U.S. patent application number 17/506702 was filed with the patent office on 2022-07-21 for construction process for quickly and integrally replacing damaged pavement slab without suspending flights of civil aviation.
The applicant listed for this patent is CHINA RAILWAY BEIJING ENGINEERING GROUP CO., LTD. Invention is credited to Gaoling Bai, Zheng Jiang, Min Jin, Tingrong Liu, Jianguo Wang, Yan Wang, Wenxiu Zhang.
Application Number | 20220228323 17/506702 |
Document ID | / |
Family ID | |
Filed Date | 2022-07-21 |
United States Patent
Application |
20220228323 |
Kind Code |
A1 |
Wang; Jianguo ; et
al. |
July 21, 2022 |
CONSTRUCTION PROCESS FOR QUICKLY AND INTEGRALLY REPLACING DAMAGED
PAVEMENT SLAB WITHOUT SUSPENDING FLIGHTS OF CIVIL AVIATION
Abstract
A construction process for quickly and integrally replacing a
damaged pavement slab without suspending flights of civil aviation
is provided according to embodiments of the present application,
including: a first stage: reinforcing a foundation of a damaged
pavement slab by grouting; and a second stage: integrally replacing
the damaged slab with early-strength and quick-drying concrete. The
construction process of fast overall replacement of a damaged
pavement slab in civil aviation non-suspend construction provided
by the embodiments of the present application solves the
limitations of the traditional pavement slab repair process well.
The present application first reinforces the damaged pavement slab
foundation through grouting construction to solve the problems of
slab bottom vacancy, foundation settlement, and insufficient
bearing capacity of the base layer; then uses the early-strength
rapid-curing concrete suitable for rapid overall slab replacement
of the pavement to carry out overall replacement construction for
the damaged pavement slab.
Inventors: |
Wang; Jianguo; (Beijing,
CN) ; Liu; Tingrong; (Beijing, CN) ; Jin;
Min; (Beijing, CN) ; Jiang; Zheng; (Beijing,
CN) ; Bai; Gaoling; (Beijing, CN) ; Wang;
Yan; (Beijing, CN) ; Zhang; Wenxiu; (Beijing,
CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CHINA RAILWAY BEIJING ENGINEERING GROUP CO., LTD |
Beijing |
|
CN |
|
|
Appl. No.: |
17/506702 |
Filed: |
October 21, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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PCT/CN2021/105043 |
Jul 7, 2021 |
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17506702 |
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International
Class: |
E01C 7/14 20060101
E01C007/14; E01C 3/00 20060101 E01C003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 15, 2021 |
CN |
202110052087.7 |
Claims
1. A construction process for quickly and integrally replacing a
damaged pavement slab without suspending flights of civil aviation,
comprising: a first stage: reinforcing a foundation of a damaged
pavement slab by grouting; and a second stage: integrally replacing
the damaged slab with early-strength and quick-drying concrete.
2. The construction process according to claim 1, wherein the first
stage comprises: (1) positioning of a slab to be grouted:
positioning and marking the damaged slab and adjacent slabs
thereof; (2) positioning of grout holes: arranging the grout holes
according to an effective diffusion radius of slurry, and shape and
size of the pavement slab; (3) drilling and blowing holes: drilling
holes on the pavement to penetrate a base layer into a soil
subgrade, and blowing the holes to clean dust in the holes after
the drilling is completed, wherein the grouting is performed after
the blowing is completed; (4) preparing of slurry: preparing slurry
while positioning the grout holes in the site; (5) grouting:
grouting the slurry into the grout holes; (6) pressure relief and
sealing holes: after the grouting is completed, pulling out a
grouting tube when a grouting pressure is dissipated; and after the
grouting tube is pulled out, sealing the holes with a quick-drying
cement mortar; (7) testing of grouting effect: performing HWD
deflection test on the grouted reinforcement area 28 days later
after the grouting is completed, to determine whether slab edge
deflection/slab interior deflection<2 and slab corner
deflection/slab interior deflection<3, which indicate a good
status of the foundation, and if yes, performing a next stage of
replacement construction; and if not, performing the above steps
(1) to (6) until the test results meet the above requirements.
