JPS609703A - Manufacture of composite concrete board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an inexpensive composite concrete board (hereinafter referred to as a composite board).

For example, it is well known to provide a cement reinforcing plate reinforced with glass fibers on the tension side of a concrete plate used for purposes such as a wide-area gutter cover where a large load is applied to one side. This composite plate is made by, for example, filling a trough-shaped formwork with a cement mixture containing glass fiber pieces, and then pouring concrete while the cement mixture is unhardened to integrally mold the two. This method is called the flat construction method.

The flat construction method is not possible, for example, when the side walls of the trench are formed using formwork. The reason for this is that if the formwork is vertical, uncured GRO will flow vertically, making it impossible to pour concrete into two layers.

The present invention was proposed to improve these points, and involves inserting a pre-formed glass fiber reinforced cement board (hereinafter referred to as a GRO board) into the formwork that forms the composite board, and One side is brought into close contact with the frame wall, and then concrete is poured on the other side. Since the GRO plates are preformed to predetermined dimensions and cured, vertical formwork can be used to back the concrete.

This will be explained below with reference to the attached drawings.

FIG. 1 is a partially cutaway perspective view of a composite board 10 produced by the method of the present invention, and FIG. 2 is a sectional view of a vertical formwork forming the composite board 10. The composite plate 10 has a GRc plate 12 arranged on the tension side of a concrete plate 11, which is a bending material on which a load is applied to one side. That is, the GRO board 12, which has been previously formed to a predetermined size, is inserted into the formwork 20. Next, one surface of the GRO board 12 is brought into close contact with the frame wall, and concrete is poured on the other surface to form the concrete board 11, which is hardened and cured.

It is preferable that the GRO board 12 is pressed into close contact with one side of the frame wall by inserting a spacer into the formwork 20.

Examples and reinforcing effects will be described below.

The GRO board 12 is made by filling a 600×1200×10 nm wooden frame with mortar and 4 parts of alkali-resistant glass fibers with a cut length of 25 mm while being sprayed with a spray gun. When the thickness reaches the predetermined value of 10 mm, defoaming is performed using a roller, and uneven lines are added just before hardening. Remove the mold the next day5.
Three GRO plates 12 measuring 70 x 390 mm were cut out. The mortar was made by kneading 40 kg of river sand passed through a 2 mm sieve, 40 kg of ordinary Portland cement, and 2.4 kg of Denka C3A, and then adding 16 kg of water in which 250 g of the water reducing agent Mighty was dissolved. .

The inside of the formwork 20 is 600 x 390 x 60 mm
The frame wall dimensions are set as follows. Three sets of these formworks 20 were stacked to form a three-speed system so that three composite plates [O] could be obtained at the same time. Inserting the ORC board 12 into each of the formworks 20,
One smooth surface of the GRC board 12 is brought into close contact with the frame wall so that the smooth surface becomes the surface of the final product.

Next, DI is placed in the space between the other surface of the GRQ board 10 and the frame.
After arranging O reinforcing bars 13 (5 main bars, 4 distribution bars) and positioning them with spacers, fresh concrete is poured and compacted with a vibrator. Through these operations, three composite plates were manufactured from the three-speed formwork.

At the same time, a concrete plate was manufactured with the same specifications except for the ORC plate, and the fracture strength of the two was compared, and the results shown in the following table were obtained.

Initial crack Failure load sample Generated load (kgf) (kgf) 1 7, 2
9.2 Average 7.2 8.9 1 2, 7 5.4 Both were left in water at 20°C for 28 days after being demolded, and the span length was maintained at 39 cm and bent toward the eye strength side. The test was conducted by applying tensile stress. As a result, OR
The one in which the C plate is arranged has an extremely good reinforcing effect.

As mentioned above, since the ORC board is pre-hardened, it is possible to use the vertical casting method to line the concrete with vertical formwork, reducing the manufacturing cost of the composite board to a fraction of that.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view of a composite concrete plate manufactured by the manufacturing method of the present invention, and FIG. 2 is a sectional view showing a vertical formwork. 10 is a composite concrete board, 11 is a bending material, 12 is an ORC board, and 20 is a formwork. Patent applicant: Jun Nagasaki, representative of Nippon Electric Glass Co., Ltd. −

Claims (1)

[Claims] In the production of composite concrete plates in which glass fiber reinforced cement plates are placed on the tension side of the bending material, a pre-formed glass fiber reinforced cement plate is inserted into the formwork that forms the composite concrete plates, and one side of the A method for producing a composite concrete plate, which comprises placing the plate in close contact with a frame wall, and then pouring concrete on the other side.