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VAULTED BRICK GON9WUCTJ0N (U GUADALAJARA
ARCHITECTURE AT RICE UNIVERSITY
NUMBER 18
ARCHITECTURE AT RICE UNIVERSITY is a series of reports on
thoughts and investigations from the School of Architecture of
the University. The series is published in the belief that archi-
tectural education can best be advanced when teachers, practi-
tioners, students, and laymen share what they are thinking and
doing.
HOUSTON, TEXAS
AUGUST, 1966
VAULTED BRICK CONSTRUCTION IN GUADALAJARA
I. FOREWORD 3
BY CAREY CRONEIS
II. STRUCTURAL EVALUATION 11
BY NAT W. KRAHL
III. DESIGN EVOLUTION 47
BY HARRY S. RANSOM
Digitized by the Internet Archive
in 2011 with funding from
LYRASIS IVIembers and Sloan Foundation
http://www.archive.org/details/vaultedbrickcons18krah
I. FOREWORD
BY CAREY CRONEIS
CHANCELLOR, RICE UNIVERSITY
Introducción
por
Carey Croneis
*
I I
Desde mediados de 1963 la Universidad de Rice ha tenido el
placer y honor de formar parte de un grupo de universidades
Norteamericanas quienes, a través de sus representantes,
se han asociado con el objeto de cooperar con el desa-
rrollo académico y físico de la Universidad Autónoma de
Guadalajara.
Profesores y funcionarios administrativos de varias univer-
sidades importantes — Arizona, California, Colorado, Colorado
State, Dallas, Denver, Kansas, New Mexico, Rice, Southern
California, Texas, y Tulane — se reunieron desde el 28 de junio
al 1°. de julio de 1963 en Guadalajara, México. A ellos se les
unió un grupo especial de invitados que incluían al Lie. Luis
M. Farias, el Director General de la Oficina de Información
del Gobierno Mexicano, el Doctor Saxton Bradford, quien
representaba a Su Excelencia, Thomas C. Mann, Embajador de
los Estados Unidos en esa época en México, el Sr. John Nagel,
representante de la Fundación Ford para México y América
Central, el Sr. Thomas Linthicum, Cónsul General de los
Estados Unidos en Guadalajara, el Ing. Salvador Ochoa Montes
de Oca, Presidente de la Junta de Directores de la Universidad
de Guadalajara, representantes de las compañías Bacardi y
Nestle de México, junto a un grupo de distinguidos profesores
y administradores de la Universidad Autónoma de Guadalajara,
incluyendo al Rector, Dr. Luis Garibay G., el Vice-Rector, Lie.
Antonio Leano A, de Castillo, el Secretario General, Lie. Carlos
Pérez Vizcaíno, y el Proboste, Dr. Ángel Morales Castro,
Since mid-1963 Rice University has had the honor and pleasure
of being one of a group of American universities which,
through their representatives, have banded together as a
consortium whose purpose it is to assist in the academic and
physical development of the Universidad Autónoma de
Guadalajara.
Professors and administrative officers of a number of major
universities — Arizona, California, Colorado, Colorado State,
Dallas, Denver, Kansas, New Mexico, Rice, Southern California,
Texas, and Tulane — met in Guadalajara, Mexico, on 28 June to
July 1, 1963. They were joined by a group of special guests
including Lie. Luis M. Farias, the Director General of the Mexi-
can Government Office of Information, Dr. Saxton Bradford,
who represented His Excellency, Thomas C. Mann, then Am-
bassador of the United States to Mexico, Mr. John Nagel, the
representative of the Ford Foundation for Mexico and Central
America, Mr. Thomas Linthicum, the Consul General of the
United States for Guadalajara, Ing. Salvador Ochoa Montes de
Oca, president of the Patrons of the University of Guadalajara,
representatives of the Bacardi and Nestle companies of Mexico,
together with a group of distinguished professors and adminis-
trators from the Universidad Autónoma de Guadalajara, includ-
ing the Rector, Dr. Luis Garibay G., the Vice-Rector, Lie.
Antonio Leano A. de Castillo, the Secretary-General, Lie. Carlos
Perez Vizcaino, and the Provost, Dr. Angel Morales Castro, as
como asimismo el Dr. Osear F. Wiegand de la Universidad de
Texas, coordinador de los planes de desarrollo para la UAG.
Estos señores han sido muy cordiales y una gran ayuda a los
miembros del cuerpo docente de la Universidad de Rice,
quienes, de varias maneras, han participado en este programa
cooperativo.
Durante el curso de la conferencia inicial del año 1963, se
plantearon los objetivos del programa cooperativo, fueron
consideradas las posibilidades de ayuda y de iniciativa privada
vis-a-vis a un desarrollo tradicional de las universidades en
México, y se llegaron a acuerdos con respecto a las distintas
áreas de colaboración por establecerse con cada una de las
universidades Americanas representadas. Ai término de las
sesiones se planteó a la asamblea una resolución dirigida a la
Fundación Ford y a la UAG, cuyo borrador original fué
preparado por el autor.
Esta resolución fué adoptada, y ha formado la base principal
para los diversos propósitos cooperativos que han sido puestos
en marcha con excelentes resultados. Como consecuencia de
ello, fondos para funcionamiento y construcción han sido
recibidos de varias instituciones, incluyendo a la Fundación
Ford, al programa US-AID y al Departamento de Estado de los
Estados Unidos.
well as Dr. Osear F. Wiegand of the University of Texas, the
coordinator of the development plans for the UAG. All of
these gentlemen have been most cordial and helpful to mem-
bers of the Rice University faculty who, in various ways, have
taken part in the cooperative program.
During the course of the 1963 initial conference, the objec-
tives of the envisaged cooperative program were spelled out,
private initiative and support possibilities vis-a-vis orthodox
university development in Mexico were considered, and agree-
ments were reached with reference to the various areas of
collaboration to be established with each of the American
universities represented. At the close of the sessions, a resolu-
tion directed to the Ford Foundation and to the Universidad
Autónoma de Guadalajara was put before the assembly, the
original draft of the proposal having been prepared by the
present writer. This resolution was adopted, and it has formed
a principal basis for the various cooperative arrangements
which subsequently have been put into effect with a gratify-
¡ngly high degree of success. As a consequence, development,
operating and construction funds have been forthcoming from
various agencies, including the Ford Foundation, the US-AID
program, and the U. S. Department of State.
En la adjudicación de las áreas académicas de la UAC a las
distintas universidades Norteamericanas, Ingeniería y Arquitec-
tura fueron las disciplinas asignadas a la Universidad de Rice,
y además, a Rice le fué entregada la responsabilidad de
desarrollar el plano regulador del nuevo campus de la UAC.
Durante la conferencia inicial, William Caudill, Director de la
Escuela de Arquitectura de la Universidad de Rice, y el autor
consideraron junto a los funcionarios de la UAG posibilidades
potenciales de sitios para el nuevo campus de la Universidad,
comparado esto con las posibilidades prácticas de desarrollar
una institución de tal envergadura en el terreno actual, en el
cual en esa época ya habían varios edificios nuevos. En última
Instancia, se llegó a la decisión de seguir adelante con el
desarrollo del sitio actual de la UAC.
Cuando los deseados fondos necesarios para situar el proyecto
de la UAC en su primera etapa de planeamiento llegaron, le
fué posible a la Universidad de Rice enviar al profesor Harry
Ransom de la Escuela de Arquitectura a Cuadalajara a trabajar
bajo la égida del Departamento de Estado de los Estados
Unidos. El proyecto comenzó en octubre de 1964 con tres
arquitectos y cuatro estudiantes, sin embargo, el 1°. de enero de
1966 participaban 30 estudiantes, 3 arquitectos y 4 ingenieros.
A través de todo el programa, a la Universidad de Rice y al
profesor Ransom les ha sido útil no sólo la eficaz cooperación
In the apportioning of areas of academic concern to the
various U. S. universities of the UAC consortium, engineering
and architecture were disciplines assigned to Rice University,
and, in addition. Rice was given the responsibility for develop-
ing the master plan of the new Autónoma campus. At the
time of the original conference, William Caudill, Director of
the Rice School of Architecture, and the writer spent some
time with the officials of the UAC in considering potential
sites for a new campus for the University, as compared with
the practicality of developing a major institution on the present
University campus which at that time was already occupied
by several new buildings. Ultimately, a decision was reached
to go ahead with the development of the present site of
the UAC.
