JPH09111741A - Foundation pc board for concrete product laying - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to prevent the generation of cracks or voids by leaving a peripheral edge slightly on the rear surface of a PC board and constructing a concrete product construction foundation PC board on which a normal temperature hardened elastic body is laminated, on a crushed stone layer and forcing the board to follow an uneven surface. SOLUTION: A polyurethane-based normal temperature hardened elastic body 2 is laminated on the whole surface with an uniform thickness except for a peripheral edge which is slightly left over on one surface of a PC board which forms a joint comprising a projected part 3 and recessed part 4 on the end in the longitudinal direction, thereby forming a foundation PC board. The foundation PC boards are constructed on the crushed stone layer consolidated on an excavated ground with the normal temperature hardened elastic body 2 placed downward while they are being jointed with the uneven joint of the PC board. The normal temperature hardened elastic body 2 follows with the uneven or undulated areas on the crushed stone and buries the cavity, thereby supporting the layer PC boards elastically. At that time, the normal temperature hardened elastic body 2, while being subjected to deformation, is pushed and extended toward the peripheral edge but it is not extended to the outside of the peripheral edge. This construction makes it possible to lay concrete products on the top of the PC boards lined up horizontally.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foundation P which is laid on the ground in advance when laying concrete products such as electric wire common grooves, underdrain and open drain in the ground.
It relates to the C plate.

[0002]

2. Description of the Related Art As a foundation work for laying concrete products such as electric wire common grooves, underdrain, open channel, etc. in the ground, a crushed stone layer is provided on the excavated ground, and after crushing gravel is added and compacted. , The method of forming the foundation concrete by cast-in-place is general.

As one of the improvements of this construction method, there is also adopted a construction method in which a PC board is laid on a crushed stone layer obtained by precasting cast-in-place foundation concrete and compacting it.

[0004]

In the conventional method of laying a PC plate on a crushed stone layer, the PC plate is only laid directly on the crushed stone layer, so that the PC plate is placed between the crushed stone layer and the crushed stone layer. It is supported by a crushed stone layer with a void left in it. Therefore, (1) PC is loaded by the concrete product.
The board breaks. (2) When scour with groundwater, cavities are generated on the bottom surface of the PC board, which accelerates damage to the PC board. Such problems have occurred, and the solution is required.

[0005]

DISCLOSURE OF THE INVENTION The present invention relates to a basic PC board which is in full contact with and supported by the crushed stone layer without leaving a void between the crushed stone layer and the crushed stone layer. By laying, it is intended to solve the above-mentioned problems caused by the use of the conventional basic PC board.

That is, according to the present invention, the room temperature curable elastic body is made to have a uniform thickness over the entire surface of one side of a rectangular PC plate having a concave-convex joint at the end in the longitudinal direction, leaving a slight margin. It is a basic PC board for laying concrete products that is laminated.

The main point of the present invention is that a room temperature hardening type elastic body is laminated on the entire surface of one side of the PC board with a slight margin to leave a uniform thickness.

The surface of the basic PC board of the present invention, on which the room temperature-curable elastic body is laminated to have a uniform thickness, is the lower surface at the time of laying, that is,
This is the surface that comes into contact with the crushed stone layer of the ground.

When the basic PC board of the present invention is laid on a crushed stone layer, even if the crushed stone layer has some irregularities or undulations, the basic PC board
Since the room temperature hardening type elastic body deforms following the irregularities and undulations of the crushed stone layer due to the weight of the plate, there is no gap between the bottom surface of the basic PC plate and the crushed stone layer, and it is elastically supported by the crushed stone layer in a well-balanced manner. To be done. This condition is further emphasized when concrete products are laid on the base PC board. Therefore, there is no place where local stress is generated on the lower surface of the base PC board without filling the recess of the crushed stone layer with sand or mortar.
The C plate is not cracked, and the bottom surface of the PC plate is not voided by scour.

The room-temperature-curable elastic body used in the present invention is a solid elastic body formed by mixing two kinds of liquids, pouring the mixture into a mold, and curing the mixture at room temperature. . A typical example thereof is a polyurethane-based elastic body in which a prepolymer, which is a reaction product of an active hydrogen-containing polymer such as polyester or polyether, and a polyisocyanate, and a curing agent are reacted at room temperature in a mold and cured. . Polyurethane elastomers vary from soft to hard depending on the type of active hydrogen-containing polymer and polyisocyanate used, the blending ratio of both, and the addition amount of auxiliary materials such as synthetic rubber and asphalt during the reaction. It is possible to produce a wide range of elastic materials,
The type and amount of raw materials used are determined according to the desired properties of the elastic body. In the present invention, a room temperature curable elastic body other than the polyurethane type elastic body, for example, a silicon type room temperature curable elastic body may be used without any problem.