3. The construction process according to claim 1, wherein the
second stage comprises: (1) selecting of quick-drying concrete and
performing of performance test: selecting a slab replacement
material and performing laboratory mixing test to the selected
material before construction in the site, and performing
construction on a test section in the site to detect and
familiarize with construction performance of the selected material;
(2) preparing of material and calibrating of a concrete mixing
vehicle: before construction in the site, loading materials
required for construction into corresponding silos of a concrete
mixing vehicle and weighing the concrete mixing vehicle, wherein
the concrete mixing vehicle has an integrated function of mixing,
transporting and pouring; calibrating a metering equipment of the
concrete mixing vehicle after the loading is completed, mixing a
small amount of concrete for test, and determining a construction
mixture ratio for the current day according to state of the
concrete; (3) entering site and positioning of slab to be replaced:
determining a position where a slab is required to be quickly
replaced according to design requirements; (4) construction
preparation before breaking of the slab: before breaking the slab,
removing navigation aid lamps on the damaged slab, laying
geotextiles on adjacent slabs, and manually trimming out edges of
the damaged slab along joints of the damaged slab with an electric
pick; (5) breaking of the slab with a breaker: using breaking the
damaged slab with a breaker from middle position of the slab,
taking out the broken concrete blocks after the middle portion of
the slab is broken, and breaking the slab toward the slab edge in
turn, wherein the slab edge of the damaged slab is reserved for
manual breaking; (6) removing concrete blocks and manual cleaning:
after the breaking of the damaged slab is completed, removing
concrete blocks, and manually clearing up fragments at the bottom
of base layer until a dense and flat base layer is obtained; (7)
Laying of geotextiles and wetting the bottom by sprinkling: after
the cleaning, laying the geotextiles, and wetting the bottom by
sprinkling the water; (8) pouring a first layer of concrete with
the concrete mixing vehicle in place; (9) laying steel meshes:
after pouring of the first layer of concrete is completed,
installing steel meshes for reinforcement; (10) pouring a second
layer of concrete: after the installation of the reinforcement
steel meshes is completed, immediately pouring a second layer of
concrete in a sequence from one side of the slab to the other, and
during pouring, performing processes of leveling and mud extracting
on concrete surface with a double steel tube vibrating beam; (11)
exact leveling and surface finishing: after the processes of
leveling and mud extracting with the double steel tube vibrating
beam is completed, scraping the concrete surface with an aluminum
alloy scraper, wherein cement slurry at the slab edge of adjacent
slabs is cleaned up before the scraping, and during scraping, the
bug holes are filled with concrete aggregate and excessive material
are shoveled away with a shovel; and performing surface finishing
after the scraping; (12) Curing: carrying out a process of a water
spray curing; (13) slitting and grooving: performing processes of
slitting and grooving according to performance of the quick-drying
concrete used; and (14) sealing crack and recovering maker
lines.
4. The process according to claim 2, wherein in drilling and
blowing holes, a drill bit of a drilling rig used for drilling
holes on the pavement is not greater than 60 mm; the drilling holes
penetrates the base layer into the soil subgrade by 10 cm; after
reaching a design depth, an air compressor is used to blow the
holes, and the blowing time is not less than 10 s.
5. The construction process according to claim 2, wherein technical
indicators to be controlled during the grouting process comprise:
(1). grouting pressure: when grouting on airport pavement, a
grouting pressure is not greater than 1.0 MPa; when the grouting
pressure is maintained at a certain value and the amount of
grouting is no longer increased during the grouting, the grouting
is stopped; (2). slab surface elevation: an allowable elevation of
the pavement slab during the grouting is no more than 5 mm, a final
allowable elevation of the pavement slab after stabilization is not
greater than 3 mm, and when the slab elevation is greater than 5
mm, the grouting is stopped; and (3). slurry overflowing situation
around the slab: the grouting is stopped when a large of slurry
overflows around the pavement slab during the grouting, and the
overflowing slurry is cleaned up in time.
6. The construction process according to claim 3, wherein in the
construction preparation before breaking of the slab, manually
trimming out, by using an electric pick, a protective layer with a
width of not less than 15 cm and a depth of not less than 10 cm
along joint of the damaged slab to prevent damage to adjacent slabs
when the slab is broken by a large machine.
7. The construction process according to claim 3, wherein in the
breaking of the slab with a breaker, a region with width of 15 cm
at the slab edge of the damaged slab is reserved for manual
breaking.
8. The construction process according to claim 3, wherein when the
thickness of a concrete slab is 40 cm, pouring thickness of the
first layer is 15 cm, and the thickness of the second layer is 25
cm; the pouring of the second layer of concrete is completed before
initial setting of the first layer of concrete to prevent cold
joints.
9. The process according to claim 3, wherein in pouring of concrete
on two adjacent slabs at the same time, in order to prevent
formation of a cold joint between the two layers when the two slabs
are simultaneously poured in a layered manner, arranging a
half-height molding board in middle of gap between the two adjacent
slabs, wherein height of the half-height molding board is 1/2 of
thickness of a slab; pouring concrete on the two adjacent slabs in
a layered manner separately, wherein a sequence for pouring is:
erecting the half-height molding board.fwdarw.pouring a first layer
of a first slab.fwdarw.pouring a second layer of the first
slab.fwdarw.removing the half-height molding board.fwdarw.pouring a
first layer of a second slab.fwdarw.pouring a second layer of the
second slab.
10. The construction process according to claim 3, wherein the
water spray curing comprises: when hands cannot press into concrete
surface and the concrete surface starts to heat up, performing the
curing by sprinkling water with a sprayer, wherein a nozzle of the
sprayer faces upwards during the early of the curing so that water
mist fall on the concrete surface; it is ensure that the concrete
surface is moist during the curing and the curing time is not less
than 3 hours.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application is a continuation of international
application of PCT application No. PCT/CN2021/105043 filed on Jul.