When the hoped-for funds necessary to put the entire UAC
project into its detailed planning stage became available, it
was possible for Rice University to send Professor Harry
Ransom, of the School of Architecture, to Cuadalajara to
work under the aegis of the United States Department of
State. The project began in October, 1964, with three architects
and four students. On January 1, 1966, however, there were 30
students, three architects and four engineers involved.
Throughout the entire program. Rice University and Professor
Ransom have profited not only from the effective cooperation
de la administración de la UAC sino que además, la ayuda
directa que han recibido de las facultades de Arquitectura e
Ingeniería de dicha Universidad. Rice está especialmente
agradecida al arquitecto Francisco Camarena, Director de la
Escuela de Arquitectura y al Ingeniero José Luis Amezcua S.,
Director del Instituto de Ciencias Exactas y Terrestres. El dibujo
de los cientos de planos fue hecho por un enorme grupo de
alumnos avanzados, sin cuya valiosa ayuda este proyecto no
podría haberse completado.
Muy pronto en el trabajo de coordinación del diseño del
campus, el profesor Ransom quedó particularmente intrigado
con la vieja costumbre local de construir sistemas de techum-
bre con bóvedas de ladrillo. Como en ello había ciertos
problemas de orden estructural invitó al profesor Nat Krahl
de la Universidad de Rice, a visitar la UAG con el propósito
de estudiar esta técnica en profundidad y especialmente para
iniciar una serie de pruebas y experimentos a fin de deter-
minar la gama de posibilidades estructurales inherentes a este
sistema de construcción local.
El informe que sigue, documenta el procedimiento arquitec-
tónico-estructural e ilustra como, en este caso en particular,
la unidad ladrillo se transformó en la determinante de diseño
de un campus universitario completo. Pruebas y análisis
estructurales tuvieron éxito al demostrar la gran resistencia
propia al sistema de bóvedas de ladrillo convencionales. Una
serie de pruebas hechas en construcciones de tamaño natural
determinaron con éxito las dimensiones de la trama estructural
of the UAG administration, but from the direct assistance of
the Autonoma's Architectural and Engineering faculties. Rice
is particularly indebted to Arq. Francisco Camarena, Director,
UAG School of Architecture, and to Ing. Jose Luis Amezcua S.,
Director, institute of Exact and Terrestrial Sciences. The draft-
ing of the hundreds of drawings was done by a large force
of advanced architectural students, without whose valued
assistance the project could not have been completed.
Early in Professor Ransom's work in coordinating the campus
design of the University, he became particularly intrigued with
an ancient local practice of constructing roof systems of
vaulted brick. Because there were certain engineering prob-
lems involved, he invited Rice Professor Nat Krahl to visit
the UAG for the purpose of examining the technique in depth,
and, in particular, to initiate a series of engineering tests and
experiments to determine the actual range of engineering
possibilities possessed by this local construction system.
The following report documents the architectural-engineering
procedure and illustrates how, in this particular circumstance,
a unit of brick became the design determinant for the architec-
ture of an entire university campus. The structural tests and
structural analysis were successful in demonstrating the great
inherent strength of the conventional brick vaults. A range of
full-size construction tests was successful in determining the
que puediese permitir la construcción de bóvedas de ladrillo
de doble curvatura sin el uso de moldajes, y que como
resultado final se consiguió un método más sofisticado de
construcción de bóvedas, una vez más, sin moldajes. Resulta
que el método no sólo es práctico, sino que permite una
rápida construcción de bóvedas soportadas por una trama de
vigas y pilares de hormigón armado. Además, no es únicamente
un proceso relativamente barato sino que su resultado es
estéticamente agradable. Esto se debe en parte a que el cielo
de la bóveda puede ser dejado a la vista dado el extra-
ordinario color y la interesantísima textura de los ladrillos
utilizados.
Al hablar en la conferencia original en Guadalajara, el autor
hizo notar lo relativamente mucho que la UAG había realizado
con el relativo poco apoyo financiero, a tal punto de situar en
una posición incómoda a varias de las universidades Ameri-
canas allí representadas que comunmente se quejan de la
suficiencia de sus mayores recursos. Con respecto a esto, se
hizo notar que la edad de una persona u organización se
puede determinar por la cantidad de dolor que el individuo
u organización experimenta al enfrentar una nueva idea. UAG
es joven y vigorosa, y no ha experimentado dolor, por lo
menos de esa naturaleza. Ha experimentado audazmente y
con éxito desarrollar una institución privada e independiente,
apoyada por particulares y corporaciones y especialmente por
dimensions of a supporting structural network that would
permit doubly curved brick vaults to be constructed without
the use of forms and eventually resulted in a more sophisti-
cated method of building such vaults, again without forms.
It turns out that the method is not only practical but that it
permits rapid construction of vaults which can be supported
on a network of reinforced concrete beams and columns.
Moreover, not only is the process relatively cheap but its
results are also aesthetically pleasing. This is true in part
because the underside of the vaults can be exposed ad-
vantageously owing to the unusually attractive color and
interesting surface texture of the bricks employed.
Speaking at the original conference at Guadalajara, the writer
observed that the UAG had accomplished relatively so much
with relatively little financial backing that it put many of the
U. S. universities represented in an embarrassing position
because they commonly complain about the adequacy of
their much greater resources. In this connection, it was also
pointed out that the age of a person or an organization can be
determined by the amount of pain the individual or the
institution experiences when encountering a new idea. UAG
is young and vigorous, and experiencing no pain, at least of
this sort. It has boldly and successfully experimented by
developing an independent private institution, supported by
10
"recibos de educación," procedimientos que son "nuevos"
y heterodoxos en la educación superior Latinoamericana. Es
por lo tanto propio y adecuado entonces, que en su moderno
y futuro desarrollo UAC tome ventaja de un "nuevo" concepto
arquitectónico-estructural, que sin embargo está firmemente
enraizado en un antiguo y atractivo procedimiento de con-
strucción característico del estado de Jalisco.
La Universidad de Rice está orgullosa de haber tomado parte
en el desarrollo de UAC, particularmente a través de los
proyectos de arquitectura e ingeniería dirigidos por los pro-
fesores Ransom y Krahl, delineados someramente en esta
publicación. Su agradecimiento a las otras universidades
Norteamericanas que forman parte del consorcio es grande,
pero a la de los líderes de la Autónoma es aún mayor. Entre
ellos los Drs. Luis Caribay C. y Ángel Morales Castro merecen
especial mención por su dedicación eficaz e incansable a una
causa extraordinaria.
El esfuerzo cooperativo entre Rice y UAC se refleja en la
mejor forma quizás en el símbolo integrado de diseño que
aparece en todos los planos. Representa el apropiado, mas
biológicamente imposible, matrimonio de las águilas Mexi-
canas de la Universidad Autónoma de Guadalajara y los buhos
Atenienses de la Universidad de Rice — colofón que orgullosa-
mente presentamos en esta publicación.
individuals and corporations, and particularly by tuition
receipts, all of which procedures are "new" and unorthodox
in Latin American higher education. It is altogether proper
and fitting, therefore, that in its modern and future develop-
ment the UAC should take advantage of a "new" structural
and architectural concept which is nonetheless firmly rooted
in an ancient and most attractive building procedure
characteristic of the state of Jalisco.
Rice University is proud to have been connected in several
material ways with the development of the UAC, particularly
through the architectural and engineering projects directed
by Professors Ransom and Krahl, which are briefly outlined in
this publication. Its indebtedness to the other U. S. universities
of the consortium is great, but its obligation to the leaders of
the Autónoma is even greater. Among them Drs. Luis Caribay
C. and Angel Morales Castro deserve special mention for their
tireless and effective dedication to an unusually worthy cause.
The cooperative effort between Rice and the UAC is perhaps
best characterized by the integrated design symbol which
appears on all of the production drawings. It represents the
appropriate, if biologically improbable, wedding of the Mexi-
can eagles of the Universidad Autónoma de Cuadalajara
and the Athenian owls of Rice University — a colophon we are
pleased to display in the present publication.
