JPH0533830Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an acid-resistant concrete pipe in which a synthetic resin sheet is bonded to the inner surface of the concrete pipe.

It has been known for a long time that concrete generally corrodes in an acidic environment. For this reason, the inner surface of concrete pipes, which are mainly used as sewer pipes, are lined with synthetic resin or bonded with synthetic resin sheets, but the adhesion between concrete and synthetic resin sheets is extremely poor. ,
Methods have been considered to use adhesives on the inner surface of concrete pipes after hardening, or to fuse them by heating, but complete adhesion cannot be expected and peeling occurs within a short period of time, making the pipes useless as acid-resistant concrete pipes. This can cause damage to the pipeline. In addition, in concrete pipes lined with synthetic resin, minute holes (pinholes) in the lining material are unavoidable, and acidic liquid or gas can enter between the concrete and the lining material through these pinholes, and in this case also for a short period of time. Over time, it became no longer useful as an acid-resistant concrete pipe, causing pipe damage.

In order to improve the adhesion of this synthetic resin sheet, a sheet with many protrusions for anchors on the back side of the sheet is used to embed the protrusions for anchors into the concrete while the concrete is still uncured when forming a concrete pipe. However, as mentioned above, the adhesion to the concrete is poor, so peeling is likely to occur, and there is also a risk that cracks may occur in the concrete layer from the protruding anchor portion. Due to recent changes in eating habits and the structure of sewer pipes, sediment from muddy water often rots in the sewer pipes and generates sulfur dioxide gas, which becomes an acidic liquid by reacting with water. Demand for acid-resistant concrete pipes is increasing because concrete corrodes, and it is currently difficult to find countermeasures for acid-resistant concrete pipes.

The present invention relates to the improvement of concrete pipes provided with such an acid-resistant coating, and uses a sheet in which a synthetic resin sheet and a bulky fiber fabric are laminated in two layers in advance to prevent the concrete from forming after forming the concrete pipe. The bulky fiber fabric is brought into contact with the concrete surface and pressurized while it is still uncured, and the bulky fiber fabric is embedded in the concrete and cured as it is to obtain an acid-resistant concrete pipe covered with a synthetic resin sheet. , provides a strongly integrated acid-resistant concrete pipe.

As the synthetic resin film used for this acid-resistant concrete pipe, a polyolein sheet that does not use plasticizers is suitable, and as the bulky fiber, a nonwoven fabric with a high basis weight is suitable, but pile weave etc. good.

The acid-resistant concrete pipe of the present invention will be explained with reference to the accompanying drawings. Fig. 1 shows an embodiment in which a humm pipe is coated, and Fig. 2 shows an embodiment in which a box culvert is coated. 1 is the concrete layer, A
is a laminated sheet consisting of a synthetic resin sheet 2 and a bulky fiber fabric 3, which is adhered and coated on the entire inner surface of a concrete pipe. As shown in the enlarged cross-sectional view of Fig. 3, this laminated sheet A has a sheet 2 and a bulky fiber fabric 3 laminated together in two layers, and this bulky fiber fabric 3 serves as the bonding surface with the uncured concrete layer. As shown in the enlarged cross-sectional view of FIG. 4, the bulky fiber fabric 3 bites into the uncured concrete layer and hardens firmly as one with the cement matrix. The synthetic resin sheet 2 on the surface is formed on the inner surface of the Cunkrete layer 1 as a stable acid-resistant coating.

FIGS. 5 and 6 are examples showing longitudinal cross-sectional views when applied to Huyum tubes, and the one shown in FIG. This is an example in which the inner surface of the concrete pipe 1 is coated with an acid-resistant laminated sheet A. Normally, such a coating is sufficient, but when considering bending of the pipe, etc. It can be said that the embodiment in which the entire inner surface of the tube up to the mouth end 6 is coated is more complete.

As mentioned above, the acid-resistant concrete pipe of the present invention can be similarly coated with a pipe body with a circular cross section such as a fume pipe, or a box culvert with a square cross section, and can be coated with a synthetic resin sheet with sufficient acid resistance and a bulky body. The acid-resistant laminated sheet A, which is made up of fiber fabric, is firmly bonded by having its bulky fiber fabric surface penetrate and embedded in the concrete layer, so that the acid-resistant laminated sheet A has no effect on the acid-resistant layer like a conventional acid-resistant concrete pipe. There is no peeling, etc., and sufficient effects can be obtained for modern sewerage construction.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of the acid-resistant concrete pipe of the present invention in the case of a humm pipe, and FIG. 2 is a cross-sectional view in the case of a box culvert. FIG. 3 is a cross-sectional view of the acid-resistant laminated sheet, FIG. 4 is an enlarged view showing the bonded state, and FIGS. 5 and 6 are longitudinal views of an embodiment in the case of a hume pipe. 1... Concrete layer, 2... Synthetic resin sheet, 3... Bulky fiber fabric.

Claims (1)

[Scope of utility model registration request] A synthetic resin sheet and a bulky fiber fabric are laminated in advance around the entire inner surface of an uncured concrete pipe immediately after molding to form a two-layer laminate sheet A, so that the bulky fiber layer of the laminate sheet A is in contact with the inner surface of the concrete pipe. Acid-resistant concrete pipe characterized by being integrated by laminating it into one piece.