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Full text of "Vaulted brick construction in Guadalajara"

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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 




^^í-íS;;:^-;--jt-:-^-:\'^^-^-H' 


~^;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 adv anced 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! 




Bi iÜm » H iift 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 

J m u i^m rab» ■ 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 




J nmHio rab» ■ !■ 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.