JP6076641B2 - Pavement concrete and its manufacturing method - Google Patents

Description

  The present invention relates to pavement concrete with few cracks and a method for producing the same.

  Traditionally, concrete and asphalt have been used as paving materials. Of these, concrete is superior in durability to asphalt, but it takes time to pave, so the pavement rate of concrete is only about 5% in the pavement field where early traffic opening is required. On the other hand, asphalt is 100% dependent on imported crude oil, so the stable supply of asphalt is becoming difficult due to the recent rise in asphalt price due to high crude oil prices. Therefore, recently, concrete that can be easily procured in Japan has been reviewed in the pavement field. However, when a concrete pavement is cracked, there is a problem that a step is generated due to a corner defect in the cracked portion, and noise and vibration are generated.

As means for solving such a problem, several paving concretes that are difficult to crack are proposed.
For example, Patent Document 1 discloses a concrete composition containing a binder containing a Portland cement having a 2CaO · SiO ₂ content of 30 to 40% by mass and a pozzolanic fine powder having a BET specific surface area of 5 to 15 m ² / g. Pavement concrete has been proposed in which the bending strength at the age of 1 day is 3.5 N / mm ² or more.
Patent Document 2 discloses cement, fine powder having a BET specific surface area of 3 to 25 m ² / g, fine aggregate, water, water reducing agent, and monofilament having a diameter of 0.02 to 0.2 mm and a length of 1 to 30 mm. Concrete pavements have been proposed that consist of a cured body of a blend containing a type of aramid fiber.
However, each concrete has an effect of suppressing cracking due to load stress, but the effect of suppressing cracking due to shrinkage is unknown.
Patent Document 3 includes cement, a shrinkage reducing agent, an expansion material, a high-performance AE water reducing agent, and an AE agent for the purpose of suppressing cracking due to shrinkage, and the cement is ordinary Portland cement and / or low heat Portland cement. A concrete composition for an overlay method is proposed. However, the effect of suppressing cracking of the composition is still not sufficient.

JP 2011-214231 A JP 2011-043008 A JP-A-11-310448

  Therefore, an object of the present invention is to provide paving concrete and the like that are less susceptible to cracking due to shrinkage.

  Then, the present inventors diligently examined the pavement concrete, and found that pavement concrete containing organic fibers and having a specific composition can suppress the occurrence of cracks, and completed the present invention.

That is, the present invention is pavement concrete having the following configuration.
[1] Pavement concrete containing organic fiber, cement, water, fine aggregate, coarse aggregate, and water reducing agent, the amount of organic fiber being 0.01 to 3.0% by volume with respect to the volume of the concrete, unit Cement amount is 300 to 420 kg / m ³ , unit water amount is 130 to 160 kg / m ³ , unit fine aggregate amount is 700 to 850 kg / m ³ , unit coarse aggregate amount is 1000 to 1350 kg / m ³ , unit water reducing agent amount 1 to 10 kg / m ³ , a water-cement ratio of 36 to 50%, and a fine aggregate ratio of 33 to 43 %.
[2] The pavement concrete according to [1], further including an expansion material.
[3] The pavement concrete according to [1] or [2] above, which contains a shrinkage reducing agent containing a compound represented by the following chemical formula.
RO-[(EO) _m1 / (PO) _m2 ] -H
(In the formula, R represents a hydrogen atom or an alkyl group having 1 to 6 or 8 to 14 carbon atoms, EO represents an oxyethylene group, PO represents an oxypropylene group, and [(EO) _m1 / (PO) _m2 ] represents a homopolymer of ethylene oxide or propylene oxide, a random copolymer of ethylene oxide and propylene oxide, or a block copolymer of ethylene oxide and propylene oxide, provided that the order of (EO) _m1 and (PO) _m2 is M1 represents the number of added moles of ethylene oxide (0 to 10), m2 represents the number of added moles of propylene oxide (0 to 10), and the sum of m1 and m2 is 1 to 10.
[4], further comprising a coating curing agent and / or made of a shrinkage reducing agent-coated body, pavement concrete according to any one of [1] to [3].
[5] A method for producing the paving concrete according to [4],
Kneading and placing a paving concrete material other than the coating film curing agent and / or shrinkage reducing agent for the coating to obtain a concrete body, and from the end of bleeding of the concrete body to the age of 7 days A method for producing pavement concrete, including a step of coating the surface of the concrete body with a coating film curing agent and / or a shrinkage reducing agent for the covering to obtain pavement concrete.

