JP2802708B2 - High fluidity super-hard cement composition, semi-flexible pavement structure and pavement method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-flow ultra-hard cement composition which exhibits strength in a short time and can maintain high flowability for a long time, and a pavement method and a pavement structure using the composition. About the body.

[0002]

2. Description of the Related Art Conventionally, a large number of ultra-fast-hardening cements have been marketed and used for various purposes including repair.
Since the hardening time of this conventionally known ultra-rapid hardening cement is too short, it is usually used after adjusting the setting time by adding an appropriate amount of a retarder. However, although the setting time can be adjusted by this method, the fluidity cannot be adjusted. That is, even if a predetermined fluidity is obtained at the time of kneading, the predetermined fluidity is maintained only for a short time of about 5 to 10 minutes, and thereafter, the composition does not cure but the fluidity is impaired. Had the disadvantage of causing difficulties.

Further, the conventional asphalt pavement method and pavement structure have disadvantages in that they are poor in durability, poor in resistance to large loads, inconvenient in construction, and require a long time.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned disadvantages of the prior art, exhibits strength in a short period of time, which is the characteristic of ultra-rapid hardening cement, and can maintain high fluidity for a long time. An object of the present invention is to provide a high fluidity super-rapid hardening cement composition, and further provide a semi-flexible pavement structure and a pavement method which are easy to construct and have excellent durability by using the cement composition. With the goal.

[0005] A high-performance water reducing agent is usually used to obtain a cement having a high fluidity, but when only a high-performance water reducing agent is used, the fluidity greatly changes with time. Furthermore, even if an oxycarboxylic acid-based retarder having a large retarding effect is used in addition to the high-performance water reducing agent, the setting is delayed, but the change in fluidity with time is still large, and the effect of maintaining high fluidity is still large. Absent.

As a result of various studies, the present inventors have found that the combined use of two types of retarders having different strains has a remarkable effect on maintaining high fluidity, and that the strength can be expressed in a short time. The effect is small, the above-mentioned object is achieved, and furthermore, if the cement composition thus obtained is used, the construction is simpler than concrete pavement, and the semi-flexible pavement structure and the pavement excellent in durability are provided. The inventors have found that a method is obtained and arrived at the present invention.

[0007]

SUMMARY OF THE INVENTION The high-flowability super-hardening cement composition of the present invention comprises a super-high-speed hardening cement and a high-performance water reducing agent.
20-1.00% by weight, lignin-based retarder 0.60-1.20
% By weight and an oxycarboxylic acid type retarder 0.01 to 0.20
% By weight.

Further, the semi-flexible pavement structure of the present invention comprises:
A super-hardened cement containing 0.20 to 1.00% by weight of a high-performance water reducer, 0.60 to 1.20% by weight of a lignin-based retarder and 0.01 to 0.20% by weight of an oxycarboxylic acid-based retarder is added to a roadbed laid with asphalt and aggregate. Characterized in that it is obtained by injecting a highly fluid ultra-rapid hardening cement composition.

Further, the semi-flexible pavement method is based on a method in which 0.20 to 1.00% by weight of a high-performance water reducing agent, a lignin-based retarding agent of 0.60%, a super-hardened cement, a roadbed on which asphalt and aggregate are laid.
~ 1.20% by weight and oxycarboxylic acid retarder 0.01
The method is characterized by injecting a highly fluid ultra-rapid hardening cement composition containing up to 0.20% by weight.

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

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

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

The compounding ratio of the lignin-based retarder is 0.60 to 1.20% by weight based on the ultra-hard cement.

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

The compounding ratio of the oxycarboxylic acid type retarder is as follows:
It is 0.01 to 0.20% by weight based on the ultra-hard cement.

In preparing the high-flowability super-hardening cement composition of the present invention, for example, a powdered high-performance water reducing agent, a lignin-based retarder and an oxycarboxylic acid-based retarder are added to the super-hardened cement, respectively. And may be mixed beforehand, or may be dissolved in water at the time of use, or a liquid high-performance water reducing agent or the like may be diluted with water and kneaded.

