U.S. patent application number 13/636981 was filed with the patent office on 2013-08-08 for system for reinforcing structure using site-customized materials.
The applicant listed for this patent is Edward Fyfe, Michael Karantzikis. Invention is credited to Edward Fyfe, Michael Karantzikis.
Application Number | 20130199715 13/636981 |
Document ID | / |
Family ID | 44673477 |
Filed Date | 2013-08-08 |
United States Patent
Application |
20130199715 |
Kind Code |
A1 |
Fyfe; Edward ; et
al. |
August 8, 2013 |
SYSTEM FOR REINFORCING STRUCTURE USING SITE-CUSTOMIZED
MATERIALS
Abstract
System and method for reinforcing structures includes basalt
textile (20) connected to surfaces of the structure (100) with
fiber anchors (30). Textile spreads forces and increases ductility
of structure. Textile may connect multiple structural elements
together, including walls, floors, columns, beams, and roofs.
Textile is covered with mortar (50) customized to match color and
texture of structure by use of locally obtained grit, aggregate, or
colorant. Basalt fiber textile is preferred to avoid degradation of
textile from alkaline components of mortar (50).
Inventors: |
Fyfe; Edward; (San Diego,
CA) ; Karantzikis; Michael; (San Diego, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Fyfe; Edward
Karantzikis; Michael |
San Diego
San Diego |
CA
CA |
US
US |
|
|
Family ID: |
44673477 |
Appl. No.: |
13/636981 |
Filed: |
March 24, 2010 |
PCT Filed: |
March 24, 2010 |
PCT NO: |
PCT/US10/00864 |
371 Date: |
January 30, 2013 |
Current U.S.
Class: |
156/252 ;
156/278; 156/279; 52/432 |
Current CPC
Class: |
E04F 13/0885 20130101;
E04C 5/00 20130101; E04G 2023/0251 20130101; E04C 5/07 20130101;
E04G 23/0218 20130101; Y10T 156/1056 20150115 |
Class at
Publication: |
156/252 ;
156/279; 156/278; 52/432 |
International
Class: |
E04C 5/00 20060101
E04C005/00; E04F 13/08 20060101 E04F013/08 |
Claims
1. A method of reinforcing structures; including the steps of:
attaching a textile composed of alkaline-resistant fibers to a
surface of the structure to be reinforced; and spreading a layer of
a hardenable slurry over the attached textile such that the slurry
covers and embeds the textile; the slurry including mineral
particles that are similar in texture, color, or both, to the
original surface of the structure.
2. The method of claim 1, the step of attaching a textile
comprising the sub-steps of: spreading a fabric composed of basalt
fibers over a surface of the structure; and attaching the fabric to
the surface with ductile attachment means.
3. The method of claim 1, wherein the step of: attaching the fabric
to the surface with ductile attachment means comprises the
sub-steps of: boring a hole through the alkaline-resistant fabric
and into the structure; inserting a length of fiber roving into the
borehole, with a free end protruding above the fabric; backfilling
the borehole with suitable backfill material; and attaching the
free end of the roving over the fabric with a suitable
adhesive.
4. The method of claim 1, the step of spreading a layer of
hardenable slurry over the fabric comprising: spreading a slurry
containing cementitious or polymer matrix and further including
mineral materials quarried in a location geographically close to
the structure to be repaired.
5. The method of claim 4, the step of spreading a layer of slurry
containing sand, ground rock, or minerals comprising: spreading a
slurry including sand, ground rock, or mineral materials that
produces a finished appearance substantially the same in color and
texture as the original surface of the structure.
6. The method of claim 1, further including the steps of: spreading
a bottom layer of hardenable slurry containing mineral particles
directly over the surface of the structure.
7. A method of reinforcing a structure including the steps of:
creating a customized surface finishing mortar by mixing mineral
materials with a hardenable fluid matrix; the customized surface
finishing mortar formulated so as to produce a finished appearance
substantially the same in color and texture as the original surface
of the structure; spreading a fabric composed of alkaline-resistant
fibers over surfaces of the structure to be reinforced; attaching
the fabric to the structure by ductile attachment means; and
spreading a layer of customized surface finishing mortar over the
attached fabric.
