JP2000226804A - Manufacture of concrete-paving plate having roughness on surface - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wide surface roughness concrete-paving plate by spraying a delay agent to the surface of unhardened concrete placed in a form, repeatedly flattening the surface by rubbing with a trowel, and continuously repeating the delay agent spray and trowel flattening processes at a required number of times. SOLUTION: Generally, concrete obtained by mixing Portland cement, water, fine aggregate (sand) and coarse aggregate (gravel) is placed, a hardening delay agent is added to the surface, the surface is flattened by rubbing the surface several times with a flat trowel, the hardening delay agent addition and trowel flattening processes are repeated at a required number of times (about three times), it is left as it is half a day (concrete of a part where a hardening delay agent does not yet permeate is hardened), and the unhardened part of the surface is washed for a required time. Thus, as the amount of a delay agent added is increased, a concrete-paving plate with a larger surface roughness is obtained, and it is possible to obtain a concrete-paving plate with a roughness far exceeding a sand patching value of 1 mm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a concrete pavement plate having a surface roughness so as to prevent slippage of the road surface by laying the same on a road pavement surface, and in particular, to reduce the surface roughness to a required roughness. The present invention relates to a method for manufacturing a pavement plate that can be formed by adjusting.

[0002]

2. Description of the Related Art Conventionally, a concrete pavement plate is roughened by spraying a curing retarder on the surface of uncured concrete cast in a formwork, leaving it to stand for about half a day, and washing the surface with water. (Coarse).

[0003]

However, in the conventional method for roughening a concrete pavement board, the surface roughness is almost constant even when the amount of the retarder added is increased, and the surface roughness is about 1 mm in sand patching value. I could only get the thing.

[0004] By the way, in the current state of road pavement, a concrete pavement plate having a wide surface roughness that greatly exceeds 1 mm in sand patching value has been required.

[0005]

SUMMARY OF THE INVENTION According to the present invention, after spreading a retarder on the surface of uncured concrete cast on a mold, the iron is leveled by repeatedly rubbing the surface with an iron,
By repeating this process of spraying the retarding agent and averaging the iron continuously for the required number of times, the retarding agent penetrates deeply into the surface layer of the concrete, and a wide range of surface roughnesses from a surface roughness of about 1 mm to significantly exceeding 1 mm by a sand patching value. The present invention proposes a method for manufacturing a concrete pavement plate that can be manufactured by adjusting the roughness appropriately.

[0006]

[Example] In a rectangular formwork 50 mm in length and 30 mm in depth, normal Portland cement 307 kg / cm ³ , water 135 kg / cm ³ , fine aggregate (sand) 801 kg / cm ³ , coarse aggregate (gravel) 1135 kg / cm ³ and admixture 3.7Kg / cm ³ kneaded concrete, add a setting retarder to the surface, level the surface by rubbing the surface several times with a flat iron, add this setting retarder After repeating the process of ironing and ironing the required number of times (about three times), leave it as it is for about half a day (until the concrete in the unimpregnated part of the setting retarder hardens), and wash the uncured part of the surface with water for the required time Thus, a plurality of pavement board samples (Experimental Examples no200-2, no-13, and noA-1) in which the addition amount of the curing retardant was changed were formed, and their surface roughness was measured by sand patching.

The results are shown in Table 1 and FIGS. 1, 2 and 3.

[0008] Sand patching is a roughness measurement method in which a predetermined amount (volume Vmm ³ ) of sand is placed at the center of the surface of a pavement plate sample, and the sand is gradually spread in a circular shape while leveling the sand. The sand patching value (SP) was calculated from the following equation (1) based on the average value (Dmm).

[0009]

(Equation 1)

On the other hand, as a conventional method, the length and width are 50 mm and the depth is 30
After placing the concrete of the above composition in a square formwork of mm and adding a hardening retardant to the surface, leave it for about half a day (until the concrete in the part where the hardening retarder has not penetrated is hardened). The uncured part is washed with water for a required time to form a plurality of pavement board samples (Comparative Examples: no200, no300, and no400) in which the amount of the curing retarder added is changed, and their surface roughness is measured by sand patching. did.

The results are shown in Table 1 and FIGS. 4, 5, and 6.

[0012]

[Table 1]

From the results shown in Table 1, it can be seen that in the method of the present invention, the surface roughness increases as the amount of the retarder added increases, and the sand patching value of the roughness far exceeds 1 mm.

On the other hand, in the conventional method, even if the amount of the retarder added is increased, the surface roughness hardly changes, and it can be seen that in all cases, only about 1 mm of sand patching can be obtained.

FIG. 7 is a graph showing these results.

In the case of manufacturing as an actual road pavement plate, it is formed as a concrete plate having a size of, for example, about 5 m in length, 1.7 m in width and about 30 cm in thickness.

[0017]

As described above, according to the present invention, by repeating the steps of adding a retarding agent and troweling a plurality of times, the retarding agent can penetrate deep into the concrete surface layer, and the amount of the retarding agent added can be reduced. A concrete pavement plate with a rougher surface roughness is obtained as it increases, and its sand patching value is 1 mm.
Is obtained.

[Brief description of the drawings]

FIG. 1 is an actual photograph showing a sand patching state of a concrete pavement plate of Experimental Example no200-2 molded according to the present invention.

FIG. 2 is an actual photograph showing a sand patching state of a concrete pavement plate of Experimental Example no-13 molded according to the present invention.

FIG. 3 is an actual photograph showing a sand patching state of a concrete pavement plate of Experimental Example noA-1 molded according to the present invention.

FIG. 4 is an actual photograph showing a sand patching state of a concrete pavement board of Comparative Example no200 formed by a conventional method.

FIG. 5 is an actual photograph showing a sand patching state of a concrete pavement board of Comparative Example no300 molded by a conventional method.

FIG. 6 is an actual photograph showing a sand patching state of a concrete pavement plate of Comparative Example no400 formed by a conventional method.

FIG. 7 is a diagram showing the results of Table 1.

Claims (1)

[Claims] 1. A method in which a retarder is sprayed on the surface of uncured concrete poured into a formwork, and the surface is leveled by repeatedly rubbing the surface with an iron. A method for producing a concrete pavement plate, characterized by repeating the required number of times continuously, leaving the surface as it is for a required time, and then washing the surface with water to make the surface rough.