Constructive characterization and degradation condition of ... · become more and more unessential and opened way to industrial production, as the Deutscher Werkbund flourished. The

Constructive characterization and degradation condition of secondary schools

Case study: Industrial Schools

Clara Isabel Fernandes Pereira

Extended abstract

Jury

President: Professor Doutor Pedro Manuel Gameiro Henriques

Supervisor: Professor Doutor Jorge Manuel Caliço Lopes de Brito

Co-supervisor: Professor Doutor João Pedro Ramôa Ribeiro Correia

Members: Professor Doutor João Paulo Janeiro Gomes Ferreira

Professor Doutor Pedro Miguel Dias Vaz Paulo

November 2012

1

1 Introduction

In 2007, the Portuguese Government created a modernization program for the public network of sec-

ondary schools, which, in some cases, had been built in the 19th century. Facing various building

maintenance problems, this program thus aimed to plan the constructive and functional rehabilitation

of the schools as well as to establish a facility management system for the future needs.

In this context, the Instituto de Estruturas, Território e Construção (ICIST) surveyed 56 secondary schools,

identifying the main building anomalies based on a visual and qualitative methodology. These surveys

paid special attention to any structural issue or humidity related anomalies. Its conclusions would then

be considered in the rehabilitation projects.

Out of the 56 schools surveyed, the following three main groups were outlined: 15 high schools, 17

pavilion like schools and 15 industrial schools. The data collected on a homogeneous sample of build-

ings, subject to the same kind of external actions, would allow identifying identical pathological pat-

terns, with similar causes, manifested in similar building anomalies. Therefore, this paper makes a con-

structive characterization of the industrial secondary schools and an analysis of their degradations pat-

terns based on the surveys’ results.

Studies on building anomalies play an important role in increasing effectiveness of building mainte-

nance strategies, contributing to promote a more sustainable construction industry. So, the organized

gathering of information may be a useful tool for a well-informed decision-making process.

The investigation aims to obtain an overview of the degradation status of school buildings by connect-

ing some deterioration factors and recognizing similar pathological processes. For this purpose, a data-

base of building anomalies was developed for the 56 surveyed schools. The collection of data on build-

ing elements, on the main school building types and on the identified building anomalies, should allow

performing a statistical analysis about the following items: age of the building, type of structure, type of

roofing, affected building elements, type of anomaly, location, causes, severity, quantification, anomaly

chains, environmental conditions and some recommended solutions.

The obtained database model was a result of team work, including concepts and a structure that could

suit investigations on high schools, pavilion like schools and industrial schools. It is composed of sev-

eral Microsoft Excel files, one for each school, with the information structured according to three main

issues: characterization, location and anomalies. Along with the database model, a user’s guide was

developed in order to establish some ground rules and to clarify concepts and designations.

In the next sections, a historical overview of the industrial schools is introduced, followed by a construc-

tive characterization, a summary of the database methodology and the presentation of the main results.

2 Historical overview

The network of public secondary schools is a testimony of Portugal’s most recent history, including

the history of the most advanced construction methods of each period since the late 19th century.


2

The first law promoting the creation of secondary schools was written by Passos Manuel in 1836. At first,

these schools occupied the empty convents and monasteries, being progressively installed in new buildings.

Technical education was also promoted, making an effort to develop the country’s industrial activity. In the

beginning, it was centred in Lisbon and Oporto, progressively expanding to other cities. The first industrial

school built was located in Lisbon and was called Marquês de Pombal Industrial Design School (1888).

The schools from the 19th century to the beginning of the 20th century were built in accordance with

some rules of good practice. The building system was based on stone masonry walls, solid brick masonry

and timber pavements, incorporating also composite walls made of masonry and timber. Occasionally,

the pavements in halls, ground pavements and wet compartments incorporated metal beams and ceramic

vaulted bricks filled with cement. Roofs were supported by wood or metal beams.

With the onset of the republican political system, great attention was paid to the expansion of the public

network of elementary schools. But still, the secondary education system continued to be revised and im-

proved. In 1938, high schools started complying with new building standards and a public institute was

created for the construction of new schools alone. In 1947, the same applied to industrial schools, as sec-

ondary education was clearly divided into high school education and industrial technical education, each

with a specific professional purpose. The use of typified projects for each kind of school played a main

role in the success of the defined measures. In industrial schools, the first prototype was built in Lisbon, in

1948, corresponding to the first period of typified projects’ use (two periods: 1952-1959 and 1960-1969).

The first Technical Elementary School project used an economic constructive solution that could be

adapted to different kinds of land. It established that a school with 1 000 students should be built on a

land of 10 000 m² (Heitor, 2010). The project included three buildings: one for classrooms and admin-

istration, a gym and one for workshops (Figure 1). Two others projects were based on this one. The

second project conceived the workshops as a one floor building with zenithal lighting coming from

shed roofing; they would vary in size according to the school curriculum. In 1952, a third project in-

corporated the need to downsize and reposition the school buildings; the classrooms decreased in area

and height and so did the workshops, and previous coatings were replaced with cheaper ones.

Until the late 1950’s, the buildings incorporated the first concrete building methods used in Portugal, as

defined by standards from 1918 and 1935. They still had load-bearing masonry walls combined with

pavements in reinforced concrete. The pitched roof was generally still supported by wood or metal

beams. Gradually, columns and frames started to be used. The workshops of industrial schools applied

earlier more advanced building methods of reinforced concrete, with prefabricated trusses supporting the

shed roofing. Only with the Portuguese concrete building standards from 1958 and 1961, were structures

built entirely in reinforced concrete. The new building standards coupled with the tripling of the number

of students from the 1950’s to the 1960’s determined the need for an expansion of the network of sec-

ondary schools. This expansion used new typified projects for high schools and for industrial schools.