II. STRUCTURAL EVALUATION
BY NAT W. KRAHL
ASSOCIATE PROFESSOR OF STRUCTURAL ENGINEERING
TABLE OF CONTENTS
1. Purpose 17
2. Origin and Description 17
3. Test Program 22
4. Analysis of Vaults 27
5. Evaluation 28
6. Conclusions 31
Appendix A. Test Results 33
Appendix B. Conversion Factors Between Metric
And English Units 45
Part II is the text of an engineering report submitted to the
campus design team at the Universidad Autónoma de Gua-
dalajara for their use in designing the new campus buildings.
LIST OF FIGURES
FIGURE 1.
FIGURE 2.
FIGURE 3.
FIGURE 4.
FIGURE 5.
FIGURE 6.
FIGURE 7.
FIGURE 8.
FIGURE 9.
FIGURE 10.
FIGURE 11.
FIGURE 12.
FIGURE 13.
FIGURE 14.
FIGURE 15.
FIGURE 16.
FIGURE 17.
FIGURE 18.
Vaulted brick floor and roof systems under
construction on steel framework 17
Vaulted brick roof system under construction on
precast concrete framework 17
Terrado construction 18
Primitive Catalan vaulting 18
Techo de bóveda 19
Hand-made mud brick drying in the open air
at Tateposco 22
Hand-made mud brick stacked for firing at Tateposco 22
Test vaults 23
Brick arches constructed for original tests 24
River sand bags being placed for uniform loading tests 24
Arch end view during early loading 24
Deflection meter placed at center of beam span 24
Instrumentation reading of vault deflection 25
Partially loaded test 25
At this point of loading the vault is supporting 388
pounds per square foot 25
With no appreciable damage to any structural element,
vaults supporting 388 pounds per square foot. This is
5.4 times design live load 25
Line of thrust of test vaults 26
Calculations for: Horizontal Thrust
Max. Compressive Stress
Tensile Stress in Tie Rods 26
FIGURE 1. Vaulted brick floor and roof systems under construction on
steel framework.
FIGURE 2. Vaulted brick roof system under construction on precast
concrete framework.
1. PURPOSE
For some time now the School of Architecture at Rice
University and the architectural firm of Caudill, Rowlett, and
Scott have been assisting representatives of the Autonomous
University of Guadalajara in the preparation of a Master
Campus Plan for the development of their university. One
concept v^hich has found favor with the planners is that of
using an indigenous construction system — namely, roofs and
floors of very flat barrel vaults of brick, supported on a struc-
ture of contemporary design — as an architectural and structural
feature of the campus buildings. This report is an outgrowth
of a trip by the writer to Guadalajara for the purpose of
observing this unique construction system and is based in part
on a continuing series of tests which have been performed at
the Autonomous University since that time. The purpose of
this report is to present an evaluation of this construction
system to the campus planning team for their use in the
preparation of their plans.
17
2. ORIGIN AND DESCRIPTION OF VAULTED BRICK
CONSTRUCTION IN GUADALAJARA
2.7 ORIGIN
This construction system, known in Guadalajara as "techo
de bóveda," is essentially a structural system whereby a roof
or floor is constructed of brick multiple barrel vaults, almost
flat, which are supported on a framework of steel (Fig. 1), or
sometimes concrete (Fig. 2). The system is apparently unique
to a portion of central Mexico and reaches its fullest expression
in the state of Jalisco and its principal city, Guadalajara.
This method of construction is an outgrowth of centuries of
experience and experimentation with this and similar methods.
18
-Earth Fill
Wood Beam •
FIGURE 3. Terrado construction.
■ X'
Fill
arase
Brick Barrel Vault ■
Wood Beam
FIGURE 4. Primitive Catala'n vaulting.
— Wearing Su
rface
Pill 1 Steel Beam
1
y-t
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~^;j^^g^^;i^áik^p¿mt¿jj^^^^^^
— Plaster
1
Brick Barrel Vault
FIGURE 5, Techo de bóveda.
It apparently stems originally from the Terrado system of
building (Fig. 3) in which the Indians of Mexico used wood
beams to support tree branches which were covered with
earth. This method was modified by the Spanish to the Catalan
system (Fig. 4), in which wood beams supported short-span
multiple brick vaults which, in turn, supported an earth or
concrete fill and wearing surface.
With the introduction of structural steel, some builders used
rolled steel beams in lieu of wood beams to support the
brick vaults, and examples of this are to be seen in Guadalajara.
Then someone observed that the shape of the steel beam
would allow it to be placed between two adjacent vaults,
thereby containing the depth of the arch rib and being
virtually concealed itself, and the final step in the evolution
of the method had been taken (Fig. 5).
2.2 DESCRIPTION
Any description, analysis, or evaluation of this construction
system must first recognize that this system is a combination
of two separate structures: first, the brick vaults, which support
the floor and the loads imposed on the floor and carry these
loads to the supporting structure; and second, the supporting
framework of steel or concrete beams, girders, and columns
which directly support the vaults.
19
20
a. Vaults '
A typical cross-section through this type of construction is
shown in Fig. 5. Typically, the supporting beams are placed
80-130 cm. (32-51 in.) center-to-center, and this distance
becomes the span of the barrel vault. The bricks comprising
the barrel vaults are laid without formwork, each successive
row of bricks in itself becoming an arch rib spanning between
steel beams. The vaults themselves are almost flat, the rise
usually being only 3-8 cm. (1.5-3 in.). The bricks are handmade
mud bricks of local manufacture, are very light in weight and
are laid with the large side flat against the adjacent arch rib.
The bricks are laid dry, and the suction of the mortar against
the side of each brick helps keep it in place until its arch rib
has been completed. Also, the vertical axis of each brick is
tilted slightly so that each brick is partly supported by the
newly-completed adjacent arch rib until its own rib is
completed. The mortar in which the brick is laid is made from
lime and sand.
A level surface above the vaults and beams is achieved by
filling with a lightweight concrete made from hydrated lime
and "Jal," which is a local pumice sand and gravel and is the
volcanic material from which the State of Jalisco takes its name.
The thickness of the fill varies, particularly on roofs, which are
usually sloped for drainage. For example, a variation of fill
thickness from 5 to 20 cm. (2 to 8 in.) over a roof would not
be unusual.
A wearing surface of burnt clay brick or tile is usually placed
on top of the concrete fill. On roofs a waterproofing layer of
asphalt or cement is placed between the concrete fill and
wearing surface.
Finally, the underside of the vaults is almost always covered
with a plaster made from lime and sand to give a perfectly
flat ceiling which conceals the vaults and beams. In some
cases a wire mesh is attached to the beam flange to support
the plaster below the flange. In a few cases the brick vaults
and steel beams have been left exposed to view from below
and achieve a dramatic architectural effect because of the
varying colors of the brick and the apparent daring of the
flatness of the vaults.
The brick vaults described above are widely used in Guadala-
jara to support the typical floor loads and roof loads encoun-
tered in houses and office buildings. The floor live load used
locally for design of dwellings is 150 kg./m,= (30.8 Ib./ft.'), and
maximum office floor live load for which this type of construc-
tion would be considered suitable by local engineers is about
350 kg./m." (71.8 Ib./ft.-'). In addition, the brick vaults them-
selves are not considered suitable for resisting heavy, con-
centrated loads. If such loads are anticipated in buildings of
this type of construction, it is customary to support these loads
on small beams of steel or reinforced concrete, which replace
the arch ribs in that immediate location and carry their loads
directly to the supporting framework of beams, girders, and
columns.
The allowable loads and the practices stated above are based
primarily on accumulated experience. Prior to the series of
tests described in this report, there were apparently no test
data available to aid in an evaluation of this structural system.
Apparently the only criticism of this system by local architects
and engineers is that a few buildings employing this system
have floors which will vibrate noticeably when excited by
such factors as nearby truck traffic, a person jumping on the
floor, etc. Some floors which can be excited to vibrate notice-
ably during construction show no objectionable vibration after
completion of the building. The writer believes this behavior
to be primarily dependent upon the supporting structure and
discusses the point further in Chapter 5.
b. Supporting structure
As mentioned above, the beams which directly support the
vaults are usually steel beams placed 80-130 cm. (32-51 in.)
apart. Typical beam sizes range from 4-inch to 8-inch I-beams,
depending on their span and their supported load. Usual spans
are in the range of 4-6 meters (13-20 ft.). Most often the steel
beams are supported by steel girders which, in turn, are
supported by steel columns. Occasionally, small precast con-
crete beams of 1-section are used in lieu of steel beams
to support directly the brick vaults (Fig. 2), and the remainder
of the supporting structure may then become reinforced
concrete.