8. The method of claim 7; the step of creating a customized surface
finishing mortar further including: obtaining mineral materials
from a source geographically local to the structure.
9. The method of claim 7, the step of spreading a fabric
comprising: spreading a fabric composed of alkaline-resistant
fibers over one or more surfaces of the structure to be
reinforced.
10. The method of claim 7, wherein the step of creating a
customized surface finishing material includes the sub-steps of:
obtaining a suitable hardenable fluid matrix from the group of:
cementitious mortar, ductile cement, epoxy, polyurethane, or
acrylic.
11. The method of claim 7, wherein the structure to be reinforced
is a historical building that must substantially retain its
original appearance after being reinforced.
12. The method of claim 7, the step of spreading a fabric
comprising: spreading a fabric composed of basalt fibers over one
or more surfaces of the structure to be reinforced.
13. A system for reinforcement of a structure; including:
alkaline-resistant textile substantially covering a structural
element of the structure to be reinforced; ductile connecting means
for connecting said textile to the structural element; and mortar
including: mineral materials selected to match the existing color,
texture, or both of the structure.
14. The system of claim 13, said alkaline-resistant textile
comprising: a fabric woven from fibers of basalt.
15. The system of claim 13, said ductile connecting means
comprising: a plurality of fiber anchors.
16. The system of claim 13, said mineral materials including at
least one component obtained geographically close to the structure
being reinforced.
Description
FIELD OF THE INVENTION
[0001] The present invention relates in general to reinforcing
structures and more particularly to materials for strengthening
existing structures without substantial change to the appearance of
the structures.
BACKGROUND OF THE INVENTION
[0002] Many existing buildings throughout the world are in need of
reinforcement to help them resist damage by earthquake, violent
storms, acidic atmosphere, vibrations due to vehicle traffic, or
similar threats. Many older buildings, especially, were designed to
handle large compressive forces but are not resistant to lateral
forces.
[0003] Buildings that are not resistant to sudden lateral force
need to be reinforced for the safety of people who live or work in,
or visit the building. Some buildings have considerable historical
or artistic value and must be protected from disasters and
environmental deterioration for their own sakes.
[0004] Some methods exist for reinforcing existing buildings. One
that is used all over the world is wrapping a structure with
fiberglass textile that is impregnated with epoxy. This method is
taught in different forms in U.S. Pat. Nos. 5,043,033, 5,649,398,
and 5,657,595. A means of connecting different components of a
structure using ductile fiber anchors is taught in U.S. Pat. No.
7,207,149 and incorporated herein by reference.
[0005] The methods of U.S. Pat. Nos. 5,043,033, 5,649,398, and
5,657,595 are effective and can be performed with little intrusion
on the occupants and visitors of the building being reinforced. A
disadvantage to these methods is that they use some specialized
materials that are not readily available in all locations. As a
result, the materials are shipped from centralized distribution
centers, sometimes to remote locations that are difficult to reach.
The shipping and round transportation of heavy materials adds
significantly to the cost of the project.
[0006] Another disadvantage of the wrapping methods is that the
materials readily available on the market are not good matches in
color and texture with old buildings. There are many buildings all
over the world that are constructed of native stone, brick from
local clay, or that are coated with plaster made with local
minerals. As a result, the materials of the methods mentioned
above, such as epoxy and fiberglass, may not match the color or
texture of a given building.
[0007] Yet another disadvantage to the method discussed above is
that some of the materials, particularly epoxy, are less fire
resistant than conventional stone, brick, or plaster construction.
It is desirable that a method for increasing a building's strength
should also increase its fire-resistance, or at least not degrade
it.