The second period of use of typified projects in industrial schools began in 1960. This new project was

called the 1st Standardized Project or Mercury Project. It adopted a (1) module for the design of the dif-

ferent buildings; (2) it provided schemes for partial articulation between buildings, according to specific


3

needs (3) and constructive details for structural and other kinds of constructive elements; (4) between

each building, standardized connection elements were included, with an extension corresponding to the

ground’s size (Figure 2). The standardized building elements were expected to contribute to an optimized

technique and a more accurate planning, and to have economic benefits as well. In the late 1950’s the

Government expected to have an industrial school for each town with about 10 to 15 000 inhabitants.

Figure 1: Perspective of the project for the Commercial and Industrial School

of Setúbal, programmed in 1948 and built in 1956 (JCETS, 1951).

Figure 2: Plan of the first floor of the Commercial and Industrial

School of Montijo, using the 1st Standardized Project (Heitor, 2010).

The 2nd and 3rd Standardized Projects followed with different kinds of functional adaptations, always

promoting a standardized kind of construction. By this time, the Portuguese Government started col-

laborating with the Organization for Economic Co-operation and Development (OECD) on pilot

projects for pedagogically adequate school buildings. These studies would originate a new kind of sec-

ondary schools for the future, incorporating prefabrication processes in their projects.

The democratic regime (1974) had tremendous consequences on education. The new Constitution insti-

tuted the right to equal opportunities in school access and success, instructing the State to ensure a free,

compulsory education for the entire population, taking place on a public network of schools. Secondary

education was then unified, and the terms high school and industrial school were phased out. Meanwhile,

structural safety standards had come a long way, as in 1983 some new, more accurate rules were pub-

lished, namely in what concerns a more advanced seismic analysis. The new standards together with an

increased prefabrication method set the schools construction expansion for the late 20th century.

The expansion of the schools network was much more intense in other countries. Until the 1900’s there

was a constructive technical revolution. At first, the use of iron in buildings was disguised by historical

shapes, but it was progressively assumed, as could be seen in the Crystal Palace (Joseph Paxton, Lon-

don, 1851), which also constituted the first prefabrication example, or the Eiffel Tower (Paris, 1889).

This kind of buildings was born in the World Fairs’ context, where each country presented the most

recent advanced technology, simultaneously stimulating the promotion of technical education. Iron was

then combined with concrete, as Portland cement was developed, and reinforced concrete was invented.

Industrial schools began to thrive in Austria, France, England, Switzerland, the United States of Amer-

ica and in Scandinavian countries, as Germany was the main reference. In England, most of the first

industrial schools were associated with private interests and local factories (Wheelwright, 1901).

In the United States of America, the first technical schools did not teach a craft or a profession, but fo-


4

cused on craftsmanship (Wheelwright, 1901). A more refined school was built in Boston in 1893, the Bos-

ton Mechanic Arts High School (Figure 3). In these American schools, as well as in Germany, special at-

tention was given to construction work, also including forestry, agriculture, mining, commerce, navigation,

weaving, pottery and other kinds of industrial work like metallurgy, tin, iron and steel work and turnery.

The search for a new industrialized architecture continued. At first, the use of vegetable shapes and fluid

lines was Arts Nouveau’s answer. It concerned about craftsmanship mastery and had some embryonic

thoughts on the shape suitability to function according to the used material. Soon, the ornament started to

become more and more unessential and opened way to industrial production, as the Deutscher Werkbund

flourished. The AEG factory (Behrens, 1908-09) was a reference on its structural concept, followed by the

Fargus factory (Gropius and Meyer, 1911), anticipating the language of rational functionalism.

Meanwhile, in Eastern Europe, futurism and constructivism set new goals. They combined the most recent

constructive techniques with the new functions attributed to buildings. In the Netherlands, neoplasticism

abolished the natural shape. On top of all these ideas the Modern Movement was born, moving away from

picturesque and historicism trends, giving way to new aesthetics. This is the context in which the Bauhaus

was founded in 1919 at Weimar (Germany). It combined the local arts and crafts school with the fine arts

academy, conceiving an idea of education that intertwined design, drawing and industry. In 1926, this school

moved to Dessau, as it was not welcome at Weimar. The new school building (by Gropius) was divided into

three different blocks. The first block was called the technical school, where classrooms and laboratories

functioned. On the opposite side of this building, the workshops’ block rose and between both an auditori-

um and a canteen were located, with the upper floors occupied by an apartments tower (Figure 4). The

whole school reflected the principles that the Bauhaus advocated, showing how well they could work.

Figure 3: The machines workshop at the Boston Mechanic Arts High

School (Boston Public Library).

Figure 4: Plan of the ground floor of the Bauhaus at Dessau (1925-

1926) with the three main buildings (Weston, 2005).

Functional rationalism was very useful in a post-war scenario with great housing needs, whereas the repro-

duction of shapes, standardization and prefabrication worked in favour of a rapid reconstruction. In the

1960’s, prefabrication was seen by the construction industry as a winning bet; even though it depended on

qualified manpower, it promised to increase rigour of construction and a positive improvement to acoustic

and thermal issues, based on a careful detailing process. England employed prefabrication models in the

post war schools on a large scale, based on a faster and more economic construction method.

Finally, in the industrial era, the school was developed into a highly controlled space which served to


5

instil a sense of discipline, seen as an essential trait to prosper in the age of the machines. The classical

classroom, which has not changed that much, was a by-product of the industrial revolution. The

school model of buildings filled with corridors and teacher centred classrooms spread and is, to this

day, the prevalent and most widely used school reference.

