The present invention relates to construction concrete blocks with a variety of surface layer pieces attached such as rubber pieces excised mainly from discarded tires of automobiles.
Rubber pieces such as ones taken from discarded tires have been used for surface layers of concrete blocks for roads or walls in order to reduce noise, echoing sound, abrasion, ice formation, black ice, colliding shock etc. In the conventional method to use rubber pieces for the surface layer, discarded tires are first shredded or granulated into rubber grains which are then solidified to make a plate with the bonding agent. In this way the problem of different thicknesses of discarded tires is solved, producing the industrial products in a desired size.
However this method has drawbacks such as requiring special facilities for the shredding procedure and solidifying. Besides, the durability of the solidified plates of rubber grains will drop considerably, compared with the original tire rubber. Therefore these plates are not allowed for the motor ways or shore walls, where these are subjected to severe environmental conditions.
The procedure of granulation followed by solidification has been applied to surface layer pieces of other materials such as wood, glass or stone. These drawbacks are inevitable with the random thickness of surface layer piece, since the blocks are required to have a given thickness.
Many trials have been carried out to hold rubber pieces on hardened concrete with strong bonding agents or devices with the result that rubber pieces separate in a short period of time. One of the reasons is the flatness of the boundary plane in which stresses are directly transferred to the adjacent, increasing the shear force to cause the separation due to stress concentration on a specific spot. The spot is subjected not only to the shear stress from the adjacent but to thermal stresses due to the temperature change. The combined stresses will accelerate the separation which could spread fast on the simple plane. Consequently the long term bond strength will drop considerably.
There are three drawbacks in the conventional method as follows:
The production cost is high:
The strength of the surface pieces is low
The long term bond between the surface pieces and the block is reduced.
The present invention is to solve these three drawbacks by a means of using blocks having surface layer piece attached thereto, as in Claim 1. The main points of the means are given in the two conditions in Claim I in the clause e as well as the clause f as follows:
These points may be illustrated in an example in which fresh concrete as a hardening material is directly placed on the bonding layer, consisting of viscose body such as bituminous material. This procedure is to make three parts contacting with each other, a surface layer piece 1, a bonding portion 2 and a curing body 3 consisting of hardening material, referring to
Since this procedure spares the procedure of granulation or shredding in the conventional practice, the cost of blocks is reduced, and the surface pieces can be made stronger than the pieces made of solidified grains. The three parts the surface layer piece 1, the bonding portion 2 and the curing body 3 can be connected tightly. Therefore the shear forces to which the surface pieces are subjected are dispersed to prevent the stress concentration, strengthening the bond. In addition, the viscose body in the bonding portion can prevent the separation by deforming, even recovering the bonding strength for a period of time. Consequently the blocks according to Claim I are able to solve the three drawbacks simultaneously.
The objective of using the bitumen-like material of the delayed bond is to connect the surface pieces with the hardening material after the hardening material hardens. This objective may be attained likewise by other means as follows: delayed heating of the bonding portion, delayed infiltration of bond or simply bonding after the hardening is over. This means is applicable to various surface layer pieces made of a variety of materials such as wooden tips, plastics, discarded ceramics and natural pebbles. Although there are many materials having suitable properties as the surfacing materials, few of them have been used for the surface layer pieces of blocks. The reason is as follows: being difficult to stick to concrete, being weak in bonding the hardening materials or being of random sizes when supplied. The use of this invention makes it possible to produce durable products of blocks in a given size, with materials difficult to use in conventional practices.
The bonding material for the bonding portion 2 is to make a binder of concrete for the curing body 3, filling the prepared space of prefabricated blocks. This method can spare the procedure to make a bonding portion. Partial separation of the bonding portion, if made of asphalt-like materials, can be repaired automatically at high temperatures so that the long term bond or durability will increase considerably.
In addition, in Claim 2 it is shown that the joint body 34 can be formed in a space between the adjacent surface layer pieces in order to connect the pieces with a curing body 3 by burying, bonding or projecting. Since the joint body thus made is restrained by a curing body so that it can restrain the surface layer piece 1, the bond durability is enhanced considerably.