At an interior beam under uniformly distributed load, the
lateral thrust from the vault on one side balances that from the
other side; but at edge beams under any loading and at interior
beams under unsymmetric loadings there are unbalanced
thrusts to be resisted. For this purpose, it is the common
practice to use tie rods between adjacent beams at intervals
along the length and to extend the lines of rods all the way
across the building. The rods are eventually concealed within
the floor construction.
Individual members of the supporting structure are, of course,
designed according to the live and dead loads, the conditions
of support, and the span or length of members.
21
3. TEST PROGRAM
In order to aid in the evaluation of this structural system, a
series of tests was performed at the Autonomous University
of Guadalajara. The original reports of these tests, in Spanish,
and an English translation are presented in Appendix A of this
report. The tests themselves can be classified into two groups:
first, tests of individual materials used in this structural system;
and, second, a test of full-scale vaults.
3.7 Tf5TS OF MATERIALS
The brick used in Guadalajara for vault construction is made
by hand in the countryside nearby, and is trucked into the
city for use. The primary ingredient is a mud made from water
and Jal, which is readily available throughout the entire area.
In addition, certain amounts of manure and maguey fiber are
used in the mixture. The bricks are formed in wood molds,
dried in the open air (Fig. 6), then stacked in large piles and
fired with mesquite logs, which are placed in slots left in the
piles. (Fig. 7). The resulting brick is light in weight, very porous,
and has beautiful variations in color, which depend largely
upon the degree of firing. Predominant colors range through
various shades of yellow, ocher, orange, red and brown.
Appendix A contains the quantitative measurements of certain
mechanical properties of samples of brick coming from the
brickyards of Tateposco and Las Pintas.
In addition to tests of the brick used for the barrel vaults,
certain mechanical tests were also performed on representative
samples of the mortar used in the vault construction, the Jal
concrete fill placed above the vaults, and the burnt clay brick
used for the wearing surface. Specifically, the samples of each
of these materials corresponded to those particular
materials used in the construction of the full-scale vaults that
were load tested. Results are given in Appendix A.
^ - J-'S^'SL'^-jLa.'^a.'^
■!?■ •■•¿^■P" *^>1^ "^-"^ ' ^ ■''^ íjÜ^ m^jHUB
FIGURE 6. Handmade mud brick drying in the open air at Tateposco.
FIGURE 7. Handmade mud brick stacked for firing at Tateposco.
•Mif
¡Jr.: ■ -p:--^, ','.1i.'^u^fr^r'-"'ii''A-
■■,<*.■*
fe
it;
►_••■' --'x^j^r'-tJ^^:-:.
e
r-\
■ 2V."*
SECTION A-A
Note: Dimensions shown in Meters,
^^nnr
3.2 TEST OF VAULTS
Appendix A contains the report of the load test of full-scale
brick vaults performed on the campus of the Autonomous
University of Guadalajara. A sketch of the structure which was
tested is shown in Figure 8 and photographs of the test are
shown in Figures 9-16. The basic aim of the test was to observe
the behavior and the strength of the brick vaults under uni-
formly distributed load. As mentioned above, the structural
system under consideration has two separate components,
the brick vaults and the supporting structure. It was felt that a
supporting structure of steel or reinforced concrete could be
readily analyzed with confidence because of the wealth of
research information which is available concerning such struc-
tures. However, no test data were available for the brick vaults,
since they seem to be unique in several respects. What was
desired, therefore, was a measure of the strength of the vaults
themselves, without a premature failure on the part of the
supporting structure. To achieve this end, the steel beams
supporting the test vaults were made arbitrarily oversize, 10-
inch I-beams on a 3 meter (9 ft. 10 in.) span, while the vaults
were constructed of conventional proportions and materials.
Sacks of river sand were used to simulate a uniformly dis-
tributed load on the structure. The sacks failed before the
structure, but the test was successful in demonstrating that the
structure was capable of sustaining a superimposed uniformly
distributed load of 1893 kg./m.= (388 lb./ft.=) without apprecia-
ble damage and without excessive deflection. Based on the
maximum live load in current use for this type of construction,
which is 350 kg./m.' (71.8 Ib./ft.-), we find a factor of safety
which must be greater than 5.4. Additional details of the vault
load test are found in Appendix A.
23
FIGURE 8. Test vaults.
FIGURE 9. Brick arches constructed for original tests.
FIGURE 10. River sand bags being placed for uniform loading tests.
24
FIGURE 11. Arch end view during early loading.
FIGURE 12. Deflection meter placed at center of beam span.
í f ■# #
FIGURE 13. Instrumentation reading of vault deflection.
FIGURE 14. Partially loaded test.
FIGURE 15. At this point of loading the vault is supporting 388 pounds per
square foot.
FIGURE 16. With no appreciable damage to any structural element, vaults
supporting 388 pounds per square foot. This is 5.4 times
design live load.
25
26
FIGURE 17. Line of thrust of test vaults.
FIGURE 18.
CALCULATIONS FOR: HORIZONTAL THRUST,
MAX. COMPRESSIVE STRESS,
TENSILE STRESS IN TIE RODS
Span: 1.30 m.
Dead Load: Paving Brick 15 kg./m^ 3 Ib./ft.'
Jal Concrete Fill 70 kg./m^ . . .14 Ib./ft.^
Brick Vault 145 kg./m^ . . . 30 Ib./ft.^
230 kg./m^ 47 Ib./ft.^
For Design Live Load of 350 kg./m.^ (72 Ib./ft,^):
Total Load = 230 + 350 = 580 kg./m.^ (119 Ib./ft.')
L, . ^ I Tu ^ wL^ 580X1.30'
Hor,zontal Thrust= — = ^^^OO^
Horizontal Thru5t = 1,630 kg./m. (1,097 Ib./ft.)
». r- • c* 2H 2X1,630X1
Max. Compressive Stress= ^ = ^^^^^^ ^
Max. Compressive Stress = 2.91 kg./cm.' (41 lb/in.')
-r ., c. ■ T- D J H 1,630X1.50
Tensile Stress m Tie Rods= — = .,
As 2 X U.71
Tensile Stress in Tie Rods=1,720 kg./cm.' (24,500 Ib./in.')
For Max. Test Live Load of 1,893 kg./m.' (388 Ib./ft.'):
Total Load = 230 + 1,893 = 2,1 23 kg./m.' (435 Ib./ft.')
Horizontal Thrust = 5,960 kg./m. (4,010 Ib./ft.)
Max. Compressive Stress = 10.64 kg./cm.' (151 Ib./in.')
Tensile Stress in Tie Rods = 6,290 kg./cm.' (89,500 Ib./in.')
4. ANALYSIS OF VAULTS
Figure 17 shows a scale drawing of a cross-section of the barrel
vault used in the load test. If we consider a unit thickness of
vault perpendicular to the plane of the paper, we can analyze
the vault as an arch rib. Since these vaults in practice are con-
structed without formwork, it must be realized that the actual
curve of the underside, or intradós, of the rib will vary some-
what from one cross-section to another. But, since the rise of
the arch is so small, only about 3% of the span, all smooth
curves of this rise and span will lie very close to one another.
FHence the small variations in construction are likely to be un-
important. For simplicity, the placement of bricks in Fig. 17 is
shown approximating the curve of a second-degree parabola.
Because this arch is of relatively short span and, in practice,
supports a relatively light, uniformly-distributed load, the so-
called "line of thrust" analysis is considered to be the most
suitable basis for analysis.* According to this analysis, the line
of thrust under uniformly distributed load becomes parabolic,
the crown thrust is horizontal, and its resultant lies at the upper
extremity of the middle third of the arch rib, while the resultant
thrust at the skewback lies at the lower extremity of the middle
third of the arch rib.
•Harry C. Plummer, Brick and Tile Engineering, Structural Clay Products
Institute, Washington, D.C., 2nd ed., 1962, pp. 199-214.
The line of thrust following these restrictions is shown in Fig.
17. Since this line of thrust lies entirely within the middle third
of the bricks making up the arch rib, no tensile stress will be
developed in any part of the rib regardless of the magnitude
of the applied load, and hence we can conclude that the arch
is stable against failure by rotation of one section of the arch
about the edge of a joint. Other possible modes of failure to
be investigated include the sliding of one section of the arch
on another, crushing of the masonry, and failure of an
abutment to provide adequate thrust resistance.
