JPH06183812A - High-fluidity ultra-rapid cement composition, semi-flexible pavement structure and pavement method - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a high-fluidity super rapid hardening cement composition that exhibits strength development in a short time and can maintain high fluidity for a long time, and further using the cement composition, (EN) Provided are a semi-flexible pavement structure and a pavement method which are simple in construction and excellent in durability. [Composition] High-performance water-reducing agent 0.20 to ultra-quick cement
1.00% by weight, lignin-based retarder 0.20 to 1.20
% By weight and oxycarboxylic acid type retarder 0.01-0.3
It is made by blending 0% by weight.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a high-fluidity super rapid hardening cement composition which exhibits strength development in a short time and can maintain high fluidity for a long time, and a pavement method and a pavement structure using the composition. Regarding the body

[0002]

2. Description of the Related Art Conventionally, a large number of ultrafast cements are commercially available and used for various purposes including repair.
Since the setting time of this conventionally known ultra-rapid hardening cement is too short, an appropriate amount of retarder is usually added to adjust the setting time. However, although the setting time could be adjusted by this method, the fluidity could not be adjusted. That is, even if a predetermined fluidity is obtained during kneading, the predetermined fluidity is maintained only for a short time of about 5 to 10 minutes, and then the fluidity is impaired although it is not cured, It had the drawback of making it difficult.

Further, the conventional asphalt pavement method and pavement structure have drawbacks that they are poor in durability, poor in resistance to a large load, not easy to construct, and require a long time.

[0004]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned drawbacks of the prior art, shows the strength development in a short time, which is a characteristic of ultra-fast hardening cement, and can maintain high fluidity for a long time. A semi-flexible pavement structure and a pavement method that are simple in construction and have excellent durability are provided by using the cement composition for the purpose of providing a high-fluidity ultra-quick cement composition. With the goal.

A high-performance water-reducing agent is usually used to obtain a highly fluid cement, but when only the high-performance water-reducing agent is used, the change in fluidity with time is large. Further, in addition to this high-performance water-reducing agent, even if an oxycarboxylic acid-based retarder having a large retarding effect is used, coagulation is delayed, but the fluidity also has a large change over time, and is effective in maintaining high fluidity. Absent.

As a result of various investigations, the present inventors have found that the combined use of two types of retarders of different strains has a remarkable effect on maintaining high fluidity, and also exerts strength in a short time. A semi-flexible pavement structure and a pavement that have a small influence and that the above-mentioned object is achieved, and that the cement composition obtained in this way is simpler in construction and more durable than concrete pavement. The present invention has been reached by finding that a method can be obtained.

[0007]

The high fluidity super rapid hardening cement composition of the present invention is a super fast hardening cement containing 0.20 to 1.00% by weight of a high performance water reducing agent and 0.20 of a lignin retarder.
˜1.20 wt% and oxycarboxylic acid retarder 0.0
1 to 0.30% by weight is blended.

Further, the semi-flexible pavement structure of the present invention is
It is obtained by injecting the cement composition into a roadbed on which asphalt and aggregate are laid.

Further, the semi-flexible pavement method of the present invention comprises injecting the cement composition into a roadbed on which asphalt and aggregate are laid.

As the high-performance water-reducing agent, for example, naphthalene sulfonic acid high-condensation product (trade name: Mighty 100 manufactured by Kao Corporation) and the like are used.

The blending ratio of the high-performance water-reducing agent is 0.20 to 1.00% by weight, preferably 0.30 to 0.80% by weight, based on the ultra-rapid hardening cement.

Examples of the lignin-based retarder include Pozzolith No. 8 (manufactured by Pozoris Bussan) and the like are used.

The blending ratio of the lignin-based retarder is 0.20 to 1.20% by weight, preferably 0.30 to 1.00% by weight, based on the ultra-rapid hardening cement.

As the oxycarboxylic acid type retarder, for example, citric acid (Jet Setter manufactured by Sumitomo Cement Co., Ltd.) or the like is used.

The mixing ratio of the oxycarboxylic acid type retarder is
0.01-0.30% by weight, based on ultra-rapid cement
It is preferably 0.01 to 0.20% by weight.

In preparing the superfluid ultra-quick cement composition of the present invention, for example, the ultra-fast cement is mixed with a powdered high-performance water-reducing agent, a lignin-based retarder and an oxycarboxylic acid-based retarder in the above-mentioned mixing ratios. May be mixed in advance, or they may be dissolved in water at the time of use, or a liquid high-performance water reducing agent or the like may be diluted in water and kneaded.