7, 2021, which claims the priority benefit of China application No.
202110052087.7 filed on Jan. 15, 2021. The entirety of the
above-mentioned patent applications is incorporated herein by
reference and made a part of this specification.
TECHNICAL FIELD
[0002] The present application relates to the technical field of
airport runway construction, in particular to a construction
process of fast overall replacement of a damaged pavement slab in
civil aviation non-suspend construction.
DESCRIPTION OF RELATED ART
[0003] With the rapid development of the domestic aviation industry
and the updating of models, the traffic volume and the passenger
flow volume are greatly increased, the operation pressure of a hub
airport is gradually increased, and many airport runways which has
not reached the design life has shown varying degrees of damage. In
addition, in recent years, a considerable portion of airport
runways have come to the design life, concrete pavement slabs are
void, and the stress pattern changes. These hidden dangers not only
influence normal transportation, but also directly threaten flight
safety. Therefore, maintenance and repair of airport pavement for
some time in the future has become an important task in airport
field work.
[0004] The runway is the main place for aircraft to take off and
land. Due to a slow growth of the strength of ordinary cement
concrete, the use of ordinary cement concrete to stop the runway
for maintenance needs to wait until the concrete coagulation
strength has increased to the design strength (usually 28 days)
before the traffic can be opened, which has a greater impact on the
airport operation. Therefore, damaged pavement slabs of the airport
runway are often repaired by non-suspend construction, that is, the
flight area is temporarily closed for a few hours in the early
morning of the night, and the damaged area is quickly repaired with
rapid-curing high-strength repair materials, and the open traffic
condition can be achieved through short maintenance after the
repairing is finished.
[0005] Non-suspend construction has extremely high requirements on
the performance of pavement repair materials and construction
process. In the past, the treatment of damaged slabs was mainly to
use epoxy resin mortar to partially repair damaged slabs. This
repairing method has certain limitations: 1. Only the damaged
surface layer is repaired, while the base layer below the damaged
surface layer is not treated. That is, the symptoms are addressed
instead of the cause. 2. Large shrinkage can easily lead to the
formation of disadvantages such as joints and dislocations between
the repaired area and the slab. 3. Due to the difference in
strength between the repaired area and adjacent slabs, the damage
of the repaired area and the adjacent slabs will be accelerated. 4.
Normal temperature epoxy resin curing agents are generally toxic
and have a greater impact on construction personnel and the
environment. 5. When the temperature is low, the epoxy resin mortar
will harden, and needs to be heated with a torch during the
construction process, which leads to the construction cumbersome
and dangerous. 6. The durability is poor, and it is easy to aging
and peeling after exposure to sunlight and rain, which will affect
the safety of airport operation.
SUMMARY
[0006] Embodiment of the present application provides a
construction process for quickly and integrally replacing a damaged
pavement slab without suspending flights of civil aviation, which
well solves the limitations of the traditional pavement slab
repairing process in engineering practice.
[0007] In order to achieve the above objective, the present
application adopts the following technical solutions.
[0008] A construction process for quickly and integrally replacing
a damaged pavement slab without suspending flights of civil
aviation includes: [0009] a first stage: reinforcing a foundation
of a damaged pavement slab by grouting; and [0010] a second stage:
integrally replacing the damaged slab with early-strength and
quick-drying concrete.
[0011] Preferably, the first stage includes: [0012] (1) positioning
of a slab to be grouted: positioning and marking the damaged slab
and adjacent slabs thereof; [0013] (2) positioning of grout holes:
arranging the grout holes according to an effective diffusion
radius of slurry, and shape and size of the pavement slab; [0014]
(3) drilling and blowing holes: drilling holes on the pavement to
penetrate a base layer into a soil subgrade, and blowing the holes
to clean dust in the holes after the drilling is completed, wherein
the grouting is performed after the blowing is completed; [0015]
(4) preparing of slurry: preparing slurry while positioning the
grout holes in the site; [0016] (5) grouting: grouting the slurry
into the grout holes; [0017] (6) pressure relief and sealing holes:
after the grouting is completed, pulling out a grouting tube when a
grouting pressure is dissipated; and after the grouting tube is
pulled out, sealing the holes with a quick-drying cement mortar;
[0018] (7) testing of grouting effect: performing HWD deflection
test on the grouted reinforcement area 28 days later after the
grouting is completed, to determine whether slab edge
deflection/slab interior deflection<2 and slab corner
deflection/slab interior deflection<3, which indicate a good
status of the foundation, and if yes, performing a next stage of
replacement construction; and if not, performing the above steps
(1) to (6) until the test results meet the above requirements.