As a measure of sliding stability we examine Fig, 17 and find
that the maximum angle between the line of thrust and the
normal to the joint between arch sections is about 6 degrees.
The significance of this number is evaluated in the next
chapter.
The rise of the arch itself is only .3.9 cm. (1.5 in.), but we see
from Fig. 17 that the rise of the thrust line is 7.5 cm. (3.0 in.).
Fig. 18 shows the calculations for horizontal thrust, maximum
compressive stress in the arch, and tensile stress in the tie rods
for two separate conditions: first, a design live load of 350
kg./m.- (72 lb. /ft.-); and, second, the maximum test live load
of 1893 kg./m." (388 Ib./ft.'). The significance of these stresses
is evaluated in the next chapter.
27
28
5. EVALUATION
5.1 VAULTS AND COMPONENT MATERIALS
Two aspects of vault construction and behavior are worthy of
comment here: first, the unique construction method whereby
the brick vaults are laid without formwork; and, second,
the ability of the vaults to carry uniformly distributed loads
of considerable magnitude without damage or excessive
deflection, despite their flatness.
The handmade bricks used in constructing the vaults are ex-
tremely porous because of the materials and methods used in
their manufacture. This high porosity is reflected in the absorp-
tion percentages reported in the test results of Appendix A. In
addition, the bricks are very light in weight, being about one-
third less in unit weight than the usual machine-made brick
used in the United States. Thus, when a brick is laid dry in
mortar against an adjacent, newly-completed arch rib, the
suction generated on the contacting large face is sufficient to
hold the light brick in place until its own arch rib is completed.
The naturally low humidity of the Jalisco climate contributes to
this process, of course. Also contributing to the support of
the new rib is the fact that the vertical axis of each brick is
slightly tilted toward the existing construction so that the
newly-completed arch rib actually provides some positive
mechanical support for the rib under construction.
In order to evaluate the load-carrying capacity of the vaults, we
shall combine the results of the load test described in Chapter
3 and the mathematical analysis reported in Chapter 4. Modes
of failure to be considered can be listed as follows: rotation
of one section of the arch about the edge of a joint, the sliding
of one section of the arch on another, crushing of the masonry,
and failure of an abutment to provide adequate thrust
resistance. We shall examine each of these possibilities in turn.
First, we see from Fig. 17 that the line of thrust under uniform
load lies entirely within the middle third of the bricks making
up the arch rib, regardless of the magnitude of the applied
load; and this precludes the possibility of a tensile stress
developing in any part of the masonry. Hence, we can state
that the arch is stable against failure by the rotation of one
section of the arch about the edge of a joint.
Next, from Fig. 17 we see that the maximum angle between
the line of thrust and the normal to the joint between arch
sections is about 6 degrees. The coefficient of friction between
the units is at least 0.50, without counting the additional
resistance to sliding provided by bond between the mortar
and the masonry units. This coefficient of friction corresponds
to an angle of friction of about 27 degrees; and, since 6 degrees
is much less than 27 degrees, the arch is quite stable against
sliding.
Concerning the possibility of masonry crushing, we should be
able to conclude that since the test vaults sustained no appreci-
able damage under a superimposed live load of 1893 kg/m."
(388 lb. /ft.-), the stresses produced by this load must be lower
than the failing stresses for the component materials. Maximum
compressive stress in the vault is calculated in Fig. 18 to be
10.64 kg. /cm.-, well below the compressive strength of
Tateposco brick, 65.5 kg. /cm.-, and even well below the com-
pressive stress at first crack, 20.8 kg. /cm.' The calculated stress
of 10.64 kg. /cm.- is slightly greater than the measured compres-
sive strength of the mortar, 8.8 kg. /cm.-; but we should
recognize that the mortar strength was measured in an uncon-
fined compression test, whereas the mortar in the vault is
stressed in a confined condition in which its strength is likely
to be much greater than in the unconfined condition. Thus
the arch rib is seen to be safe against crushing with a large
factor of safety for a design load of 350 kg./m.", and this is seen
to be true by both analytical and experimental considerations.
Thrust resistance is provided by the steel beams and tie rods.
The only question concerning the adequacy of the thrust resist-
ance arises in the case of an unbalanced thrust, as on an edge
beam. The edge beam transfers this thrust to the tie rods,
which tie the two edge beams together across the width of all
the vaults. Fig. 18 indicates a calculated tensile stress of 6290
kg./cm.= (89,500 Ib./in.") in the tie rods of the test vaults at
maximum load. The test results give no data concerning the
yield strength of the particular grade of steel from which the
tie rods were manufactured; but for most grades of structural
steel rods, the yield strength would be well below 6290
kg. /cm.- If the tie rods had yielded, this would likely have been
reflected in a sudden increase of vault deflection; and, since
no such increase was observed, it is likely that the tie rods did
not yield and that the calculated stress in the tie rods is too
high. Several factors help to explain this situation. First, the
entire test structure was only 3 meters long between centers
of end supports. Through friction at the bearings of the steel
beams on the end supports, some force may have been
transferred into the supports so that they participated with
the tie rods in providing thrust resistance. Also, the Jal concrete
and paving brick are considered to be only dead weight, and
the only load-resisting masonry element in the floor construc-
tion is assumed to be the brick arch. Actually, the jal concrete
and the paving brick have structural strength in themselves and
may well participate with the brickwork in supporting the
loads. If so, the line of thrust would have a much greater depth
available for its equilibrium position, the magnitude of the
thrust would be reduced, and the resulting stresses would
thereby be reduced. This is to say that the line of thrust analysis
illustrated in Fig. 17 is conservative for design, but may be
overconservative for the evaluation of test results when applied
to this particular structure. It would seem prudent, however.
29
30
to provide tie rods in accordance with the requirements of
the line of thrust analysis for any construction contemplated
on the UAC campus.
It would seem unnecessary to check the ability of the edge
beam to withstand the bending produced by the horizontal
thrust between tie rods, since the great stiffness of the vaults
in the horizontal plane would make possible a horizontal
arching between tie rods even if the beam were relatively
flexible in this direction.
A word of caution should be mentioned concerning the proper
elevation of the tie rods. In order to avoid eccentricities which
could produce secondary moments and stresses in the struc-
ture, it will be desirable to keep the elevation of the tie rods
as close as possible to the intersection of the line of thrust
with the web of the steel beam. According to Fig. 17, it looks
as if this requirement can be satisfied and still keep the tie
rods concealed in the depth of the arch rib.
A final word of caution concerns the handling of concentrated
loads. The test program did not investigate concentrated loads,
nor is the line of thrust analysis recommended for treating
concentrated loads. Unless further investigations are made
into this type of loading, it is recommended that the limitations
on the use of this structural system which have been accumu-
lated through experience be strictly followed where concen-
trated loads are involved. In general, this would mean leaving
out arch ribs in the immediate location of the concentrated
loads and replacing them with beams of steel or reinforced
concrete.
5.2 SUPPORTING STRUCTURE
As mentioned above, a great deal of research information is
available concerning the behavior of a structural framework
of steel or reinforced concrete when subjected to a known
loading condition. Therefore, the design of such a framework
to resist certain specified loads is, to some extent, a straight-
forward matter. However, two special conditions pertaining
to the structures supporting brick vaults in Guadalajara deserve
special consideration.
The latest specifications of the American Institute of Steel Con-
struction recommend* that the depth of fully stressed beams
and girders in floors be not less than Fy/800,000 times the span;
and, where subject to shock or vibration, not less than Fy/650,-
000 times the span. In their notation Fy is the specified mini-
mum yield point of the type of steel being used, in pounds per
square inch. If members of less depth are used, the unit stress
in bending should be decreased in the same ratio as the depth
•Section 1.13, "Commentary on the Specification for the Design, Fabrication
anci Erection of Structural Steel for Buildings," April 17, 1963, American
Institute of Steel Construction.
is decreased from that recommended above. These specifica-
tions also requiret that the depth of beams and girders sup-
porting flat roofs be not less than fi,/600,000 times their span
length whether designed as simple or continuous spans, where
fb is the computed bending stress in pounds per square inch.