3 Constructive characterization

This research uses a sample of 15 industrial schools, listed in Table 1. Information on their constructive

systems was gathered in a database. It included a general plan, the year of construction and areas. Each

building was also characterized and included in a functional typology of industrial school buildings, such

as I.TF1 Main building, I.TF3 Workshop building and I.TF4 Gym. The structural materials and the main

coatings were described, based on a list of materials collected from all kinds of secondary schools.

Table 1: Identification of the industrial schools.

Name City Year Observations

Tomás Cabreira Secondary School Faro 1950 industrial school adapted from a preexisting high school to the

functional program of industrial schools from 1947

Sebastião da Gama Secondary School Setúbal 1956 industrial school: typified project from the 1947 reform

Francisco de Arruda Secondary School Lisboa 1956 industrial school: typified project from the 1947 reform

S. Lourenço Secondary School Portalegre 1958 industrial school: typified project from the 1947 reform

Jácome Ratton Secondary School Tomar 1958 industrial school: typified project from the 1947 reform

Emídio Navarro Secondary School Almada 1958 industrial school: unique project similar to the typified project from

the 1947 reform

Dr. Solano de Abreu Secondary School Abrantes 1959 industrial school: unique project similar to the typified project from

the 1947 reform

D. Manuel I Secondary School Beja 1961 industrial school: typified project from the 1947 reform

D. Sancho II Secondary School Elvas 1961 industrial school: unique project from the expansion begun in 1958

Ferreira Dias Secondary School Sintra 1962 industrial school: 1st standardized project, from the expansion

begun in 1958

Moura Secondary School Moura 1963 industrial school: 1st standardized project, from the expansion

begun in 1958

Jorge Peixinho Secondary School Montijo 1963 industrial school: 1st standardized project, from the expansion

begun in 1958

Rainha Santa Isabel Secondary School Estremoz 1964 industrial school: 1st standardized project, from the expansion

begun in 1958

Pedro de Santarém Secondary School Lisboa 1968 industrial school: unique project from the expansion begun in 1958

Henriques Nogueira Secondary School Torres

Vedras 1969

industrial school: 1st standardized project, from the expansion

begun in 1958

The industrial schools were based on two main projects. The first one, from 1947, assumed the main

building as the most important one and gave it a noble entrance. Its plan was a rectangle, with the en-

trance on one of the extremes, on top or laterally, according to the ground needs. It had three floors

with central corridors and staircases on both tops, which were well lit so that the corridor was also

illuminated. It should not be too long. Corridors were kept as short as possible. South to the corridor

there were classrooms, and on the North side there were drawing rooms. The solution for the gym

building had already been tested in some high schools: the gym was on the upper floor while, on the


6

ground floor, the kitchen and the canteen were installed, as well as some accessory rooms. The work-

shops building had only one floor with large rooms for manual and workshop education.

As for the second project, known as the 1st Standardized Project, the target number of students ranged

from 800 to 1 200. The functional program was distributed by multiple blocks, not only the main

building, the gym and the workshops building, but also some smaller blocks like toilets, students asso-

ciation and isolated classrooms. The main building sheltered the classrooms and had a linear configura-

tion. It maintained the use of a central corridor, in the middle of which a third staircase was included,

connecting two subsidiary bodies of 44 m. One corridor was transformed into two that could also be

uneven by ½ or 1 pavement. The used module was conceived for classes with 36 students, and it had

7 x 8 m2. The structure could assume a solution of 1/3, with façade columns every 2.7 m, or a solution

of 1/2, with façade columns every 4 m. The second solution allowed opening windows in entrances

and some other special rooms. The structural system was composed of reinforced concrete frames,

lightweight slabs over classrooms and solid slabs over corridors. The different buildings were united by

an exterior walkways system, structurally autonomous, as they were separated by extension joints.

The results obtained regarding the constructive characterization revealed that 7 out of 15 schools were

built in the 1950’s, while 8 were built in the 1960’s. According to the British standard BS 7543:1992 (Dias,

2003), school buildings are planned for a life cycle of, at least, 60 years. In 2011, industrial schools were

reaching the end of their service life expectancy, if no rehabilitation work was done.

Excluding walkways, a total of 84 buildings were surveyed, of which 24% are workshop buildings, 19%

are minor buildings and 18% are main buildings, as well as gyms. Within the sample, 8 of the 84 buildings

were built from the ground up or adapted later, after the construction of the school.

Distinguishing schools exclusively built in reinforced concrete structures from the ones also using stone

masonry walls provides interesting results (Figure 5). There are 6 out of 15 main buildings, and 6 out of

15 gyms, using stone masonry walls, combined with concrete slabs and, occasionally, concrete columns.

In total, the structural use of stone masonry represents 21% of the buildings sample. It is also important

to analyze data on the roofing type used on school buildings. From the three types identified, 68% of

buildings had a pitched roof, 55% flat roofs and 21% had a shed roof. Pitched roofs are more common

in main buildings and gyms (Figure 6). Only workshops have shed roofs, although one of the schools

uses a similar system combining pitched and flat roofs instead. Flat roofs are much more common in

external walkways. Claddings vary from ceramic tiles, fibrocement plates and cement tiles. Ceramic tiles

are more common in main buildings and fibrocement plates in workshop buildings. There is a resem-

blance between main buildings and gym buildings. They are both unique buildings in each school, with

similar constructive systems and use of structural materials, roofing and claddings.

The sample represents industrial schools in use, without any kind of rehabilitation, except for some

occasional maintenance work done to solve local problems and the degradation of materials. Aside

from the structural materials, already mentioned, walls are built in ceramic masonry, plastered and

painted. Windows have frames in wood, anodized aluminium, steel and concrete to support simple

panes of glass. In some cases, these materials were replaced by double glazed lacquered aluminium.


