KR100908213B1 - Rapid hardening concrete composition and repairing method using the same - Google Patents

Abstract

A rapid-hardening concrete composition and a method for repairing a concrete pavement using the same are provided to shorten a curing time while improving mechanical strength and to prevent excessive contraction and minute cracks. A rapid-hardening concrete composition is composed of 10-46wt% of a first composition, 50-86wt% of aggregate, 3-25wt% of water and SBR latex. The first composition contains 45-55wt% of C2S(Ca2SiO4), 30-40wt% of calcium sulfoaluminate(C4A3S), 7-14wt% of C4AF(4CaO.Al2O3.Fe2O3), 4-11wt% of CSH(Calcium silicate hydrate), 0-2wt% of C3S(Ca3SiO5) and 0-3wt% of C3A(Ca3Al2O6).

Description

Rapid hardening concrete composition and repairing method using the same}

The present invention relates to a fast-hard concrete composition, and more particularly to a fast-hard concrete composition and a concrete road or bridge deck repair method using the same, such as roads, bridges, runways for emergency repair or emergency work.

As industrial development and traffic increase, road structures such as concrete pavement and bridge joints are subject to premature deterioration due to the load of the vehicle. However, concrete requires sufficient curing time to develop strength. Fast-hardening cement concrete has the advantage of expressing strength in a short time compared to general concrete, it is widely used in concrete pavement, runway repair work and general civil building construction.

In general, Portland cement has a low coagulation and hardening rate, and thus improves the practical strength (200㎏ / ㎠) by controlling the mineral composition and powder level of cement or by using a curing accelerator. However, only calcium silicate (3CaO · SiO ₂ ) There is a limit to promoting the practical strength. However, the calcium aluminate-based _{(CA-C 12 A 7,} CA-CA 2 system), and calcium fluoride aluminate-based _{(C 11 A 7 · CaF 2} -C 3 SC 3 A series), a calcium sulfo aluminate-based (CSA-based _{; C 3 a 3 · CaSO 4} -C 2 S-CaSO 4 system), amorphous calcium aluminate-based _{(C 11 a 7 · CaF 2} -C 12 a in hard cement separated by _seven system) 7 of the ordinary Portland cement As it can express daily compressive strength in 2 ~ 3 hours, it is used for urgent civil engineering and construction work, especially calcium sulfoaluminate system (C ₃ A ₃ · CaSO ₄ -C ₂ S-CaSO ₄ system) By using the characteristics of ettringite (C ₃ A ₃ · CaSO ₄ · ₃₂ H ₂ O) produced by the hydration reaction, it is widely used as an expansion material of sludge, sludge and waste solidification and soft ground reinforcement.

In hard cement manufacturing is the calcium aluminate _{(CaO · Al 2 O 3,} 12CaO · 7Al 2 O 3), calcium flow climb aluminate _{(11CaO · 7Al 2 O 3 ·} CaF 2)), amorphous calcium aluminate, calcium sulfonate Clinker minerals such as aluminate (3CaO · 3Al ₂ O ₃ · CaSO ₄ ) are used, or calcium aluminate minerals such as CaO · Al ₂ O ₃ or 12CaO · 7Al ₂ O ₃ are usually used in portland cement. Fast-hardening cement mixed with alumina cement and anhydrous gypsum is commercialized and sold in Japan.In Japan, when manufacturing clinker of Portland cement, calcium aluminate mineral, an intermediate product, is usually used as calcium fluoroaluminate (11CaO · 7Al ₂ O ₃ ·). A fast-hardening cement made from calcium fluoroaluminates substituted with CaF ₂ ), arit (3CaO.SiO ₂ ) and anhydrous gypsum (CaSO ₄ ) as main minerals is sold.

However, the cemented carbide cement concrete generates high heat of hydration for early strength, and a lot of fine cracks are generated due to thermal stress and shrinkage due to heat and moisture movement in concrete when constructing a large structure. The micro cracks generated in this way increase the permeability of the concrete and eventually lead to a decrease in durability of the concrete structure.

Therefore, an object of the present invention is to provide a fast concrete composition comprising a fast cement composition to shorten the curing time and a concrete road or bridge deck repair method using the same.

In addition, an object of the present invention is to provide a fast-hard concrete composition comprising a fast cement composition, which shortens the curing time and prevents shrinkage and does not generate fine cracks, and a concrete road or bridge deck repair method using the same.