In addition, in Claim 3, the peripheral sides of the surface layer piece 1 can be shaped uneven either by forming dents or the holding hands 7 so that a curing body 3 can be also shaped likewise, strengthening the bond of the surface layer piece. Especially the holding hands 7 made of rubber can be held in a curing body 3 so that the bond can be enhanced further between the surface layer piece 1 and a curing body 3. The bond strength goes up by the undercut shape between the holding hand 7 and a curing body 3.
In addition, Claim 4 shows that the independent blocks can be connected with a net-like member, or a net or a holed sheet, 5 to be one so that the arrangement of blocks can be accurate with directions and the joint widths at the construction site in order to enhance the resistance against the deformation due to the traffic loads. Besides, the unit of connected blocks is more beneficial because it is easy to handle with a handling means such as a crane, raising the construction efficiency considerably.
Blocks claimed in Claim 5 are illustrated in
Blocks claimed in Claim 6 are illustrated in
As claimed in Claim 7, a bonding portion 2 of blocks can have materials such as carbon fibers to generate the heat by the electrical currency, the microwave or the high frequency. The bonding portion can be made separately as a membrane. Since the bonding portion 2 can be controlled by heating, it is easy to check the arrangement of the surface layer pieces before bonding or to change the positions of the surface layer pieces. In such blocks, it is possible to reduce the cost of maintenance and repair, since it is possible at will either to bond a curing body 3 to the surface layer piece or to separate the bonded.
As shown in Claim 8, separators 33 can be inserted in a curing body to divide it so that cracks due to the traffic vibration or the base slide are forced along the separators since the shift or damage at the adverse positions in a block can be prevented.
The figures in these drawings are described in the followings.
In the general procedure of this invention, each block is covered with one surface layer piece at least. In the case 1, the surface layer piece is of the 120 mm×120 mm square. Each block has four of the pieces with joints 4 mm wide. A bonding portion or an Asphaltic one is formed on the back side of the surface layer piece on which concrete is placed. When the rubber thickness is 10 mm and asphalt thickness is 1 mi-n, the concrete thickness can be 19 mm. In accordance with the rubber thickness, concrete thickness can be adjusted to make a block, 246×246×30 mm. As concrete hardens, the unification advances between rubber of the surface layer piece and a curing body of concrete to make a combined block. In this example, 16 of the blocks can be arranged in one square meter with the width of joints of 4. These blocks are either for multifunctional block roads by being placed on the base 6 of sand or rubber walls by being laid vertically. Consequently this procedure makes it possible to control the height of rubber blocks regardless of the thickness of the pieces attached, keeping the strength of these and the bond between them and a curing body.
The vertical cross section, when the practice is finished, is shown in
As in claim 1, the bonding portion 2 can be made of asphalt. Therefore the partial separation between the surface layer piece I and a curing body 3 is recovered when the temperatures are high. In addition, the bond and the separation can be controlled with heat and pressure so that the work for construction and maintenance is made simple.
As shown in claim 2, at least the part of a curing body 3, forming the jointing body 34, can be projected into the joint space 4. The jointing body 34 has a function to transfer forces to a curing body 3, to which the surface layer pieces 1 are subjected. Therefore a variety of surface materials such as plastics and metals can be used for the surface layer pieces 1.
In claim 4, the holding arm 7 can be formed to be held by a curing body 3. The said arm 7 is to prevent the surface layer piece I separated in order to secure the traffic safety. The said arm 7 can be club-shaped or holed to be held by the undercut of a curing body 3, increasing the bonding strength.
As claimed in claim 5, independent blocks can be connected with a net-like member 5 so that it prevents each block from being dislodged from the road surface, increasing the handling efficiency in construction.
As explained above, this invention of blocks for paving has the merits as follows;
In addition, this invention of rubber blocks for walls, banks or floor has the merits as follows:
In addition, this invention can contribute to prevent the environmental pollution by reducing heat or harmful gas, generated when the waste such as discarded tires are burnt for processing.
Number | Date | Country | Kind |
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2002-30835 | Feb 2002 | JP | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP03/01155 | 2/5/2003 | WO | 6/30/2005 |