7

0

5

10

15

20

25

30

Nu

mb

er of b

uil

din

gs

or

walk

ways

stone

masonry walls

reinforced

concrete columns

I.TF1 Main building, I.TF2 Buildings for collective use,

I.TF3 Workshops building, I.TF4 Gym, I.TF5 Auxiliary buildings, I.TF6 Minor buildings, I.TF7 Preexisting buildings,

I.TF8 External walkways

Figure 5: Structural materials used in vertical elements on buildings

and external walkways according to each kind of building.

0

5

10

15

20

25

Nu

mb

er o

f b

uil

din

gs

or

walk

ways

pitched

roof

shed

roof

flat

roof

I.TF1 Main building, I.TF2 Buildings for collective use,

I.TF3 Workshops building, I.TF4 Gym, I.TF5 Auxiliary buildings, I.TF6 Minor buildings, I.TF7 Preexisting buildings,

I.TF8 External walkways

Figure 6: Types of roofing used on buildings and walkways according to

each kind of building.

4 Methodology

Based on the surveys’ results, a building anomalies database was conceived, suitable for the established

groups of schools. Its content was organized according to a given list of constructive elements defined

by ICIST. In that list, constructive elements were grouped by material and function, such as 03 Concrete

elements or 10 Walls claddings. While filling in the database, there was a need to include some elements

that had been left out of the ICIST’s list, mainly distinguishing between different kinds of concrete

slabs and beams (for example: a roofing slab and a ground floor slab), or adding up some claddings

(like hydraulic tiles). The surveys’ reports also included an anomalies listing that was also very im-

portant to the database. However, it needed some adaptation, as pointed out in Table 2.

The process of elaborating the database model was a group work. The database required adaptation to the

three kinds of secondary schools and to incoming studies on building anomalies, and it had to be flexible,

readable and based on strict parameters for filling in every field of information. Each Microsoft Excel file

was divided into three spreadsheets (Characterization, Location and Anomalies), also including auxiliary spread-

sheets with information that was to be entered in the main spreadsheets. There was a specific list of mate-

rials to include in the Characterization spreadsheet (constructive characterization contents), a constructive

elements spreadsheet to identify the location of the anomaly, a list of anomalies (Table 2), a list of rooms

to specify the context of anomalies in the interior, a list of possible causes to describe the anomaly and a

list of recommendations to solve each anomaly. These lists were either in the reports or created based on

their contents and general knowledge on building pathology. They were an essential tool towards obtaining

a coherent and concise database. The Location spreadsheet aimed, essentially, at describing the context of

the school based on the urban density of the surroundings and environmental exposure.

The Anomalies spreadsheet was organized into different levels of information. The first one distin-

guished between anomalies found in the exterior surroundings of the school or in a school building.

The second level applied to building anomalies, and to whether the anomaly was in the outer envelope

or in the interior. Every constructive element in an external environment or that linked the exterior to


8

the interior, such as structural, primary and secondary elements and every external claddings and coat-

ings, were considered to be on the outer envelope. Every interior cladding and coating, ground level

slabs, interior structural, primary and secondary elements were considered to belong to the interior set

of constructive elements. This included claddings and coatings on the interior side of the outer envelope

elements and roofing structural elements (except concrete slabs). In the third level, constructive ele-

ments were identified by group and by specific designation. The fourth level included the record of each

anomaly: first the identification of the building and then the anomaly itself. The record included a pho-

tograph to illustrate each kind of anomaly and a number of items, as indicated in Table 3.

To describe one anomaly, more than one designation could be used. For instance, to describe an occur-

rence, a chart on staining in the plaster could be used simultaneously to another on paint blistering. In any

event, there were some criteria about the specific situation each designation should apply to. In Table 2,

some of the criteria about the constructive elements the anomaly should apply to are highlighted. The spe-

cific definition of the anomaly is easily understandable, and is described in detail in the main document. Still,

cracking anomalies (A4 and A5) had specific instructions. Due to the fact that the surveys were merely visu-

al, crack depth could not be verified. Not knowing whether the crack was limited to coating or cladding or if

it spread through the entire surface (including a structural element, for example) led to repetitions in the

anomaly chart. Therefore, if, for instance, a crack was identified in a painted, plastered column, it was identi-

fied as being present in the concrete column (as A5 Linear cracking), in the plaster [A5.a) Linear cracking] and

in the painting [A5.b) Linear cracking]. The same logic applied to A4 Mapped cracking.

Generally, identical anomalies, with the exact same characteristics (same designation, building, causes,

precedencies and consequences, severity and recommendations) were only registered once. If the oc-

currence implied more than one anomaly, it was described with more than one chart, with indications

of the chain of events in the adequate fields, provided the suggested recommendation solved the entire

occurrence, from preliminary work to adequate coating.

In terms of quantifying the affected area of the constructive element, there were only two simple options:

the anomaly could be localized or widespread. Either one was directly related with the anomaly severity, as it

was considered as another field of information. The anomaly’s severity depended on the following factors:

i) The immediate perception of severity, comparable between similar anomalies;

ii) Ranking the various anomalies according to the way they could compromise the occupiers’ safety

and building integrity, or jeopardize functional performance of the constructive element;

iii) Ranking of the various kinds of constructive elements according to their importance towards

building integrity and its occupiers’ safety.

The mentioned ranks were determined by indicating a factor (between 0 and 1) associated to each

anomaly and to each constructive element listed. The factors were 0.3, 0.7 and 1, from the least to the

most important. They were then multiplied by a preliminary severity level (1, 2 or 3, 1 being the least

severe and 3 the most severe) obtaining a final severity level. An example is given in Table 4.


