Note: Descriptions are shown in the official language in which they were submitted.
CA 02207074 1997-06-OS
METHOD OF CONSTRUCTING BLOCK PAVEMENT
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to a method of constructing block pavement.
More particularly, the present invention relates to a method of constructing
block
pavement which is applicable to a sidewalk, a community road, a shopping mall,
a
cycling road, a park, an~ open space, a parking space and an ordinary roadway,
and is
excellent in appearance and durability.
Description of the Related Art
While block pavement has long been applied, it has been applied in a full
scale
to ordinary roadways only recently.
A conventional method of constructing a block pavement as a general practice
comprises the steps of laying and leveling cushion sand on a subbase course or
a base
course, or a base of the road so on, arranging paving blocks, roller-
compacting the
surfaces thereof with a roller compactor, and filling up the joint spaces
between the
thus arranged paving blocks with joint filler sand for finishing. Application
of this
conventional method for constructing block pavement on a roadway poses however
the
following problems. More specifically, in block pavement constructed by this
method
using non-adhesive sand, joint filler sand flows out or splashes under the
effect of rain
water or wind. As a result, traffic of vehicles accelerates generation of
shock and
vibration, which cause displacement of cushion sand, thus resulting in early
occurrence of destruction of the block pavement.
With a view to coping with these problems, therefore, there has been
proposed and applied a method using a dry- mixed cement mortar formed by
mixing
cement and sand in place of conventional cushion sand and joint filler sand.
This
method comprises the steps of placing and leveling dry- mixed cement mortar,
arranging and roller-compacting paving blocks thereon, filling up the joint
spaces with
the dry- mixed cement mortar, then sprinkling water thereunto, and causing
rain
water to generate a hydration reaction of cement contained in the dry- mixed
cement
mortar to fix cushion sand and joint filler sand into mortar state with the
dry- mixed
cement mortar, thereby securing the paving blacks onto the base course to
construct
block pavement.
In this method, however, although giving an effect to some extent for light
traffic, the solidified dry-mixed cement mortar is brittle, so that joints
suffer from
early occurrence of cracks under heavy traffic of large vehicles on an
ordinary raad.
Joints are broken into pieces, and the result is almost the same as in a case
using
CA 02207074 1997-06-OS
cushion sand, leading to breakage of the block pavement.
Other methods proposed for fixing cushion sand and joint filler sand upon
constructing block pavement include one comprising spraying a water- soluble
prepolymer to fix cushion sand and joint filler sand, and one using a mixture
of a
hydraulic slag and a water- soluble macromolecular substance in place of
cushion sand
and joint filler sand. These methods are defective in that the pavement
suffers from
cracks under heavy trafficrand rain water causes joint filler sand to flow
out, and the
r.
problem of block pavement broken under heavy traffic involving large vehicles
on an
ordinary road.
The present invention has an object to provide a method of constructing block
pavement,which solves these conventional problems, is applicable not only to
landscape pavement of a sidewalk or an open space, but also to an ordinary
roadway
having heavy traffic of large vehicles, and makes available block pavement
provided
with a beautiful appearance and an excellent durability.
SUMMARY OF THE INVENTION
The present invention proposes a method of, upon constructing block pavement,
using a cement asphalt mortar (hereinafter simply referred to as "CA mortar")
as means
to fix paving blocks.
More specifically, the present invention provides a method of constructing
block pavement provided with a beautiful appearance and an excellent
durability, which
comprises the steps of providing a tack coat layer by spraying an asphalt
emulsion on a
road base, then, forming an aggregate layer by placing and leveling aggregates
on the
upper surface thereof, arranging a plurality of blocks on the upper surface
thereof with
upper surfaces of the blocks in flush, pouring CA mortar into joint spaces
formed
between the blocks by means of a pouring pot, a pouring funnel or a tremie
pipe,
forming a buffer support layer by filling up void of the foregoing aggregate
layers by
pouring uniformly, filling the foregoing joint spaces with CA mortar or a
pouring joint
filler material other than CA mortar to integrally secure the blocks onto the
base.
CA mortar used in the method of constructing block pavement in the present
invention is to give the viscoelasticity in addition to being adhesive unlike
ordinary
cement mortar. The buffer support layer formed by filling up void of the
aggregate
layers which are supporting layers of the blocks with CA mortar has an
excellent
function as an adhering layer as well, firmly bonding the base and the blocks
through
the tack coat layer, and at the same time, block are effectively secured to
each other
by joints comprising CA mortar or a pouring joint filler material other than
CA mortar
filling the joint spaces. It is thus possible to provide block pavement
capable of
sufficiently withstanding even when applied to an ordinary roadway.
CA 02207074 1997-06-OS
Since the CA mortar used in the method of constructing block pavement is to
give. the viscoelasticity unlike ordinary cement mortar, the buffer support
layer as an
adhering layer has an excellent function also as a cushion layer which absorbs
and
alleviates shock and vibration caused by traffic of vehicles, and at the same
time, the
joints comprising CA mortar or a pouring joint filler material other than CA
mortar
filling the joint spaces can well cope with behavior of the individual blocks
caused by
vehicle traffic and ca-nprovi~lei~l9~kpavementexcelLentin durability even
under
heavy traffic. '
BRIEF DESCRIPTION OF THE DRAWINGS
Figs. 1, 2 and 3 are longitudinal sectional side views illustrating an outline
of
application of the method of constructing block pavement in the present
invention; Fig.
1 is longitudinal sectional side view illustrating a state in which paving
blocks are
temporarily placed on an aggregate layer formed by laying aggregates; Fig. 2
is a
longitudinal sectional side view illustrating pouring of CA mortar to the void
of
aggregate layer and joint spaces; and Fig. 3 is a longitudinal sectional side
view
illustrating completed block pavement.
Fig. 4 illustrates provision of fine grooves on the bottom surface of a paving
block; Fig. 5 illustrates provision of fine grooves on the upper portion of
the aggregate
layer; Fig. 6 illustrates a hollow porous pipe buried in a fine groove
provided on the
upper portion of the aggregate layer. Fig. 7 illustrates temporary provision
of a joint
space stopper as CA mortar flowing stopper; and Fig. 8 is a longitudinal
sectional side
view illustrating pouring of CA mortar into joint spaces partitioned by the
joint space
stopper.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now, the method of constructing block pavement of the present invention will
be described below in detail.