[0019] Preferably, the second phase includes: [0020] (1) selecting
of quick-drying concrete and performing of performance test:
selecting a slab replacement material and performing laboratory
mixing test to the selected material before construction in the
site, and performing construction on a test section in the site to
detect and familiarize with construction performance of the
selected material; [0021] (2) preparing of material and calibrating
of a concrete mixing vehicle: before construction in the site,
loading materials required for construction into corresponding
silos of a concrete mixing vehicle and weighing the concrete mixing
vehicle, wherein the concrete mixing vehicle has an integrated
function of mixing, transporting and pouring; calibrating a
metering equipment of the concrete mixing vehicle after the loading
is completed, mixing a small amount of concrete for test, and
determining a construction mixture ratio for the current day
according to state of the concrete; [0022] (3) entering site and
positioning of slab to be replaced: determining a position where a
slab is required to be quickly replaced according to design
requirements; [0023] (4) construction preparation before breaking
of the slab: before breaking the slab, removing navigation aid
lamps on the damaged slab, laying geotextiles on adjacent slabs,
and manually trimming out edges of the damaged slab along joints of
the damaged slab with an electric pick; [0024] (5) breaking of the
slab with a breaker: using breaking the damaged slab with a breaker
from middle position of the slab, taking out the broken concrete
blocks after the middle portion of the slab is broken, and breaking
the slab toward the slab edge in turn, wherein the slab edge of the
damaged slab is reserved for manual breaking; [0025] (6) removing
concrete blocks and manual cleaning: after the breaking of the
damaged slab is completed, removing concrete blocks, and manually
clearing up fragments at the bottom of base layer until a dense and
flat base layer is obtained; [0026] (7) Laying of geotextiles and
wetting the bottom by sprinkling: after the cleaning, laying the
geotextiles, and wetting the bottom by sprinkling the water; [0027]
(8) pouring a first layer of concrete with the concrete mixing
vehicle in place; [0028] (9) laying steel meshes: after pouring of
the first layer of concrete is completed, installing steel meshes
for reinforcement; [0029] (10) pouring a second layer of concrete:
after the installation of the reinforcement steel meshes is
completed, immediately pouring a second layer of concrete in a
sequence from one side of the slab to the other, and during
pouring, performing processes of leveling and mud extracting on
concrete surface with a double steel tube vibrating beam; [0030]
(11) exact leveling and surface finishing: after the processes of
leveling and mud extracting with the double steel tube vibrating
beam is completed, scraping the concrete surface with an aluminum
alloy scraper, wherein cement slurry at the slab edge of adjacent
slabs is cleaned up before the scraping, and during scraping, the
bug holes are filled with concrete aggregate and excessive material
are shoveled away with a shovel; and performing surface finishing
after the scraping; [0031] (12) Curing: carrying out a process of a
water spray curing; [0032] (13) slitting and grooving: performing
processes of slitting and grooving according to performance of the
quick-drying concrete used; and [0033] (14) sealing crack and
recovering maker lines.
[0034] Preferably, in drilling and blowing holes, a drill bit of a
drilling rig used for drilling holes on the pavement is not greater
than 60 mm; the drilling holes penetrates the base layer into the
soil subgrade by 10 cm; after reaching a design depth, an air
compressor is used to blow the holes, and the blowing time is not
less than 10 s.
[0035] Preferably, technical indicators to be controlled during the
grouting process include: 1. grouting pressure: when grouting on
airport pavement, a grouting pressure is not greater than 1.0 MPa;
when the grouting pressure is maintained at a certain value and the
amount of grouting is no longer increased during the grouting, the
grouting is stopped; 2. slab surface elevation: an allowable
elevation of the pavement slab during the grouting is no more than
5 mm, a final allowable elevation of the pavement slab after
stabilization is not greater than 3 mm, and when the slab elevation
is greater than 5 mm, the grouting is stopped; and 3. slurry
overflowing situation around the slab: the grouting is stopped when
a large of slurry overflows around the pavement slab during the
grouting, and the overflowing slurry is cleaned up in time.
[0036] Preferably, in the construction preparation before breaking
of the slab, manually trimming out, by using an electric pick, a
protective layer with a width of not less than 15 cm and a depth of
not less than 10 cm along joint of the damaged slab to prevent
damage to adjacent slabs when the slab is broken by a large
machine.
[0037] Preferably, in the breaking of the slab with a breaker, a
region with width of 15 cm at the slab edge of the damaged slab is
reserved for manual breaking.
[0038] Preferably, when the thickness of a concrete slab is 40 cm,
pouring thickness of the first layer is 15 cm, and the thickness of
the second layer is 25 cm; the pouring of the second layer of
concrete is completed before initial setting of the first layer of
concrete to prevent cold joints.
[0039] Preferably, in pouring of concrete on two adjacent slabs at
the same time, in order to prevent formation of a cold joint
between the two layers when the two slabs are simultaneously poured
in a layered manner, arranging a half-height molding board in
middle of gap between the two adjacent slabs, wherein height of the
half-height molding board is 1/2 of thickness of a slab; pouring
concrete on the two adjacent slabs in a layered manner separately,
wherein a sequence for pouring is: erecting the half-height molding
board.fwdarw.pouring a first layer of a first slab.fwdarw.pouring a
second layer of the first slab.fwdarw.removing the half-height
molding board.fwdarw.pouring a first layer of a second
slab.fwdarw.pouring a second layer of the second slab.