9

Table 2: List of the identified building anomalies, based on ICIST’s anomalies list. Anomalies A5 and A7 were adapted and A6, A11, A13,

A15, A26, A27, A32-A34 were eliminated and, in some cases, included in the definition of other anomalies.

Code Anomaly Possible constructive elements

A1 Differential dirt Claddings

A2 Uniform dirt Claddings

A3 Discoloration or stain Claddings

A4 Mapped cracking Cladding; it is repeated on coatings as A4.b) (if applies)

A5 Linear cracking Structural and primary elements; it is repeated on claddings as A5.a) and on coatings

as A5.b) (if applies)

A7 Fracture / broken elements Primary and secondary elements and roofing claddings

A8 Spalling, peeling or flaking Structural and primary elements, claddings and coatings

A9 Alveolization or pits Claddings and coatings

A10 In depth lacuna All kinds of constructive elements

A12 Corrosion Structural and secondary elements

A14 Loose elements All kinds of constructive elements

A16 Missing elements All kinds of constructive elements

A17 Localized wear Claddings and coatings

A18 Uniform wear Claddings and coatings

A19 Faulty functioning All kinds of constructive elements

A20 No functioning All kinds of constructive elements

A21 Infiltrations Structural, primary and secondary elements and roofing claddings

A22 Concretion Concrete elements

A23 Biologic attack or colonization Claddings

A24 Parasitic vegetation Primary elements and claddings

A25 Bird droppings Claddings

A28 Debris Claddings

A29 Excessive deformation/settlement Structural, primary and secondary elements

A30 Graffiti Coatings or non coated claddings

A31 Blistering Coatings

A6 Medium cracking Eliminated and included in A5, because the anomaly designation had a notion of gravity.

A11 Deterioration Eliminated and included in more specific anomalies.

A13 Visible reinforcement Eliminated, because it was equivalent to have A12 and A8 together.

A15 Broken elements Eliminated and included in A7, as they were not easily distinguishable.

A26 Disturbing noise Eliminated, because the reports did not include this kind of survey

A27 Foul smell Eliminated, because the reports did not include this kind of survey

A32 Thermal discomfort Eliminated, because the reports did not include this kind of survey

A33 Acoustic discomfort Eliminated, because the reports did not include this kind of survey

A34 Inadequate lighting Eliminated, because the reports did not include this kind of survey

Finally, some limitations found during the study should be mentioned. Generally, the surveys implied a

task force of ICIST surveyors that, even though following identical criteria, could have produced slightly

different reports. For example, some reports gave more emphasis to the chains of anomalies than oth-

ers. This situation had to be mitigated by the analysis of the reports and the database construction. The

first reports tended to embrace more kinds of anomalies and constructive elements. Only on a subse-

quent phase was it understood that that the amount of information was impractical to gather for every

school. Occasionally, the cause of the anomaly was impossible to determine and there were many situa-

tions in which neither a solar orientation nor the room were in any way identified or possible to find.


10

Table 3: Anomaly chart with basic instructions for the insertion of data.

[building

identification]

[reference

to the

anomaly

code]

[reference to

the anomaly

name]

Image [anomaly photograph: 450 pixel wide, 150 dpi]

[image code in the report] – [caption]

Quantification localized / widespread

Buildings I.TF# [reference to the building typology – Characterization spreadsheet]

Possible causes C# [reference to the group of causes – Possible causes list]

C#a [reference to the cause – Possible causes list]

Precedent anomalies A# [reference to a preceding anomaly – Anomalies list]

Solar orientation North / South / East / West

Room E# [reference to the room – Rooms list]

Severity 1/2/3

Subsequent anomalies A# [reference to a subsequent anomaly – Anomalies list]

Recommendation R# [reference to the group of recommendations - Recommendations list]

R#a [reference to the recommendations – Recommendations list]

Observations [optional non specific considerations]

Table 4: Example of severity calculation on A8 anomaly.

Level 1 flaking (A8) of paint (Jorge

Peixinho Secondary School).

Level 2 peeling (A8) of joint (Dr.

Solano de Abreu Secondary School).

Level 3 peeling (A8) of ceiling plaster

(S. Lourenço Secondary School).

Anomaly factor (a) 1 1 1

Element factor (b) 0.3 1 0.7

Intermediate result (a x b) 0.3 1 0.7

Final factor (d) 0.7 1 1

Preliminary severity (c) 1 2 3

Result (d x c) 0.7 2 3

Final severity 1 3 3

5 Results and discussion

In total, 2822 anomalies were registered, from 119 buildings and walkways (24 anomalies average) be-

longing to 15 schools (188 anomalies average). Only 1.5% of these anomalies were found in the sur-

roundings of the school buildings, corresponding to about 33% anomalies in surface drains and gutters

and 40% on fibrocement boards in external walkways roofing.

The main results refer to anomalies found in school buildings. They were equally distributed between

the outer envelope (1434 anomalies in 64 different constructive elements) and the building interior

(1345 anomalies in 34 different constructive elements).

Nevertheless, degradation found in these environments has different profiles, highlighted in Table 5. Clad-

dings are affected in both environments, specifically the ones more relevant to each context, but concrete

elements are more affected when located outside, and paint is more affected on the inside (Figure 7). On

the outer envelope, wall plaster specifically had a great amount of anomalies and, in the interior, paint was

the most affected element. Linear cracking and discoloration or staining were common in both environ-


11

ments, but infiltrations were more prevalent on the outer envelope, while, in the interior, several situations

of peeling were found. As for the causes of anomalous occurrences (Figure 8), both environments reveal

these are very often related to design or execution issues.

Table 5: Main differences and common points between the outer envelope and the building interior.