These specifications are mentioned because apparently some
of the beams used in Guadalajara to support the vaulted brick
construction are too shallow to meet these standards. The
excessive flexibility of some of these beams is the most likely
source of the noticeable vibration which is occasionally present
in a structure of this sort, and which was mentioned in Chapter
2. It is recommended that all of the AISC Specifications be
strictly followed in the detailed design of structural steel for
the buildings of the UAC campus, and that the latest specifica-
tions of the American Concrete Institute be followed in the
detailed design of any concrete framework.
The second special condition worth mentioning is the fact
that Guadalajara lies in a region where earthquake activity is
frequent and, occasionally, severe. It has been some time since
a major earthquake was felt in this area, but such earthquakes
are a matter of historical record here. Earthquake engineering
has advanced to the point where it is perfectly feasible for a
tSection 1.13, "Specification for the Design, Fabrication and Erection of
Structural Steel for Buildings," adopted April 17, 1963, American Institute
of Steel Construction.
building to be designed to pass through a minor seismic dis-
turbance without appreciable damage and to survive a major
seismic disturbance. Proper design for these conditions requires
a consideration of the overall configuration of the building in
addition to individual member sizes, connections, etc. It
is recommended that due attention be given to seismic
considerations in the design of the UAG buildings.
6. CONCLUSIONS
Based on the considerations outlined in the first five chapters
of this report, the following conclusions are offered:
1. it has been demonstrated by load test and by mathematical
analysis that multiple barrel vaults of handmade brick, when
constructed of the proportions and the materials customary
in Guadalajara, can be used with a high factor of safety to
support their own dead weight plus a uniformly distributed live
load up to 350 kg./m.= (72 lb./ft.=). For a live load of 350
kg./m-. the factor of safety is greater than 5.4.
2. In any use of these brick vaults in the new buildings on the
UAG campus, it is recommended that tie rods between sup-
porting beams be designed to resist the thrust obtained by
making a line of thrust analysis (or similar analysis) on the
vaults themselves.
31
3. Since no tests have been made to determine the behavior
of the brick vaults under concentrated loads, it is recom-
mended that any use of the vaults strictly observe the limita-
tions which have been accumulated through experience
regarding the support of concentrated loads. In general, this
would mean leaving out brick arch ribs in the immediate
location of the concentrated loads and replacing them with
beams of steel or reinforced concrete. If any modification of
this recommendation is desired, additional tests should be
performed to justify such modification.
4. It is recommended that any steel members, in the structural
framework which supports the vaults, be designed in accord-
ance with the latest specifications and recommendations of the
32 American Institute of Steel Construction. Special attention is
called to Section 1.13 of the Specifications and the- Commen-
tary on the Specifications concerning limitations on depth of
flexural members, since apparently some steel beams used in
Guadalajara to support brick vaults are shallower than these
provisions recommend.
5. It is recommended that any concrete members, in the struc-
tural framework which supports the vaults, be designed in
accordance with the latest specifications of the American
Concrete Institute.
6. It is recommended that due attention be given to seismic
considerations in the design of the UAG buildings.
APPENDIX A
TEST RESULTS
^acultab he ingeniería Chnl
REPORTE DE AHALIliia DE t.UTERIALeS EFECTUADOS EN EL
LABORATüfilO DE LA FACULTAD DE INGEMJRIA Ü.A.G.
MATERIAL ENSAYADO ;
Ladrill* de lama hecli* a man* procadenta
.......^ A,.,™ .. .„^,.i.,. ^g ^^g ladrilleras de "Tatepe«8«".
Jiuarponiba ■ (■ enftimUlab
lÜiobMb «nítitnitarta ^ulóaz
Qltl. S-95-a6
34
Muestra
1 . 2
3,4,5
Pr»m.
Fes* V*lum<-
tric* Sec*
K*/M3
1260 "1255
1200 '1210 '1370
1259
IlÜdul* de Bup-
tura.
(K«/o«2)
15.4 |9.41
16.7 '15.6 '25
16.42
Beslstencla a
la o«inpreBi<n
(K«/oiii2)
50.35 !55.5
37.00 ¡ 66.0 ¡118.5
65.47
Primera Grieta
(Kí/cb2)
16.9 ! 30
17.2 ¡ 20 ¡19.8
20. ?8
Aba*rai<n
(24 ha.)
27.6?í ¡ 32^
32.83É|31.6?t |27.5?í
30.3*
AbsoraKn
(5 ha. eljulll-
ci<n)
36.5^ ¡38.7^
33* ;38.23í ; 32%
35.68*
C*eficieiita da
Saturaoiín
1
0.75 ¡0.83
1.0 ¡0.83 ¡0.86
0.854
HOTAi Temperatura del A^a para aaturacidn en 24 ha.,
17.5 "C.
Fírmula Mídul* de ruptura 3 PL ,
Fírmula ompreaiín I „ *
Abs*rBÍ<n Ph-Pa ,„„ _
— Pi— 10° ■= *
C*eficieiite da saturacián = Ph2 - Ps
Ph-Pa
REPORT OF ANALYSIS OF MATERIALS PERFORMED IN THE
LABORATORY OF THE SCHOOL OF ENGINEERING U.A.G.
MATERIALS TESTED:
Handmade mud brick coming from the brickyards of "Tateposco/
Test
Units
Sample
Average
1
2
3
4
5
Volumetric
Weight, Dry
kg/m'
lb/ft 3
1260
78.6
1255
78.4
1200
75.0
1210
75.5
1370
85.5
1259
78.6
Modulus
of Rupture
kg/cm2
Ib/in2
15.4
219
9.41
134
16.7
237
15.6
222
25
356
16.42
234
Compressive
Strength
kg/cm^
Ib/in2
50.35
716
55.5
789
37.0
526
66.0
939
118.5
1,685
65.47
931
First
Crack
kg/cm3
Ib/in2
16.9
241
30
427
17.2
245
20
285
19.8
281
20.78
296
Absorption
(24 hours)
%
27.6
32
32.8
31.6
27.5
30.3
Absorption
(5 hrs. boiling)
%
36.5
38.7
33
38.2
32
35.68
Coefficient
of Saturation
-
0.75
0.83
1.0
0.83
0.86
0.854
35
NOTE: Temperature of the water for saturation in 24 hours,
17.5° C (63.5° F).
3 PL
Formula for Modulus of Rupture -^ t-Tj
Formula for Compressive Strength "T ~ f
Absorption ^ " ' . 100 =W
P - P
Coefficient of Saturation = -^ p-^
Jfacultab be ingeniería (Eitril
3«tiTpar.t>. . I. enit.n.ib«ft Reporte de análisis de materiales efectuados en el Labora
Mnhicul bi ^cilcD
aitob-b BBto.rtitari- A»i¿™«- torio de la Facultad de Ingeniería de la U.A.O.
tnil. 9-95-38
Material ensayado í
Ladrillo de lama hecho a Baño proceden-
te de las ladrilleras de "Las Pintas".
36
1 f » t 1 t 1 1
, Kuestra ,1,2,3 ,4 , 5 , Prom. ,
' Peso volume t t i f » t i
• l'^h'^S ' 1180 ' 1070' 1180 • 1180 ' 1180 • 1158 '
Kg/n
» seco lililí f
! Kídulo de - ' • i n i i i
, ruptura lililí 1
(Kg/om'^) 11.4 11.9 13-55 16-50 11.35 12-94
• Reei Btencia " ' 'i • * » •
, a la compre , 33-15, 43-2 , 72-2 ,6l-2 , 14.6 , 44.87 ,
Bien
» Primera - - • » » » ' • •
, grieta , 12.3 , 14-7 , 15-7 , 30-3 , 9-9 i 16.58 ,
Ka/cB'^
i "nfj" 1 ^^•«'^ ', 51-'*^ /36-35íí|^30-8lí 1 38-8Í | 35-03% '
• (Shr'e^ll.' -T-'^^- • ^"-^^I "5-5''; tlfí : 46?6 ,' 42.82# 1
Coeficiente
' de satura— • 1 • 0-71 ' 0.79 ' 0.75 ' 0.64 ' 0.8l5 •
I oiín lililí I
encargado del Laheratsrlo
Jefe del Eepto. de Física
Tng. Carlcs-^rujillo del Río
%
Fi^arjel
ROO Niíñez Farias
REPORT OF ANALYSIS OF MATERIALS PERFORMED IN THE
LABORATORY OF THE SCHOOL OF ENGINEERING U.A.G.
MATERIALS TESTED:
Handmade mud brick coming from the brickyards of "Las Pintas.'