[0040] Preferably, the water spray curing comprises: when hands
cannot press into concrete surface and the concrete surface starts
to heat up, performing the curing by sprinkling water with a
sprayer, wherein a nozzle of the sprayer faces upwards during the
early of the curing so that water mist fall on the concrete
surface; it is ensure that the concrete surface is moist during the
curing and the curing time is not less than 3 hours.
[0041] It can be seen from the technical solutions provided in the
above embodiments of the present application that the construction
process of fast overall replacement of a damaged pavement slab in
civil aviation non-suspend construction provided by the embodiments
of the present application has the following advantages. [0042] (1)
scope of application of the process: the present application adopts
a two-stage construction. The first stage is to reinforce a
foundation of a pavement through a grouting method. This process
technology is simple without a large mechanical equipment. It is
convenient to enter and exit the field, the construction speed is
fast, and it does not affect the flight safety of the pavement. It
does not destroy the existing structural layer of the pavement, but
also can effectively solve the problem of voiding at the bottom of
the pavement slab, and can improve the density, strength and ground
reaction modulus of the foundation. The second stage uses a
quick-drying and early-strength concrete to quickly and integrally
replace the damaged slab. Through the application of the new
equipment of the concrete intelligent all-in-one vehicle and the
improvement of concrete construction process of the traditional
pavement, the construction time has been greatly shortened and the
investment of equipment and personnel has been reduced. This
process is very suitable for projects with limited space or
projects that are not suitable for investing a large amount of
machinery due to other reasons but with high engineering quality
requirements and tight schedules, especially suitable for airport
non-suspend construction; [0043] (2) In terms of equipment
efficiency: the process personnel and equipment have a clear
division of labor, and the construction process is arranged
compactly. Especially when the foundation reinforcement or
replacement construction are performed on multiple slabs, various
construction equipment forms a benign cycle state, which
effectively reduces the idle rate of equipment and increases the
utilization; [0044] (3) In terms of construction quality:
reinforcing the foundation of the pavement by the grouting method
can effectively improve the bearing capacity of the foundation of
the pavement, thereby improving the durability of the pavement
slab. The optimization and improvement of the ordinary pavement
concrete construction process ensures the construction quality of
the concrete, and at the same time the adoption of the quick-drying
and early-strength concrete can meet the intensity requirements of
open traffic in a very short time; [0045] (4) In terms of
construction progress: this process can effectively resolve the
contradiction between construction schedule and construction
quality, and accelerate the progress of the project; [0046] (5) In
terms of engineering cost: the process uses the concrete
intelligent all-in-one vehicle to complete the concrete mixing work
with only 2 people, which not only improves the mixing quality, but
also greatly reduces the labor and the investment of transportation
machinery and equipment, effectively saving the cost.
[0047] The additional aspects and advantages of the present
application will be partly given in the following description,
which will become apparent from the following description, or
learned through the practice of the present application.
BRIEF DESCRIPTION OF THE DRAWINGS
[0048] In order to explain the technical solutions of the
embodiments of the present application more clearly, the following
will briefly introduce the accompanying drawings that need to be
used in the description of the embodiments. Obviously, the
accompanying drawings in the following description are only some
embodiments of the present application. For those of ordinary skill
in the art, without creative work, other drawings can be obtained
based on these drawings.
[0049] FIG. 1 is a schematic flow diagram of a construction process
for quickly and integrally replacing a damaged pavement slab
without suspending flights of civil aviation according to an
embodiment of the present application;
[0050] FIG. 2 is a schematic flow diagram of a process (first
stage) of reinforcing a foundation of a damaged pavement slab by
grouting construction according to an embodiment of the present
application;
[0051] FIG. 3 is a schematic layout diagram of grouting holes
according to an embodiment of the present application;
[0052] FIG. 4 is a schematic flow diagram of a process (second
stage) of integrally replacing a damaged pavement slab with the
early-strength and quick-drying concrete according to an embodiment
of the present application.
DESCRIPTION OF THE EMBODIMENTS
[0053] The following describes the implementation of the present
application in detail. Examples of the implementation are shown in
the accompanying drawings, wherein the same or similar reference
numerals represent the same or similar elements or elements with
the same or similar functions. The following reference is made to
the accompanying drawings. The described implementation is
exemplary, and is only used to explain the present application, but
cannot be interpreted as a restriction on the present
application.
