JPS59195905A - Semi-rigid paving construction - 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 The present invention relates to a semi-rigid pavement construction method, and more particularly to a cement paste or mortar (hereinafter referred to as cement milk) composition used in the construction method.

Conventionally, there have been two major systems of pavement: asphalt pavement and concrete pavement, but recently semi-rigid pavements that combine the features of both have been proposed and put into practice. Semi-rigid pavement is generally made by first applying an open-grained sphalid concrete layer with a porosity of 20-30% on a pavement base, which is a mixture of 3-5KM% (relative to aggregate) of open-grained aggregate and asphalt. After pouring, Then, after spreading cement milk containing Co-9 mutex from the open-grained asphalt concrete and injecting the cement milk into the voids of the asphalt concrete using a vibrating roller, the cement milk remaining on the surface is removed using a rubber rake or the like. Semi-rigid pavement was obtained by scraping and solidifying the cement milk. therefore,
The cement milk used in this construction method is required to have the following properties.

(1) It must have appropriate consistency.

(2) Fine racks should not occur on the surface of the completed semi-rigid pavement.

The above consistency requirement is a condition for smooth injection and penetration of cement milk into open-grained asphalt concrete. Cement milk having a consistency of 9 to 20 (preferably 9 to 12) is suitable. In addition, the requirement to prevent the occurrence of cracks is a natural requirement for maintaining the performance of the paving slab, but with mere cement milk, cracks are unavoidable as long as the consistency requirements are satisfied. In order to satisfy consistency requirements and crack prevention requirements, it is necessary to blend commercially available rubber latex in cement milk. Based on our extensive experience in construction, the amount of rubber latex that satisfies the requirements for preventing crack generation is 3.7 to 3.8% by weight or more based on the cement weight in terms of solid content of rubber latex.

However, rubber latex increases the construction cost of other materials used in semi-rigid pavements, such as cement, aggregate, asphalt, and semi-rigid pavements, which is a cause of hindering its widespread use.

An object of the present invention is to provide a method for reducing the amount of rubber latex required to be mixed in cement milk used in semi-rigid pavement construction methods, that is, to provide a cement milk composition for semi-rigid pavement construction methods that contains a small amount of rubber latex. shall be.

As a result of intensive research by the present inventors to achieve the above objective,
The present invention was completed by discovering that by mixing a specific cement admixture into cement milk, cracks would not occur on the pavement surface even if the amount of rubber latex blended was significantly reduced.

The present invention relates to a semi-rigid pavement construction method in which a pavement slab is formed by injecting and permeating cement paste or mortar after pouring an open-grain asphalt concrete layer with a porosity of 20 to 30% on a base (a) solidifying rubber latex. Condensation product of formaldehyde of aromatic hydrocarbon sulfonic acid, formaldehyde condensate of aromatic hydrocarbon sulfonic acid, formaldehyde of sulfonic group-containing aminotrianone 1
Contains one selected from the group consisting of human metal products and lignin sulfonates, and contains 2 to 0.4 parts of Id2 or more based on the cement weight, and the consistency of the cement milk is P. This is a semi-rigid pavement construction method characterized by the use of cement milk with a funnel run-off time of 9 to 20 seconds.

In the present invention, the rubber latex is a natural rubber or a synthetic rubber such as polybutanoene, butadiene-styrene copolymer, polystyrene, butanoene-acrylic copolymer, polyimbutylene, polychloroprene, imbutylene-imlune copolymer, ethylene-propylene copolymer, etc., in water. These rubber latexes are emulsified and dispersed in the form of an emulsion, and these rubber latexes may be used alone or in combination. In particular, styrene-butadiene copolymers are preferably used.

Among the additives used in the present invention, formaldehyde condensates of aromatic hydrocarbon sulfonic acids are products obtained by condensation reaction with alkyl-substituted or unsubstituted benzene, and salts thereof. The sodium or calcium salts of formaldehyde high condensates of sulfonic acids are preferably used. The formaldehyde condensate of aminotriazine containing a sulfonic group was published in
3 = at least 2 as described in Publication No. 21659
It is a product obtained by condensing formaldehyde with a substrate in which a sulfonic acid group has been introduced into Ryomino-8-) riazine having 2 amino groups.A specific example is a formaldehyde condensate of melamine sulfonic acid. can. Furthermore, lignin sulfonate is manufactured industrially using sulfite i9 lupus as a raw material, and is well known as a cement dispersant. Various methods have been proposed to improve the quality of lahinyl lignin sulfonate, such as a method for producing lignin sulfonate for use as a cement dispersant using sulfite/gulp waste liquid as raw materials, but these methods have not been applied. or genin sulfonate can be used.