OUTER ENVELOPE BUILDING INTERIOR

Most affected constructive elements

Concrete elements

Wall claddings

Roof claddings

Paintings

Wall claddings

Ceiling claddings

Most common anomalies

Linear cracking

Infiltrations

Discoloration or staining

Linear cracking

Discoloration or staining

Spalling, peeling or flaking

Most common causes

Draining water

Thermal hygrometric effects

Faulty drainage

Thermal hygrometric effects

Lack of tightness to external agents

Expansion joints (faulty or nonexistent)

0%

5%

10%

15%

20%

25%

30%

35%

outer envelope interior

03 Concrete elements, 06 Masonry, 09 Expansion joints, 10 Wall

claddings, 11 Paving, 12 Ceiling claddings, 14 Pitched roofs claddings, 18 Blacksmith's, 20 Paintings and coatings, 22 Plumbing

Figure 7: Comparison between affected groups of constructive elements on

the outer envelope and in the interior.

0%

5%

10%

15%

20%

25%

C1b C1f C2a C2d C3c C4d C4e C4g C4i C4l C5b

outer envelope interior

C1b Expansion joints (faulty or nonexistent), C1f Differential

settlement, C2a Thermal hygrometric effects, C3c Lack of tightness to external agents, C4d Draining water, C4e Poor dimensioning,

C4g Faulty drainage, C4i Poor waterproofing, C4l Excessive stiffness in elements connection, C5b Lack of maintenance work

Figure 8: Comparison between main causes of anomalies on the outer

envelope and in the interior.

On the outer envelope, lack of maintenance stands out as a common origin of anomalies. Understandably,

managing a school implies establishing maintenance priorities, and interior areas are considered more im-

portant in that sense. But these decisions usually stem from a lack of information about building mainte-

nance needs. Furthermore, the surveyed school buildings did not have means of safe access to all building

exterior areas, particularly roofs. This leads to expensive and difficult, hence, rare cleaning operations.

Roofing maintenance (or the lack thereof) is the most flagrant and problematic situation, as about 41%

of registered anomalies occurred on roofing constructive elements and drainage systems. Despite the

importance of the design of these systems, their longevity depends on adequate maintenance. Probably

due to a short variety of claddings and coatings in building interiors, mainly applied on concrete and

masonry, interior anomalies are distributed between only 15 constructive elements, less than half of the

constructive elements affected on the outer envelope.

Seventeen different groups of constructive elements were affected, mostly paint, wall cladding, concrete

elements, ceilings and masonry. The predominance of anomalies in paint often points to more severe


12

anomalies in/on the underlying constructive elements. Wall claddings, and specifically exterior wall plasters

have a higher percentage of discoloration or stain anomalies, due to exposure to environmental agents,

also relevant as a cause for biological colonization. Roofing concrete slabs have a worrying amount of

infiltrations, of which about 83% are critical. On ceilings, if compared with wall claddings, there is a higher

proportion of staining rather than cracking. Rooftop ceilings are especially affected by infiltrations, which

cause stains, as well as condensation phenomena, as slabs insulation is almost nonexistent. The results on

masonry are related to the rigidity of masonry walls when compared to structural elements.

All of the main constructive elements had a large amount of linear cracking (Figure 9). On the one

hand, this fact may be attributed to the large variety of constructive elements that may crack; on the

other, cracking may be a symptom of severe structural problems. Therefore, surveyors may tend to be

more alert to this kind of anomaly. One way or another, the figures are a cause for concern.

Causes related to design and execution issues in all kinds of constructive elements. These data meet the

results obtained by the Bureau Securitas and by Chong and Low (2006). Particularly, the cause associated

with thermal hygrometric effects is highlighted in Figure 10. These are often the origin of cracking, even

more if its depth is unknown, which leads to this assumption. It refers to dimensional changes of differ-

ent constructive elements, specifically plaster mortars.

0%

10%

20%

30%

40%

50%

60%

70%

80%

A3 A5* A8 A12 A21 A23 A31

20 10 03 12 06

20 Paintings and coatings, 10 Wall claddings, 03 Concrete elements,

12 Ceiling claddings, 06 MasonryA3 Discoloration or stain, A5* Linear cracking [including a) and b)

options], A8 Spalling, peeling or flaking, A12 Corrosion, A21Infiltration, A23 Biologic attack or colonization, A31 Blistering

Figure 9: Comparison between the main anomalies found in the most

affected groups of constructive elements.

0%

5%

10%

15%

20%

25%

30%

35%

C1b C1f C2a C2d C3c C4a C4d C4g C4i C4l

20 10 03 12 06

20 Paintings and coatings, 10 Wall claddings, 03 Concrete elements,

12 Ceiling claddings, 06 MasonryyC1b Expansion joints (faulty or nonexistent), C1f Differential

settlement, C2a Thermal hygrometric effects, C2d Humidity, C3c Lack of tightness to external agents, C4a Faulty abutments, C4d

Draining water, C4g Faulty drainage, C4i Poor waterproofing, C4l Excessive stiffness in elements connection

Figure 10: Comparison between the main causes of anomalies in the

most affected groups of constructive elements.

Of the 22 anomaly types found, linear cracking, discoloration or stain, peeling, infiltration and biologi-

cal attack or colonization are the most common. If the age of the building is taken into account, there

are two prevalent periods of original construction date for which these are most relevant, correspond-

ing to buildings between 53 and 48 years old (a range to which most schools belong). In 53 years old

buildings, there is a higher proportion of infiltrations, biological attacks and linear cracks. In 48 years

old buildings, still, a higher proportion of discoloration or stains and peeling was found. The building

anomaly affecting higher mean age of constructive elements was A23 (50.59 years old); the inverse

corresponded to A5 (49.33 years old).