In addition, the present invention is a fast-concrete concrete composition containing a fast-hard cement with improved mechanical strength, low chloride ion permeability, and increased adhesion, emergency repair of deteriorated concrete pavement such as concrete road, bridge deck, port, airport It aims to provide a repair method, etc.

In order to achieve the above object, the present inventors have C ₂ S (Ca ₂ SiO ₄ ) and calcium sulfoaluminate (C ₄ A ₃ S) as main components, and C ₃ S (Ca ₃ SiO ₅ ) and C ₃ A (Ca ₃ Al ₂ O ₆ ), C ₄ AF (4CaO · Al ₂ O ₃ · Fe ₂ O ₃ ), CSH (Calcium silicate hydrate) by mixing the appropriate ratio improves adhesion and mechanical strength and significantly reduces microcracks A fast hard concrete composition can be prepared comprising the hard cement composition.

Specifically, the present invention is 45 to 55% by weight C ₂ S (Ca ₂ SiO ₄ ), 30 to 40% by weight calcium sulfoaluminate (C ₄ A ₃ S), C ₄ AF (4CaOAl ₂ O ₃ · Fe ₂ O ₃ ) 7-14% by weight, 4-11% by weight of Calcium silicate hydrate (CSH), more than 0% by weight to 2% by weight of C ₃ S (Ca ₃ SiO ₅ ) and C ₃ A (Ca ₃ Al ₂ O ₆ ) Provides a fast cement composition comprising more than 0% by weight to 3% by weight.

In addition, the present invention provides a mortar composition for repairing concrete pavement or bridge construction including 10 to 46% by weight of the fast cement composition and 50 to 86% by weight of aggregate and 3 to 25% by weight of water to repair the degraded concrete pavement. do.

In addition, the present invention comprises 10-46% by weight of the fast cement composition and 54-90% by weight of the dry aggregate, and provides a unit-packable fast-hard concrete composition.

In addition, the present invention provides a fast-hard concrete composition, characterized in that further comprising at least one of a retarder, a water reducing agent and an antifoaming agent in the fast-hard concrete composition.

In addition, the present invention provides a fast-hard concrete composition, characterized in that further comprising SBR latex in the fast-concrete concrete composition.

The concrete containing the fast-hardening cement composition of the present invention significantly shortens the hardening time and prevents excessive shrinkage, thereby significantly reducing the occurrence of microcracks. The resistance to sulfuric acid is increased and the chloride permeability is low, thereby improving mechanical strength. Was increased.

The fast-hardening cement composition of the present invention is 45 to 55% by weight of C ₂ S (Ca ₂ SiO ₄ ), calcium sulfoaluminate (C ₄ A ₃ S) 30 to 40% by weight, C ₄ AF (4CaOAl ₂ O ₃ Fe ₂ O ₃ ) 7-14% by weight, CSH (Calcium silicate hydrate) 4-11% by weight, C ₃ S (Ca ₃ SiO ₅ ) greater than 0% to 2% by weight and C ₃ A (Ca ₃ Al ₂ O ₆ ) more than 0% to 3% by weight is prepared.

C ₂ S (Ca ₂ SiO ₄ ) and C ₃ S (Ca ₃ SiO ₅ ) have a function of strength development of concrete.

Carbonation reactions occur when carbon dioxide in the air carbonizes while reacting with calcium hydroxide in cement. Most calcium hydroxide is the result of hydration of C ₃ S, which occurs in a modified form. Usually, Portland cement contains about 50% by weight of C ₃ S. However, the fast-hardening cement composition of the present invention contains a small amount of C ₃ S, so that no calcium hydroxide is generated, so that carbonation reaction hardly occurs. For this reason, shrinkage on drying is minimized.

The fast-hardening cement composition of the present invention contains C ₂ S (Ca ₂ SiO ₄ ) in the range of 45 to 55% by weight, but less than 45% by weight has a problem in developing sufficient long-term strength, and more than 55% by weight is uneconomical to be. C ₃ S (Ca ₃ SiO ₅ ) is preferably in the range of more than 0% by weight to 2% by weight, but more than 2% by weight causes a shrinkage problem due to carbonation reaction.

The fast cement composition of the present invention contains 30-40% by weight of calcium sulfoaluminate (C ₄ A ₃ S), and this range is most preferred in view of fast hardening and microcracking and strength.