The term "base" as used in the present invention means, for example, existing
asphalt pavement, concrete pavement or a base course, and further include
soil-based pavement in a sidewalk, a park or an open space, bridge surface
pavement,
a concrete slab or a steel floor slab.
The term "asphalt emulsion" as used in the present invention means an asphalt
emulsion or a modified asphalt emulsion.
An asphalt emulsion is formed by emulsifying and dispersing asphalt in water
with the use of an emulsifier, a dispersant or a stabilizer. Asphalt emulsions
are
classified, in terms of the emulsifier used for emulsification, into cationic
asphalt
emulsion, anionic asphalt emulsion, nonionic asphalt emulsion and clay- type
emulsion.
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CA 02207074 2005-O1-10
In the present invention, a cationic asphalt emulsion is used as the tack coat
layer on the base.
Applicable cationic asphalt emulsion include, for example, PK1 to 4 specified
in Japanese
Industrial Standard (JIS) K2208 as shown in "JIS Handbook 12, Petroleum",
published by
Japanese Standard Association, 1997, pages 74-76. A nonionic asphalt emulsion
is mainly
used as the asphalt emulsion for CA mortar. Values of standard for nonionic
asphalt
emulsions are set forth in Japanese Industrial Standard (JIS) K2208 as shown
in "JIS
Handbook 12, Petroleum", published by Japanese Standard Association, 1997,
pages 74-76,
MN-1.
A modified asphalt emulsion is prepared by mixing asphalt with natural rubber,
a
macromolecular polymer or the like, and emulsifying and dispersing the thus
modified asphalt
in water by the use of an emulsifier, a dispersant and a stabilizer, or adding
and mixing natural
rubber, a macromolecular polymer latex or an emulsion to the above asphalt
emulsion.
Representative modified asphalt emulsions include PKR-T and PKR-S specified in
the
standard for rubber-modified asphalt emulsions published by the Japan
Emulsified Asphalt
Association.
Aggregates applicable in the present invention include those specified in the
"MANUAL FOR ASPHALT PAVEMENT" published by the Japan Road Association:
crushed stone, cobble stone, gravel, and blast furnace slag. An asphalt-coated
aggregate made
by coating any of these aggregates with asphalt or a recycled aggregate is
also applicable.
Granular materials similar to those mentioned above such as an artificial
burnt aggregate, a
burnt foamed aggregate, an artificial lightweight aggregate, a ceramic grains
and emery are
applicable as well. Furthermore, aggregates may be single-sized or have a
continuous grading.
The grade 6. crushed stone or cobble stone having a particle size within a
range of from 5 to
13 mm is generally adopted.
The paving block used in the present invention is a natural stone, a paving
concrete
plate, a brick, an interlocking block, an elastic block or a tile. Fine
grooves should preferably
be provided on the bottom surface of the paving block.
Stones such as marble, granite, andesite and Mikage-granite may be used as a
natural
stone. Applicable stone shapes include a cube rubble, a formed stone slab and
a non-formed
stone slab.
Applicable paving concrete plates include ones specified in "Japanese
Industrial
Standard (JIS) A 5304, Sidewalk Concrete Flags", published by Japanese
Standard
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CA 02207074 2005-O1-10
Association,1969, pages 1-3: an ordinary block, a colored block, a mortar
washed out surface
block, and an imitation stone block, and in addition, a porous block, a tile
worn block and a
pictured surface block are also applicable.
As bricks, an ordinary brick, and an interlocking brick can be used and
ordinary bricks
complying with Japanese Industrial Standard (JIS) R 1250 as shown in "JIS
Handbook 24-l,
Architecture, Material" published by Japanese Standard Association,1995, pages
248-249 are
applicable.
The interlocking block should be in conformity to the quality requirements for
interlocking block as set forth in the "Interlocking Block Pavement" edition
1994 published
by the Japan Interlocking Block Association.
An elastic block is prepared by adding a liquid urethane resin as a binder to
granular
rubber obtained mainly by milling waste tires and forming the mixture through
heating and
compression.
Applicable tiles include porcelain, stoneware and ceramic ware type ones as
specified
in JIS A5209. An elastic tile prepared by imparting viscoelasticity to a tile
is also applicable.
The CA mortar as used in the present invention comprises, relation to 100
weight parts
cement, from 50 to 230 weight parts asphalt emulsion, from 0 to 100 weight
parts
rapid-hardening admixture, from 60 to 330 weight parts fine aggregate, from 0
to 5 weight
parts setting adjusting agent, from 0 to 0.05 weight parts aluminum powder,
from 0 to 40
weight parts expansive admixture, from 1 to 5 weight parts additive, and added
water in a
required amount.
Cement used in the CA mortar should be any of, for example, normal Portland
cement,
high-early-strength Portland cement, extra-high-early-strength Portland
cement, moderate heat
Portland cement, Blast-furnace slag cement, silica cement, fly ash cement,
sulfate resistant
cement and j et cement.
The asphalt emulsion used in the CA mortar may or may not contain a polymer,
whereas a polymer-modified asphalt emulsion is preferable.
A polymer-modified asphalt emulsion is a nonionic asphalt emulsion obtained by
mixing an asphalt emulsion and a synthetic latex at a weight ratio of 99 to
75:1 to 25, or more
preferably, 95 to 75:5 to 25. The asphalt emulsion used in the polymer-
modified asphalt
emulsion should be a nonionic asphalt emulsion prepared by emulsifying and
dispersing
asphalt in water by the use of a nonionic emulsifier, a dispersant and a
stabilizer. The solid
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CA 02207074 2005-O1-10
content in a nonionic asphalt emulsion must usually be within a range of from
40 to 70 wt. %.
With a solid content of under 40 wt. %, it is impossible to impart a
satisfactory viscoelasticity
to the CA mortar. With a solid content of over 70 wt. %, on the other hand, an
increased value
of viscosity impairs availability of a satisfactory CA mortar. Asphalt in the
nonionic asphalt
emulsion should preferably have a penetration (at 25° C.) within a
range of from about
40 to 300, after due consideration of the physical properties after the CA
mortar hardened.