  The pavement concrete of the present invention is less susceptible to cracking due to shrinkage.

It is a top view of the formwork used for the crack test. It is sectional drawing of the formwork used for the crack test.

  As described above, the paving concrete of the present invention contains organic fibers and has a specific composition for each constituent material. Hereinafter, regarding the present invention, organic fibers, cement, water, fine aggregate, coarse aggregate, and water reducing agent that are essential constituent materials, and expansion materials, shrinkage reducing agents, and coating film curing agents that are optional constituent materials This will be explained separately.

[Organic fiber]
Examples of the organic fiber used in the present invention include at least one selected from polypropylene fiber, vinylon fiber, polyethylene fiber, aramid fiber, polyvinyl alcohol fiber, and cellulose fiber. Among these, in the present invention, polypropylene fiber is preferable because it has a high cracking suppression effect and is easily available.
The diameter of the organic fiber is preferably 0.005 to 0.5 mm, more preferably 0.01 to 0.3 mm. If the value is less than 0.005 mm, the strength of the fiber itself is insufficient and it is easy to cut when subjected to tension. If the value exceeds 0.5 mm, the number of fibers in the paving concrete is relatively reduced with the same fiber content. The effect of suppressing cracking is reduced.
Moreover, the length of the organic fiber is preferably 5 to 25 mm, more preferably 7 to 20 mm. If the value is less than 5 mm, the adhesion to the matrix is reduced and the effect of suppressing cracking is reduced, and if it exceeds 25 mm, fiber balls are likely to occur during kneading.
The compounding amount of the organic fiber is 0.01 to 3.0% by volume, preferably 0.05 to 2.0% by volume, based on the volume of the paved concrete. If the value is less than 0.01% by volume, the shrinkage reducing effect and cracking suppressing effect of the paved concrete are low, and if it exceeds 3.0% by volume, the workability of the paved concrete is lowered and the cost is increased.

[cement]
The cement used in the present invention is not particularly limited, and is at least selected from ordinary Portland cement, early-strength Portland cement, moderately hot Portland cement, low heat Portland cement, blast furnace cement, fly ash cement, eco cement, silica fume premix cement, and the like. 1 type or more is mentioned.
The unit cement amount is 300 to 420 kg / m ³ , preferably 310 to 380 kg / m ³ , more preferably 320 to 350 kg / m ³ . When the value is less than 300 kg / m ³ , the workability of the paving concrete decreases, and when it exceeds 420 kg / m ³ , the self-shrinkage of the paving concrete tends to increase.

[water]
The water used in the present invention is not particularly limited, and tap water, sludge water, sewage treated water, and the like can be used. The unit water amount is 130 to 160 kg / m ³ , preferably 132 to 150 kg / m ³ , more preferably 135 to 140 kg / m ³ . If the value is less than 130 kg / m ³ , the fluidity of the paving concrete may be low and molding may be difficult, and if it exceeds 160 kg / m ³ , the strength of the paving concrete may be reduced.
The water cement ratio is 36 to 50%, preferably 38 to 48%, more preferably 40 to 46%. If the value is less than 36%, the flowability of the pavement concrete may be low and molding may be difficult, and if it exceeds 50%, the strength of the pavement concrete may decrease.

[Fine aggregate]
The fine aggregate used in the present invention is not particularly limited, and examples thereof include at least one selected from river sand, mountain sand, land sand, sea sand, crushed sand, quartz sand, slag fine aggregate, and the like. The unit fine aggregate amount is 700 to 850 kg / m ³ , preferably 725 to 825 kg / m ³ , more preferably 750 to 800 kg / m ³ . When the value is less than 700 kg / m ³ , the shrinkage reduction effect is lowered, and when it exceeds 850 kg / m ³ , the fluidity and consistency of the paving concrete may be lowered and workability may be deteriorated.
The fine aggregate ratio is 33 to 48%, preferably 35 to 45%, and more preferably 38 to 43%. If the value is less than 33%, the workability of the paving concrete decreases, and if it exceeds 48%, the fluidity and consistency of the paving concrete may decrease and workability may deteriorate.