[0054] Those skilled in the art can understand that, unless
specifically stated, the singular forms "a", "an", "the" and "this"
used herein may also include plural forms. It should be further
understood that the term "comprising" used in the description of
the present application refers to the presence of the described
features, integers, steps, operations, elements, and/or components,
but does not exclude the presence or addition of one or more other
features, integers, steps, operations, elements, components, and/or
the combination thereof. It should be understood that when we say
that an element is "connected" or "coupled" to another element, it
can be directly connected or coupled to the other element, or there
may be intermediate elements. In addition, the "connected" or
"coupled" used herein may include wireless connection or coupling.
The term "and/or" as used herein includes any unit and all
combinations of one or more associated listed items.
[0055] Those skilled in the art can understand that, unless
otherwise defined, all terms (including technical and scientific
terms) used herein have the same meaning as the general
understanding of the ordinary skilled in the art to which the
present application belongs. It should also be understood that,
terms such as those defined in a general dictionary should be
understood to have a meaning consistent with the meaning in the
context of the prior art, and unless defined as here, they will not
be interpreted with idealized or overly formal meanings.
[0056] In order to facilitate the understanding of the embodiments
of the present application, several specific embodiments will be
used as examples for further explanation and description in
conjunction with the accompanying drawings, and each embodiment
does not constitute a limitation on the embodiments of the present
application.
[0057] As shown in FIG. 1, a construction process for quickly and
integrally replacing damaged pavement slab without suspending
flights of civil aviation according to an embodiment of the present
application includes the following steps.
[0058] In a first stage, a foundation of the damaged pavement slab
is reinforced by grouting. In the first stage, a layout surveying
is performed to position grout holes, and then the holes are
drilled and meanwhile the grouting liquid is prepared. The drilling
depth is required to be able to penetrate into the soil subgrade.
After the above operations are completed, a grouting construction
will be performed. The grouting construction is performed until the
grouting pressure or the slab elevation reaches a critical value.
After stopping the grouting, a grouting tube is pulled out after
the grouting pressure is dissipated, and then the holes are sealed
with a quick-drying mortar. After the grouting fluid reaches a
design time, a HWD deflection test is performed on the grouted area
to test a grouting effect. If the foundation bearing capacity meets
the specification requirements, a next stage of replacement
construction can be performed.
[0059] In a second stage, the damaged slab is replaced integrally
with an early-strength and quick-drying concrete, which includes:
breaking and removing positioning of the slab, laying geotextiles
on the adjacent slabs, removing lamps, manually trimming the edge
with an electric pick, breaking the slab from the middle position
with a breaker in place, transporting concrete blocks, manually
cleaning the edge and bottom with an electric pick, checking and
accepting the base layer, laying geotextiles, wetting the base
layer by sprinkling water, putting the concrete mixing vehicle in
place and starting concrete pouring construction for two layers, in
which a reinforced mesh is laid for reinforcement after pouring a
first layer of concrete and then pouring a second layer of
concrete; then performing operations of leveling and extracting by
a vibrating beam of double steel tube, surface troweling,
maintenance, joint-cutting and grooving and the like in order. The
process of expanding and filling joints and recovery of the maker
line is to be performed on the next day in the site.
[0060] The two-stage construction process is specifically described
as follows. [0061] As shown in FIG. 2, in the first stage, the
foundation of the replacement area is reinforced by grouting.
[0062] (1) Positioning of slabs to be grouted [0063] In order to
ensure the quality of the replacement process, not only the slab
foundation of the replacement area is reinforced by grouting, but
also the foundation of a slab adjacent to the replacement area is
also reinforced by grouting. Before starting the grouting process,
the slabs to be grouted shall be positioned and marked. [0064] (2)
Positioning of grout holes [0065] Under the premise of ensuring the
construction effect and uniformity, the layout of grout holes
should take the following two important factors into account. The
first factor is an effective diffusion radius of the slurry. For a
foundation with larger gaps, the effective diffusion radius of the
slurry is generally 1.5 m. The second factor is a shape and a size
of the concrete pavement slab. It should be ensured that each part
of the slab is stressed uniformly as much as possible. According to
the shape and the size of the pavement slab, the layout of grout
holes is shown in FIG. 3. [0066] (3) Drilling and blowing holes
[0067] A suitable drilling rig should be used for drilling on the
pavement with a drill bit not greater than 60 mm for example. The
drilling depth is required to be able to penetrate the base layer
