JP6254440B2 - Polymer cement grout material for submarine tunnel repair and repair method for submarine tunnel - Google Patents

Description

  The present invention relates to a polymer cement grout material for repairing a submarine tunnel and a repair method for a submarine tunnel.

  Undersea tunnels are prone to degradation because seawater penetrates the tunnel wall from the surroundings and oozes out into the tunnel. For this reason, submarine tunnels are frequently repaired. In particular, in the case of a road tunnel, the deterioration of the tunnel is more likely to proceed due to the acidic gas such as carbon dioxide in the exhaust gas discharged from the vehicle. Concrete such as reinforced concrete is used for the tunnel itself and the internal structure.

  If the reinforced concrete deteriorates, the concrete in the deteriorated part is removed to expose healthy concrete, and then the part removed with the concrete or repair mortar is reconstructed. Deteriorated part of reinforced concrete, that is, when the repair range is deep and wide, it becomes repair of a large cross section, and after assembling the formwork in the repaired part, inject grout material between the formwork and the exposed healthy concrete, Machine construction such as grout formwork injection is increasing.

  Repair mortar for concrete is required to have the ability to suppress the intrusion of deterioration factors such as carbon dioxide and chloride ions into the concrete structure and the adhesion to concrete. To obtain these performances, polymer cement Mortar is often used. As an example, a grout material made of a polymer cement mortar containing cement, a re-emulsifying powder resin of an acrylate copolymer, an expanding material, a powder drying shrinkage reducing agent, a dispersant, and an aggregate has been proposed (for example, Patent Document 1).

JP 2008-169085 A

  However, conventional repair mortars have the ability to suppress the ingress of deterioration factors such as carbon dioxide and chloride ions, and the high fluidity, material separation resistance and strength required for repair grout materials. However, the grout material described in Patent Document 1 also has an insufficient ability to suppress the intrusion of deterioration factors such as carbon dioxide and chloride ions.

  Accordingly, an object of the present invention is to provide a polymer cement grout material for repairing a submarine tunnel that has both performance as a repair mortar for repairing a submarine tunnel and performance as a grout material for repair. Another object of the present invention is to provide a repair method for a submarine tunnel that provides a highly durable submarine tunnel.

  Therefore, as a result of intensive studies for solving the above problems, the present inventor found that the above problems can be solved by including early-strength cement, water reducing agent, polymer dispersion and water together with the aggregate in a specific ratio, The present invention has been completed.

That is, the present invention provides the following [1] to [4].
[1] 1.0 to 2.0 parts by mass of water reducing agent, polymer dispersion is more than 10 parts by mass and 22 parts by mass or less, and water is 45 to 60 parts by mass with respect to 100 parts by mass of early-strength cement. And a polymer cement grout material for repairing submarine tunnels containing fine aggregates.
[2] The polymer cement grout material for repairing a submarine tunnel according to [1], comprising 80 to 350 parts by mass of fine aggregate with respect to 100 parts by mass of early-strength cement.
[3] The polymer cement grout material for repairing a submarine tunnel according to [1] or [2], wherein the polymer dispersion is a liquid polymer dispersion stabilized by emulsifying the polymer in water.
[4] (A) The process of removing the deteriorated concrete in the submarine tunnel and exposing the sound concrete,
(B) a step of installing a formwork on the front surface of the concrete surface exposed in the step (A),
as well as,
(C) A submarine tunnel including a step of filling the polymer cement grout material for repairing a submarine tunnel according to any one of [1] to [3] between a formwork installed in the step (B) and a concrete surface. Repair method.
[5] Furthermore,
(D) A step of applying a chloride ion penetration preventing material to the concrete surface exposed in the step (A),
And / or
(E) The step of applying a rust inhibitor to the concrete surface exposed in the step (A) and / or the reinforcing bar exposed in the step (A) is performed before the step (C). 4] The method for repairing a submarine tunnel according to the above.

  ADVANTAGE OF THE INVENTION According to this invention, the polymer cement grout material for seabed tunnel repair which has the performance as repair mortar for seabed tunnel repair, and the performance as a grout material for repair is obtained. According to the present invention, the ability to suppress the intrusion of deterioration factors such as carbon dioxide and chloride ions is high, the adhesion to concrete is high, the shrinkage is small, the compressive strength is high, the fluidity is high, and the material is separated. It is difficult to obtain polymer cement grout materials for repairing undersea tunnels. Further, according to the present invention, a highly durable submarine tunnel can be obtained.