[Coarse aggregate]
The coarse aggregate used in the present invention is not particularly limited, and examples thereof include at least one selected from river gravel, crushed stone, slag coarse aggregate and the like. The amount of unit coarse aggregate is 1000 to 1350 kg / m ³ , preferably 1050 to 1200 kg / m ³ , more preferably 1100 to 1150 kg / m ³ . When the value is less than 1000 kg / m ³ , the durability and wear resistance of the paving concrete are lowered, and when it exceeds 1350 kg / m ³ , the workability of the paving concrete may be lowered.
The maximum particle size of the coarse aggregate is preferably 20 to 45 mm, more preferably 25 to 40 mm. If the value is less than 20 mm, the wear resistance of the paving concrete is lowered, and if it exceeds 45 mm, it is difficult to obtain and the workability of the paving concrete may be lowered.
The fine aggregate and the coarse aggregate may be natural aggregate as well as recycled aggregate.

[Water reducing agent]
Examples of the water reducing agent used in the present invention include at least one selected from lignin sulfonic acid, naphthalene sulfonic acid formaldehyde condensate, melamine sulfonic acid formaldehyde condensate, polycarboxylic acid and salts thereof. Examples of the salt include at least one selected from alkali metal salts such as sodium and potassium, and alkaline earth metal salts such as calcium and magnesium. These water reducing agents are classified into AE water reducing agents, high performance water reducing agents, high performance AE water reducing agents, and the like according to water reducing performance and air entrainment performance. Among these, the water reducing agent used in the present invention is preferably an AE water reducing agent from the viewpoint of ensuring workability (kneading property, workability) and durability, and more preferably lignin sulfonate as an active ingredient. It is an AE water reducing agent.
The amount of the water reducing agent is 1 to 10 kg / m ³ , preferably ³ to 8 kg / m ³ , more preferably 4 to 6 kg / m ³ . If the value is less than 1 kg / m ³ , the water reducing performance is low, and if it exceeds 10 kg / m ³ , the setting of the cement may be delayed and the cost is increased.

[Expandable material]
The expansion material used in the present invention may be any material that grows crystals of hydrates such as calcium hydroxide and ettringite by hydration and increases the bulk volume. For example, quick lime, calcium sulfoaluminate, gypsum, magnesia And at least one selected from lime-based expansion materials, ettringite-based expansion materials, and the like. Among these, a lime-based expansion material or ettringite-based expansion material that conforms to JIS A 6202 “Concrete expansion material” is suitable for suppressing cracking of paving concrete because the expansion rate according to the amount added is stably obtained. It is.
Unit expandable material amount, shrinkage reducing effect, cracking inhibiting effect, and the strength development of points, preferably at 30kg / ^{m 3} or less, more preferably 10-20 kg / ^{m 3.}

[Shrinkage reducing agent]
The shrinkage reducing agent used in the present invention contains a compound represented by the following chemical formula as an active ingredient.
RO-[(EO) _m1 / (PO) _m2 ] -H
Here, R represents a hydrogen atom or an alkyl group having 1 to 6 or 8 to 14 carbon atoms.
R preferable from the viewpoint of reducing drying shrinkage is a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, or a tert-butyl group. N-pentyl group, iso-pentyl group, tert-pentyl group, n-hexyl group, iso-hexyl group, and tert-hexyl group, more preferably methyl group, n-butyl group, iso-butyl group , Sec-butyl group, and tert-butyl group.

  R preferable from the viewpoint of reducing self-shrinkage is iso-octyl group, 2-octyl group, 4-methyl-4-heptyl group, 2-ethyl-1-hexyl group, iso-nonyl group, 2-nonyl. Group, 3,5,5-trimethyl-1-hexyl group, iso-decyl group, 2-decyl group, iso-undecyl group, 2-undecyl group, 2-lauryl group, iso-lauryl group, 2-tridecyl group, It is a branched alkyl group derived from an iso-tridecyl group, a 2-tetradecyl group, an iso-tetradecyl group, and a secondary alcohol having 12 to 14 carbon atoms made from normal paraffin, more preferably an iso-octyl group, 2-octyl group, 4-methyl-4-heptyl group, 2-ethyl-1-hexyl group, iso-nonyl group, 2-nonyl group, 3,5,5-trimethyl-1 It is a branched alkyl group derived from a secondary alcohol having 12 to 14 carbon atoms using hexyl group, iso-decyl group, 2-decyl group and normal paraffin as a raw material, and more preferably 2-ethyl-1-hexyl. And an iso-decyl group.

