JP3324089B2 - Sand cushion material and joint material for paving stones and construction method of paving stones using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sand cushion material and a joint material to be applied to a lower part of a ground on which paving stones are laid such as a sidewalk, a roadway, a park, an amusement park, and a method for constructing a paving stone using the same. In more detail, while maintaining the fluidity as sand at the time of construction, after applying compaction, it has moderate hardness, flexibility to alleviate the load on paving stones, and anti-flow which is not washed away by rain etc. The present invention relates to a sand cushion material, a joint material, and the like having properties.

[0002]

2. Description of the Related Art The structure of a paved road for a conventional roadway is shown in FIG.
As shown in (A), a layer subjected to asphalt stabilization processing is formed on crushed stone, the above-mentioned sand cushion material called coarse sand is applied thereon, and further, paving stones are laid, and fine sand is used between the paving stones. It has a structure with joint material. Also, as shown in FIG. 3 (B), the structure of the paved road for sidewalks is such that sand cushion material is directly applied on the crushed stone, paving stone is laid thereon, and jointing material with fine sand is applied between the paving stones. It has a structure. This sand cushion material is expected to play a role in adjusting the unevenness of the pavement and pavement surface, ensuring the flatness of the pavement stone, and at the same time, dispersing the load applied to the pavement stone and transmitting it to the subgrade, thereby stabilizing the pavement stone. I have.

However, in the structure of the above-mentioned paved stone road, first, the sand at the joint portion is easily exposed to the wind and rain and easily flows out. When the sand at the joint portion disappears, mutual support between the paved stones is lost and the paved stone is moved in the horizontal direction. To the right and left and right due to biased load.
There is a serious drawback in that, since the saw motion is repeated, the surface becomes rough and uneven, and the road becomes dangerous.

On the other hand, there is an attempt to apply a kind of concrete called a blank kneading mortar as an underlaying material. However, since it is too hard and lacks elasticity, the mortar is cut off when the paving stones perform a shearing motion, and the load is further increased. However, there is a problem that the pavement is damaged or cracked when drainage is added, and the drainage is poor.

[0005] The same applies to the jointing material. The jointing material is capable of connecting the paving stones to each other to prevent the members from being dropped, thereby increasing the durability, and at the same time, having the effect of relaxing the thermal expansion and shrinkage of the paving stones. It is expected, however, that if the conventional gap is just filled with fine sand, it will easily be washed away by the weather, and if a hard thing such as mortar is used to prevent this, the above-mentioned relaxation action will be lost and the pavement itself will be damaged Cause inconsistency of cracking.

[0006]

The inventor of the present invention has conducted intensive studies on such problems, and as a result, has focused on the characteristics of asphalt and maintained an appropriate fluidity for leveling work during construction. In addition, after compaction, a suitable compaction can be obtained, and a means capable of eliminating adverse effects such as outflow due to wind and rain, rattling and breakage due to knitting load, and the present invention has been completed.

[0007]

The sand cushion material for paving stones of the present invention is intended for sand having a grain size of 13.2 mm or less, and is mixed with asphalt in a total weight ratio of 1 to 4 wt%. It is configured by forming an asphalt layer around it. The mixing ratio of the asphalt is 2.5 wt.
% Is desirable.

Further, the joint material for paving stones of the present invention comprises
For sand with a particle size of 36 mm or less, the total weight ratio is 1.5
The asphalt layer is formed around the sand by mixing asphalt in a range of about 4.5 wt%. The mixing ratio of the asphalt is desirably 3.0 wt%.

Another joint material for paving stones is silica sand No. 4 to No. 7, and asphalt is mixed at a total weight ratio of 0.1 to 2 wt% to form an asphalt layer around the sand. It is composed. The mixing ratio of asphalt is desirably 0.5 wt%.

The method for constructing a paving stone according to the present invention comprises the steps of:
For sand with a particle size of 3.2 mm or less, the total weight ratio is 1
A sand cushion material for paving stone having an asphalt layer formed is laid around the sand by mixing asphalt in a range of 4 wt%, and a paving stone is laid thereon, and a grain size of 2.36 mm or less in a gap between the paving stones. Of sand, and asphalt is mixed in a total weight ratio of 1.5 to 4.5 wt% to fill a joint material for paving stone having an asphalt layer formed around the sand.

