JPS6393957A - Execution of concrete floor - Google Patents

Abstract

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

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention provides a method for applying a coated floor or a molded floor (
The present invention relates to a method for constructing a concrete floor, which shortens the construction period for a concrete floor forming a surface floor such as a plastered floor, and improves the adhesive strength of the surface floor to a concrete surface.

(Prior art) Conventionally, in the construction of painted floors and molded floors, after the base concrete is poured, a curing period of 2 to 3 weeks is required until the moisture content in the concrete decreases to about 8 to 10%, and then Remove the laitance layer by mechanical sanding, apply a primer, wait for the primer to dry, then apply a coating material such as epoxy resin, or apply an epoxy resin adhesive and attach the molded floor. This is how it has been done.

The curing period of 2 to 3 weeks is intended primarily to evaporate surplus water in the concrete and to reduce peeling and blistering phenomena of the painted or molded floor that are thought to be caused by the surplus water.

(Problems to be Solved by the Invention) However, there are often cases where the painted or molded floor peels or bulges even after the above curing period. This was also an issue that had a considerable impact on the length of the construction period.

In view of these circumstances, the present invention aims to significantly shorten the construction period compared to conventional floor construction methods, while at the same time improving the adhesive strength of painted or molded floors. The construction method was developed based on the viewpoint of ease of removal of water and the idea that negative pressure will be generated within the concrete as a result of a decrease in volume within the concrete due to a decrease in water due to hydration reaction. be.

(Means for Solving the Problems) Therefore, the object of the present invention is to remove the concrete from the concrete at an early stage, most preferably within 30 hours after the concrete is placed, after the breathink water floating on the surface of the concrete that has been placed has disappeared. After removing the laitance layer formed on the surface, immediately apply a primer, particularly preferably a hydrophilic primer, to the concrete surface, and after drying the primer, apply a synthetic resin flooring material or coat the molded floor with a synthetic resin adhesive. This can be achieved by installation methods such as pasting.

According to this construction method, after placing concrete, there is a time lag until the bleeding water disappears depending on various conditions such as the moisture content of the concrete, temperature, humidity, etc., but after the bleeding water floating on the surface disappears, it is preferably early, especially about about The laitance layer formed on the surface is removed relatively early within 30 hours, and a primer is applied. Removal of the laitance layer is
Broom made by Jun Muku.

The removal shall be carried out using appropriate removal means while the laitance layer is still in an uncured state, such as a scrubbing brush, a metal scrubbing brush, a metal brush, etc., which can be easily removed by manually scraping the surface layer of the concrete. If the floating (breezing) water on the surface has disappeared, it is possible to apply a primer, but since the concrete itself is still wet, a solid epoxy resin that is compatible or wettable can be applied with a solvent. It is preferable to use an appropriate hydrophilic primer, such as a primer or a liquid epoxy resin, because it allows for easy and uniform application and ensures reliable adhesion and integration with concrete.

The adhesion between the primer applied in this manner and the concrete is extremely good, as shown in the Examples below, even when the concrete is applied under a still wet condition.

This is because the concrete is young and the laitance layer is unhardened, so the laitance layer can be easily and reliably removed. Since the primer is in a porous state, it can adhere to the concrete surface reliably and uniformly, and the hydration reaction progresses rapidly, especially within 30 hours after concrete is placed, and moisture due to the hydration reaction increases. Negative pressure is generated within the concrete in response to the decrease in the concrete, and this negative pressure increases to a maximum of approximately 0.3 kg/cJ, and this increasing negative pressure causes the applied primer to be sucked into the concrete. It penetrates further, and the area near the concrete surface becomes like a composite layer of inorganic and organic materials made of concrete and primer, resulting in a stronger adhesion compared to conventional application on dry surfaces, and the area near the concrete surface becomes stronger. This is thought to be due to the formation of a coated surface with -N stronger integration. The graph shown in Figure 1 shows an inner diameter of 150 mm, a depth of 75 μl, a depth of 150 mm, and a depth of 300 mm.
ms three types of completely sealed containers Δ that cannot drain excess water,
B, C, water 185, cement 286, fine aggregate 887
, coarse aggregate 905 kg/+t? , water-cement ratio 65
%, fine aggregate ratio 49.7%, and measured slump 9el11 to prepare specimens A, B, and C. These were cured in 206C 165%RH, and their negative pressure was reduced to mercury. It shows changes over time measured with a manometer. It was thus confirmed that negative pressure was generated along with the hydration reaction, rapidly increased until about 30 hours had passed after concrete placement, and then gradually increased over the next 10-odd days. This negative pressure is thought to encourage the primer applied to the concrete to penetrate deeper into the concrete surface and become integrated.