EO represents an oxyethylene group, PO represents an oxypropylene group, [(EO) _m1 / (PO) _m2 ] represents ethylene oxide or a homopolymer of propylene oxide, a random copolymer of ethylene oxide and propylene oxide, or Represents a block copolymer of ethylene oxide and propylene oxide. However, the order of (EO) _m1 and (PO) _m2 does not matter. [(EO) _m1 / (PO) _m2 ] is preferably a random copolymer of ethylene oxide and propylene oxide, or a block copolymer of ethylene oxide and propylene oxide, from the viewpoint of reducing self-shrinkage. A block copolymer of ethylene oxide and propylene oxide is preferred.
M1 represents the number of moles of ethylene oxide added, and m2 represents the number of moles of propylene oxide added, both of which are preferably 0 to 10, more preferably 2 to 5. Moreover, the sum total of m1 and m2 is 1-10. If m1 and m2 are in the range of 0 to 10, the shrinkage reduction effect is high, and adjustment of the amount of air in the mortar and concrete is easy.
Furthermore, m1 / (m1 + m2) representing the content of oxyethylene group (EO) is preferably 0.5 to 1.0, more preferably 0.6 to 1.0, in terms of the effect of reducing self-shrinkage. More preferably, it is 0.7-1.0, Most preferably, it is 0.9-1.0.

Moreover, the carbon number of R is 8 to 14, and the compound having the weight average molecular weight (Mw) / number average molecular weight (Mn), which is an index of molecular weight distribution, satisfies the following formula, has an influence on the fluidity of paving concrete. Therefore, it is possible to maintain almost the same workability as pavement concrete not containing a shrinkage reducing agent.
Mw / Mn ≦ 1.520 × e ^{(−0.030 × N)}
Here, Mw and Mn represent the average molecular weight (polystyrene conversion value) measured using gel permeation chromatography, and N represents the carbon number of R.

The amount of the unit shrinkage reducing agent is preferably 2 to 9 kg / m ³ , more preferably ³ to 8 kg / m ³ . If the value is less than 2 kg / m ³ , the shrinkage reduction effect and the effect of suppressing the occurrence of cracks are low, and if it exceeds 9 kg / m ³ , the amount of air in the paving concrete increases and poor curing may occur.
In the present invention, the shrinkage reducing agent is used to coat the surface of a concrete body (molded body) made of organic fibers, cement, water, etc., in addition to those kneaded with organic fibers, cement, water, etc. Can also be used.
Thus, as a shrinkage reducing agent used for coating, what contains the said component of the shrinkage reducing agent used as a material which comprises a concrete main body can be used. Note that the shrinkage reducing agent used for coating and the shrinkage reducing agent used as a material constituting the concrete body may be the same type or different types.
When the shrinkage reducing agent is coated on the surface of the concrete body, the amount used is preferably 50 to 150 g, more preferably 70 to 130 g per 1 m ² of the concrete body. When the shrinkage reducing agent is applied a plurality of times, the shrinkage reducing effect is further improved.
In addition, in this invention, a coating means the state which apply | coated, spread | dispersed or sprayed the shrinkage reducing agent and the coating-film curing agent of the postscript on the surface of a concrete main body, and the state which this chemical | medical agent covered the surface of the concrete main body.

[Coating film curing agent]
The film curing agent used in the present invention is at least one selected from paraffin, lower alcohol alkylene oxide adducts, celluloses, polyvinyl alcohol, vinyl acetates, acrylic copolymers, silane compounds, and alkenyl ester compounds. Is mentioned. Such a compound can be used in the form of an emulsion or a solution by coating, spraying or spraying on the surface of the paving concrete.
The amount of the coating curing agent is preferably, 50 to 150 g per paving concrete 1 m ^2, more preferably 70～130G. When the value is in the range of 50 to 150 g, the shrinkage reduction effect and the crack suppression effect are high, and the cost effectiveness is excellent. Further, when the coating film curing agent is applied a plurality of times, the shrinkage reduction effect is further improved.
In addition, when a coating-film curing agent is used for the paving concrete containing the said shrinkage reducing agent and / or an expansion material, the shrinkage reduction effect will improve further.