  The polymer cement grout material for repairing submarine tunnels of the present invention is (a) 100 parts by mass of early-strength cement, (b) 0.5 to 2.0 parts by mass of water reducing agent, and (c) non-volatile polymer dispersion. It contains more than 10 parts by weight and 22 parts by weight or less, (d) 45-60 parts by weight of water, and (e) fine aggregate.

    As (a) early-strength cement in the present invention, early-strength Portland cement specified in JIS R 5210 “Portland cement” can be used.

  Examples of the water reducing agent (b) in the present invention include naphthalene sulfonic acid water reducing agents, lignin sulfonic acid water reducing agents, polycarboxylate water reducing agents, melamine sulfonic acid water reducing agents, and the like. Or 2 or more types can be used. The (b) water reducing agent in the present invention includes a water reducing agent, an AE water reducing agent, a high performance water reducing agent, a high performance AE water reducing agent, and a fluidizing agent, and is a cement dispersant. In these, since a high fluidity | liquidity and high intensity | strength are easy to be obtained, a high performance water reducing agent is preferable. Moreover, a water reducing agent shall be 0.5-2.0 mass parts with respect to 100 mass parts of cement. If it is less than 0.5 part by mass, the effect of the water reducing agent is poor, and the consistency is remarkably lowered. If it exceeds 2.0 parts by mass, material separation tends to occur. Since it is easy to obtain high fluidity without causing material separation, the water reducing agent is preferably 1.0 to 2.0 parts by mass, and 1.0 to 1.7 parts by mass with respect to 100 parts by mass of cement. More preferably.

  As the (c) polymer dispersion in the present invention, any of those usually used in polymer cement mortars can be used. Acrylic resins, styrene / acrylic copolymer resins, styrene / butadiene copolymer resins, Examples thereof include vinyl acetate resins, vinyl acetate / veova copolymer resins, methyl methacrylate / butadiene copolymer resins, polyvinyl alcohol resins, and polymer dispersions of these modified resins. The modified resin refers to, for example, a resin modified with carboxyl, epoxy, or silicon. The polymer dispersion may be a liquid that is stabilized by emulsifying the resin in water, or a powder (re-emulsifying powder resin) as long as it is re-emulsified with water. More than one species may be used in combination. Since the polymer dispersion used in the present invention has a high ability to suppress the ingress of deterioration factors such as carbon dioxide and chloride ions, among the above polymer dispersions, a liquid emulsified and stabilized in water In particular, a polymer dispersion mainly composed of a styrene / butadiene copolymer resin is preferred. The re-emulsification type powder resin needs a larger amount in order to suppress the intrusion of deterioration factors by the re-emulsifier such as polyvinyl alcohol contained therein. Then, the viscosity of the polymer cement grout material becomes high and it becomes difficult to use it as a grout material.

  In the present invention, the amount of (c) polymer dispersion in the submarine tunnel repair polymer cement grout material is more than 10 parts by mass and less than 22 parts by mass in terms of the amount of non-volatile components with respect to 100 parts by mass of cement. If it is 10 parts by mass or less, the permeation suppressing effect of deterioration factors such as acid gas and chloride ions is poor, and if it exceeds 22 parts by mass, the fluidity as a grout material decreases. A more preferable amount of the polymer dispersion is 10.1 to 21 parts by mass in terms of nonvolatile components with respect to 100 parts by mass of cement.

  In the present invention, the amount of (d) water in the polymer cement grout material for submarine tunnel repair is 45 to 60 parts by mass with respect to 100 parts by mass of cement. If it is less than 45 parts by mass, it is difficult to ensure the fluidity required for mold injection, and if it exceeds 60 parts by mass, deterioration factors such as carbon dioxide and chloride ions are likely to penetrate. Despite the high fluidity, the material separation resistance is high and the deterioration factor is difficult to penetrate. Therefore, the amount of water in the polymer cement grout material for submarine tunnel repair is 45 to 56 parts by mass with respect to 100 parts by mass of cement. It is preferable to do. The amount of water in the present invention also takes into account the amount of water contained in the aqueous liquid admixture when an aqueous liquid admixture (for example, an admixture aqueous solution or a liquid polymer dispersion) is added.

  The (e) fine aggregate in the present invention is not particularly limited, and for example, river sand, land sand, sea sand, crushed sand, quartz sand, artificial fine aggregate, slag fine aggregate and the like can be used. You may use the above together. In the present invention, it is preferable that the fine aggregate is 80 to 350 parts by mass with respect to 100 parts by mass of the cement because drying shrinkage is small and material separation is difficult while obtaining high fluidity, and more preferably 100 to 300 parts by mass. Part.