to 10cm into the soil subgrade. Taking a second runway of Chongqing
Jiangbei Airport as an example, the drilling hole depth=40 cm of
pavement slab+36 cm of cement stabilized gravel+10 cm of the soil
subgrade=86 cm. After drilling to a design depth, an air compressor
should be used to blow the hole. The blowing time should not be
less than 10 s to ensure that the dust in the holes should be blown
out. The grouting should be carried out after the blowing process
is completed. [0068] (4) Preparing of slurry [0069] The preparing
of slurry should be carried out while positioning the holes in the
site. The construction mix ratio is measured in strict accordance
with the design requirements, and operations of adding and feeding
materials are carried out according to the procedures to ensure the
timely preparation and supply of the slurry. The proportion of the
cement slurry should be detected in time with a slurry specific
gravity detection recorder. [0070] (5) Grouting [0071] A grouting
gun is inserted into the formed grout hole of the pavement slab to
an appropriate depth, a seal rubber ring of the grouting gun is
tighten, and a grouting pump is activated for slurry injection. The
grouting amount is carefully recorded with a grouting automatic
recorder. To ensure the quality of grouting and the flatness of the
pavement, there are three main technical indicators to be
controlled in the grouting process. 1. Grouting pressure: when
grouting the airport pavement, a grouting pressure should be not
greater than 1.0 MPa, preferably 0.3 Mpa-0.5 Mpa. When the grouting
pressure is maintained at a certain value and the amount of
grouting is no longer increased during the grouting, the grouting
may be stopped. 2. Slab surface elevation: the allowable elevation
of the pavement slab during the grouting is generally required to
be no more than 5 mm, the final allowable elevation of the pavement
slab after stabilization is required to be no greater than 3 mm,
and when the slab elevation (elevation of non-settlement plate) is
greater than 5 mm, the grouting should be stopped. 3. Slurry
overflowing situation around the slab: the grouting should be
stopped when a large of slurry overflows around the pavement slab
during the grouting, and the overflowing slurry should be cleaned
up in time. [0072] (6) Pressure relief and sealing holes [0073]
After the grouting is completed, the grouting tube should not be
pulled out immediately to prevent the slurry from leaking. With
letting stand for 5-10 minutes or installing a pressure relief
valve on the grouting tube, the grouting tube can be pulled out
after the grouting pressure is relieved. After pulling out the
grouting tube, the holes are sealed with a quick-drying cement
mortar. [0074] (7) Testing of grouting effect [0075] HWD deflection
test is performed on the grouted reinforcement area 28 days later
after the grouting is completed. The situations of void beneath
slab edge and void beneath slab corner are determined based on a
ratio of "slab edge/slab interior" and "slab corner/slab interior"
deflection, and the criterion follows the technical standards
recommended in the "Technical Specifications for the Evaluation and
Management of Civil Airport Pavements". That is, "slab edge
deflection/slab interior deflection<2" and "slab corner
deflection/slab interior deflection<3" indicate a good status of
the foundation, and then a next stage of replacement construction
can be performed; and if the above requirements are not met, the
above steps (1) to (6) are performed until the test results meet
the requirements.
[0076] As shown in FIG. 4, the second stage in which the damaged
slab is quickly replaced will be described below. [0077] (1)
Selecting of quick-drying concrete and performing of performance
test [0078] The present application mainly aims at the replacing of
the damaged pavement slabs without suspending flights. Short
construction time and high-quality requirements are the most
important characteristics of non-suspend construction. Therefore,
before construction in the site, it is necessary to carefully
select the replacement materials, and a laboratory test of mixing
is performed on the selected materials and on-site construction is
carried out on a test section to detect and familiarize with its
construction performance, thereby ensuring that the formal
construction in the filed can proceed smoothly. [0079] (2)
Preparing of materials and calibrating of a concrete mixing vehicle
[0080] The concrete mixing vehicle in the present application is a
new equipment with an integrated function of mixing, transporting
and pouring the concrete. This equipment can effectively solve the
problem that the quick-drying concrete used in construction has a
short coagulation time and is not suitable for long-distance
transportation. Also, it has the advantages of ready-to-use and
cast-in-place, convenient and fast, accurate measurement, and fast
discharge. Before construction in the site, the quick-drying
cement, gravel, water and other materials required for construction
are loaded in corresponding silos of the concrete mixing vehicle,
and are weighed at the same time to ensure that the concrete mixing
volume of the current day can be met. The amount of material
feeding must exceed the design demand of the current day by 20% to
prevent insufficient material feeding due to loss and other
factors. After the material feeding is completed, each silo of the
all-in-one vehicle shall be closed and covered to prevent spilling.