13

The group that stands out with more linear cracking, peeling and infiltrations is that of concrete ele-

ments (Figure 11). As expected, the frequency of spalling in concrete elements is close to the number

of precedent corrosion situations. Steel reinforcement corrosion implies a volume increase of about

eight to ten times, which is followed by the spalling of the concrete. This is often related to a too thin

layer of concrete cover. Wall and ceiling claddings stand out, on the other hand, as the constructive

elements with more discoloration or stain and biological attack anomalies, normally associated with

faulty drainage (Figure 12). These anomalies take part in a chain of events going from the primary con-

structive elements to its coating that starts with an infiltration, which is followed by a stain, biological

colonization and, finally, blistering and peeling. Although discoloration or staining occur frequently, it

is not worrying, as mainly claddings are affected (with only two level 3 severity situations). But if stain-

ing is included in a chain of events, it may be much more worrying.

0%

10%

20%

30%

40%

50%

60%

03 05 06 09 10 11 12 14 18 20

A5 A3 A8 A21 A23

A5 Linear cracking, A3 Discoloration or stain, A8 Spalling, peeling

or flaking, A21 Infiltration, A23 Biologic attack or colonization03 Concrete elements, 05 Wood structures, 06 Masonry, 09

Expansion joints, 10 Wall claddings, 11 Paving, 12 Ceiling claddings, 14 Pitched roofs claddings, 18 Blacksmith's, 20 Paintings

and coatings

Figure 11: Comparison between the main groups of constructive elements

affected, according to the main anomalies.

0%

10%

20%

30%

40%

50%

C1b C1f C2a C2d C3c C4d C4g C4i C4l C5b

A5 A3 A8 A21 A23

A5 Linear cracking, A3 Discoloration or stain, A8 Spalling, peeling

or flaking, A21 Infiltration, A23 Biologic attack or colonizationC1b Expansion joints (faulty or nonexistent), C1f Differential

settlement, C2a Thermal hygrometric effects, C2d Humidity, C3c Lack of tightness to external agents, C4d Draining water, C4g Faulty

drainage, C4i Poor waterproofing, C4l Excessive stiffness inelements connection, C5b Lack of maintenance work

Figure 12: Comparison between the main causes of anomalies according

to the main anomalies.

Linear cracking is the kind of anomaly with the highest proportion of critical anomalies, whose severity

lowers as cracking is identified in claddings or in coatings only. Anomalies A7 Fracture / broken elements,

A12 Corrosion and A21 Infiltration also have high proportions of critical occurrences, as they easily imply a

reduction of building structural safety. Anomalies A3 Discoloration or stain, A28 Debris and A31 Blistering do

not constitute immediate threat. They are widely aesthetic anomalies, and although they may be the first

symptom of a much more severe process, they do not affect safety by themselves.

As every school has, at least, a main building, a workshop and a gym, it is interesting to compare their

degradation patterns. In gyms, discoloration or stain anomalies appear in a higher proportion, while in

main buildings and in workshops, linear cracks tend to be more common. In workshops, the proportion

of infiltrations is higher than that found in other building types (Figure 13), and about 71% of these are

critical (level 3 severity). The percentage of critical infiltrations in gyms is similar, but, in those buildings,

the total amount of infiltrations is about half of that of workshops. This draws attention to shed roofing,

demanding careful detailing and safety access for maintenance work.


14

As for the affected constructive elements, paint, wall claddings and concrete elements are greatly affected

in every building type (Figure 14). Nevertheless, in gyms, concrete elements have a higher percentage of

degradation. Similarly, workshops have more anomalies in the claddings of pitched roofs, stressing the

importance of the usage of shed roofs. There is also a higher proportion of anomalies in the gyms’ ceilings,

which may be related to the fact, that in gym rooms, special ceilings are often found, namely in timber.

0%

2%

4%

6%

8%

10%

12%

14%

16%

18%

I.TF 1 main

building

I.TF 3

workshop

I.TF 4 gym

A3

A5

A5.a)

A5.b)

A8

A19

A21

A23

A3 Discoloration or stain, A5* Linear cracking [including a) and

b) options], A8 Spalling, peeling or flaking, A19 Faulty functioning, A21 Infiltration, A23 Biologic attack or colonization

Figure 13: Comparison between the main anomalies found in main

buildings, workshops and gyms.

0%

5%

10%

15%

20%

25%

I.TF 1 main

building

I.TF 3

workshop

I.TF 4 gym

03

06

10

12

14

20

03 Concrete elements, 06 Masonry, 10 Wall claddings, 12 Ceiling

claddings, 14 Pitched roofs claddings, 20 Paintings and coatings

Figure 14: Comparison between the main groups of constructive elements

affected in main buildings, workshops and gyms.

It was previously concluded that, from a constructive standpoint, the main buildings and the gyms

were alike. However, looking at their degradation profiles, these building types are not affected by

anomalies in the same way. The circumstances for degradation are most likely associated with the func-

tional programme of each building and with different intensity of use.

For each anomaly, a set of solutions was recommended. There are 14 028 recommendations for 2 779

building anomalies (an average of five recommendations per anomaly). Of these, 24% are cleaning

measures, 18% refer to the partial removal of elements and 17% refer to finishing. These main rec-

ommendations constitute basic or preliminary operations used in various repair works. Painting in

particular was highly recommended, as almost every constructive element was painted.

Meanwhile, only 1% of the recommendations indicated strengthening measures.

Some general recommendations can be taken into account to solve the main groups of anomalies

found. A set of anomalies is often related to thermo-hygrometric effects, faulty or nonexistent expan-

sion joints, differential settlement and excessive rigidity in the connection of elements. All of these may

be eradicated or minimized if carefully considered in the design or in execution.