  The polymer cement grout material for repairing submarine tunnels of the present invention includes one or more selected from other cements, admixtures and aggregates in addition to early-strength cement, water reducing agent, polymer dispersion, water and fine aggregate. Can be used in combination as long as the effects of the present invention are not substantially impaired. Examples of the admixture include a thickener, an expansion material, a waterproofing material, a rust prevention agent, a shrinkage reducing agent, a water retention agent, a pigment, a fiber, a water repellent, a whitening prevention agent, a quick setting agent (material), and a rapid hardening. Examples thereof include agents (materials), setting retarders, foaming agents, antifoaming agents, fine powder of blast furnace slag, pozzolanic substances, water repellents, and surface hardeners. Examples of the aggregate include river gravel, land gravel, crushed stone, lightweight coarse aggregate, artificial coarse aggregate, and the like.

The repair method of the submarine tunnel of the present invention is:
(A) The process of removing the deteriorated concrete in the submarine tunnel and exposing the healthy concrete,
(B) a step of installing a formwork on the front surface of the concrete surface exposed in the step (A),
as well as,
(C) A step of filling the polymer cement grout material for repairing a submarine tunnel between the formwork and the concrete surface installed in the step (B) is included.

  In the step (A), the method for removing the deteriorated concrete is not particularly limited. Suitable removal methods include cutting with a diamond cutter or wire saw, scraping with a concrete breaker such as a concrete hammer, filling holes or grooves in a deteriorated concrete surface with a crushing agent such as a static crushing agent. A method of crushing with generated pressure, a method of crushing wedges or the like into holes or grooves provided in deteriorated concrete surfaces, a method of scraping with a road surface cutting machine or a pavement surface cutting machine, a blasting material such as sand blasting Examples include a method of scraping and scraping against a deteriorated concrete surface, a method of cutting or scraping using a water jet, or a method of using two or more of these in combination.

  Examples of the method for confirming whether the exposed concrete is healthy include, for example, a method for visually confirming, a method for confirming by hammering with a hand hammer or a concrete breaker, a method using a tester such as a Schmitt hammer, a phenolphthalein solution. A method of confirming the ion concentration in the exposed concrete by applying a reagent such as a method, a method of measuring the concentration of ions that are chemically or physically contained in a portion of the exposed concrete, and two or more of these You may confirm using together.

  In the step (B), the method of installing the formwork on the front surface of the concrete surface exposed in the step (A) and the material to be used are not particularly limited, and are used for formwork injection of general grout materials. Methods and materials can be used. In this step (B), it is preferable that the gap between the exposed concrete surface and the formwork is 1 to 20 cm because the integrity between the concrete and the polymer cement grout material is good and easy to fill, and further 2 10 cm is more preferable. If it is less than 1 cm, it is difficult to fill, and cracking or peeling due to drying shrinkage may occur unless sufficient care is taken after curing. On the other hand, if it exceeds 20 cm, heat generation increases and the possibility of thermal cracking increases.

  In the step (C), the method and equipment for filling the above-mentioned polymer cement grout material for repairing a submarine tunnel between the formwork and the concrete surface installed in the step (B) are not particularly limited, and a general grout The methods and equipment used for material form injection can be used. The grout material can be kneaded using, for example, a commercially available grout mixer or a hand mixer using a pail. As a filling method, for example, an air bleeding hose may be installed and filled with a hand pump, an electric squeeze pump, a snake pump, or the like.

In the submarine tunnel repair method of the present invention, in addition to the steps (A), (B) and (C),
(D) A step of applying a chloride ion penetration preventing material to the concrete surface exposed in the step (A),
And / or
(E) It is preferable to perform the step of applying a rust inhibitor on the concrete surface exposed in the step (A) and / or the reinforcing bar exposed in the step (A) before the step (C). The step (D) and the step (E) may be performed after the step (A) and before the step (C), and may be performed before or after the step (B). However, since it is easy to apply a chloride ion permeation preventive material or a rust preventive agent, it is preferably performed before the step (B). Moreover, when performing both a process (D) and a process (E), you may perform any of a process (D) and a process (E) previously, but the rust prevention agent exposed in the process (A) It is preferable to perform the step (E) before the step (D) because the rust preventive agent easily reaches the reinforcing bars inside the exposed concrete surface by diffusion.