[0008] To avoid the disadvantage of the flammability of epoxy or
other organic polymers, the textile could be coated with an
inorganic hardenable paste such as mortar. However, this leads to a
different disadvantage, which is that inorganic mortars are
alkaline and tend to degrade ordinary fiberglass. Special
alkaline-resistant glass textile is available, but is quite
expensive. This has discouraged the use of glass textile with
mortar for reinforcement of structures. Graphite carbon or aramid
fiber textiles would be compatible with mortar, but these textiles
are also very expensive and not widely available in all
countries.
SUMMARY OF THE INVENTION
[0009] The present invention is a system of materials and methods
for reinforcing structures using some locally derived materials.
The system includes a textile wrap attached to the structure with
fiber anchors and a finishing layer of mortar made with grit and
aggregate that was obtained from sources in the vicinity of the
structure being reinforced.
[0010] The textile is composed of fibrous basalt, which is
resistant to alkaline and compatible with inorganic mortar. The
textile is typically an open-weave fabric that is strong and
ductile. The fabric is attached to the structure in a ductile
manner, such as with fiber anchors as taught in U.S. Pat. No.
7,207,149. The fiber anchors are preferably also created from
basalt fiber.
[0011] A mortar finishing material is mixed, beginning with a
hardenable liquid matrix, such as slurry of calcined mineral
particles that harden to create a solid mortar after being mixed
with water. Grit, aggregate, or both are added to the hardenable
liquid matrix. The grit or aggregate add color and texture to the
mortar finishing material.
[0012] The reinforcing system is intrinsically fire resistant and
does not increase the fire risk to a structure.
[0013] By using grit and aggregate that are mined or quarried
locally, it is often possible to match the color and texture of the
original building very well. The final appearance of the reinforced
structure is relatively unchanged from the original, possibly
historic, appearance. Further, the ability to use local mineral
materials saves money on shipping material to a remote
location.
[0014] Utilizing local minerals for the mortar finishing material
is made possible by the use of basalt fiber textile and fiber
anchors.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a top plan view, partly cut away, of the
reinforcement system of the present invention, as used to
strengthen a wall of a building.
[0016] FIG. 2 is a sectional view, taken on line 2-2 of FIG. 1.
[0017] FIG. 3 is a top plan view of the reinforcement system of the
present invention, as used to strengthen an expansion joint of a
structure.
[0018] FIG. 4 is a sectional view, taken on line 4-4 of FIG. 3.
DETAILED DESCRIPTION OF THE INVENTION
[0019] FIG. 1 is a top plan view of the reinforcement system 10 of
the present invention, partly cut away. FIG. 2 is a sectional view
of reinforcement system 10, taken on line 2-2 of FIG. 1, as used to
strengthen a structure 100, for example a wall 110 of a
building.
[0020] Reinforcement system 10 include alkaline-resistant textile
20 stretched over wall 110. Textile 20 is attached to wall 110 with
a plurality of fiber anchors 30. A mortar 50, containing mineral
products preferably obtained in the same geographic region as
structure 100, is spread over textile 20 and fiber anchors 30.
[0021] Textile 20 is preferably a lightweight, mesh fabric, woven
or knit of suitable ductile, strong, and alkaline resistant fibers
such as basalt. Conventionally, structures have been reinforced
with fabrics made of glass fibers. Ordinary glass fabric must be
covered with a protective finishing material that is pH neutral,
that is, neither strongly alkaline nor acidic. Many alkaline or
acidic materials, including cementitious materials such as mortar
and concrete, degrade glass and weaken it. For this reason,
structural reinforcing systems that include glass fiber fabric also
typically include a finishing layer of epoxy or polyurethane, which
are substantially neutral.
[0022] Of course, other alkaline-resistant fibers with good
ductility and high tensile strength may be used to create textile
20 in place of basalt. The choice of specific fiber for textile 20
may be made for each application based upon availability, strength,
and cost. Basalt is found to be the preferred material at this
time, but other materials may become available in the future.
