The Kimbell Art Museum features a unique vaulted concrete roof structural system that provides an impression of simplicity from the outside but hides layers of complexity. The roof acts as a series of arches that counteract outward thrust and are supported only by corner columns. Beams hang from the roof and act in tension through post-tensioning. Together, the roof, beams, and post-tensioning tendons form an integrated structural whole that eliminates the need for visible load-bearing walls.

1. The Kimbell is a unique building which upon first inspection appears rather
simple; however, closer scrutiny of the construction documents and
multitudinous detailed sketches reveals layers of complexity seemingly in
the service of this initial perception of the building.
Which parts of the Kimbell are structural?
The structural impression of the Kimbell encountered by visitors to the site is
of a simple, repetitive rectangular bay system with a vaulted roof. This
observation is misleading because, by and large, vaulted roof structures
organized over a rectangular bay system are supported by massive bearing
walls along their length and at their ends. The requisite long, massive
bearing walls are seemingly present as large, travertine clad partitions which
run directly underneath the springing line of the vault. However, when one
approaches the building it can be seen that entire sections of the supposed
bearing wall are absent.
Then how the structure stands?
The answer to this question is modern concrete technology.
According to the drawings and force diagrams, the only members in the
building which are transmitting load to the foundations vertically are
columns at the extreme four corners of the vaulted roof sections. These

2. heavily reinforced concrete columns are topped with thickened concrete
arch-caps at either end of the vault which carry the weight of the roof shell
and its underlying beams. The beams in this system are extraordinary as they
are carried by the vaulted roof. The roof is the star of the structural system
because it maintains a thickness of only four inches and integrates several
structural functions into one elegant member.
In actuality, the roof of the Kimbell is not technically a vault because it is a
cycloid in section. A cycloid is the curve traced by a point on the
circumference of a circle that rolls on a straight line. This distinction is
significant structurally because the edges of the cycloid shape which rest on
the beam are tangent to that beam, thus allowing the roof to transmit loads
to the columns via pure compression.
How does the roof function within this structural system?
Structurally, the roof acts as a series of arches repeated in front of one
another along the length of the 102 foot span. The reinforced concrete
partitions between skylights in the apex of the roof complete the arch and tie

3. the two halves of the shell together into one structural unit. The outward
thrust of these stacked arches is counteracted by another set of arches that
span lengthwise within the concrete via draped posttensioning tendons.
Thrust produced by these longitudinal arches is countered by the tendons
which terminate within the arch-caps on either end of the vault.
The structural function of the roof shell is particularly well suited to the
composite nature of reinforced concrete because the amorphous concrete
can be molded into a relatively thin compressive shell which clings to the
embedded tensional steel reinforcement.
In the Kimbell, the composite properties of reinforced concrete are exploited
so as to resolve this dilemma of missing load bearing walls within the
concrete itself thereby obviating the need for an unsightly, exterior solution.
The response to this problem was to create “hidden” longitudinal arches
within the concrete roof shell which counteract the outward thrust of the
traditional arches and span the length of the vaults (102 feet). These
“hidden” arches were created by placing arch shaped sections of concrete
into compression along the length of the vaults vis a vis the draped post-
tensioning tendons. Holistically, the concrete within the roof shell is
segregated into several strategically placed areas within which varying
degrees of initial compressive stress are stored. An important realization at
this point is that all of the concrete is under some degree of compression,
and all of the tendons are under some degree of tension. The end result of

4. this structural complexity is a composite structure which integrates several
structural functions into a visually simple form.
How do the beams function within this structural system?
In general, the beams act as structural stabilizers which hang from the
bottom edges of the vaulted shells. These beams are connected to the roof
shell structure by reinforcement bar sticking out of the beam and into the
concrete shell at closely spaced intervals along the entire 102 foot span.
Specifically, the beams act in tension to counteract the tendency of the vault
to bow under its own weight. How can a concrete beam act in tension? As in
the roof shells, the beams are post-tensioned to produce a large compressive
force within the beam prior to loading. This compressive force is lessened
due to the use of the member in tension; however, the net force acting in the
beam after loading is still compressive in nature. Once more, the composite
nature of reinforced concrete is used to allow it to serve a function.
The result is a seemingly monolithic and seamless integration of the beam
and roof to the extent that neither element is visually distinct.