The synthetic latex used in the polymer-modified asphalt emulsion should be
any of
a Styrene-Butadiene Rubber latex (SBR latex), an acrylic latex and an Ethylene
Vinylacetate
copolymer latex (EVA latex). In the present invention, an SBR latex is mainly
used. The SBR
latex is weak-alkaline and has a satisfactory mixing ability with cement and a
nonionic asphalt
emulsion. The SBR latex has usually a solid content of 50 wt. %.
Usually a polymer-modified asphalt emulsion is obtained by high speed mixing
of
synthetic latex with nonionic asphalt emulsion to disperse synthetic latex
into nonionic asphalt
emulsion uniformly.
Generally, the weight ratio of nonionic asphalt emulsion and synthetic latex
in a
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CA 02207074 1997-06-OS
polymer- modified asphalt emulsion should be within the range of 9 9 to 7 5 :
1 to 2 5 ,
or more preferably, ~ 95 to 75 : 5 to 25. With a consumption of the synthetic
latex of
under 1 weight part, it is impossible to impart a satisfactory viscoelasticity
to the CA
mortar. A consumption of the synthetic latex of over 5 weight parts is
preferable,
because it makes possible to impart a satisfactory viscoelasticity. On the
other hand,
with a consumption of the synthetic latex of over 25 weight parts, the
viscoelasticity
of a polymer- modified asphalt emulsion becomes too high to obtain satisfying
CA
r
mortar. In addition, it becomes difficult to transfer CA mortar with the
pressure
generated by pump operation.
The consumption of the polymer-modified asphalt emulsion should usually be
within a range of from 50 to 230 weight parts relative to 100 weight parts
cement.
With a consumption of the polymer-modified asphalt emulsion of under 50 weight
parts, it is impossible to impart a satisfactory viscoelasticity. With a
consumption of
the polymer-modified asphalt emulsion of over 230 weight parts, on the other
hand,
a reduced strength of CA mortar causes a decrease in the supporting force of
the CA
mortar filled up layer.
The rapid- hardening admixture used for CA mortar is a mixture obtained by
mixing calcium aluminate and gypsum anhydride at a weight ratio of I : I . 4
to 2. 9.
This mixture imparts rapid- hardenability to cement and permits rapid
expression
ability of strength of CA mortar. With a blending ratio of gypsum anhydride of
under
I . 4 , rapid- hardenability is low. With a blending ratio of gypsum anhydride
of over 2.
9, on the other hand, rapid-hardenability becomes excessively high, making it
difficult to control the available time.
The consumption of the rapid- hardening admixture should be within a range of
from 0 to 100 weight parts relative to 100 weight parts cement, or more
preferably,
from 0 or 40 to ~0 weight parts. With a consumption of the rapid-hardening
admixture of over 100 weight parts; rapid-hardenability becomes excessively
high;
making it' difficult to carry on operations.
The fine aggregate used in CA mortar is any of river sand, land sand, pit
sand,
screenings and silica sand. The particle size thereof should usually be such
that the
FM- value (fineness module) is preferably within a range of from 1. 0 to 1. 6.
An
FM- value of under I . 0 leads to a higher viscosity and hence to a lower
filling up
property of CA mortar.
An FM- value of over I . 6 leads to easy occurrence of material separation.
In place of the fine aggregate, a mineral powder material such as fly ash or
silica powder may be used.
The consumption of the fine aggregate should usually be within a range of from
- 60 to 330 weight parts relative to 100 weight parts cement. With a
consumption of
g
CA 02207074 1997-06-OS
the fine aggregate of under 60 weight parts. CA mortar after hardening tends
to suffer
from easy occurrence of volume shrinkage. A consumption of the fine aggregate
of
over 330 weight parts causes material separation, making it difficult to
continue
operations .
The setting adjusting agent used in CA mortar is polycarboxylic acid or the
like
including, for example, a jet setter, useful for adjusting the available time
of CA
mortar. The consumption of the setting adjusting agent should usually be
within a
range of from 0 to 5 weight parts relative to 100 weight parts cement. With a
consumption of the setting adjusting agent of over 5 weight parts, early
expression of
strength cannot be expected, although the available time is sufficient.
Aluminum powder used in CA mortar is used for adjusting the expansion
coefficient in an amount within a range of from 0 to 0.05 weight parts. A
consumption of over 0.05 weight parts should be avoided because it may lead to
expansion cracks of CA mortar.
Expansive admixture used for CA mortar include lime- based and CSA- based
ones. The expansion admixture is effective not only for preventing cracks
caused by
volume shrinkage of CA mortar poured and filled up the void of aggregate layer
and
joint spaces, but also for preventing material separation of CA mortar to
bring about
dispersibility and watertightness. The consumption of the expansive admixture
should
usually be within a range of from 0 to 40 weight parts, or more preferably,
from 0 or
to 15 weight parts relative to 100 weight parts cement. A consumption of the
expansive admixture of over 40 weight parts should be avoided since it may
cause
expansion cracks of CA mortar.
Additives used for CA mortar include a fluidizing agent and an air entraining
agent. The fluidizing agent is for improving operability of CA mortar, and the
air
entraining agent is effective for improving freezing resistance of CA mortar.
The
consumption of each of these additives is usually within a range of from 1 to
5 weight
parts relative to 100 weight parts cement. A consumption of the fluidizing
agent of
under 1 weight part can give no effect, whereas a consumption of over 5 weight
parts
should be avoided because it causes material separation or defective hardening
of CA
mortar. A consumption of the air entraining agent of under 1 weight part gives
no
effect, whereas a consumption of over 5 weight parts seriously hinders
hardening of
CA mortar. The fluidizing agent and the air entraining agent may be used
singly or in
combination.
As additive water used for CA mortar, fresh water is usually used, such as,
for example, supply water, industrial water, ground water or river water.