The second method for constructing paving stones is to apply sand having a grain size of 75 μm or more and 13.2 mm or less on a crushed stone layer or an asphalt-stabilized layer, Asphalt is mixed in the range of 1 to 4% by weight, and a sand cushion material for paving stone having an asphalt layer formed around the sand is laid, paving stone is laid thereon, and silica sand Nos. 4 to 7 are provided in gaps between the paving stones. The asphalt layer is formed by mixing asphalt in a total weight ratio of 0.1 to 2% by weight and filling the sand with an asphalt layer.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The sand cushion material of the present invention
When sand is used as a sand cushion material, which is called coarse sand, and it is defined by its particle size, it can be screened.
It is 2 mm or less. Table 1 shows the results of the particle size test of one example.

[Table 1]

Next, for the above-mentioned sand cushion material,
Asphalt is mixed at a ratio of 1 to 4% by weight based on the total weight, and an asphalt layer is formed on the surface of the sand grains of the sand cushion material. Here, asphalt refers to a semi-solid or solid sticky substance mainly composed of bitumen as a distillation residue of natural or petroleum-a mixture of hydrocarbons soluble in carbon disulfide. As described above, asphalt is semi-solid or solid and has the property of exhibiting tackiness. Therefore, paying attention to the properties of the semi-solid or solid and the tackiness, the asphalt is coated on the surface of coarse sand. However, if the proportion of the asphalt component is too large, the adhesiveness and the bonding property of the two are too strong, and when performing the work for laying the paving stones, when the sand cushion material is laid on the asphalt-stabilized layer, the Because of lack of properties, the leveling work becomes difficult, and the sand cushion material cannot be laid flat. On the other hand, if the amount of asphalt is too small, there is a lack of mutual bonding, and therefore, as in the case of the conventional sand cushion material, there is a drawback that the asphalt easily flows out due to wind and rain and has an uneven surface. Then, when an experiment was conducted on the characteristics of asphalt, the results shown in the following table were obtained. Test method: Asphalt 0 to 5.0 wt% of a mixture of 7
Each kind was produced, and it was swept with a broom and its workability was observed.

[Table 2] As a result, up to 3.0% by weight, the semi-solid or solid nature of asphalt is strong, it does not stick to each other even when it touches each other, keeps fluidity, and maintains the fluidity on crushed stone or asphalt stabilization treatment. It was confirmed that the work of flatly laying the sand cushion material on the applied layer, that is, the so-called leveling work, could be performed well. However, 3.0 wt%
When it exceeds 4.0 wt%, the adhesive property of asphalt becomes stronger, and the leveling work becomes difficult,
If it is 5.0 wt%, the work becomes almost difficult.

Next, after flattening and laying work to make a smooth surface, rolling was applied thereto and a compaction test by the rolling was performed. Test method: Asphalt 0 to 5.0 wt% of a mixture of 7
Each type was prepared, filled into a mold for marshall test at room temperature, and one side was compacted five times with a marshaller. After the compaction, the compact was removed from the mold and the state of compaction was observed.

[Table 3] As a result, when the content is 1.0 wt% or less, there is almost no adhesion and the sands are separated from each other, which causes the generation of uneven surfaces as in conventional sand. On the other hand, if the content is 4.0 wt% or more, mutual adhesion is too strong, which may cause breakage and cracks due to uneven load described later. 2.0 wt% is slightly weak in adhesiveness and 3.0 w%
Although t% tends to have strong adhesion, use is possible, and the optimum value was shown at 2.5 wt%.

[0015] Further, after compaction, paving stones were laid, and the road was used as a road to drive a car to test load resistance. Test method: 600 x 300 x 60 mm block granite was laid, and a 10-ton truck was run at a frequency of 100 vehicles per day (12.5 vehicles / hour in 8 hours during the day)
The condition of the paved stone was observed.

[Table 4] As a result, when the content was 1.0 wt% or less, an uneven surface was generated as in the case of conventional sand, and rattling occurred. On the other hand, if the content is 4.0 wt% or more, the hardness is too high, and damage and cracks are caused by the reaction force of the load applied by the vehicle running on the paved stone. And 2.0
In the range of wt% to 3.0 wt%, the flexibility and the restoring property were obtained, and the load could be reduced, and the optimum value was 2.5 wt%.

Table 5 summarizes the results of the leveling workability, compaction after rolling, and load resistance.

[Table 5] As a result, it was found that when the mixing ratio with the coarse sand was set to 2 to 3 wt%, the conventional defect as the sand cushion material could be solved, and the optimum value was shown at 2.5 wt%. However, since the specific gravity of paving stones differs depending on the collection site, etc., ± 1 wt
% Error must be expected, so the mixing ratio is 1 to
The range is 4 wt%.