5. This Building includes galleries
for exhibitions, the museum's
library, an auditorium; capacity
of 180 spectators, an art
library, a laboratory for
conservation of works of art
and a restaurant.
Inside the galleries the
architect included three yards, created from the vaults of the court
Air ducts and mechanical services are located in the spaces where edges of
vaults come close to meeting.

6. PLAN OF KIMBELL ART MUSEUM
Traventine, concrete and white oak are the major key materials.
The symmetry of design is enhanced by the use of natural materials like
travertine and white oak, combined with glass, concrete, stainless steel and
aluminum.

7. The finely textured, unblemished surface serves to reduce glare and provide
a glowing interior presence which changes according to season and daily
climate. Bare concrete gives silvery appearance to the natural sunlight.
These skylights were the main focus of design. It creates elegant spaces for
the art it houses. The skylights are made such that it itself divides the
galleries itself into three parts. Skylights are such that they do not allow
direct light to come in but diffused sunlight so that it does not harm the
visitors. These are rimmed with narrow
plexiglass skylights Below these skylights
pierced-aluminum reflectors shaped like
wings hang to diffuse the light.

8. When light falls smooth surfaces of the concrete vault get illuminated and
provide elegant and enchanting light conditions and give the building its
loftiness as well as its intimacy.
On the front facade three 100-foot bays that are each fronted by a barrel-
vaulted portico comprise the main facade to the west, where the central
entrance is marked by its glazing and recession from the rest of the facade.
Its surrounding ambience, calm facade and beautiful view make it a very
simple, elegant and well-proportioned design. Front has a large water pond
and a suburban park .Porches and reflecting pools look out upon a park
setting, along with intimate courtyards variously adorned with sculpture,
plants, and a fountain, and contribute to the serene atmosphere.

9. Three courtyards are there which allow more light, air flow inside and bring
exterior inside with natural beautiful elements .GEOMETRY is kept simple
yet elegant. There are grand open courtyards so as to open up the building
and bring in more light and nature. Beautified interiors walls and floor
cladded with Traventine tiles and roof with concrete having glass and
perforated Aluminium fittings. Galleries were kept on the second floor so
that they get more exposed to the light coming from ceilings. Sides were
perforated but not the center so as to avoid UV rays to fall on the people
inside the corridors.
Kahn gave a deep thought to the use of materials. He thought that giving a
rich look on the ceilings will attract eyes of visitors on the ceiling but
ultimately they find nothing much useful there and will shift to the walls
which are not that attractive comparatively and can’t hold gaze for long and
ultimately it shifts to the works kept there.

10. Served-spaces for gallery, gathering, dining, sales, etc surrounded by the
gentle travertine tile, are more important.
The servant-space used for air conditioning, electric, plumbing, etc. is
enclosed by plain gray concrete, and brushed steel or aluminum fixtures.
It was the new building basically built to provide extra gallery spaces to be
used for classrooms and studios. Auditorium is acoustically impressive and
considerably large. Initially there was an option kept to expand the old
building itself but later on the plan was changed because they did not want

11. to disturb the unique graceful and the most famous design by Louis I Kahn .
Kahn while designing had never thought of parking space because he never
drove a car and he expected that people will come by foot and will enter
from front side only but later parking was provided on the side garden that
was present there and which directed the entry of people from the rear side.
So to solve the problem Renzo Piano made a building just in front of it and
the parking is provided in between both of these building to guide the entry
as Kahn thought of from the front of both the buildings. Respecting the
Kahn’s design - the front will echo the height, width and the three-bay
structure of Kahn's plan.
 The inflexibility of the design of the museum, the design was so rigid
that there was no scope of either horizontal or vertical expansion
 In spite of the fact that walls were not load bearing, they were made
permanent. Instead they could have been just temporary partitions
which could be opened at the time of need
 Another problem with the old building was with the parking which
was restrained and unplanned. It lead to the entry of the visitors from
the backside instead of front