For traditional plasters, mortars should be thoroughly mixed and formulated with selected materials,

considering the specificity of each layer. When adherence problems are foreseen or when there is a

higher probability of cracking, the plaster should be reinforced with steel net or fibreglass net.

In framed concrete structures combined with masonry walls, a resilient material must be introduced be-

tween the structure and bricks, to absorb different dimensional variations. A polystyrene board of about


15

20 mm may be used, enclosed with mastic and a groove. To avoid differential settlement, every project

should be based on a detailed geotechnical study of the terrain, leading to a more adequate structural system.

Expansion joints are now recommended by current standards. Still, they should be correctly detailed,

including a compressible material in its interior, a regulating material and a closing treatment. During

construction, joints should be carefully protected from any debris that may accumulate inside (usually,

and above all, mortar) and compromise its future behaviour. Joint finishing should be periodically sub-

stituted, according to manufacturers’ instructions.

Humidity issues are often associated with lack of façade detailing, leading to water flowing down and

staining façade claddings. A simple groove in sills and capstones is enough to avoid this kind of anom-

aly. As for roofing, there are several factors to be considered during design. The system should be

carefully chosen, including an adequate drainage system, detailing the intersection with any projecting

element and providing safe access for maintenance work. Tilting, cladding ventilation, thermal insula-

tion, the tightness and flexibility of expansion joints, protection of the drains from debris and appro-

priate positioning should be taken into account.

6 Conclusions

The public network of secondary schools is an educational infrastructure of great importance, as a

space of knowledge with patrimonial value, standing out in urban tissues.

The study considered a homogeneous set of school buildings 42 to 61 years old, generally, with a con-

crete reticulated structure, concrete slabs and masonry walls. Some schools still included some load bear-

ing walls in stone masonry. With these detailed in a database of constructive and pathological infor-

mation, it was possible to assemble results about recurring anomalies, the most affected constructive

elements and the most significant causes. With these results, weaknesses may be identified and addressed.

The surveys’ methodology and, subsequently, the database elaboration methodology, was very im-

portant for the reliability of the results. The concepts in use had to be clear, and the guidelines to fill in

each database item had to be strictly followed.

In summary, two main groups of anomalies can be considered: anomalies due to structural issues (con-

crete elements and masonry linear cracking and peeling) and anomalies associated with humidity-

related issues (infiltration, staining, biological attack and flaking of claddings and coatings). They can be

improved or completely solved if addressed in project.

In terms of severity, results are not very worrying, as critical situations only represent about a quarter

of the total amount of anomalies found. Besides, 90% of anomalies are localized.

In the future, an analysis comparing degradation patterns in industrial schools, high schools and pavil-

ion like schools may reveal interesting results. On the other hand, focusing the study on one of the

industrial schools that has been refurbished may be useful to consider whether the main anomalies

were properly addressed.


16

The database model could also be used in the study of other building types, with some adaptations and

improvements to the model and thorough specifications of a proper surveying protocol. Also, a com-

plementary method indicating auxiliary means of diagnostic could be developed for more complex and

severe anomalies. Also, the database model should probably be developed in more advanced software,

and one more user-friendly and appropriate for professional use in the context of building manage-

ment and maintenance. If this software were to include a timeline of maintenance operations and sur-

veys, then it would also be able to indicate appropriate periods for the next operation.

In the context of pathology studies, it is not only necessary, but vital, to create a communication chan-

nel that reaches all main agents in the construction industry, showing which specific problems should

be urgently addressed in design and on site. In fact, this is vital not only in that context, but for the

improvement, in the widest of senses, of architecture as an art or craft, construction practice, the con-

struction industry and the public perception of all these things. This improvement should run from the

satisfaction of a client for the quality and longevity of the final product to the improvement of the

urban landscape as a living environment and a heritage.

References

BRANCO, Fernando A., BRITO, Jorge de, FERREIRA, João, RORIZ, Luís, CORREIA, João, PAU-

LO, Pedro, FLORES, Inês, Secondary Schools constructive anomalies survey, ICIST Reports 27/07 to 32/10,

Lisbon, 2007-2010 (in Portuguese).

CHONG, Wai-Kiong, LOW, Sui-Pheng, «Latent building defects: causes and design strategies to pre-

vent them», August 2006, Journal of Performance of Constructed Facilities, Vol. 20, Issue 3, pp. 213-221.

COSTA, Jorge Moreira da, Quality assessment methods of residential buildings projects, Porto, Civil Engineering

PhD Dissertation, Universidade do Porto - Faculdade de Engenharia, 1995, pp. 7-9 (in Portuguese).

ESCOLA Industrial Marquês de Pombal, Marquês de Pombal Industrial School, 1888-1963, [n.l.], Aço Ir-

mãos Lda., 1963 (in Portuguese).

HEITOR, Teresa (coord.), High schools, technical and secondary schools, Lisbon, Parque Escolar EPE, Ar-

gumentum Edições, 2010 (in Portuguese).

JUNTA das Construções para o Ensino Técnico e Secundário, Setúbal Commercial and Industrial School,

1951, [cover drawing], Ensino Técnico e Secundário in Núcleo do Arquivo Técnico das Construções

Escolares of Ministério da Educação (in Portuguese).

WESTON, Richard, Plans, sections and elevations. Key buildings of the 20th century, Barcelona, Editorial Gus-

tavo Gili, 2005 (in Portuguese).

WHEELWRIGHT, Edmund March, School architecture. A general treatise for the use of architects and others,

Boston, Rogers & Manson, 1901.

DIAS, W. P. S., Useful life of buildings, Sri Lanka, Sri Lanka Accounting and Auditing Standards Monitor-

ing Board, 2003.

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Constructive characterization and degradation condition of ... · become more and more unessential and opened way to industrial production, as the Deutscher Werkbund flourished. The