Test
Units
Sample
Average
1
2
3
4
5
Volumetric
Weight, Dry
kg/m3
Ib/ft3
1180
73.7
1070
66.8
1180
73.6
1180
73.6
1180
73.6
1158
72.3
Modulus
of pupture
lb/in 2
11.4
162
11.9
169
13.55
193
16.50
235
11.35
161
12.94
184
Compressive
Strength
ka^cm2
lb/in 2
33.15
472
43.2
615
72.2
1,026
61.2
870
14.6
208
44.87
638
First
Crack
kg/cm 2
lb/in 2
12.3
175
14.7
209
15.7
223
30.3
431
9.9
141
16.58
236
Absorption
{24 hours)
%
37.8
31.4
36.35
30.8
38.8
35.03
Absorption
(5 hrs. boiling)
%
37.4
44.2
45.5
41
46
42.82
Coefficient
of Saturation
-
'
0.71
0.79
0.75
0.84
0.818
37
Director of the Laboratory
Head of the Department of Physics
Engineer Carlos Tru¡illo del Rio
Engineer Francisco Nunez Farias
Jfaotltali be ^ngetrierta fflitti!
BiiÜm»Hiift Antóiu
Mnboi*
bi
^«to
aUnbab »ittti
raita
ri« ABt¿
«•t.
s-a.
-3B
38
LABORATORIO DE RESISTENCIA DE MATERIALES
FACULTAD DE IBIJEHIERIA D.A.G.
Informe de las pruetas de Resistencia de tiveda de
ladrillo de lama apoyada en viga de fierr».
Datos de Csnstruocijn.- La tiéveda se construya con
ladrillo de lama proaedente de "Tateposoo" con un claro
de 1.30 mtB. y una flecha de 3.9 eme. (3^ olaro) sóbre-
la tóveda ee colocó un bormigiSn de Cal y Jal hidratada-
de un espesor promedio de 7 eme. y por último se coloca
en la parte superior un enladrillado consistente de la-
drille de harro cocido con dimensiones 20 Z 20 X 1 eme*
Las dimensiones totales de las bóvedas fueron: 3*15 X -
2.69 mts. dando una superficie de 8,4735 M2. Se usa mor
tero de Cal y arena amarilla en proposiciones comunes.
Prueba.— Se carg6 la bóveda con sacos de arena de-
río que se fueron pesando independientemente, y colocan
do en la bóveda para dar una carga uniformemente repara*
tida en toda la superficie; ee midieron las deformacio-
nes de los arcos de bóveda así como las de las viguetas
de apoyOf llegando a tener una carga total de 16.033 ^g
y una deformación de 6.9& milimetros sin tener fallas —
considerables en todo el elemento estructural.
Resultados:
Resistencia de la bóveda sin llegar a la ruptura.
1892.92 Kg8/B2.
Deformación de toda estructura.
6.98 milimetrod.
No hubo fallas de consideración.
Resistencia del mortero 8.8 Eg8./cm2. a la compre-
sión.
Guadalajara, Jal. 10 da Diciembre de 1964.
lio del Río.
STRENGTH OF MATERIALS LABORATORY
SCHOOL OF ENGINEERING U.A.G.
Report of the strength tests of a vault of mud brick supported on
steel beams.
Construction data.- The vault was constructed of mud brick from
"Toteposco" with a span of 1 ,30 meters (4 feet 3,2 inches) and a rise of
3.9 centimeters (1 .5 inches), 3% of the span. Over the vault was placed
a concrete of Jal and hydrated lime of an overage thickness of 7 centi-
meters (2.8 inches), and lost, on the upper part was placed o firm paving
of burnt clay brick with dimensions 20 x 20 x 1 centimeters (7,9 x 7.9 x
0.4 inches) . The total dimensions of the vaults were: 3.15 x 2.69 meters
(10 feet 4.0 inches x 8 feet 9.9 inches) giving on area of 8.4735 square
meters (91 .2 square feet) . A mortar of lime and yellow sand in the usual
proportions was used.
Test.- The vault was loaded with sacks of river sand which were
weighed independently and were placed on the vault in order to give a
load uniformly distributed over the whole surface; the deformations of the
arches of the vault were measured as well as those of the supporting
beams, reaching a total load of 16,033 kilograms (35,350 pounds) and a
deformation of 6.98 millimeters (0.27 inch) without appreciable damage
in any structural element.
Results:
Strength of the vault without reoching failure
1,892.92 kilogroms/square meter
(388 pounds/square foot)
Deformation of the whole structure
6,98 millimeters
(0.28 inch)
There was no damage of importance.
Compressive strength of the mortar
8.8 kilogroms/square centimeter
(125 pounds/square inch)
Guada
a
ara.
Ja
isco
Decembe
Director
Engineer
r 10,
ofth
Carl
1964
s Laboratory
DS Trujillo de
1 Rio
39
^aadtab be ^ngenieibt (Shiil
Bnlmmtiafi Astáaana bi 9iutula|ai
Jmui^mrab» ■ 1< Bafimvlteb
Mnfaiual til ^áltc
Cfaibob SniStnitarÍB ^ftiitóminu
QUI. S-S5-3B
Oficina da Planeacidn de
Ciudad Universitaria Autánoma.
Atte. Arn. iiansoni.
Informe de laa pruebas de ííeaigtencia de
TOateri^lea aolicitaria por esa H, úficina.
1 .-
A.- Peso volumétrico del hormigán de Jal
'isado en bóvedas de la prueba reali-
zada en Oicierabre prdxlnio pasado.
IluálFICACIüK EN VCLtaiSN.
JAL 2
40
AH.íFí \':AaiLiA 1
CAL 0.75
AG a A 0.50
Peso volumétrico a la edad de
10 días 938.89 Kgs/M^
6 días 1047.60 Kgs/M^
B.- I.'ODULO DE HUPTURA.
2.535 Kgs/cm.^
C- RESIáTirCIA A LA COIirPRESION
la. grieta; 3.52 Kgs/om 2
Ruptura: 4.35 Kgs/om. 2
2o.- l'eso volumétrico del ladrillo de ba
rro recüoldo usado cono impermeaoilisante de bóvedas.
P£30 VOLUt.-iíRICO.
1464.29 Kga/cm2
Office of Planning of the
Autonomous University City
Attention: Architect Ransom
Report of the strength of materials tests requested by
that Honorable Office.
A.- Volumetric weight of the Jal concrete used in the
vaults in the test performed last December.
PROPORTION BY VOLUME
lAI
2
YELLOW SAND 1
LIMF
0.7.S
WATFR
n.-io
Volumetric weight at
lOdays 938.85>kg./m3 {58.5 lb./ft.= )
6days 1047.ó0kg./mJ (65.5 Ib./ft.M
B. MODULUS OF RUPTURE
2.535 kg./cm.' (36.1 lb./!n? )
C. COMPRESSIVE STRENGTH
Cracking: 3.52kg./cm; (50.0 Ib./in.' )
Rupture: 4.35 kg ./cm? (61 .9 Ib./in.M
2. - Volumetric weight of the burnt clay brick used to
moke the voults impermeable.
VOLUMETRIC WEIGHT
1 464. 29 kg ./m .3 (91.4 Ib./ft? )
41
J)[acultab be ^tigenirrta flihril
JnmHiorab» ■ !■ Buftiinlftaa
flintisil VnOitnttaiÍM ^linamm
Sfl. 5-95-36
3.- 3EFLEXI0N JO^AL DE LA BOV"£DA
6.98 mm.
DEFLEXION DS LA VIGA DE ACERO
2,446 mm,
DEFLEXION ti -ILATIVA 'JE LA "BÓVEDA.
6,98-2.446= 4.534 mm.
PEHALTE DE LA VIGA - 10"
CLARO DE LA VIGA - 2.67 Kts.
42
Atentamente
" CIENCIA Y LIBEaTAD "
Guadalajara, Jal., Abril 9 de 1965.
Encargado del Laboratorio de Resistencia de
Materiales.