[0023] Test results show that system 10 greatly increases the
load-bearing ability of wall 110 even if the weave of textile 20
includes openings as wide as three or four inches across, although
1 inch across is a more typical size. A plain or twill weave with
square or rectangular openings has been found to be convenient to
apply and to provide sufficient strength and ductility. Textile 20
is typically woven from yarns or bundles consisting of many
individual thin filaments of basalt fiber.
[0024] Textile 20 is stretched over surfaces of various structural
elements of a structure 100 to be reinforced. Panels of textile 20
may be wrapped over interior or exterior corners so as to connect
different walls 110, or to connect a wall 110 to a ceiling, or
other combinations as appropriate. Textile 20 may be temporarily
attached to wall 110 by suitable clips, staples, or adhesive.
[0025] In the case of structures 100 that are built of fragile
materials, or that have been damaged by weathering or environmental
degradation, it is preferable that the mesh opening size be small,
such as 0.5 inch across.
[0026] Many types of structural element can be reinforced by using
textile 20 to connect walls 110 to floors or ceilings, columns or
beams to ceilings, roofs to walls 110, and so on.
[0027] The next step in the reinforcement method is to permanently
attach textile 20 to wall 110 or other structure using suitable
ductile connecting means, such as a plurality of fiber anchors 30,
as are well known in the art. Fiber anchors 30 are created by
boring a hole through an opening in textile 20 and into the
underlying wall 110. A length of fiber roving, preferably also
composed of fibrous basalt, is inserted into the borehole with a
free end extending above textile 20.
[0028] A backfill material, such as grout or polymeric adhesive, is
pushed or injected into the borehole. The free end of the roving is
attached to the outer surface of wall 110 and over textile 20, such
as with adhesive or mortar. The backfill material retains the
roving within the borehole such that fiber anchor 30 forms a sort
of large pin attaching textile 20 to wall 110. Fiber anchor 30 is
the most preferred ductile connecting means for system 10 because
fiber anchor 30 spreads forces over a broad area and so is unlikely
to pull out from wall 110 as a mechanical fastener might, or pull
off a section of wall 110 as a surface adhesive might.
[0029] The final process is to cover textile 10 and fiber anchors
30 with a mortar finish coat 50. Mortar finish coat 50 covers
textile 20 so that it will not be damaged by weather, or snagged.
Mortar 50 contacts and adheres to the original surface of wall 110
through the openings of the weave of textile 20, embedding textile
20 and helping spread any large lateral forces such as from
earthquake or wind. Mortar 50 mechanically holds textile 20 in
place near wall 110 but cannot entirely take the place of ductile
connection means such as fiber anchors 30.
[0030] Mortar finish coat 50 is largely for creating a uniformly
textured and colored surface for the reinforced wall 110.
Conventional epoxy and glass fiber textile reinforcement typically
gives a structure a smoother texture and slightly hazy coloration.
Although the epoxy can be covered with paint of other finish,
mortar is not advised due to possible degradation of the glass
fiber.
[0031] Mortar finish coat 50 works well for replicating the
appearance of original concrete, stucco, or plaster walls 110. With
additional modeling and coloring work, mortar finish 50 can even
replicate the appearance of historical stone or brick walls
110.
[0032] Mortar 50 is customized to suit the structure to be
reinforced. Typically, mortar 50 is based on a matrix of hardenable
paste, such as ductile concrete. Uncured ductile concrete may be
termed a slurry, that is, a mixture of solid particles suspended in
a liquid, with sufficient viscosity or surface tension that the
particles remain suspended for a long time and yield a mixture that
can be handled like a liquid or paste.
[0033] Ductile concrete is not typically used as a finish coat for
homes, historical buildings, or other structures where appearance
is important but a modern "industrial" look is not desired.
However, it is a strong, ductile material that is less likely to
crack under lateral forces than standard concrete.
[0034] Other matrix materials such as organic polymers or other
inorganic cementitious materials may also be used to create mortar
50.