[Production method of paving concrete]
A method for producing pavement concrete, in which a concrete surface is coated with a shrinkage reducing agent and / or a coating curing agent, is kneaded and mixed with a pavement concrete material other than the coating curing agent and / or the shrinkage reducing agent for coating. The concrete body using a coating curing agent and / or a shrinkage reducing agent for the coating between the step of obtaining the concrete body and the end of bleeding of the concrete body until the age of 7 days The process of covering the surface of this and obtaining the pavement concrete is included.
Examples of the method for covering the surface of the concrete main body include application, spreading, spraying, and the like. If application | coating etc. are performed in the said period, a shrinkage | contraction reducing agent etc. will osmose | permeate pavement concrete easily.
For the kneading, an omni mixer, a pan-type mixer, a biaxial kneading mixer, a tilting cylinder mixer, or the like can be used. Moreover, the said application | coating etc. can be performed using a brush, spray, a spraying apparatus, etc.

EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples.
[Materials used]
(1) Cement: Blast furnace cement type B (manufactured by Taiheiyo Cement)
(2) Expansion material: Hyperexpan (registered trademark, manufactured by Taiheiyo Materials Co., Ltd.)
(3) Water: Tap water (4) Fine aggregate: Mountain sand (Kakegawa City, Shizuoka Prefecture)
(5) Coarse aggregate (i) Crushed stone 4005 (from Tomiya, Sakuragawa City, Ibaraki Prefecture), Example and Comparative Example 1 were used.
(Ii) Crushed stone 2005 (produced by Tomiya, Sakuragawa City, Ibaraki Prefecture) was used in Comparative Examples 2-5.
(6) AE water reducing agent: Pozzolith no. 70 (registered trademark, manufactured by BASF Pozzolith)
(7) Polypropylene fiber: Vallink (registered trademark, manufactured by Taiheiyo Materials Co., Ltd.), fiber length 12 mm, diameter 0.043 mm
(8) Shrinkage reducing agent (a) Crack Saver (registered trademark, manufactured by Taiheiyo Materials Co., Ltd .; material for covering the surface of concrete body)
(B) Tetragard AS21 (registered trademark, manufactured by Taiheiyo Materials Co., Ltd .; material for concrete body)
(9) Coating film curing agent: Cure keeper (registered trademark, manufactured by Taiheiyo Materials Co., Ltd.), paraffin emulsion.

[Examples 1 to 10, Comparative Examples 1 to 5]
The bending strength, the rate of change in length due to drying shrinkage, and the crack area of the pavement concrete shown in Table 1 were measured by the following methods.
The concrete was kneaded using a biaxial mixer, and the fiber and the shrinkage reducing agent (b) were mixed during the preparation of the concrete raw material.
Moreover, the coating film curing agent was applied to the surface of the test specimen in an amount of 100 g / m ² using a brush after bleeding water disappeared. The shrinkage reducing agent was applied to the surface of the specimen immediately before demolding in an amount of 100 g / m ² using a brush.
(1) Bending strength Bending strength of pavement concrete was measured according to JIS A 1106 “Bending strength test of pavement concrete” using specimens of 10 × 10 × 40 cm and ages 7 and 28 days. . The molding was performed in a constant temperature room at 20 ° C., and the mold was removed after curing in the air at 20 ° C. for 24 hours.
Thereafter, it was cured in water at 20 ° C. until the age of 7 and 28 days.
(2) Length change rate The length change rate of pavement concrete during the 26-week drying period is dialed using a 10 × 10 × 40 cm specimen in accordance with JIS A 1129 “Mortar and concrete length test method”. It was measured by the gauge method (Whitmore). The molding was performed in a constant temperature room at 20 ° C., and the mold was removed after curing in the air at 20 ° C. for 24 hours.

(3) Crack generation ratio on concrete surface The crack generation ratio on the concrete surface was determined according to the following (i) to (iv).
(I) As shown in FIGS. 1 and 2, the mold 1 in which steel bars 3 having a diameter of 8 mm are internally welded at intervals of 30 mm is kept constant in a room having a temperature of 50 ± 5 ° C. and a relative humidity of 30 ± 10%. After placing, the concrete was placed in the mold 1 to finish the surface of the concrete specimen. The formwork shown in FIGS. 1 and 2 has a function of restraining the shrinkage until the concrete starts to harden. Moreover, in FIG.1 and FIG.2, the code | symbol 2 shows a side plate and the code | symbol 4 shows a baseplate.
(Ii) Next, after the bleeding water disappeared, the surface of the concrete specimen was blown with a fan at a wind speed of 5 to 6 m / sec for 24 hours to promote evaporation of moisture. The mold was removed 24 hours after blowing.
(Iii) Further, the specimen was allowed to stand in a room at 20 ° C. and a relative humidity of 60% until the material age was 28 days, and then was left still in a room at 20 ° C. and a relative humidity of 40% until the material age was 56 days.
(Iv) At a material age of 56 days, a value obtained by totaling the products of the length of cracks generated on the surface of the specimen and the maximum width of the cracks was determined as a crack area.
The results are shown in Table 1.
In addition, the crack generation ratio of Examples 1 to 10 and Comparative Examples 2 to 5 shown in Table 1 is the ratio (%) of the crack area of each Example and Comparative Example when the crack area of Comparative Example 1 is 100. It is.
As shown in FIGS. 1 and 2, for the purpose of restricting the shrinkage of the mold 1 until the hardening of the concrete, an 8 mm diameter steel rod 3 was welded to the inner bottom 4 of the mold at intervals of 30 mm. A 10 × 100 × 3.5 cm mold 1 was used.