Next, the joint material of the present invention will be described.
The joint material of the present invention includes a case where fine sand is used and a case where silica sand is used. Fine sand refers to sand having a grain size of 2.36 mm or less, for example, a sand having a grain size test shown in Table 1 except for a portion above 2.36 mm. For the fine sand, asphalt, 1.5 to the total weight
Mix at 4.5wt% ratio, optimally 3.0wt%,
An asphalt layer is formed on the surface of the sand grains of the sand cushion material. The fine sand was used because the joint gap was 0.05.
It is necessary to reduce the particle size in order to sweep the sand into the gap of about 5 mm. The reason why the asphalt mixing ratio was increased compared to the above-mentioned sand cushion material is that the wind blows to the joints as the car travels. This is because it is necessary to increase the adhesiveness and the adhesiveness.

In the case of silica sand, asphalt is mixed with silica sand Nos. 4 to 7 in a total weight ratio of 0.1 to 2 wt%, optimally 0.5 wt%, and the sand is mixed. Form an asphalt layer around. In the case of the silica sand, the mixing ratio of asphalt is smaller than that in the case of the fine sand, because the silica sand has silicon dioxide as a main component and a low rate of absorbing asphalt inside, so that the asphalt layer can be formed in a small ratio. It is.

As a result of an outflow test of the joint material with water such as rain, the results were as follows. Test method: 5 squares of 300 x 100 x 60 mm square
A test device having a gradient of 2% was prepared by arranging the test pieces in parallel, and a filling material using fine sand was filled in the cells, and after compaction was applied, a large amount of water was injected from the upper surface, and After that, the amount flowing out of the cells was measured, and the outflow rate was calculated.

[Table 6] As a result, in the case of 0 wt%, a phenomenon of saturating water after 5 minutes was observed, but the liquefaction phenomenon was not observed in the case where asphalt of 1.0 wt% or more was applied, and 2.0 wt%.
As described above, the outflow rate was 1.0 wt% or less, and it was confirmed that there was almost no outflow. This result is presumed to work in the case of a sand cushion material.

Therefore, the joint material using the fine sand is appropriately 1 wt% or more from the outflow property due to rain or the like. However, like the sand cushion material, the workability of leveling, compaction after compaction, and Since load resistance is required, this was taken into consideration, and the adhesiveness was slightly increased to 1.5 to 4.5 wt%, and the optimum value was set to 3.0 wt%. In addition, when silica sand Nos. 4 to 7 were used, the above range was determined from the same viewpoint as that of the fine sand, while considering that the rate of absorbing asphalt therein was low.

In the method for producing the above-mentioned sand cushion material and joint material, in a hot-mix type asphalt plant, river sand heated by a drum dryer is weighed and put into a mixer, and then 1 to 4 wt% of asphalt is injected. Mix until asphalt has covered all of the river sand.

Next, a construction method using the above-mentioned sand cushion material and joint material and its operation will be described. First, crushed stone is laid on the lowermost layer to a thickness of about 150 mm, and a layer subjected to asphalt stabilization treatment for suppressing deformation of the pavement surface to a low level is formed thereon to a thickness of about 100 mm. Then
The sand cushion material of the present invention is laid at room temperature without heating to about 20 mm. At this time, when flattening work, in the case of no pressure at room temperature, the sand cushion material has no tackiness at all and maintains a smooth fluidity with each other, so it can be spread evenly on the road surface, flat Ensure the nature. This is due to the semi-solid or solid nature of asphalt.

Next, after the leveling work, block-shaped paving stones are laid and constructed. However, since the sand cushion material is kept flat, the paving stones are also laid sufficiently flat and easily. it can. The paving stones are mainly made of concrete and include natural stones, porcelain tiles and bricks.

The joint material is swept with a broom or rubber rake into the joint between the paving stones. At this time, since the joint material has a fine particle size and a smooth state, it can be easily swept even in a narrow gap.

When the above-described jointing operation is completed, compaction is performed by applying a compaction pressure on the pavement and joints using a vibration compactor or the like. At this time, when a certain pressure is applied, an appropriate compaction state is obtained, so that the compaction work can be easily performed, and at the same time, the paving stones can be laid uniformly and flat.

As a result, the joint material is sandwiched between the left and right paving stones after being swept and compacted when pressure is applied, and mutual adhesion prevents the joint material from flowing out due to rain or the like. In addition, the joint portion is likely to be scattered by the wind due to the running of the car, but this is also prevented. As a result, the paving stone members are prevented from being lost, and the paving stones can be effectively engaged with each other.

Also, when pressure is applied from the vertical and horizontal directions due to an uneven load on the pavement, or when expansion or contraction due to heat occurs, the pavement has flexibility so that this force is alleviated and an adjusting function is exhibited.