CA mortar used in the present invention can be prepared by the following
method. The first charging the asphalt emulsion in a required amount into a
7 _
CA 02207074 1997-06-OS
prescribed container, adding additive water, the setting adjusting agent and
the
additives in required amounts to prepare a mixed liquid, by the use of a hand-
type
portable mixer, then adding cement, the rapid- hardening admixture, the fine
aggregate and aluminum powder in respective required amounts to this mixed
liquid,
and kneading the resultant solution through high- speed stirring, by the use
of a
hand- type portable mixer, thereby preparing CA mortar of the present
invention.
For the purpose of improving the operational efficiency, a mixture prepared by
blending the rapid-hardening admixture, the fine aggregate and aluminum powder
in
respective required amounts may be added to cement, or an asphalt -emulsion
prepared
by previously mixing additives in required amounts into the asphalt emulsion
may be
used. The thus prepared CA mortar should immediately be subjected to pouring
operation in practice.
The above fine aggregate used for CA mortar is used as the joint filler sand
in
the present invention.
As the joint filler material other than CA mortar used for filling the joint
spaces,
a heating- type joint sealer or a cold joint sealer is used. A heating- type
joint filler is
selected from among elastomer asphalt and eiastomer resin fillers. A cold
joint sealer
is selected from polysulfide, urethane resin, epoxy resin, acryl resin and
silicon resin
filler products for the road joint.
Now, application of the method of constructing block pavement of the present
invention will be described below with reference to the drawings.
In Fig. 1, 1 is a base comprising, for example, existing asphalt pavement.
and 2 is a tack coat layer formed by spraying an asphalt emulsion on the base
1.
Under a certain condition of the site, a tack coat layer is not provided. In
order to
ensure a firm adherence of the base layer and the aggregate layer, however, it
is
preferable to provide a tack coat layer. In Fig. 1, 3 is an aggregate layer
formed by
placing aggregates on the base; and 4 is a paving block in a temporary placing
state as
arranged 'on the aggregate layer 3. Joint spaces 5 are formed between adjacent
paving blocks 4, 4 . . . . thus arranged; 6 are side portion of the paving
blocks 4, 4 '
. . . . . opposite to each other at the joint space 5. Previously coating the
surfaces of
the side portions 6. 6 . . . . . and the bottom surfaces of the paving blocks
4 , 4 . . . . .
with an asphalt coating of an asphalt emulsion is effective for improving
adhesion
between the paving blocks 4 and a buffer support layer 9 described later in
this
specification.
In Fig. 2, ? is CA mortar which is poured along joint spaces 5 by means of a
pouring pot $ . The poured CA mortar 7 fills up the void of the aggregate
layer 3 .
bonds individual pieces of aggregate for solidification, and forms a cement
asphalt
concrete (hereinafter simply referred to as "CA. concrete") in which CA mortar
and
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CA 02207074 1997-06-OS
aggregate are mixed and solidified. The ~A concrete layer, formed by adhesive
and
viscoelastic CA mortar and aggregate, firmly secures the base 1 and the paving
blocks
4, elastically supports the paving blocks 4, 4 . . . . . , and serves as a
buffer support
layer 9 which effectively absorbs and alleviates shock and vibration caused by
traffic of
vehicles. CA mortar 7 filled up the joint spaces 5 forms an elastic joint
filler 10, and
combines the paving blocks 4, 4 . . . . . . While all the joint spaces 5 may
be filled
with this elastic filler 10, joint spaces may partially be left at top
portions of the joint
spaces 5 which may be filled with joint filler sand 11, as shown in Fig. 2 and
3.
After filling the aggregate layer with CA mortar, the joint spaces 5 may be
filled with a heating- type joint filler or an ambient- temperature joint
filler other than
CA mortar. When the joint spaces 5 are filled with a pouring joint filler
other than
CA mortar, it is possible to further improve imperviousness of joints in
service, and
follow up property to expansion and shrinkage of the joints.
Fine grooves 12 may be provided as shown in Fig. 4 on the bottom surfaces of
the paving blocks 4. By providing these fine grooves 12 on the bottom surface
of the
paving block 4 , air in the aggregate layer 3 is promptly discharged outside
through
these fine grooves 12 upon pouring CA mortar as shown by an arrow in Fig. 4.
It is
therefore possible to improve the filling up speed of CA mortar. Since CA
mortar
itself can flow through the fine grooves 12, there is available an effect that
CA mortar
can be rapidly poured even into a depth of the aggregate layer 3 covered with
the
paving blocks 4. In addition, CA mortar which has been poured and filling up
the fine
grooves 12 and has hardened there can serve as a stopper of the paving block 4
relative to the buffer support layer 9, and has a function of preventing the
paving
blocks 4 from moving forward and backward and to the right and to the left
under the
effect of vibration and shock of vehicles.
Fig. 4 shows provision of two parallel fine grooves 12 in a direction on one
paving block 4. The direction and number of the fine grooves are not however
limited
to the above, but two additional fine grooves may be provided in a direction
at right
angles to the two fine grooves i2 shown in Fig. 4, or may be diagonally
crossed each
other provided. It is needless to mention that three or more fine grooves may
be
provided per paving block, or on the contrary, a single such fine groove may
be
provided. When providing a smaller number of grooves, it is favorable to
increase
the width and the depth of a groove.
In place of providing fine grooves on the bottom surface of the paving block,
a
fine groove 13, as shown in Fig. 5 for example, may be provided on the upper
surface
of the aggregate layer 3. This fine groove 13 may be formed by any method, for
example, by disentangling pieces of aggregate on the upper surface of the
aggregate
layer 3_ and removing part of aggregates. It may be formed by making a
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CA 02207074 1997-06-OS
groove- shaped recess on the upper surface of the aggr egate layer 3 by
pushing a
formed plate against the layer 3. Discharge of air in the aggregate layer 3 as
a result
of filling of CA mortar is promptly accomplished through the fine groove I 3
provided on
the upper surface of the aggregate layer 3 as shown by an arrow in Fig. 5.
Since CA
mortar itself can flow through this fine groove, it is possible to rapidly
fill up even the
void of the aggregate layer covered with the paving block 4 with CA mortar.
While Fig. 5 covers a case with two parallel fine grooves 13 per paving block,
the number of groovestand the direction thereof are not limited to the above.