[0017]

The high-flowability ultra-hardening cement composition of the present invention is characterized by using two types of retarders, lignin-based retarders and oxycarboxylic acid-based retarders, which are different from each other, to obtain the properties of the ultra-fast-hardened cement. It is possible to maintain high fluidity for a long time without impairing strength development in a short time.

Further, by using the high fluidity super-rapid hardening cement composition of the present invention, a novel pavement method (semi-flexible pavement) in which the cement composition is injected into a roadbed on which asphalt and aggregate are laid. Law).

According to the semi-flexible pavement method, it is possible to obtain a durable semi-flexible pavement structure which is easier to construct than conventional pavement.

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

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

In the semi-flexible pavement method of the present invention, immediately after the cement composition is injected into the roadbed, the cement composition has a high fluidity, and the cement is uniformly infiltrated. (Approximately 20 to 30 minutes) Since the curing reaction progresses rapidly after a short time, it takes 3 hours from the completion of the injection to the opening of the road
４4 hours, which is much shorter than conventional semi-flexible pavement.

That is, the conventional super-hardened cement hardens before penetrating into the roadbed, so that the quality is deteriorated and a 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 entire construction period can be shortened, and a great advantage can be obtained when paving a road where it is necessary to block 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-bearing capacity is required, and the like.

Hereinafter, the present invention will be described in detail with reference to examples.

[0027]

【Example】

Examples 1 to 6 A super-high-speed 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.), lignin-based retarder (Pozoris No. 8 manufactured by Pozoris Co., Ltd.) and oxycarboxylic acid-based retarder (Jet Setter Sumitomo Cement Co., Ltd.) in the proportions shown in Table 1. Thus, a highly fluid super-rapid hardening cement composition of the present invention was prepared.

Next, a 1: 1 mortar was prepared using the obtained high-flowability super-hardened cement composition, and the mortar was tested for flowability and compressive strength (3 hours). The sand used was a silica sand passing through a 1.2 mm sieve, and the amount of water was adjusted such that the fluidity of the kneading was 6 to 8 seconds with a J14 funnel. The time for maintaining the fluidity was defined as the time required for the flow time of the J14 funnel to exceed 10 seconds according to the standards of the Japan Highway Public Corporation. Table 1 shows the results.

Comparative Examples 1 to 5 For comparison, when no lignin-based retarder was used (Comparative Examples 1 and 2) and when no oxycarboxylic acid-based retarder was used (Comparative Example 3), a high-performance water reducing agent was used. In the case of not performing (Comparative Example 4) and the case where the blending ratio of the lignin-based retarder was too large (Comparative Example 5), a cement composition was prepared, and a 1: 1 mortar was further prepared. Tested. Table 1 shows the results.

As is clear from Table 1, when only the high-performance water reducing agent and the oxycarboxylic acid-based retarder are used (Comparative Examples 1 and 2), the fluidity cannot be maintained, and the fluidity maintaining time is reduced. Even if the length is slightly increased, the strength is significantly reduced.

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

Further, when no high-performance water reducing agent is used (Comparative Example 4), the amount of water for obtaining a predetermined fluidity increases, and the strength is low.

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

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

[0035]

[Table 1]

Examples 7 to 12 A super-high-speed hardening cement (trade name: Jet Cement 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 (Pozzolith No. 8 manufactured by Pozoris Co., Ltd.) and an oxycarboxylic acid-based retarder (Jet Setter Sumitomo Cement Co., Ltd.) in the proportions shown in Table 2. Thus, a highly fluid super-rapid hardening cement composition of the present invention was prepared.