[0017]

In the high-fluidity ultra-quick cement composition of the present invention, the characteristics of ultra-fast cement can be obtained by using two kinds of retarders, a lignin-type retarder and an oxycarboxylic acid-type retarder having different systems. It is possible to maintain high fluidity for a long time without impairing strength development in a short time.

A novel pavement method (semi-flexible pavement) in which the cement composition is injected into a roadbed on which asphalt and aggregate are laid by using the high-fluidity ultra-fast cement composition of the present invention. Called the law) can be provided.

According to this semi-flexible pavement method, it is possible to obtain a semi-flexible pavement structure which is simple in construction and durable as compared with the conventional concrete pavement.

In carrying out the semi-flexible pavement method of the present invention, for example, asphalt and aggregate are laid in advance on the roadbed, and then the cement composition of the present invention is injected into the gap between the aggregates.

At this time, the cement composition as it is,
Alternatively, it is injected as a mortar prepared by adding sand.

In the semi-flexible pavement method of the present invention, immediately after injecting the cement composition into the roadbed, the fluidity of the cement composition is high, the cement permeates uniformly, and a certain time after the injection. (Approximately 20 to 30 minutes) Since the curing reaction proceeds rapidly, it takes 3 minutes from the completion of injection to opening the road.
It can be shortened to about 4 hours, which is much shorter than the conventional semi-flexible pavement.

That is, the conventional ultra-rapid cement is hardened before it penetrates the roadbed, so that the quality is deteriorated and sufficient working time cannot be secured. However, the cement composition of the present invention is used. In the semi-flexible pavement method, these problems are solved because the initial fluidity of the cement composition is high.

Moreover, since the cement composition can be injected even if the heated asphalt is not sufficiently cooled, the whole construction period can be shortened, which is a great advantage for road pavement where it is necessary to cut off traffic. Become.

The semi-flexible pavement method of the present invention is suitable for pavement at intersections where road surfaces are easily damaged, around bus stops, parking lots, places where load resistance is required, and the like.

The present invention will be described in detail below with reference to examples.

[0027]

【Example】

Examples 1 to 6 A super high-performance hardener (trade name: Jet Cement, manufactured by Sumitomo Cement Co., Ltd.) was added to a commercially available high-performance water reducing agent (Mighty 1).
00 Kao Co., Ltd.), a lignin-based retarder (Pozoris No. 8 manufactured by Pozzolis Co., Ltd.), and an oxycarboxylic acid-based retarder (Jet Setter Sumitomo Cement Co., Ltd.) were added at the mixing ratios shown in Table 1. Thus, a high-fluidity ultra-rapid cement composition of the present invention was prepared.

Then, a 1: 1 mortar was prepared using the obtained high-fluidity ultra-rapid cement composition, and the flowability and the compressive strength (3 hours) were tested using the mortar. The sand used was silica sand that passed through a 1.2 mm sieve, and the amount of water was adjusted so that the fluidity after kneading was 6 to 8 seconds with a J14 funnel. The fluidity maintenance time was defined as the time until the flow-down time of the J14 funnel exceeded 10 seconds according to the standards of the Highway Public Corporation. The results are shown in Table 1.

Comparative Examples 1 to 5 For comparison, when a lignin-based retarder is not used (Comparative Examples 1 and 2), an oxycarboxylic acid-based retarder is not used (Comparative Example 3), a high-performance water reducing agent is used. When not doing (Comparative Example 4) and when the blending ratio of the lignin-based retarder was too large (Comparative Example 5), a cement composition was prepared, and further 1: 1 mortar was prepared, and the same as in Example 1. Tested. The results are shown in Table 1.

As is clear from Table 1, when only the high-performance water reducing agent and the oxycarboxylic acid type retarder are used (Comparative Examples 1 and 2), the fluidity cannot be maintained and the fluidity maintenance time is Even if it is made slightly longer, the strength will be greatly reduced.

Also, when the oxycarboxylic acid type retarder is replaced with a lignin type retarder (Comparative Example 3), the fluidity cannot be maintained.

Further, when the high-performance water reducing agent is not used (Comparative Example 4), the amount of water for obtaining a predetermined fluidity increases and the strength development is small.

When the blending ratio of the lignin-based retarder is too large (Comparative Example 5), the strength development in a short time is remarkably reduced.

On the other hand, as is clear from Table 1, in the case of the present invention in which three kinds of admixtures are used in combination, fluidity can be maintained for a long period of time without impairing short-term strength development.

[0035]

[Table 1]

Examples 7 to 12 A commercially available high-performance water-reducing agent (Mighty 1) was added to a super fast-setting cement (trade name: Jet Cement manufactured by Sumitomo Cement Co., Ltd.).
00 Kao Co., Ltd.), a lignin-based retarder (Pozoris No. 8 manufactured by Pozzolis Co., Ltd.) and an oxycarboxylic acid-based retarder (Jet Setter Sumitomo Cement Co., Ltd.) were added at the mixing ratios shown in Table 2. Thus, a high-fluidity ultra-rapid cement composition of the present invention was prepared.