A metering equipment of the concrete mixing vehicle is calibrated
after the material feeding is completed, and at the same time a
small amount of concrete is mixed for test, and a construction mix
ratio of the current day is determined according to the state of
the concrete. [0081] (3) Entering the site and positioning the slab
to be replaced [0082] The position where the slab needs to be
quickly replaced is determined according to the design
requirements. [0083] (4) Construction preparation before breaking
the slab [0084] Before breaking the slab, the navigation aid lamps
on the damaged slab are removed, and geotextiles are laid on the
adjacent slabs at the same time to prevent the broken concrete
blocks from falling on and hurting adjacent slabs. Before breaking
the slab, an electric pick may be used to manually trim out a
protective layer with a width of not less than 15 cm and a depth of
not less than 10 cm along the joint of the damaged slab to prevent
damage to adjacent slabs when the slab is broken by a large
machine. [0085] (5) Breaking the slab with a breaker [0086] A
breaker is used to break the slab from the middle position. After
the middle portion of the slab is broken, the broken concrete
blocks are taken out to release the stress in the slab interior so
as to prevent the broken slab from pressing and damaging the
adjacent slabs, and then the breaking is carried out toward the
slab edge in turn. The region with width of 15 cm at the slab edge
of the damaged slab is reserved for manual breaking. [0087] (6)
Removing concrete blocks and manual cleaning [0088] After breaking
of the slab is completed, the concrete blocks are removed with an
excavator, and fragments at the bottom are manually cleared up
until a dense and flat base layer is obtained. [0089] (7) Laying of
geotextiles and wetting the bottom by sprinkling [0090] After the
cleaning, the geotextiles are laid, and the bottom is wet by
sprinkling the water. [0091] (8) Pouring a first layer of concrete
with the concrete mixing vehicle in place [0092] Due to the
construction performance of the quick-drying concrete used in this
process, the concrete pouring construction adopts two-layered
pouring. When the thickness of a concrete slab is 40 cm, the
pouring thickness of the first layer is preferably 15 cm, and the
thickness of the second layer is preferably 25 cm. The pouring of
the second layer of concrete is required to be completed before the
initial setting of the first layer of concrete to prevent cold
joints. During the pouring process, two high-frequency insertion
vibrators are used to vibrate at a discharge port while pouring.
[0093] (9) Laying steel meshes [0094] After pouring the first layer
of concrete with 15 cm thick is completed, steel meshes are
installed for reinforcement. [0095] (10) Pouring a second layer of
concrete [0096] After the installation of the reinforcement steel
meshes is completed, a second layer of concrete is immediately
poured in a sequence from one side of the slab to the other. During
pouring, leveling and mud extracting are performed on the concrete
surface with a double steel tube vibrating beam. [0097] When the
pouring concrete on two adjacent slabs at the same time, in order
to prevent the formation of a cold joint between the two layers
when the two slabs are simultaneously poured in a layered manner, a
half-height molding board is arranged in the middle of the gap
between the two adjacent slabs, that is, the height of the
half-height molding board is 1/2 of the thickness of the slab; then
the two adjacent slabs are poured in a layered manner separately.
The sequence for pouring is: erecting the half-height molding
board.fwdarw.pouring a first layer of a first slab.fwdarw.pouring a
second layer of the first slab.fwdarw.removing the half-height
molding board.fwdarw.pouring a first layer of a second
slab.fwdarw.pouring a second layer of the second slab. [0098] (11)
Exact leveling and surface finishing [0099] After the leveling and
mud extracting with the double steel tube vibrating beam is
completed, the concrete surface is scraped with an aluminum alloy
scraper. The cement slurry at the slab edge of the adjacent slabs
must be cleaned up before scraping. During scraping, the bug holes
are filled with concrete aggregate, while excessive material are
shoveled away with a shovel. After the scraping, the surface
finishing is performed with a plastic trowel for twice and an iron
trowel for twice. [0100] (12) Curing [0101] When hands cannot press
into the concrete surface and the concrete surface starts to heat
up, a curing is performed by sprinkling water with a sprayer.
During the early of the curing, instead of aim the nozzle of the
sprayer directly at the concrete surface, the nozzle should face
upwards so that the water mist can naturally fall on the concrete
surface. It should ensure that the concrete surface is moist during
the curing and the curing time should not be less than 3 hours.
[0102] (13) Slitting and grooving [0103] According to the
performance of the quick-drying concrete used in this process,
processes of slitting and grooving are carried out 1.5 hours after
the pouring is completed. [0104] (14) crack sealing and recovery of
the maker line [0105] Since the concrete curing, slitting and
grooving are wet operations, processes of crack sealing and
recovery of the maker line cannot be carried out. Thus, processes
of crack sealing and recovery of the maker line may be conducted on
the next day.
[0106] In sum, the embodiments of the present application provide a
construction process of fast overall replacement of a damaged
pavement slab in civil aviation non-suspend construction, which
solves the limitations of the traditional pavement slab repair
process. The present application first reinforces the damaged
pavement slab foundation through grouting construction to solve the
problems of slab bottom vacancy, foundation settlement, and
insufficient bearing capacity of the base; then uses the
early-strength rapid-curing concrete suitable for rapid overall
slab replacement of the pavement to carry out overall replacement
construction for the damaged pavement slab. The present application
effectively solves the contradiction between construction period
and construction quality, and has the advantages of significantly
shortening construction period, improving construction quality,
reducing equipment and labor input, etc., and can achieve good
economy benefits and social benefits.
[0107] Those of ordinary skill in the art can understand that the
drawings are only schematic diagrams of an embodiment, and the
modules or processes in the drawings are not necessary for
implementing the present application.
[0108] The above are only the preferred specific embodiments of the
present application, but the protection scope of the present
application is not limited thereto. Any person skilled in the art
can easily think of changes or modifications within the technical
scope disclosed in the present application, which should be covered
within the protection scope of the present application. Therefore,
the protection scope of the present application should be subject
to the protection scope of the claims.
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