The fast-hardening cement composition of the present invention contains C ₄ AF (4CaO.Al ₂ O ₃ .Fe ₂ O ₃ ) 7-14% by weight, and this range is most preferred in view of fast hardening and microcracks and strength.

The fast cement composition of the present invention contains C ₃ A in an amount of more than 0% by weight to 3% by weight or less, but when it exceeds 3% by weight, this causes a problem of binding methane with methane ettringite.

It has been known that certain concretes degrade properties in the presence of sulfur compounds. This causes sulfur to react with C ₃ A to form malignant ettringite, which expands in volume to crack and weakens the binding and mechanical strength of concrete. Contact with sulfur also transfers the sulfur compound solution into the concrete and the sulfur salts react with the evaporated water to crystallize in the pores of the surface. Concrete prepared from the fast cement composition of the present invention has a very low C ₃ A content, thereby increasing resistance to sulfur.

The fast-hardening cement composition of the present invention contains 4 to 11% by weight of CSH, and this range is most preferable in terms of fast-hardness, microcrack suppression and strength.

Concrete prepared from the fast-hardening cement composition of the present invention is completely hydrated with a W / C ratio of 0.4 to 0.5, so that the mixed water is quickly consumed chemically and no water flows out, and surface shrinkage is prevented.

 Plain portland cement  Invention fast cement Ingredient C ₃ S 40 to 55% by weight C ₂ S 20 to 40% by weight C ₃ A 4 to 10% by weight C ₄ AF 9 to 12% by weight CSH 4 to 6% by weight C ₃ S More than 0 ~ 2 wt% C ₂ S 45 ~ 55 wt% C ₃ A More than 0 ~ 3 wt% C ₄ AF 7-14 wt% C ₄ A ₃ S 30-40 wt% CSH 4-11 wt%  W / C  0.22-0.25  0.4-0.5 Surface Area of Bran Cement Particles (Classification) ㎠ / g  3,500-4,000  6,500

In addition, the present invention is a fast-hard concrete composition that mixes 10 to 46% by weight of the fast cement composition of the present invention, 50 to 86% by weight of aggregate and 3 to 25% by weight of water, and the fast cement composition without water Provides a fast-hard concrete composition capable of unit packaging in a zone or vinyl bag consisting of 10 to 46% by weight and 54 to 90% by weight of dry aggregate.

The antifoaming agent, the water reducing agent, and / or the retardant may be added to the composition of the present invention, if necessary, in the range of more than 0% by weight and 1% by weight or less.

The composition of the present invention may increase the flexural strength and tensile strength by adding SBR latex within the range of more than 0 parts by weight and 15 parts by weight or less based on 100 parts by weight of the total weight of the hard concrete composition.

The powdery polymer may be added to the composition of the present invention as needed within the range of 1 to 10% by weight.

The powdered polymer may include polyvinyl vinyl acetate (POLY EVA) reemulsified powder resin, polyvinyl acetate-vinyl versalate (PVA-VeoVa) reemulsified powder resin, polystyrene-acrylic ester (POE SAE) reemulsified powder resin and PAE At least one selected from (polyacrylic ester) reemulsified powder resins is used.

In addition, the present invention is to remove the fragile portion of the concrete pavement;

       Cleaning the concrete pavement from which the fragile portion has been removed;

Maintaining a wet state of the cleaned vulnerable portion;

Primer process for uniformly applying the concrete primer on the weak part of the wet state;

Laying the fast concrete composition flat on the primer-treated concrete pavement;

It relates to a concrete pavement and structure repair method using a fast-hard concrete composition comprising the step of curing the hard concrete composition.

In addition, the present invention is to remove the fragile portion of the concrete pavement;

      Cleaning the concrete pavement from which the fragile portion has been removed;

Maintaining a wet state of the cleaned vulnerable portion;

Primer process for uniformly applying the concrete primer on the weak part of the wet state;

Laying the fast concrete composition flat on the primer-treated concrete pavement;

Curing the laid fast hard concrete composition;

Spraying an epoxy primer for ascon on the curing surface; And

It relates to a concrete pavement and structure repair method using a fast-hard concrete composition comprising a; step of laying epoxy asphalt concrete (epoas) on the sprayed primer.

Aggregate uses less than 2.5mm or 5mm aggregate when the deteriorated part of the concrete deck is small, and 13-25mm aggregate may be used when the deteriorated part is deep and wide.