In the semi-rigid pavement construction method of the present invention, the above-mentioned comb latex is mixed with a cement foreground standard of 1.5 to 2.5, and one or more of the additives are mixed with a cement type bone standard of 0.2 to 0. .4 tonnage The consistency formed by blending P funnel flow time is 9 to 2 degrees (preferably 9 to 12 degrees)
Second cement milk is used as cement milk for injection penetration. If the amount of comb latex added is less than 1.5% by weight based on the cement weight, cracks will occur in the paving slab to a degree that is not desirable for practical purposes, and if it exceeds 2.5% by weight, the effect of reducing construction costs can be measured, so it is preferable. do not have. The occurrence of cracks in the paving slab can be completely prevented by using cement with a weight of 2 or more based on the weight of cement. On the other hand, if the amount of the additive used is less than 2 1/2 cups of cement weight standard, the effect of reducing the amount of rubber latex blended is not sufficient, and even if it exceeds 0.4% by weight, the effect of reducing the amount of rubber latex blended is not sufficient. This is not desirable as it hardly increases and becomes uneconomical.

The preferable amount of the additive used is based on the cement weight, since injection and penetration into the concrete may be insufficient. In addition,
In order for cement milk to fully penetrate the entire height of the open-grained asphalt layer (total penetration type), the consistency must be less than 12 seconds, but it will penetrate to about half the depth of the open-grained asphalt layer. do it(
In cases (called semi-immersive type), conocystency can be tolerated up to 1 second.

In the present invention, the rubber latex and the additives are
Both may be measured and added separately when preparing cement milk, or both may be mixed in advance at a predetermined ratio and added as a one-liquid type. In addition, additive materials other than rubber latex and the specific additives mentioned above, such as retarders, early strengthening agents, swelling agents, stone powder, fly ash, etc., may be added. A crack-free semi-rigid paving slab can be obtained by injecting and penetrating the asphalt concrete into one layer using a rubber rake or the like, and then scraping off the cement milk remaining on the surface using a rubber rake or the like.

By blending specific additives into cement milk, the present invention can reduce the amount of rubber latex blended to approximately 1/2 compared to conventional methods, significantly reducing the construction cost of semi-rigid pavement construction. can be reduced. Furthermore, this cement milk has various advantages such as better permeability at high temperatures such as summer than conventional cement milk, and less amount of breathing.

The present invention provides a semi-rigid pavement construction method that is low in construction cost, has excellent workability, and has good physical properties.
The industrial significance of the widespread use of this method is extremely significant.

Hereinafter, the present invention will be explained in more detail using examples. However, the scope of the present invention is not limited to the following examples.

Example (1) E grain! Asphalt concrete slope degree 80
An open-grained asphalt concrete with a porosity of 25%, in which 3.5% of paving asphalt of ~100 is blended with an open-grained aggregate having a particle size distribution shown in Table 1.

Styrene-butadiene copolymer rubber latex: solid content 42.5% by weight (3) Additive (a) Formaldehyde compaction sodium salt of naphthalene sulfonic acid (abbreviated as NSF); Commercially available cement dispersant (b) Contains sulfone group Formaldehyde condensate sodium salt of melamine (abbreviated as SMF): commercially available cement dispersant (c) lignin sulfonate calcium (abbreviated as L-G): commercially available cement dispersant (4) Cement milk formulation and consistency Cement milk of various formulations was prepared, and the cysticity was measured by the 'Pot outflow time.

Mixing ratio and P funnel runoff time are shown in Table 2.1 Table 2 Cement: Onoda ordinary Portland cement used =/
c = 5o% * Weight ratio based on cement weight (5) Construction test Among the cement milk shown in Table 2, consistency is Nα1.2 within the range of P funnel outflow time of 9 to 12 seconds.
．． A total penetration type construction test was conducted using the cement milk of 4.-8.11.12, and the occurrence of cranks was observed.

(b) Open-grained asphalt concrete was placed on the construction test base over an area of 9 m x 10 m to 5 sub-thickness, and 3 m
The whole was divided into 6 sections, each section having an area of 5 m. Pour the cement milk corresponding to N[L 1.2.4.8.11.12 in Table 2 into each compartment, and use a vibrating roller to sufficiently inject and permeate into the voids of the asphalt concrete layer. The remaining cement milk was scraped off using a comb rake in the same tube as the asphalt concrete layer. The temperature at the time of construction was 5°C and the weather was sunny.

(b) Table 3 shows the results of observing the surface condition of the paving slab 7 days after the test.

As is clear from Table 2 NcLIO, if the compounding amount of rubber latex is reduced without using additives, the consistency condition P funnel runoff time is 9 to 12 in the Wlo = 5Q section.
Unable to satisfy seconds.

It is clear from Table 3 N (L 12) that cracking cannot be prevented by adding only a cooling agent.

As is clear from Table 3, the amount of rubber latex blended in the present invention is about 1/2" of the amount of rubber latex blended when no additive is used (N[Lll).

Patent applicant: Haruyuki Ito, agent of Niso Master Builders Co., Ltd.

Claims (1)

[Claims] 1. Open grain size Asfuj with a porosity of 20 to 30 on the base
2 In the semi-rigid pavement construction method in which a cement paste or mortar is injected and permeated after pouring a concrete layer to form a pavement slab, % (b) One or more selected from the group consisting of a formaldehyde condensate of an aromatic hydrocarbon aqueous sulfonic acid, a formaldehyde condensate of a sulfonic group-containing aminotriazine, and a lignin sulfonate are added to the cement ■ Amount standard 0
．． A semi-rigid pavement construction method characterized by using a cement paste or mortar containing 2 to 0.4% by weight and having a funnel flow time of 9 to 20 seconds.