The
fine grooves 13 may be provided diagonally to the paving block, or may cross
each
other.
A hollow porous pipe 14 may be buried in the fine groove 13 provided in the
aggregate layer 3 as shown in Fig. 6. The hollow porous pipe I 4 may be made
of a
metal such as steel or plastics such as polyvinyl chloride. The buried pipe is
not
limited to the one shown in Fig. 6, but may be a pipe formed by winding a
metal wire
such as a steel one or a plastic wire such as a polyvinyl chloride one into a
coil spring
shape, or a hollow gridiron pipe made of a metal such as steel or a plastics
such as
polyvinyl chloride. It is also possible to use these hollow porous, coil-
spring- like
and hollow gridiron pipes in an appropriate combination.
As shown in Fig. 6, along with filling of CA mortar, air in the aggregate
layer
3 flows from a hole 15 of the hollow porous pipe 14 into the interior of the
hollow
porous pipe 14, and is rapidly discharged outside through the hollow porous
pipe 14.
In the above description, the case with fine grooves provided in the paving
block, the case with fine grooves provided on the upper portion of the
aggregate layer,
and the case with a hollow porous pipe provided in a fine groove on the upper
portion
of the aggregate layer have been presented as separate examples, but these
three
means may of course be appropriately combined.
Upon pouring CA mortar, joint space stoppers I 6, 16 . . . . . , as CA mortar
flowing stopper, should preferably be temporarily provided at appropriate flat
positions
of the joint spaces 5 formed between the paving blocks 4 , 4 . . . . . as
shown in Fig.
7 . The joint space stoppers 16 , 16 . . . . . are round- rod- shaped members
made of
foamed styrol, for example, with the lower end thereof in contact with the
upper
surface of the aggregate layer 3, installed substantially vertically to fill
the joint spaces
5. The joint space 5 is divided into a plurality of flat areas by the
plurality of joint
space stoppers 16, 16 . . . . . . While a joint space stopper is temporarily
provided
at a point of intersection of three paving blocks in Fig. 7, the position of
temporary
installation is not limited to the above, but installation may be at any
arbitrary position
of the joint spaces formed by adjacent paving blocks.
Fig. $ illustrates a case where CA mortar is poured into an area of the joint
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CA 02207074 2005-O1-10
space 5 surrounded by the joint space stoppers 16, 16 . . . . . As is clear
from Fig.
8, the poured CA mortar is dammed up by the joint space stoppers 16. 16 .. . .
clogging the joint spaces 5, and never diffuses to the aggregate layer surface
in a range
wider than the necessary extent. In CA mortar staying within a certain area,
an
osmotic pressure of CA mortar into the aggregate layer 3 is produced by the
gravity,
permitting rapid penetration into the aggregate layer 3 as shown by an arrow
in Fig. 8,
leading to improvement of filling up operation efficiency of CA mortar and
filled up ratio.
After sufficient penetration and filling up of CA mortar into the aggregate
layer 3,
the joint space stoppers 16, 16 . . . . . are removed, and then, CA mortar or
a joint
filler material other than CA mortar is poured into the joint spaces 5.
Now, the features of the present invention will be described below in detail
by
means of examples.
(Example 1 )
The method of constructing block pavement of the present invention was applied
to an existing asphalt pavement road which was estimated the road
classification A by
traffic volume on the basis of about 80 of one way daily traffic of the line
buses as
heavy vehicles.
The tack coat layer in this Example is provided for firmly bonding a buffer
support layer filled with CA mortar which is an adhering layer of existing
asphalt
pavement forming a base and paving block to the base. The asphalt emulsion
used for
this tack coat was rubberized cationic asphalt emulsion, and actually,
CATIOZOL GM*
made by NICHIREKI COMPANY (evaporation residue: 55. 0 wt. %, penetration of
evaporation residue (at 25° C): 93) was employed.
The aggregate layer in the Example is first formed by laying the grade 6.
crushed stone on a base, having a tack coat layer for installing paving
blocks, into a
thickness of about 3 cm. After filling up and solidification of CA mortar into
the void
between pieces of aggregate in the aggregate layer upon the completion of
installation
of the paving blocks, the aggregate layer serves as a bonding layer between
the base
and the paving blocks, and in service, functions as a buffer support layer
which
effectively absorbs and alleviates shock and vibration caused by traffic of
vehicles.
This buffer support layer also plays the role of an irregularities correcting
layer when
the base contains surface irregularities of flatness.
For balance in landscape because the site was adjacent to a park, a natural
stone was used. The stone block was a formed stone of Mikage-granite produced
in
China (size = 30 cm long, 30 cm wide, 12 cm thick).
The natural stone block had previously been covered with an asphalt coating on
the sides and bottom thereof to intensify adherence to the buffer support
layer formed
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CA 02207074 2005-O1-10
with aggregate and CA mortar and the elastic joints formed with CA mortar. The
same material as that used in the tack coat was used in the asphalt coating of
the
natural stone block, as an asphalt emulsion.
CA mortar comprised, relative to 100 weight parts cement, 200 weight parts
polymer-modified asphalt emulsion, 56 weight parts rapid-hardening admixture,
166
weight parts fine aggregate, 0. 7 weight parts setting adjusting agent, 0. 03
weight
parts aluminum powder, I. 0 weigh parts air entraining agent as an additive,
and 30
weight parts water as additive water.
Cement used was normal Portland cement made by Chichibu- Onoda Cement
Corporation. NICHIREKI COMPANY's NICHIREKI PMS Emulsion*(nonionic asphalt
emulsion: synthetic latex = 87. 5: 12. 5, evaporation residue: 60. 5 wt. %,
penetration
(at 25° C): 87) was used as a polymer-modified emulsion. APS*made by
ONODA
CORPORATION, prepared by mixing calcium aluminate and gypsum anhydride at a
weight ratio of I . 0 : 2. 0 was used as a rapid- hardening admixture. The
fine
aggregate was the grade 6. silica sand (silica sand produced in Yamagata; FM-
value: I .
