JPS61236641A - Mortar or concrete for pavement - 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 a. Field of Industrial Application The present invention relates to paving mortar or concrete with improved wear resistance.

b. Prior Art As is well known, concrete has been widely used for road pavement.

Methods for paving roads with concrete include pouring fresh concrete directly at the paving site, the so-called pour-in-place method, and paving plates, etc., which are manufactured in advance at a factory and brought to the site. There is also a way to lay them out.

The former pour-in-place method includes a method in which only one layer of concrete is poured on top of the tamped roadbed, and a two-layer method in which a base layer concrete is poured and a surface layer concrete is poured on top.

In the latter method, interlocking blocks have recently been used. The interlocking block is made by pouring two layers of hard-mixed concrete and hard-mixed mortar into a mold and pressurizing them while applying vibrations to form one piece.

C1 Problems to be Solved by the Invention However, with conventional cast-in-place concrete pavements and interlocking blocks, the surfaces of the conventional cast-in-place concrete pavements and interlocking blocks are subject to abrasion damage and unevenness caused by running vehicles, which can hinder the running of vehicles and cause road damage. In places where the brakes are applied frequently, such as in curved areas or in front of crosswalks, the surface may become more prone to slipping due to abrasion. Therefore, there was also the disadvantage that in order to maintain the pavement surface well, it had to be frequently repaired.

In addition, dust from vehicles is dispersed into the atmosphere.
Another drawback was that it could pose a health hazard to residents living near the road.

Means for Solving the d0 Problem The present inventors conducted research to eliminate the above-mentioned drawbacks, and found that surface wear can be reduced by incorporating crushed rubber pieces into mortar or concrete. The present invention was completed by obtaining the following.

That is, the present invention resides in a mortar or concrete containing 45% by volume or less of crushed rubber pieces having a maximum external dimension of 0.6 to 5 mm.

Rubbers used in the present invention include, for example, commercially available new natural rubber, synthetic rubber (e.g., acrylonitrile-butadiene copolymer rubber, styrene-butadiene copolymer rubber), and waste rubber from used tires, healds, hoses, etc. etc.

In the present invention, these rubbers are cooled with liquid nitrogen or the like, crushed, and used as crushed rubber pieces having a maximum external dimension of 0.6 to 5 mm. Preferably it is 1.2-5. If it is less than 0.6 mm, the amount of wear will be large, and if it is more than 5 iris, the crushed rubber pieces exposed on the surface layer are likely to peel off, which is not preferable. Although the shape of the rubber pieces is not particularly limited, it is preferable that the rubber pieces have an irregular shape because they are better entangled with mortar or concrete. Further, the content of crushed rubber pieces is 45% by volume or less, preferably 10 to 40% by volume, of the volume of the mortar or concrete. If it exceeds 45% by volume, separation of materials will occur during kneading, which is not preferable.

Next, apply the mortar or concrete of the present invention.
1. The manufacturing method will be specifically described.

First, in the case of cast-in-place concrete pavement, cement 300
~400kg/r+? , sand 350-850k as aggregate
g/r+? .

Crushed stone 450-870kg/rd, and crushed rubber pieces 1
00 to 400 kg/rrr and dry kneading, then adding 150 to 160 kg/rd of water, kneading, and casting. After pouring, smooth the surface and curing as usual. 2
After curing for ~3 weeks, concrete pavement with crushed rubber pieces embedded in the surface is completed. In addition, when applying two layers,
Ordinary paving concrete is poured onto the roadbed, and after hardening, the above concrete is poured on top of it.

Next, the case of interlocking blocks will be described. In the case of an interlocking block, it consists of a base layer and a surface layer, and the mixture of these two layers is sequentially poured into a mold to be integrally molded. The base layer is cement 300-500kg/rr
r, sand 1100-1300 kg/m and crushed stone 650
After mixing ~750kg/tri and dry kneading, add 1 part of water.
30 to 140 kg/m is added and kneaded, and the mixture is put into a mold and molded by vibration. The vibration causes the kneaded material to sink, creating a void in the upper part of the mold. In this gap, cement 5
00~600kg/m, sand 560~1470kg/m
After dry kneading cJ and 100 to 400 kg/g of crushed rubber pieces, 150 to 170 kg/rd of water was added and the kneaded mixture was added, and the mixture was heated to about 100 kgf while adding vibration.
/cJ to integrally mold. If the mold is removed immediately after molding and cured at room temperature or in steam, an interlocking block with crushed rubber pieces embedded in the surface can be obtained.

e. Example Hereinafter, the present invention will be explained by examples.

Examples 1-7. Comparative Examples 1 to 6 Ordinary Portland cement (manufactured by Nippon Cement Co., Ltd.) was used as the cement, sand for average particle size 2.5n was used as the aggregate, crushed stone for road use (G-A, produced in Mizuho), and crushed stone for concrete (G-B) was used as the crushed stone. Rubber pieces obtained by pulverizing rubber belts and rubber belts were air-kneaded for 1 minute using the formulation and formulation shown in Table 1, and then water was added and kneaded for 3 minutes. Kneaded material 1010X2
The mold was placed in a 0x8 mold, and the mold was pressurized for 3 seconds at 100 kgf/ciil while applying vibrations of 80011 PM, and then immediately removed from the mold to obtain a molded product. The molded product is stored in a room at approximately 20°C for 2
It was cured for 8 days and used as a test specimen.

The specimen was subjected to an abrasion test using STM C=779, and the depth of abrasion on the surface of the specimen was measured. Measured values are shown in Table 1.
Also listed. Examples 8-9. Comparative Example 7 Examples 1 to 7
．． The same materials used in Comparative Examples 1 to 6 were blended as shown in Table 1, and after dry kneading for 1 minute, water was added and kneaded for 3 minutes. The kneaded material was put into a mold of 30 x 30 x 5 cm, and a rod-shaped pie break was inserted into the kneaded material to perform vibration compaction for about 3 seconds, and then it was left at 20°C for 24 hours to be demolded and molded. I got something. The molded product was cured at 20° C. for 28 days to obtain a test specimen. ASTM C-779 for the obtained test specimen
We conducted a wear test and measured the depth of surface abrasion.
Also listed in 1.

10 Effects of the Invention The present invention is a paving mortar or concrete containing crushed rubber pieces, which is a conventional mortar.

It has much better wear resistance than concrete. Furthermore, when the mortar or concrete of the present invention is used for roadways, it has the advantage of increasing the frictional resistance, thereby improving the braking force of vehicles.

=207-

Claims (1)

[Claims] A paving mortar or concrete containing 45% by volume or less of crushed rubber pieces having a maximum external dimension of 0.6 to 5 mm.