ING. CARLOS J«ÍJILL0 DEL IilO
3. - TOTAL DEFLECTION OF THE VAULT
6.98 mm. (0.28 Inch)
DEFLECTION OF THE STEEL BEAM
2.446 mm. (0.10 inch)
RELATIVE DEFLECTION OF THE VAULT
6.98 - 2.446 = 4.534 mm. (0. 18 Inch)
DEPTH OF THE BEAM - 10 inches
SPAN OF THE BEAM - 2.67 meters (8 feet 9.2 inches)
Sincerely,
"SCIENCE AND LIBERTY"
Guadalajara, Jal., April 9, 1965
Director of the Strength of Materials Laboratory
Engineer Carlos Trujillo del Rio
43
APPENDIX B
CONVERSION FACTORS
BETWEEN METRIC AND ENGLISH UNITS
METRIC UNITS TO ENGLISH UNITS
1 meter = 39.37 inches
1 square meter = 10.76 square feet
1 kilogram = 2.205 pounds
1 kilogram/meter = 0.6721 pound/foot ^^
1 killogram/square centimeter = 14.22 pounds/sq. inch
1 kilogram/square meter = 0.2049 pound/sq. foot
1 kilogram/cubic meter = 0.06243 pound/cu. foot
ENGLISH UNITS TO METRIC UNITS
1 inch = 0.02540 meter
1 square foot = 0.09290 square meters
1 pound = 0.4536 kilogram
1 pound/foot = 1.488 kilogram/meter
1 pound/square inch = 0.07031 kilogram/square centimeter
1 pound/square foot = 4.883 kilograms/square meter
1 pound/cubic foot = 16.02 kilograms/cubic meter
DESIGN EVOLUTION
BY HARRY S. RANSOM
ASSOCIATE PROFESSOR OF ARCHITECTURE
LIST OF FIGURES
FIGURE 1. One way growth system 52
FIGURE 2. View of ceiling of "La Casa de las Artesanias" in
Guadalajara, showing doubly curved, two way vaults 53
FIGURE 3. Two way growth system 52
FIGURE 4. Forming of test structure, December 1965. Note small
wood pieces used for forms. Plywood is quite expensive.. 54
FIGURE 5. Reinforcing being placed in the test structure, 3
modules by 5 modules, two end modules cantilevered 54
FIGURE 6. Concrete being placed 54
FIGURE 7. Diagonal and circular doubly curved vaults constructed
for study purposes 54
FIGURE 8. Diagonal vault completed. Labor time; 3 hours, 45
minutes. Labor time for circular vault; 7 hours 55
FIGURE 9. Forms removed; the effect of the concrete coffered
ceiling 55
FIGURE 10. The diagonal vault system. Electrical outlet box
fully recessed in brick depth 55
FIGURE 11. Rectangular brick vault. Labor time; 1 hour, 10
minutes. This is the vaulting system that will be
used in the new university buildings 55
FIGURE 12. Aerial view of model of the proposed campus 56
The preceding sections of this report technically document the
structural capacity of a traditional regional building technique:
the building of brick barrel vaults.
In the architectural programming for all of the proposed new
buildings for the Universidad Autónoma de Guadalajara it
became evident that a system of architectural flexibility must
be an integral part of the structural skeleton. It is imperative
that, with relative ease, walls may be relocated, modules
added, spaces rearranged. Versatility is essential. The barrel
brick vault system satisfied these requirements to a workable
degree. But it was recognized as basically a one-way growth
system with the opportunity to expand or move in only one
direction. For example, partitions can be only reasonably
relocated at the supporting beams, framing in the same
direction (Fig. 1).
A two-way directional system was therefore desired so that
expansibility could occur in either of two directions. Such a sys-
tem can be seen today (Fig. 2) in one building in Guadalajara,
"La Casa de las Artesanías." In this handsome structure two-
way doubly curved brick vaults are employed, spanning
approximately 16 feet and supported upon square steel-framed
bays. But elaborate formwork was necessary to achieve this
striking result.
Consequently, a subsequent series of tests was undertaken
by the architectural design group in Guadalajara to discover
that dimension of supporting structural network that would
permit the doubly curved brick vaults to be constructed with-
out the use of forms; and to retain a low rise of the vault
capable of inclusion within a normal ceiling-floor thickness
(Fig. 3).
Several trial-and-error, full-size tests were conducted; calcu-
lations reviewed and refined; and visual details studied. To
transcribe all of the testing procedures would make this investi-
gation a purely text oriented writing. Suffice to say that the
original tests acted as a springboard for the development of
a more sophisticated method of building vaults of brick; in
this instance, doubly curved brick vaults — built without the
use of forms — spanning 5'-2^Ir" (1.60 meters) rising 3.9" (10
centimeters). These vaults are in turn supported upon an
aggregate network of reinforced concrete beams and columns.
The underside of the brick vaults will be exposed to take
advantage of their rich color and textura! surface (Fig. 4-11).
This evolved system then becomes the structural design
determinant for all of the architecture of the new campus of
the Universidad Autónoma de Guadalajara — a system rich in
both the past and the present (Fig. 12).
51
FIGURE 1. One way growth system.
FIGURE 2. View of ceiling of "La Casa de las Artesanías" in Guadalajara, í>
showing doubly curved, two way vaults.
FIGURE 3. Two way growth system.
w\
mt,:»
'M- *
mmmm0mm0mt0mmmmBÍmgmí0^m
'if >
4
54
FIGURE 4. Forming of test structure, December 1965. Note small wood
pieces used for forms. Plywood is quite expensive.
FIGURE 6. Concrete being placed.
FIGURE 5. Reinforcing being placed in the test structure, 3 modules by
5 modules, two end modules cantilevered.
FIGURE 7. Diagonal and circular doubly curved vaults constructed for
study purposes.
- ^-^.
FIGURE 8. Diagonal vault completed. Labor time; 3 hours, 45 minutes.
Labor time for circular vault; 7 hours.
FIGURE 9. Forms removed; the effect of the concrete coffered ceiling
FIGURE 10. The diagonal vault system. Electrical outlet box fully recessed
in brick depth.
FIGURE 11. Rectangular brick vault. Labor time; ^ hour, 10 minutes. This
is the vaulting system that will be used in the new university
buildings.
55
^ >yy
t
»
;.vv.i
FIGURE 12. Aerial view of model of the proposed campus.
56
ARCHITECTURE AT RICE SERIES
, 1 ON PEOPLE AND THINGS, William W. Caudill, September 1961
2 UNITED NATIONS' CONFERENCE ON NEW SOURCES OF ENERGY, Paul Jacques Grillo, October 1961
3 RICE PRECEPTORSHIP PROGRAM, William W. Caudill, December 1961
4 ALVAR AALTO AND THE ARCHITECTURE OF FINLAND, Scott D. Hamilton, Jr., March 1962
5 THE ALUMNUS CRITIC PROGRAM, Morton L, Levy, Jr., May 1962
6 ARCHITECTURE FOR OUR TIMES, Howard E. Eilenberger, Author; L. James McCuIlar, Illustrator, June 1962
7 THE PEOPLE'S ARCHITECTS, William W. Caudill, March 1963
8 SKETCHES, Charles Schorre, Special Editor, April 1963
9 WILLIAM WARD WATKIN TRAVELING FELLOWSHIP WINNERS, Coryl LaRue Jones, May 1963
10 THREE CITIES, Paul Jacques Grillo, September 1963
11 THE AESTHETICS OF FOLDED PLATES, Clovis B. Heimsath, January 1964
12 AN EVALUATION— THE RICE PRECEPTORSHIP PROGRAM, Coryl LaRue Jones, April 1964
13 THE RICE DESIGN FETE, AN EXPERIMENT IN EXPERIENCE, Coryl LaRue Jones, Author, Maurice Miller, Photographer, June 1964
14 FOUR PLANNING CONCEPTS FOR BAY CITY, TEXAS, William T. Cannady & Architecture 300 Students, September 1964
15 THE CONCEPT OF PLASTIC FORM, Bill N. Lacy and Frank S. Kelly, April 1965
16 LAKE HOUSTON DEVELOPMENT STUDIES, William T. Cannady & Architecture 300 Students, August 1965
17 POBLACIÓN ALMIRANTE GOMEZ CARRENO, Andrew Belschner, February 1966
18 VAULTED BRICK CONSTRUCTION IN GUADALAJARA, Nat W. Krahl and Harry S. Ransom, June 1966
with a foreword by Carey Croneis, August 1966
Direct requests to Publications, School of Architecture, Rice University, Houston, Texas 77001
©ARCHITECTURE AT RICE, 1966. All contents are the sole possession of the contributors; partial or total
reproduction of the material herein contained is prohibited by law.
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