47). AP Setter made by Chichibu-Onoda Cement Corporation was used as a setting
adjusting agent. C- 250 made by Nakajima Kinzoku Hakufun Kogyo Company was
used as aluminum powder. The additive used was an air entraining agent VINSOL*
made by Yamaso Kagaku Company and supply water was used as the additive water.
In this Example, silica sand was used as the joint filler sand.
Now, application of the present invention in the Example will be described
below further in detail.
First, a tack coat layer was provided by spraying CATIOZOL GM in an amount
of 0. 4 liters/m 2 on the surface of the existing asphalt pavement. Then,
after laying
and leveling the grade 6. crushed stone into an average thickness of about 3
cm, an
aggregate layer was provided by slightly roller-compacting the same with a
steel- wheel roller. Subsequently, the natural stone blocks previously applied
with
CATIOZOL GM on the bottom and sides thereof substantially at a rate of 0. 5
liter/m 2
as an asphalt coating were temporarily arranged one by one at prescribed
positions on
the aggregate layer while keeping prescribed joint intervals. The upper
surface
thereof was then slightly roller-compacted so that the upper surface of the
Mikage- granite was at uniform height, thus completing laying of Mikage-
granite.
Then, prior to pouring operation of CA mortar, preparation of CA mortar was
conducted.
Preparation of CA mortar was accomplished by the use of a polyvinyl chloride
container having a capacity of 100 liters and a hand mixer. In the first run
of
preparation of CA mortar, the PMS emulsion and additive water in required
amounts
were first charged into a container, and the setting adjusting agent AP setter
in a
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CA 02207074 1997-06-OS
required amount was added while slowly stirring the mixture by the hand mixer
to
prepare a mixed solution. Then, ordinary cement, the rapid-hardening
admixture,
the grade 6. silica sand, aluminum powder and the air trapping agent were
added in
required amounts, and then, the mixture was kneaded and mixed up for three
minutes at a stirnng rate of 1000 times/minute, thereby preparing CA mortar.
The
thus prepared CA mortar was immediately poured, and the second and subsequent
runs of preparation of mortar were carried out in response to the progress of
pouring
t .'
operations.
As a result of tests, this CA mortar and CA concrete prepared by mixing and
solidifying this CA mortar and aggregate had physical properties as shown in
Table 1.
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CA 02207074 1997-06-OS
Table 1 Physical properties of CA mortar and CA concrete
DivisionItem Measured Measuring method
of value
measurement
Initial 6.8 sec Civil Eng.Soc.J type
flow funnel method
time
CA CA mortar 20.0 C Rod=type thermometer
temp.
Available 30 min 8ithin flow time range
time 6-12 sec
mortar Hardening 70 min Finger-sensed hardening
start.
time
Adhesive 10.3 kgf/cmzBuilding Research Institute
strength Method
(material .
age:
28
days)
Un- Material
age:
confined2 hr 6.1 kgf/cm2 Sample was prepared by
placing the
compres-3 hr 11.2 kgf/cm2grade 6. crushed stone
in a Marshall
live 1 day 16.3 kgf/cm2test mold (dia.: 101.6
mm, height
strength7 days 28.6 kgf/cm2: 76 mm) and filling
the mold with
CA 28 days 35.7 kgf/cmzCA mortar.
concrete Material
age:
2 hr (Unmeasurable)Sample was prepared by
placing the
(Note 3 hr (Unmeasurable)grade 6. crushed stone
1) in a form of
Shear 1 day 21.4 kgf/cm230 cm long X 30 cm wide
x 5 cm
7 days 40.8 kgf/cm2high. filling it with
CA mortar for
stress 28 days 48.9 kgf/cm2hardening, and after
wet air curing.
cutting out 5 cm deep
x 5 cm wide
X 20 cm long pieces at
a prescribed
material age.
Elastic 15400 kgf/cmz-
modules
(material
age:
28
days)
(Note 1): Test temperature: 20 ° C
1 4 _
CA 02207074 2005-O1-10
The pouring operation was carried out by immediately subdividing the thus
prepared CA mortar into a pouring pot provided with a discharge port meeting
the joint
width of the joint spaces, inserting the tip of the discharge port of the
pouring pot,
and pouring CA mortar along the joint space at a low speed, to form a buffer
support
layer by filling up the void of the aggregate layer with CA mortar, and to
form an
elastic joint filling part of the joint space. CA mortar filling operability
was satisfactory.
Finally, the remaining upper portion of the joint space was filled with silica
sand for
finishing, thereby completing application of the method of the present
invention.
Because the CA mortar was of the rapid- hardening type, the pavement could
be opened to traffic promptly after the construction.
The natural stone blocks in the thus constructed block pavement is firmly
secured on the base by the buffer support layer and the elastic joints, and at
present
when about a year has passed, no damage is observed, keeping the initial
completed
state of pavement, in a very good condition.
(Example 2)
Block pavement was constructed directly on a base course for pavement.
The method of the present invention was applied in the same manner as in the
Example 1 in terms of both materials used and constructing steps except that a
different CA mortar was used.
The CA mortar used in this Example comprised, relative to 100 weight parts
cement, 130 weight parts polymer-modified asphalt emulsion. 150 weight parts
fine
aggregate, 0. 02 weight parts aluminum powder, 2 weight parts air entraining
agent
as an additive, and 35 weight parts additive water. High- early- strength
Portland
cement made by Chichibu- Onoda Cement Corporation was used as cement.
NICHIREKI PMT Emulsion'' made by NICHIREKI COMPANY (nonionic asphalt
emulsion: synthetic latex = 90 : 10; evaporation residue: 60. 8 wt. %,
penetration (at
25° C): 83) was used as a polymer-modified asphalt emulsion. The grade
6. silica
sand (produced in Yamagata; FM-value: 1. 47) was used as a fine aggregate. C-
300
made by Nakajima Kin2oku Hakufun Kogyo Company was used as aluminum powder.
VINSOL made by Yamaso Kagaku Company was used as an air entraining agent.
Supply water was used as additive water.