Then, a 3: 1 mortar was prepared using the obtained high-fluidity ultra-quick cement composition, and the 3: 1 mortar was tested for fluidity and compressive strength (3 hours). The sand used is No. 7 silica sand, and the amount of water has a fluidity of P1 after kneading.
It was adjusted so as to be 11 to 12 seconds with 3 funnels. The fluidity maintenance time was the time until the P13 funnel flow time exceeded 14 seconds. The results are shown in Table 2.

Comparative Example 6 For comparison, a cement composition was prepared and a 3: 1 mortar was prepared in the case where a lignin-based retarder was not used, and the same test as in Example 7 was carried out. The results are shown in Table 2.

As is clear from Table 2, the fluidity cannot be maintained when only the high-performance water reducing agent and the oxycarboxylic acid type retarder are used (Comparative Example 6).

On the other hand, as is clear from Table 2, Example 1
In the case of the cement compositions having higher fluidity than Examples 6 to 7 (Examples 7 to 12), it is possible to maintain the fluidity for a long time without impairing the short-term strength development by using three kinds of admixtures together. it can.

[0041]

[Table 2]

Examples 13 to 21 A super-high-speed hardening cement (trade name: Jet Cement manufactured by Sumitomo Cement Co., Ltd.) was added to a commercially available high-performance water reducing agent (Mighty 1).
00 Kao Co., Ltd.), a lignin-based retarder (Pozoris No. 8 manufactured by Pozzolis Co., Ltd.), and an oxycarboxylic acid-based retarder (Jet Setter Sumitomo Cement Co., Ltd.) were added at the mixing ratios shown in Table 3. Thus, a high-fluidity ultra-rapid cement composition of the present invention was prepared.

Then, a 3: 1 mortar was prepared using the obtained high-fluidity ultra-rapid cement composition, and the 3: 1 mortar was tested for fluidity and compressive strength (3 hours). The sand used is No. 7 silica sand, and the amount of water has a fluidity of P1 after kneading.
It was adjusted so as to be 11 to 12 seconds with 3 funnels. The fluidity maintenance time was the time until the P13 funnel flow time exceeded 14 seconds. The results are shown in Table 3.

Comparative Examples 7 to 9 For comparison, in the case where the lignin-based retarder was not used, a cement composition was prepared, 3: 1 mortar was prepared, and the temperature was changed. Tested. The results are shown in Table 3.

As is clear from Table 3, when only the high-performance water reducing agent and the oxycarboxylic acid type retarder are used (Comparative Examples 7 to 9), when the temperature changes, the development of strength is not impaired. Maintaining liquidity is difficult.

On the other hand, as is clear from Table 3, in the case of the present invention in which three kinds of admixtures are used in combination, the amount of the oxycarboxylic acid type retarder is increased or decreased without impairing the short-term strength development. The fluidity can be maintained for a long time.

[0047]

[Table 3]

Test Example 1 Open-graded asphalt concrete having a porosity of 22% was heated and kept at 80 ° C. to obtain the high-fluidity super rapid hardening cement composition of the present invention (Example 7) and conventional super quick hardening cement ( (Jet cement) milk was injected and the penetration depths were compared. The results are shown in Table 4.

[0049]

[Table 4]

As is clear from Table 4, the high-fluidity ultra-rapid cement composition of the present invention can be applied to high-temperature asphalt as well.
Penetrates deeply.

[0051]

INDUSTRIAL APPLICABILITY According to the present invention, by using two kinds of retarders in combination, strength is exhibited in a short time over a wide temperature range, and high fluidity can be maintained for a long time. It is possible to provide a high-fluidity ultra-rapid hardening cement composition whose time is easily adjusted. Furthermore, by using the high-fluidity ultra-rapid cement composition of the present invention, it is possible to provide a semi-flexible pavement structure and a pavement method that are simple in construction and have excellent durability.

Claims (3)

[Claims] 1. A high-performance water-reducing agent for super-quick hardening cement 0.2
0-1.00% by weight, lignin-based retarder 0.20-1.
20% by weight and 0.01 to oxycarboxylic acid retarder
A high-fluidity ultra-rapid cement composition containing 0.30% by weight. 2. A semi-flexible pavement structure, which is obtained by injecting the cement composition according to claim 1 into a roadbed on which asphalt and aggregate have been laid. 3. A semi-flexible pavement method, which comprises injecting the cement composition according to claim 1 into a roadbed on which asphalt and aggregate are laid.