[0035] Generally, building materials such as stone, brick, and
adobe are not transported farther than necessary. As a result,
structures in a given country or geographic area tend to have
distinctive appearances. To customize mortar 50, it is preferred
that mineral materials are used that are similar to those used for
the structure originally.
[0036] In the case of historical buildings, it is often desirable
to determine the components of the original materials, such as by
microscopic examination or chemical analysis.
[0037] For example, many older public buildings in the American
Midwest are of the tan stone call Indiana limestone. In the
American Southwest, many historical buildings are of adobe bricks,
which vary in color depending upon the iron content of the local
clay.
[0038] Thus, to reinforce a structure in the Midwest it might be
appropriate to incorporate ground limestone into mortar 50 to
produce a smooth tan surface on the reinforced structure. In the
Southwest, adobe clay or ground sandstone might be added to mortar
50 to make it resemble brick or stone.
[0039] Mineral materials obtained locally may include sand, clay,
gravel, ground stone, or mineral colorants. Although the minerals
used for customized mortar finish coat 50 are described herein as
locally obtained, it is to be understood that the mineral materials
are to be obtained preferably from the same source as the materials
of the original structure. For example, if an historical structure
in Indonesia was built originally of imported Italian marble, it
may be aesthetically desirable to obtain material from the same
quarry in Italy to customize mortar 50 if reinforcing the structure
in Indonesia.
[0040] An alternative embodiment of reinforcing system 10 is
illustrated in FIGS. 3 and 4. FIG. 3 is a top plan view of
reinforcement system 10, as used to strengthen an expansion joint
122 of a structure, such as a bridge 120. FIG. 4 is a sectional
view; taken on line 4-4 of expansion joint 122 of FIG. 3.
[0041] Expansion joint 122 is a design feature of bridge 120. It is
a gap of a few inches width, left between sections of bridge 120 to
allow for thermal expansion of the bridge material. The gap of
expansion joint 122 is typically filled to provide a smooth surface
for traffic.
[0042] The filling of expansion joint 122 must be of a material
that is ductile and will not interfere with the function of
expansion joint 122. The alternative embodiment of reinforcing
system 10 as illustrated in FIGS. 3 and 4 has been found to be a
low cost and very effective way of dressing expansion joint
122.
[0043] Expansion joint 122 has been created with a recess 125 to be
filled to provide a smooth upper surface. To fill expansion joint
122 using system 10 of the present invention, a first layer of
mortar 50 is laid into recess 125, filling recess 125 approximately
halfway. Next, a strip of textile 20, as described above, is laid
over mortar 50. A second layer of mortar 50 is poured or spread
over textile 20 to fill recess 125 to the desired level. Mortar 50
may be textured as desired or left in the as-applied state. Fiber
anchors 30 are typically not required for this embodiment of system
10.
[0044] It may be noted that reinforcement system 10, as practiced
for reinforcing structures such as buildings, may be optionally
installed similarly to the method of filling expansion joints 122.
That is, a first layer of mortar 50 may be spread on the original
wall 110 of the structure, then textile 20 attached over the first
layer of mortar 50. Fiber anchors 30 are preferably still employed
as detailed above. Fiber anchors 30 are preferably installed after
the first layer of mortar 50. A second layer of mortar 50 is
applied over textile 20 and fiber anchors 30, then finished, also
as described above.
[0045] This method of practicing the present invention is
especially useful in the case of buildings that are constructed of
fragile materials, or that have been weakened by weather,
degradation by pollution, or earthquakes. Another precaution taken
in the case of fragile buildings is to create a borehole for fiber
anchor 30 that is deeper than is typically used for a strong matrix
such as undamaged concrete.
[0046] Although particular embodiments of the invention have been
illustrated and described, various changes may be made in the form,
composition, construction, and arrangement of the parts herein
without sacrificing any of its advantages. Therefore, it is to be
understood that all matter herein is to be interpreted as
illustrative and not in any limiting sense, and it is intended to
cover in the appended claims such modifications as come within the
true spirit and scope of the invention.
* * * * *