JPH02167962A - Draining method of concrete milk excessive water - Google Patents

Abstract

PURPOSE:To obtain better hardening by including a permeable fiber layer with a specific value of an average fiber diameter and METSUKE, and laying a sheet-like object having the smooth surface brought into contact with concrete milk between a form and the concrete milk. CONSTITUTION:When concrete milk is poured into a form to harden the concrete, an average fiber diameter is less than 15 microns, including a permeable fiber layer with 10 - 1,000g/m<2> of METSUKE, and a sheet-like object with the smooth surface brought into contact with the concrete milk is spread to the inside of a concrete form. The concrete milk is poured into the form, the sheet-like object is laid between the form and concrete milk, and excessive water coming gradually out of the concrete milk with the hardening of the concrete is drained through the sheet-like object. According to the constitution, better hardening can be promoted.

Description

[Detailed description of the invention] [Industrial use! f] The present invention relates to a method for smoothly draining excess water generated from concrete milk when hardening concrete to make a concrete structure.

[Conventional technology]

To obtain a concrete structure, it is common to first pour so-called concrete milk, a mixture of cement, sand, pebbles, and water, into a formwork. The water in the concrete milk poured into the formwork is gradually drained from the concrete milk from the time it is poured, and the concrete begins to harden. At this time, with the drainage, some of the concrete milk also flows out of the formwork, which not only causes a loss of concrete milk, but also causes unevenness on the hardened concrete surface, which reduces the strength of the concrete surface. .

Therefore, in order to prevent these drawbacks, attempts have been made to arrange paper, cloth, or film inside the formwork.

[Problem to be solved by the invention]

However, none of these methods can simultaneously satisfy the requirements of preventing concrete milk from flowing out and providing smooth drainage, and therefore ultimately it has not been possible to obtain a concrete structure with excellent surface strength. This is the current situation.

In view of the above-mentioned problems, the present invention efficiently drains excess water that gradually arises from concrete milk when hardening concrete to make concrete structures, thereby efficiently producing concrete structures with excellent surface strength. The purpose of the present invention is to provide a drainage method that makes it possible to obtain water.

[Means and actions for solving problems]

The present inventor has made extensive studies to achieve the above-mentioned object, and as a result, has arrived at the present invention.

That is, when pouring concrete milk into a formwork and hardening the concrete, a water-permeable fiber layer with an average fiber diameter of 15 microns or less and a basis weight of 10 to 1000 g/% is placed between the formwork and concrete milk. By interposing a sheet-like material containing a smooth surface that comes into contact with concrete milk, excess water that gradually arises as concrete hardens is smoothly drained, promoting good hardening, and allowing concrete to harden. It has been found that when this is done, the surface strength of the concrete surface, that is, the side that is in contact with the fiber layer, is significantly improved.

Here, the fibrous layer having an average fiber diameter of 15 microns or less can be obtained, for example, by the melt-blowing method described in US Pat. No. 3,849,241. A fiber layer composed of fibers with an average fiber diameter of more than 15 microns cannot sufficiently prevent concrete milk from flowing out. In this sense, it is particularly preferable that the average fiber diameter is 10 microns or less.

Also, the date of the fibrous layer must be in the range of 10 to 1000 g/rrT. In other words, the fabric weight of the fiber layer is 1
If it is less than 0 g/rd, the concrete will not be sufficiently prevented from flowing away. On the other hand, the basis weight is 1000g/
If it is larger than nf, although it is effective in preventing concrete milk from flowing away, water permeability becomes poor and a concrete structure with excellent strength cannot be obtained.

In addition, in order to give the fiber layer sufficient strength, the fiber layer may be subjected to empos processing, calendar processing, Pinsonic (&H
It is preferable to use it in the form of a so-called non-woven fabric, which is reinforced with a sonic wave treatment or an adhesive. In addition, non-woven fabrics are suitable for use with water-permeable materials such as fabrics, non-woven fabrics, plastic nets, perforated films, etc., in order to ensure that the concrete milk does not break when poured and that the drainage rate can be well controlled. It is also preferable to use it as a sheet-like product laminated together by a suitable method.

Furthermore, the surface of the sheet-like material on the side that comes into contact with the concrete milk needs to be smooth so that the sheet-like material and the concrete can be easily separated after the concrete cube has hardened. In order to smooth the surface of the sheet-like material, for example, cold calender treatment, preferably hot calender treatment, etc. are used. Of course, it is effective to laminate a water-permeable porous film with a smooth surface or a net.

In the present invention, the fiber layer having an average fiber diameter of 15 microns or less needs to be water permeable in order to drain water from the concrete milk. At this time, the fiber material has
Various types of fibers can be used, but it goes without saying that it is desirable that they have properties that do not deteriorate with respect to the discharged liquid.

When using a hydrophobic material such as polyolefin fiber, it is more preferable to impart water permeability to the material by kneading a surfactant into the material or by surface treatment.

Example 1 A web having an average fiber diameter of 8 microns and a basis weight of 40 g/rrt was obtained by melting polypropylene, extruding it from a nozzle, and blowing hot air at the same time, using a so-called melt-blowing method. At this time, a hydrophilic oil agent was applied to impart water permeability to the web.

This web was sandwiched between two water-permeable polypropylene spunpond nonwoven fabrics having a basis weight of 30 g/- on both sides, and then subjected to heat calender treatment to obtain a sheet with a smooth surface. This sheet-like material had water permeability even after heat calendering.

The obtained sheet material is stretched inside the concrete formwork,
When concrete milk was poured, excess water that gradually formed in the concrete milk as it hardened was smoothly drained through the sheet material, promoting good hardening. In addition, the outflow of the concrete milk itself through the sheet material was well suppressed.

Further, when the formwork was removed after the concrete had hardened, the sheet-like material could be easily peeled off from the concrete.

The surface hardness of the concrete after one month was on average 45% better than when the sheet material was not used.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, surplus water that gradually arises from concrete milk during hardening is smoothly drained through the sheet-like material, promoting good hardening, while concrete milk The outflow of the concrete itself is sufficiently prevented, and extremely excellent effects such as being able to efficiently obtain a concrete structure with excellent strength can be achieved.

Claims (1)

[Claims] When pouring concrete milk into the formwork and hardening the concrete, between the formwork and the concrete milk,
The average fiber diameter is 15 microns or less and the basis weight is 10.
A method for draining excess water from concrete milk, characterized by interposing a sheet-like material containing a water-permeable fiber layer of 1000 g/m^2 to 1000 g/m^2 and having a smooth surface in contact with concrete milk.