By applying the above-mentioned primer, the concrete is covered with the primer or the surface layer in an undried state, so it is possible to prevent the temperature of the concrete from decreasing due to outside air to a certain extent, and it also helps the early development of concrete strength. In the following, we will discuss examples of painted floors, but even if the floor is pasted with a synthetic resin adhesive, i.e., a molded floor, etc., the adhesion and integration with the primer will be as strong as in the case of painted floors. Therefore, the surface flooring material can be molded flooring or any other flooring material.

(Example 1) A coated floor (sample) was formed according to the present invention, and the adhesion between the coated floor and the underlying concrete was examined. According to this, it was confirmed that the adhesive force between the coated floor formed by removing the laitance layer and concrete was stronger than the concrete breaking force.

First, prepare 8 molds with a depth of 10 cffl and 20 cm in length and width, and fill each with 185 ml of water. Cement 308° Fine aggregate (average particle size 2n or less) 870. Coarse aggregate (average particle size 20~
25 Tsuru) 905 each kg/I, water reducing agent to cement ratio 0.2
Concrete with a compressive strength of 210 kg/- after 28 days of curing, consisting of a mixture of 5 m%, water-cement ratio of 60%, and fine aggregate ratio of 49.5%, was poured.
For four of them, the laitance layer was removed at the time when the breathing water disappeared and the laitance layer was formed, and a certain period of time after concrete placement (listed in Table 1 below), and then the primer was immediately applied. Each 0. 32
kg/rrr (conventional method averages 0.16 kg/m) =
2 hours after removing the laitance layer, apply 4 kg/m of filler primer (resin to filler 1:1) and scrub with a metal trowel. 18 hours after removing the laitance layer, apply each epoxy resin flooring material. 0.0, 7 kg/rd (same as the conventional construction method), and 4.
Two specimens were obtained, and a Kenken type adhesion test was conducted on each specimen 24 hours after application of the flooring material. The test was conducted at three arbitrary locations on each specimen.

On the other hand, for the four concrete ponds mentioned above, without removing the formed laitance layer, the primer was applied as it was according to the construction time of each of the above-mentioned invention specimens, and then the same procedure as above was applied sequentially. A filler primer and an epoxy resin flooring material were applied to obtain four comparison specimens, and the same Kenken type adhesion test as above was conducted.

The results are shown in the table below.

Table 1 (Samples of the Present Invention) The laitance layer could be easily removed for specimens of Types 1 to 3 using a scouring brush, and for specimens 4 using a metal scouring brush.

Table 2 (Comparative specimen) The failure conditions in Table 2 above are all interfacial failures between the laitance layer and the base concrete (100%).
Indicates that The interface failure in the specimens of the present invention shown in Table 1 was 0%.

The primer used was a base material made of a solid epoxy resin and methyl ethyl ketone mixed with a thinner made of toluene, isobutanol, methanol, etc., and a polyamide curing agent.

(Example 2) In actual kitchen renovation work, in addition to waterproofing,
Water 208kg/n? , cement 347kg/n? , with a water-cement ratio of 60% and a fine aggregate ratio of 48.8%, the absolute cement capacity is 110j! /%, average particle size 2,5111 or less per second 3131/rd, average particle size 20B or less lightweight coarse aggregate 3
29 j! Lightweight concrete consisting of a mixture of /rrr (
Compressive strength 135 kg/cd) in the range of approximately 15M, approximately 1
It was poured to a thickness of 3c1.