The sand cushion material is such that sand particles adhere to each other and are compacted due to the adhesiveness of asphalt.
Although it gains flexibility, this adhesion is very weak and not excessively strong. Therefore, the flexibility reduces the stress against the load applied to the paving stones due to the running of the car, etc., and exerts the adjusting function against the load and the vibration. In addition, since it is not excessively adherent, it may cause damage, cracks, etc. due to the reaction. do not do. This property is persistent, and no performance deterioration such as an increase in hardness with time is observed.

Further, when water invades due to a large amount of rainfall, water plays a role of a kind of lubricating material in a conventional sand cushion and causes a so-called liquefaction phenomenon. And the oil-based asphalt is insoluble in water, so that the adhesion is not affected by water and the liquefaction phenomenon is prevented. At the same time, if there is a risk of freezing in winter, it is not affected by the thawing.

Since the oily asphalt component has a repelling effect on plants, it prevents weeds from growing.

[0031]

EXAMPLE The following sand and asphalt were used as a sand cushion material, and the mixing ratio was 2.5 wt%. (Coarse sand) The same as the particle size in Table 1. Table dry specific gravity: 2.604 Bulk specific gravity: 2.556 Apparent specific gravity: 2.686 Water absorption: 1.9% (Asphalt) Cosmo Oil Co., Ltd. 60-80 strain -Asphalt Penetration (25 ° C): 69 Softening point: 49.5 ° C Elongation (15 ° C): 100+ Density (15 ° C) g / cm ³ : 1.034 Kinematic viscosity 120 ° 931 150 ° C 212 180 C. 71.3 The following sand and asphalt were used as a sand cushion material, and the mixing ratio was 3.0 wt%. (Fine sand) Use the sand cushion material of Table 1 with 4.75 mm or more removed. Other conditions are the same as those of the sand cushion material. (Asphalt) Same as the sand cushion material. , 600 × 30
Three types of paving stones, a 0x60 mm porcelain tile block, a granite block and a concrete block, were laid.
And, from January to April 1996, exposed to the open-air, and
A large 10 ton truck was driven for 100 vehicles a day (8 hours during the day). As a result, the leveling work is good, even if there is a large amount of rainfall, there is no joint material flowing out, there is no dropout of paving stones, and even if the load due to running of the car is repeated, unevenness, damage, cracks Was not observed at all.

[0032]

As described above, the present invention maintains a suitable fluidity for leveling work during construction as a sand cushion material, and has a suitable hardness and flexibility after rolling. And an excellent effect that satisfies the conflicting demands of preventing runoff due to wind and rain and movement of paving stones and eliminating the adverse effects such as breakage and cracks due to knitting load.
In addition, as a joint material, there is no danger of runoff due to rain, and it is possible to prevent loss of paving stones. Since it is flexible, it exerts a buffering effect on pressure and expansion and contraction from vertical and horizontal directions of paving stones, and can prevent weeds from growing. According to the construction method in which the sand cushion material and the joint material are combined, the leveling work and the laying work are simple, and the compacting state is moderate at a constant pressure, so that the rolling work is easy. This is a very advantageous invention that has an excellent effect on the work surface, such as being laid flat.

[Brief description of the drawings]

FIG. 1 is a schematic partial sectional view of a roadbed for roads provided with a sand cushion material and a joint material of the present invention.

FIG. 2 is a schematic partial cross-sectional view of a sidewalk roadbed provided with the sand cushion material and the joint material of the present invention.

FIG. 3 is a schematic partially enlarged sectional view of a sand cushion material and a joint material of the present invention.

FIG. 4 is a schematic partial cross-sectional view of a conventional roadbed provided with a sand cushion material and a joint material, and FIG.
(B) is for a sidewalk.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP2-15605 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) E01C 7/18

Claims (3)

(57) [Claims] 1. A pavement joint comprising: asphalt mixed with silica sand Nos. 4 to 7 in a total weight ratio of 0.1 to 2 wt% to form an asphalt layer around the sand; Wood. 2. The mixing ratio of asphalt is 0.5 wt%.
The joint material for paving stones according to claim 1, wherein 3. Asphalt is mixed on a crushed stone layer or on a layer on which asphalt stabilization treatment has been performed with a sand having a grain size of 13.2 mm or less in a total weight ratio of 1 to 4 wt%. Laying a paving stone sand cushion material with an asphalt layer formed around the sand, laying a paving stone thereon, targeting silica sand No. 4 to 7 in the gaps between the paving stones,
A method of constructing a cobblestone, characterized by mixing asphalt in a total weight ratio of 0.1 to 2 wt% and filling a joint material having an asphalt layer formed around the sand.