Next, a 3: 1 mortar was prepared using the obtained high-flowability super-rapid hardening cement composition, and the mortar was tested for flowability and compressive strength (3 hours). The sand used was No. 7 silica sand.
It was adjusted so as to be 11 to 12 seconds with three funnels. The fluidity maintaining time was a time required for the flow time of the P13 funnel to exceed 14 seconds. Table 2 shows the results.

Comparative Example 6 For comparison, a cement composition was prepared and a 3: 1 mortar was prepared in the same manner as in Example 7 except that no lignin-based retarder was used. Table 2 shows the results.

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

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

[0041]

[Table 2]

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

Next, a 3: 1 mortar was prepared using the obtained high-flowability super-hard cement composition, and the mortar was tested for flowability and compressive strength (3 hours). The sand used was No. 7 silica sand.
It was adjusted so as to be 11 to 12 seconds with three funnels. The fluidity maintaining time was a time required for the flow time of the P13 funnel to exceed 14 seconds. Table 3 shows the results.

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

As is clear from Table 3, when only the high-performance water reducing agent and the oxycarboxylic acid-based retarder were used (Comparative Examples 7 to 9), the strength was not impaired when the temperature was changed. It is difficult to maintain liquidity.

On the other hand, as is apparent from Table 3, in the case of the present invention in which three kinds of admixtures are used in combination, by increasing or decreasing the amount of the oxycarboxylic acid-based retarder, the short-term strength development is not impaired. Fluidity can be maintained for a long time.

[0047]

[Table 3]

Test Example 1 Open-grained asphalt concrete having a porosity of 22% was heated and kept at 80 ° C. to obtain a highly fluid ultra-rapid hardening cement composition of the present invention (Example 7) and a conventional ultra-rapid hardening cement ( Jet cement), and the penetration depth was compared. Table 4 shows the results.

[0049]

[Table 4]

As is clear from Table 4, the high-flow ultra-rapid hardening cement composition of the present invention can also be used for high-temperature asphalt.
Penetrate deep.

[0051]

According to the high fluidity super-rapid hardening cement composition of the present invention, the mixing ratio of the lignin-based retarder is relatively large.
0.60 to 1.20% by weight and a small amount of oxycarboxylic acid-based retarder at 0.01 to 0.20% by weight In addition, high fluidity can be maintained for a long time, and the working time can be easily adjusted. Further, in the semi-flexible pavement structure and pavement method according to the present invention, the use of the high-fluidity ultra-rapid hardening cement composition having the above-described composition reduces time, which is a problem of the conventional semi-flexible pavement, and reduces the roadbed. Solidification or the like due to infiltration can be eliminated, and a pavement structure and a pavement method that are easy to perform and have excellent durability can be obtained.

Continuation of the front page (51) Int.Cl. ⁶ Identification code FI C04B 24:18) (56) References JP-A-2-302352 (JP, A) JP-A-2-85405 (JP, A) JP-A 3-295905 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C04B 28/02 C04B 24:00 C04B 24:04 C04B 24:18

Claims (3)

(57) [Claims] 1. A high-performance water reducing agent of 0.20 to
1.00% by weight, lignin-based delay agent from 0.60 to 1.20 weight%
And a high fluidity super-rapid hardening cement composition containing 0.01 to 0.20 % by weight of an oxycarboxylic acid-based retarder. 2. A roadbed on which asphalt and aggregate are laid,
0.20-1.00 weight of high performance water reducing agent for ultra-fast hardening cement
%, Lignin-based retarder 0.60-1.20% by weight and oxy
Carboxylic acid-based retarder 0.01 to 0.20% by weight
That high fluidity can be obtained by injecting the super fast cement composition you wherein semi flexible pavement structure. 3. A roadbed on which asphalt and aggregate are laid,
0.20-1.00 weight of high performance water reducing agent for ultra-fast hardening cement
%, Lignin-based retarder 0.60-1.20% by weight and oxy
Carboxylic acid-based retarder 0.01 to 0.20% by weight
Semi flexible pavement method you characterized by injecting a high flow ultra rapid setting cement composition that.