3 hours after pouring the concrete, press it with a wooden trowel,
After 5.5 hours (the same applies hereafter), the laitance layer was started to be removed, and after 6 hours, a primer was applied.
After 2 hours had elapsed, filler reprimer was applied and iron troweling was performed, and after 25 hours, an epoxy resin flooring material was applied. Note that each condition and composition are the same as in Example 1.

A Kenken type adhesion test was conducted on the floor obtained by the above construction method of the present invention at two locations 46 days after the concrete was poured.
% failure, the interface failure between the primer (painted floor) and concrete was 0%, and the adhesive strength at each of the two locations was 13.1%.
and 17.9 kg/y, with an average of 15.5 kg/y.

The breaking force of this concrete is stronger than that of lightweight concrete made using conventional construction methods. Further, after 50 days had elapsed, no blistering phenomenon occurred on the coated floor surface.

(Effects of the Invention) As described above, the present invention removes the laitance layer early after pouring concrete, applies a primer, and then coats the surface with a coating material or adheres a molded floor. According to this, the construction period for floor coating construction can be shortened by about 2 to 3 weeks, for example, about 2 to 3 weeks, which is approximately the conventional curing period, thereby significantly improving construction efficiency. Furthermore, the adhesive strength of this surface layer is strong enough to prevent peeling between the concrete and the primer, ie, the surface layer, and to prevent blistering, and does not weaken the strength of the concrete.

[Brief explanation of the drawing]

Figure 1 is a graph showing the change in pressure (negative pressure) within concrete due to the hydration reaction of young concrete as a function of time and mercury column difference.The vertical axis shows the mercury difference (fi1 fl).
The horizontal axis shows the negative pressure (g/cd) and the elapsed time after concrete placement. Applicant: NBC Shokai Co., Ltd. (Amendment to Sosho ♂ 21) Title of the invention: Concrete floor construction method 3, relationship with the case of the person making the amendment Applicant representative: Tadashi Samura - 4, agent [stock] 101 5, Spontaneous amendment 6, subject of amendment Clarification) The claims of the book of lil, detailed description of the invention 1, and the claims are amended as follows. Note (1) After the breathink water floating on the surface of the poured concrete base disappears, remove the laitance layer as soon as possible and immediately apply a primer to the concrete surface, and after the primer dries, apply a synthetic resin flooring material. Or a concrete floor construction method that forms a surface floor such as pasting a molded floor. (2) The method for constructing a concrete floor according to item 1, wherein the removal of the laitance layer is performed within about 30 hours after concrete placement. (3) The method for constructing a concrete floor according to item 1 or 2, wherein the primer is a 6-shape 2-lance-shaped epoxy resin cut with a damaging solvent. 2. The "1st layer %" at the end of page 7 of the specification is a typographical error and has been corrected to rw%J. 3. In Table 2 on page 10, "0% of all fractures in concrete" in the column of each type of fracture for types 1 to 4 is not clearly marked.
Correct this to r interface failure 100% J 4, unpublished r on the same page
(100%)" should be corrected to "100%, indicating that there was no destruction within the concrete. Further, the above includes 1001 type solid epoxy resin 60-1% (same units below) as solid content, modified polyamide amine 15 (curing agent), methyl ethyl ketone 19 (base) as solvent, and toluene 65 (Base 13. Curing agent 52), Isobutanol 37 (Base 8. Curing agent 29)
), and Others 4 (curing agent) are blended with a base and a curing agent in a ratio of 1:1. that's all

Claims (3)

[Claims] (1) After the breathink water floating on the surface of the concrete base has disappeared, the laitance layer is removed at an early stage and a primer is immediately applied to the concrete surface, and after the primer dries, a synthetic resin flooring material is applied, or A concrete floor construction method that forms a surface floor, such as pasting a molded floor. (2) Removal of the laitance layer takes approximately 30 minutes after concrete placement.
The method for constructing a concrete floor according to paragraph 1, which is performed within a certain time. (3) The method for constructing a concrete floor according to item 1 or 2, wherein the primer is a hydrophilic primer.