CA mortar was prepared at the site by the use of a capacity of 70 liters
polyvinyl chloride container and a hand mixer. First, the PMT emulsion and
additive
water were placed in the container, and the grade 6. silica sand, aluminum
powder
and the air entraining agent were added thereto while slowly stirring the
mixture by the
hand mixer. Then, after adding high- early- strength Portland cement, the
mixture
was kneaded and mixed at a stirring speed of 1. 000 revolutions/minute of the
mixer for
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CA 02207074 1997-06-OS
four minutes, thereby preparing CA mortar. CA mortar and CA concrete prepared
by
mixing and solidifying this CA mortar and an aggregate had physical properties
as
shown in Table 2.
r ..
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CA 02207074 1997-06-OS
Table 2 Physical properties of CA mortar and CA concrete
DivisionItem Measured Measuring method
of value
measurement
Initial 8.0 sec Civil Eng.Soc.d type funnel
flout method
time
CA CA mortar 22.0 C Rod-type thermometer
temp.
Available 60 min Range of flout time 6
time to 12 sec
mortar Expansion 130 min Finger-sensed
gel
start
time
Expansion + 1.2 % Measuring cyiinder method
coefficient
Breezing 0.0 % Civil Eng.Soc.polyvinyl
rate bag method
Unit 1.527 g/cm3 Triangular flask method
volumn
weight
Adhesive 9.2 kgf/cm2 Building Research Institute
strength Method
(material
age:
28
days)
Un- Material
age:
confined2 hr (Unmeasurable)Same sample preparing
method
compres-3 hr (Unmeasurable)as in Table 1
sive 1 day 7.1 kgf/cm2
strength7 days 26.5 kgf/cm2
CA 28 days 45.9 kgf/cm2
concrete Material
age:
2 hr (Unmeasurable)Same sample preparing
method
(Note 3 hr (Unmeasurable)as in Table 1
1)
Shear 1 day 3.1 kgf/cm2
7 days 15.3 kgf/cm2
stress 28 days 34.7 kgf/cm2
Elastic 9267.9 kgf/cm2-
modulus
(material
age:
28
days)
(Note 1): Test temperature: 20 ° C
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CA 02207074 1997-06-OS
The natural stone block in the block pavement constructed by the use of this
CA
mortar was firmly secured to the base course by the buffer support layer and
the elastic
joint filler as in the Example 1, and has a sufficient durability against
heavy traffic on
an ordinary roadway.
(Example 3)
As in the Example 2, block pavement was constructed directly on the base
r
course for pavement. -
A paving concrete plate was used as a paving block. Fine grooves were
formed on the bottom surface thereof for the purpose of rapidly discharging
air in the
aggregate layer along with placing of CA mortar to permit rapid filling of CA
mortar into
the aggregate layer. The formed fine groove had a width of 1 cm and a depth of
1
cm, and two such fine grooves were provided per a block.
After arrangement of the paving blocks and prior to filling of CA mortar,
joint
space stoppers as CA mortar flowing stopper were temporarily provided in the
joint
spaces between the paving blocks. Foamed styrol formed into a round rod having
a
diameterof 13 mmwas usedas ajoint space sto~per,andsuch joint space stoppers
were inserted substantially vertically at appropriate intervals at arbitrary
positions in the
joint spaces extending flat so that the lower ends of the joint space stoppers
are in
contact with the upper surface of the aggregate layer. These joint space
stoppers
partitioned the joint spaces into areas at intervals of about 1 m 2 on the
paved surface.
CA mortar was poured into the partitioned joint space areas to fill the
aggregate
layer. Upon confirmation of the completion of filling of the aggregate layer,
the joint
space stoppers were removed. Then, CA mortar was poured also into the joint
spaces, thereby completing the block pavement.
CA mortar used in this Example comprised, relative to 100 weight parts
cement, 150 weight parts polymer-modified asphalt emulsion, 120 weight parts
fine
aggregate; 18 weight parts expansive admixture, 0.01 weight parts aluminum
powder, 1 weight part air entraining agent as an additive, and 50 weight parts
additive water.
High- early- strength Portland cement made by Chichibu- Onoda Cement
Corporation was used as cement. NICHIREKI PMT Emulsion made by NICHIREKI
COMPANY (nonionic asphalt emulsion: synthetic latex = 90:10; evaporation
residue: 61.
0%, penetration: 93 (at 25° C)) was used as a polymer- modified
emulsion. The
grade 6. silica sand was used as a fine aggregate.. Lime-based Onoda AP made
by
ONODA CORPORATION was used as an expansive admixture. C- 300 made by
Nakajima Kinzoku Hakufun Kogyo Company was used as aluminum powder. Air
entraining agent VINSOL made by Yamaso Kagaku Company was used as an additive.
1 g _
CA 02207074 1997-06-OS
Supply water was used as additive water.
CA mortar was prepared at the site by the use of a grout mixer having a
capacity of 120 liters. First, NICHIREKI PMT emulsion and additive water were
charged, and the grade 6. silica sand, aluminum powder and the additive were
added
while stirring the mixture at a low speed (300 rpm). Then, after adding the
expansive admixture and high- early- strength Portland cement, the mixture was
kneaded and mixed for three minutes at a high speed (500 rpm) of the mixer,
thereby
preparing CA mortar. t ,
CA mortar and CA concrete prepared by mixing and solidifying this CA mortar
and the aggregate had physical properties, as a result of tests, were as shown
in
Table 3.
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CA 02207074 1997-06-OS
Table 3 Physical properties of CA mortar and CA concrete
DivisionItem Measured Measuring method
of value
measurement
Initial 6.3 sec Civil Eng.Soc.J type
flog funnel method
time
CA mortar 21.5 C Rod-type thermometer
temp.
Available 60 min Range of flout time 6
time to 12 sec
Expansion I10 min Finger-sensed
gel
start
time
r.