As shown in Table 1, the cracking ratio of the pavement concrete (Examples 1 to 10) of the present invention is as low as 59% or less compared to Comparative Example 1. Among these, Example 6 and 7 which used together the fiber, the shrinkage reducing agent (a), and the expansion material, and Example 10 which used the fiber, the coating film curing agent, the shrinkage reduction agent (b), and the expansion material are used. The occurrence rate of cracks was even lower at 20% or less. In particular, in Example 10, no cracks were generated.
In contrast, Comparative Examples 3 to 5 (corresponding to conventional paving concrete) in which the unit cement amount is less than 300 kg / m ³ and the water cement ratio exceeds 50% are the same fiber, shrinkage reducing agent (a), and shrinkage reduction. Even when the agent (b) is used, the generation ratio of cracks is as high as 67% or more. In Comparative Example 4, the length change rate is as small as 377 × 10 ⁻⁶ , but is larger than the length change rate of 240 × 10 ⁻⁶ in Example 3 using the same fiber and the shrinkage reducing agent (b). Moreover, the crack generation rate is as high as 71%.
Therefore, the pavement concrete of the present invention is expected to have high pavement durability because it has less cracks than conventional pavement concrete, and can reduce repair frequency, noise, vibration, and the like over a long period of time.

1 Formwork 2 Side plate 3 Steel bar 4 Bottom plate

Claims (5)

Pavement concrete containing organic fiber, cement, water, fine aggregate, coarse aggregate, and water reducing agent, the amount of organic fiber being 0.01 to 3.0% by volume with respect to the volume of pavement concrete, unit cement amount Is 300 to 420 kg / m ³ , the unit water amount is 130 to 160 kg / m ³ , the unit fine aggregate amount is 700 to 850 kg / m ³ , the unit coarse aggregate amount is 1000 to 1350 kg / m ³ , and the unit water reducing agent amount is 1 Pavement concrete with 10 to 10 kg / m ³ , water cement ratio of 36 to 50%, and fine aggregate ratio of 33 to 43 %.   Furthermore, the paving concrete of Claim 1 containing an expansion | swelling material. The pavement concrete of Claim 1 or 2 containing the shrinkage | contraction reducing agent containing the compound represented by the following chemical formula.
RO-[(EO) _m1 / (PO) _m2 ] -H
(In the formula, R represents a hydrogen atom or an alkyl group having 1 to 6 or 8 to 14 carbon atoms, EO represents an oxyethylene group, PO represents an oxypropylene group, and [(EO) _m1 / (PO) _m2 ] represents a homopolymer of ethylene oxide or propylene oxide, a random copolymer of ethylene oxide and propylene oxide, or a block copolymer of ethylene oxide and propylene oxide, provided that the order of (EO) _m1 and (PO) _m2 is M1 represents the number of added moles of ethylene oxide (0 to 10), m2 represents the number of added moles of propylene oxide (0 to 10), and the sum of m1 and m2 is 1 to 10. Furthermore, the pavement concrete of any one of Claims 1-3 which has a coating body which consists of a coating-film curing agent and / or a shrinkage reducing agent. A method for producing the paving concrete according to claim 4,
Kneading and placing a paving concrete material other than the coating film curing agent and / or shrinkage reducing agent for the coating to obtain a concrete body;
Between the end of bleeding of the concrete body and the age of 7 days, the surface of the concrete body is coated with a coating curing agent and / or a shrinkage reducing agent for coating to obtain paving concrete. A method for producing pavement concrete including a process.

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