The composition of the present invention is a fast cement composition 10 to 46% by weight of the fast cement composition, 50 to 86% by weight of aggregate and 3 to 25% by weight of water, and 10 to 46 of the fast cement composition without water There are two types of fast-hardening concrete composition for repairing concrete that can be unit-packed in a zone or vinyl bag composed of 54% to 90% by weight of dry aggregate.

The fast-hard cement composition of the present invention is suitable for 10 to 46% by weight of the total weight of the composition, when less than 10% by weight of the adhesive strength and strength is lowered, if it exceeds 46% by weight is not economical.

Aggregate is preferably 54 to 90% by weight of the total composition, less than 54% by weight is not suitable for concrete repair applications due to the incorporation of fast-hardening cement composition, if there is more than 90% by weight there is a problem of strength strength .

Powder type polymer is preferably 1 to 10% by weight of the total composition, when less than 1% by weight, the adhesion and bonding strength is lowered, when it exceeds 10% by weight rather the strength is lowered, workability is lowered.

Water is preferably from 3 to 25% by weight of the total composition, when less than 3% by weight is not smoothly mixed due to fluidity decrease, when more than 25% by weight is improved fluidity, but the strength is lowered and the curing is late Occurs.

Hereinafter, the configuration of the present invention will be described in more detail with reference to the following examples. However, it will be apparent to those skilled in the art that the scope of the present invention is not limited only to the description of the embodiments.

Example 1

50% by weight of C ₂ S (Ca ₂ SiO ₄ ), 34% by weight of calcium sulfoaluminate (C ₄ A ₃ S), 10% by weight of C ₄ AF (4CaOAl ₂ O ₃ .Fe ₂ O ₃ ), CSH ( 4% by weight of Calcium silicate hydrate, 1% by weight of C ₃ S (Ca ₃ SiO ₅ ) and 1% by weight of C ₃ A (Ca ₃ Al ₂ O ₆ ) 18.3% by weight cement composition, 74.3% by weight aggregate, water 7.4 wt% was mixed to prepare a fast cement concrete composition.

Example 2

50% by weight of C ₂ S (Ca ₂ SiO ₄ ), 34% by weight of calcium sulfoaluminate (C ₄ A ₃ S), 10% by weight of C ₄ AF (4CaOAl ₂ O ₃ .Fe ₂ O ₃ ), CSH ( 4% by weight of Calcium silicate hydrate, 1% by weight of C ₃ S (Ca ₃ SiO ₅ ) and 1% by weight of C ₃ A (Ca ₃ Al ₂ O ₆ ), 19% by weight cement composition, 70.4% by weight aggregate, water 7.6% by weight, and 3% by weight of a reducing agent, a fast cement cement composition was prepared.

Example 3

50% by weight of C ₂ S (Ca ₂ SiO ₄ ), 34% by weight of calcium sulfoaluminate (C ₄ A ₃ S), 10% by weight of C ₄ AF (4CaOAl ₂ O ₃ .Fe ₂ O ₃ ), CSH ( 4% by weight of Calcium silicate hydrate, 1% by weight of C ₃ S (Ca ₃ SiO ₅ ) and 1% by weight of C ₃ A (Ca ₃ Al ₂ O ₆ ) 19.8% by weight cement composition, 69.4% by weight aggregate, water 7.8% by weight and 3% by weight of a reducing agent were mixed to prepare a fast cement concrete composition.

Comparative Example 1

As the aggregate, aggregate having the same weight percentage as in Examples 2 to 4 was used. A concrete composition was prepared by mixing 17.5% by weight, aggregate 73.3% by weight, 5.6% by weight of SBR latex, and 3.6% by weight of water with the same fast-hardening cement composition (manufactured by S Company) in the same mixing ratio described in Example 1.

Comparative Example 2

As the aggregate, aggregate having the same weight percentage as in Examples 2 to 4 was used. The concrete composition which mixed 20 weight% of fast cement compositions (made by domestic S company), 74 weight% of aggregates, and 6 weight% of water similar to the mixing ratio of the said Example 1 was manufactured.

Test pieces were prepared from the concrete compositions according to Examples 1 to 3 and Comparative Examples 1 and 2 and cured for 1-5 hours. The flexural and compressive strengths were measured, and the bond strengths were measured after 28 days of curing.

Adhesion strength was measured according to KS F 2762 (Adhesive Strength Test Method of Concrete Repair Repair).