Expansion + 2.1 ~ Measuring cylinder method
coefficient
CA Breezing 0.0 ~ Civil Eng.Soc.polyvinyl
rate bag method
Unit 1.520 g/cm3 Triangular flask method
volumn
Weight
Adhesive 10.4 kgf/cm2Building Research Institute
strength Method
mortar (material
age:
28
days)
Material
age:
Cracking91 days No cracks Visual observation
test
(Note Material
2) age:
180 days No cracks
Un- Material
age:
confined1 day 5.8 kgf/cm2 Same sample preparing
method
CA compres-7 days 23.2 kgf/cmzas in Table 1
sive 28 days 38.0 kgf/cm2
concretestrength
(N
t
1)
o -
e
Elastic 8100 kgf/cmz-
modulus
(material
age:
28
days)
(Note 1): Test temperature: 20 ° C
(Note 2)'- The sample for the cracking test was prepared by placing CA mortar
in
a form of 200 cm long x 100 cm wide X 1 cm high and solidifying it.
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CA 02207074 1997-06-OS
Except for the above, block pavement was constructed directly on a base
course for pavement in the same manner as in the Example 2.
The thus constructed block pavement, as in the Example 1, was firmly
secured to the base course by the buffer support layer and the elastic joints,
and had a
sufficient durability against heavy traffic on an ordinary roadway. As a
result. of
provision of fine grooves on -the bottom surface of the paving blocks used and
temporary installation of joint space stoppers as CA mortar flowing stopper in
the joint
spaces, pouring and filling of CA mortar could rapidly be carried out, and
penetration
of CA mortar into the aggregate layer was very uniform and sufficient, as
compared
with that in the Example 2.
Blending of expansive admixture into CA mortar permitted achievement of an
expansion coefficient of CA mortar of +2. 1 (%) which represented a smaller
volume
shrinkage as compared with the expansion coefficient of + 1. 2 (%) of the CA
mortar in
the Example 2.
(Example 4 )
A 60 cm long, 40 cm wide and 5 cm thick paving concrete plate was
employed as a paving block. In place of providing fine grooves on the bottom
surface
of the paving concrete plate, semicircular fine grooves having a diameter of
about 2
cm were provided in parallel with the longitudinal direction of the road at
intervals of 20
cm on the upper portion of the aggregate layer. Except for the above, block
pavement was constructed with the same materials in the same constructing
steps as in
the Example 3.
It was possible to carry out pouring and filling of CA mortar rapidly, and
penetration of CA mortar into the aggregate layer was very uniform and
sufficient.
The constructed block pavement was firmly secured to the base course by the
buffer
support layer and the elastic joint filler, and had a sufficient durability
against heavy
traffic on an ordinary roadway as in the Example 1.
(Example 5)
Block pavement was constructed with the same materials and in the same steps
of construction as in the Example 4 except that polyvinyl chloride hollow
porous pipes
having a diameter of 2 cm were buried in parallel with the longitudinal
direction of the
road at intervals of 20 cm in fine grooves provided on the upper portion of
the
aggregate layer.
It was possible to carry out pouring and filling of CA mortar rapidly, and
penetration of CA mortar into the aggregate layer was very uniform and
sufficient.
The constructed block pavement was firmly secured to the base course by the
buffer- -
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CA 02207074 2005-O1-10
support layer and the elastic joints, and had a sufficient durability against
heavy traffic
on an ordinary roadway as in the Example 1.
(Example 6)
Block pavement was constructed with the same materials and in the same steps
of construction as in the Example 3 except that a polysulfide cold joint
sealer (made by
NICHIREKI COMPANY; NEOTAIYUSEALCOLD~ was used as a joint filler into joint
spaces between paving blocks after filling of CA mortar into the aggregate
layer, and
that no joint space stopper as CA mortar flowing stopper was temporarily
provided in
the joint spaces upon filling CA mortar into the aggregate layer.
The thus constructed block pavement was firmly secured onto the base course
by the buffer support layer and the highly expanding and shrinking filled
joints, and had
a further higher durability against heavy traffic on an ordinary roadway.
INDUSTRIAL APPLICABILITY
The present invention having the construction as described above brings about
the following effects:
I ) According to the method of the present invention, unlike the conventional
methods, it is possible to easily adjust the correct upper surface height of
the paving
blocks by means of adjusting the thickness of aggregate layer, even with
slight
irregularities in the base, or further even with paving blocks of non- uniform
thickness,
and by filling the void of the aggregate layer with CA mortar giving a uniform
strength,
it is possible to easily form a buffer support layer bonding the paving blocks
and the
base, thus providing an excellent installation operability.
2) Because CA mortar filling the aggregate layer has a high adhering property
in the present invention, it suffices only to temporarily install the paving
blocks, thus
permitting rapid installing operation, not requiring masonry specialists,
providing
excellent placing operability.
3) When using rapid- hardening type CA mortar, the resultant pavement can
be promptly opened for traffic.
4) Since CA mortar having a high adherence and a satisfactory elasticity is
used
in the present invention, the buffer support layer filled with CA mortar
causes firm
securing of the paving blocks to the base, and the elastic joints comprising
CA mortar
can firmly secure the blocks to each other. The block pavement constructed in
the
present invention can therefore effectively absorb and alleviate shock and
vibration
caused by traffic of vehicles, and sufficiently cope with stress produced by
traffic of
vehicles. It is therefore possible to provide block pavement excellent in
durability
against heavy traffic on an ordinary roadway.
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CA 02207074 1997-06-OS
5) By forming fine grooves on the bottom surface of the paving blocks or on
the upper portion of the aggregate layer, or by burying hollow porous pipes
into fine
grooves formed on the upper portion of the aggregate layer, it is possible to
rapidly
discharge air in the aggregate layer upon filling CA mortar, thus permitting
further
improvement of placing operability.
6) Temporary installation of joint space stoppers as CA mortar flowing stopper
at arbitrary flat positions in the joint spaces formed between paving blocks
improves
filling operability of CA mortar, and in addition, improves filling rate of CA
mortar into
the aggregate layer.
7) By using a pouring joint filler material rich in elasticity other than CA
mortar in the joint spaces formed between the paving blocks after filling the
aggregate
layer with CA mortar, it is possible to further improve imperviousness of
joints in
service and follow up property to expansion and shrinkage of joints.
Construction of block pavement in the present invention brings about such
excellent effects, so that it is possible to provide block pavement having an
excellent
durability with a beautiful appearance by applying for pavement of an ordinary
roadway.
It is needless to mention that the present invention displays an excellent
durability in application to various kinds of block pavement in an existing
sidewalk or
open space.
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