coatings (ESM 10) (cf. Fig. 13 for anomalies list code).
3
500 451
450
EXTERIOR
420
INTERIOR
400 350
ENVELOPE
324
C0 - Unknown causes
300
266
C1 - Structural causes
234
250
196
200
C2 - Environmental causes
183
173
160
C3 - Temporal causes
128
150
C4 - Design or execution errors
97
100
C5 - Human or animal causes
50
50
5
9
0
21
10
23
5
20
4
C6 - Accidental causes
0 C0 (1%)
C1
C2
C3
C4
C5
C6
(16%)
(24%)
(12%)
(29%)
(14%)
(4%)
Fig. 20 - Absolute frequency of the most probable causes identified in the survey, according to their specific location (overall relative frequencies of each group of causes in brackets).
Fig. 21 - Illustration of the pathological process stemming from the lack of waterproofing of pitched roofs: a) broken ceramic tiles and vegetation in gutter, b) timber elements of the roof structure with rot fungi attack; and c) ceiling coating complete detachment.
4
1200 20.5% 19.7% 18.3%
1000
R1 - Cleaning 15.1%
800
R2 - Superficial treatment or finishing R3 - Replacement 10.9%
600
R4 - Fastening or strengthening
8.9%
R5 - Application or execution
400 R6 - Removal 4.3%
R7 - Reconstitution
200
2.3%
R8 - Maintenance
0 R1
R2
R3
R4
R5
R6
R7
R8
Fig. 22 - Absolute frequency of the general recommendations of the anomalies identified in the survey (relative frequency above the columns).
350 322 305 295
300
ESM 03 ESM 06 ESM10
250 196
200
180
173
166
168 155
150 118
122
116
100
76 60
57
55 42
50
36 25
16 5
12 15
7
0 R1
R2
R3
R4
R5
R6
R7
R8
Fig. 23 - Absolute frequency of the general recommendations for concrete elements (ESM 03), masonry walls (ESM 06) and wall coatings (ESM 10).
5