In addition, the bending strength measured the bending strength of the specimen by KS F 2408 (test method of bending strength of concrete).

The compressive strength of the specimens was measured by KS F 4042 (Test method for compressive strength of concrete).

division Example 2 Example 3  Example 4 Comparative Example 1 Comparative Example 2 Compounding cost Aggregate (5 mm or less) (%) 74.3 70.4 69.4 73.3 74 Fast hard cement composition (%) 18.3 (invention) 19 (present invention) 19.8 (Invention) 17.5 (third party) 20 (third party) SBR Latex (%) - - - 5.6 - water(%) 7.4 7.6 7.8 3.6 6 Reducing Agent (%) - 3 3 - -  Test Items Flexural strength (N / ㎡) 40 or more 4-5 hours 28 days 45 or more 2.5 hours 2 hours 1 hours Compressive strength (N / ㎡) 210 or more 4-5 hours 28 days More than 240 2.5 hours 2 hours 1 hours Adhesive strength (N / mm2) 1.0 or higher 28 days 28 days Adhesive strength (N / mm2) 1.5 or more 28 days 28 days 28 days

Claims (7)

_{C 2 S (Ca 2 SiO 4} ) 45 ~ 55 % by weight, calcium sulfo aluminate _{(C 4 A 3 S) 30} ~ 40 _{weight%, C 4 AF (4CaO ·} Al 2 O 3 · Fe 2 O 3) 7 ~ 14 wt%, 4-11 wt% of calcium silicate hydrate (CSH), more than 0 wt% to 2 wt% of C ₃ S (Ca ₃ SiO ₅ ) and more than 0 wt% of C ₃ A (Ca ₃ Al ₂ O ₆ ) ~ 10 to 46% by weight of a hard cement composition comprising 3% by weight; 50-86 weight percent of aggregate; And Fast concrete composition comprising 3 to 25% by weight of water. _{C 2 S (Ca 2 SiO 4} ) 45 ~ 55 % by weight, calcium sulfo aluminate _{(C 4 A 3 S) 30} ~ 40 _{weight%, C 4 AF (4CaO ·} Al 2 O 3 · Fe 2 O 3) 7 ~ 14 wt%, 4-11 wt% of calcium silicate hydrate (CSH), more than 0 wt% to 2 wt% of C ₃ S (Ca ₃ SiO ₅ ) and more than 0 wt% of C ₃ A (Ca ₃ Al ₂ O ₆ ) ~ 10 to 46% by weight of a hard cement composition comprising 3% by weight; And Unit paving fast concrete composition comprising 54 to 90% by weight aggregate. The method according to claim 1 or 2, POLY EVA (Ethylene Vinyl Acetate) reemulsified powder resin, PVA-VeoVa (polyvinyl acetate-vinyl versalate) reemulsified powder resin, POLY SAE (styrene-acrylic ester) reemulsified type based on 100 parts by weight of the fast-hard concrete composition A fast-drying concrete composition, characterized in that it further comprises 1-10 parts by weight of at least one powdered polymer selected from powdered resin and PAE (polyacrylic ester) reemulsified powdered resin. The method according to claim 1 or 2, A fast-hardening concrete composition, characterized in that it further comprises at least one of a retarder, a water reducing agent, and an antifoaming agent. The method according to claim 1 or 2, Fast-hard concrete composition, characterized in that it further comprises SBR latex. Removing the fragile parts of the concrete pavement; Cleaning the concrete pavement from which the fragile portion has been removed; Maintaining a wet state of the cleaned vulnerable portion; Primer process for uniformly applying the concrete primer on the weak part of the wet state; Flatly laying the fast concrete composition of claim 1 on the primer-treated concrete pavement; The process of curing the laid fast concrete composition; Concrete pavement and structure repair method using a fast hard concrete composition comprising a. Removing the fragile parts of the concrete pavement; Cleaning the concrete pavement from which the fragile portion has been removed; Maintaining a wet state of the cleaned vulnerable portion; Primer process for uniformly applying the concrete primer on the weak part of the wet state; Flatly laying the fast concrete composition of claim 1 on the primer-treated concrete pavement; Curing the laid fast hard concrete composition; Spraying an epoxy primer for ascon on the curing surface; And Concrete pavement and structure repair method using a fast-hard concrete composition comprising the step of laying the epoxy asphalt concrete on the sprayed primer.