In the present invention, the PC plate is laid horizontally on the bottom plate in order to stack the room temperature curable elastic body on one surface of the PC plate so that the peripheral portion is slightly left and to have a uniform thickness. Line up,
A mold may be assembled around the four sides of the PC plate, and a predetermined amount of liquid, which is a reaction raw material, may be poured into the mold and reacted at room temperature in the mold to form a room temperature curable elastic body.

In the present invention, by adopting the room temperature curing type elastic body, it is possible to simultaneously form the elastic body and laminate it on the surface of the PC board by operating at room temperature, and heat and melt rubber or asphalt. It is easier to operate and consumes less energy than the method of pouring fluidity.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of a basic PC board of the present invention,
(A) is a side view in the longitudinal direction, (b) is a plan view, and (c) is a side view in the width direction.

The basic PC board of the present invention comprises a PC board 1 and a room temperature-curable elastic body laminated on the entire surface with a slight margin to leave a uniform thickness (about 5 to 30 mm). It consists of two.

A convex portion 3 is formed on one end face of the PC board 1 in the longitudinal direction, and a concave portion 4 is formed on the other end face thereof. The convex portion 3 and the concave portion 4 form an uneven joint. There is.

The room temperature hardening type elastic body 2 is laid on the bottom plate horizontally on the PC plate 1, and a mold is assembled around the four circumferences of the PC plate 1, and a predetermined amount of liquid as a reaction material is poured into the mold to fill the mold. It was made to react at room temperature at room temperature and laminated at the same time as it was formed, and was not laminated at the peripheral edge (width of about 10 to 30 mm).

FIG. 2 shows an example of laying a basic PC board of the present invention, (a) is a side view and (b) is a front view.

A compacted crushed stone layer 5 on the excavated ground
Lay the basic PC board on top.

The base PC board is laid with the PC board 1 on top and the room temperature curing type elastic body 2 on the bottom. The room temperature-curable elastic body 2 elastically supports the PC board 1 while following the irregularities and undulations on the upper surface of the crushed stone layer 5 and filling the depressions. Due to the deformation, the room temperature curable elastic body 2 is expanded toward the peripheral portion, but is not expanded to the outside of the peripheral edge. Continue laying while joining with the concavo-convex joint. Since the room-temperature-curable elastic body 2 of the existing base PC board is not expanded to the outside of the peripheral edge, it does not hinder the deformation of the room-temperature-curable elastic body 2 of the new base PC board. In parallel with the laying of the basic PC board, the concrete product 6 is laid on the existing PC board 1. Laying up to the specified length, backfilling the excavated ground, and laying is completed.

[0021]

By laying the basic PC board of the present invention on the crushed stone layer, the basic PC board is elastically balanced by the crushed stone layer without forming a gap between the lower surface of the basic PC board and the crushed stone layer. Supported. No local stress is generated on the lower surface of the base PC board, cracks are not generated on the PC board, and cavities due to scour are not formed on the lower surface of the PC board. In addition, since the room-temperature-curable elastic body is not laminated on the peripheral portion and a space in which the room-temperature-curable elastic body can be deformed is ensured, the deformation of the room-temperature-curable elastic body is joined to the basic PC. Deformation of the room temperature hardening type elastic body on the lower surface of the board is not hindered, and each laid base PC board is elastically supported in a well-balanced manner by the crushed stone layer.

[Brief description of the drawings]

FIG. 1 shows an example of a basic PC board of the present invention, (a) is a side view in the longitudinal direction, (b) is a plan view, and (c) is a side view in the width direction.

FIG. 2 shows an example of laying a basic PC board of the present invention, (a)
Is a side view, and (b) is a front view.

[Explanation of symbols]

1 ... PC plate, 2 ... Room temperature curing type elastic body, 3 ...
4 ・ ・ Concave, 5 ・ ・ Crushed stone layer, 6 ・ ・ Concrete product

Claims (1)

[Claims] 1. A room temperature-curing elastic body is laminated on one surface of a rectangular PC plate having a concavo-convex joint at a longitudinal end with a uniform thickness, leaving a slight margin. Basic PC board for laying concrete products.