  Examples of the chloride ion penetration preventing material used in the step (D) include polyurethane resins, polyurea resins, acrylic resins, acrylic urethane resins, acrylic silicon resins, silicone resins, epoxy resins, styrene / butadiene. Polymer dispersions such as rubber and fluororesins; Alkali silicate aqueous solutions such as lithium silicate aqueous solutions; Silane compounds such as alkylalkoxysilanes and polyorganosiloxanes; Waterproof coatings such as solvent-based paints, polymer cement pastes, polymer cement mortars, and paraffin emulsions Materials: Adhesives such as epoxy adhesives; colloidal silica and the like can be mentioned as suitable materials, and two or more of these may be used in combination. The chloride ion permeation preventive material used in the step (D) includes amines such as tertiary amines, nitrites such as calcium nitrite and lithium nitrite, phosphates, chromates, organophosphates, esters. It may contain a rust inhibitor such as a salt, organic acid, sulfonic acid, alkylphenol, mercaptan, or nitro compound. In addition, the method for applying the chloride ion permeation preventive material to the exposed concrete surface is not particularly limited, for example, a method using a brush, scissors, sponge, etc., a spraying method using a sprayer, a method using a sprinkler, etc. And a cement paste containing the chloride ion permeation preventive material, a method of applying mortar, and the like.

  Examples of the rust inhibitor used in the step (E) include amines such as tertiary amines, nitrites such as calcium nitrite and lithium nitrite, phosphates, chromates, organic phosphates, and ester salts. Organic acids, sulfonic acids, alkylphenols, mercaptans, nitro compounds and the like are preferable, and two or more of these may be used in combination. Moreover, it does not specifically limit as a method of apply | coating to the concrete surface which exposed the rust preventive agent, or the reinforcing bar exposed at the process (A), For example, the method using a brush, a wrinkle, sponge etc., spraying with a sprayer, watering, etc. Examples of suitable methods include a method of pouring using rust, a cement paste containing the above rust inhibitor, and a method of applying mortar.

  In the above step (A), when the deteriorated concrete is removed, if the exposed reinforcing bar is severely damaged due to corrosion or the like, it is preferable to perform a step of replacing the reinforcing bar (step F). At this time, the concrete is further removed until the healthy reinforcing bar is exposed, the deteriorated reinforcing bar is removed by cutting, and the new reinforcing bar and the healthy reinforcing bar are joined. This joining method is preferably by welding, fastening with a fastener, or binding with a wire or the like.

  Moreover, after the said process (C), it is preferable to provide the process of forming a surface coating material in the surface of the repair mortar for repairing a submarine tunnel, since the penetration | invasion of a deterioration factor can be suppressed. Examples of the surface coating material used at this time include polyurethane resins, polyurea resins, acrylic resins, acrylic urethane resins, acrylic silicon resins, silicone resins, epoxy resins, styrene / butadiene rubbers, fluorine resins, and the like. It is mentioned as a suitable thing and you may use these 2 or more types together. These resins are preferably used in the form of polymer dispersion such as emulsion paint, solvent paint, polymer cement paste, polymer cement mortar and the like.

  Examples of the present invention will be described below together with comparative examples, but the present invention is not limited to the examples.

[Example 1]
A grout composition of 285 parts by mass of fine aggregate and 1.6 parts by mass of a water reducing agent was produced with respect to 100 parts by mass of early strong cement. A polymer dispersion and water (added water) were added to the grout composition at a mass ratio shown in Table 1, and then kneaded with a hand mixer for 90 seconds to produce a polymer cement grout material. Each polymer cement grout material is kneaded with a hand mixer for 90 seconds, and then evaluated for fluidity, flow, material separation resistance, compressive strength, adhesive strength, length change, neutralization depth, and chloride ion penetration depth. Went. The ambient temperature (test room temperature and material temperature before kneading) was 20 ° C. In addition, tests were conducted in the same manner except for some tests using a commercially available mortar containing powder resin. The test results are shown in Tables 1 and 2.

(Materials used)
-Early strength cement: Early strength Portland cement (manufactured by Taiheiyo Cement Co., Ltd., commercial product)
Water reducing agent: Naphthalenesulfonic acid powder high-performance water reducing agent (product name “Mighty 100” manufactured by Kao Corporation)
Fine aggregate: Limestone sand (FM: 2.92, 30% by mass remaining on 1.2 mm sieve) and quartz sand (FM: 1.56, 50% by mass remaining on 0.3 mm sieve) ) Ratio of 1: 1 (mass ratio) mixed sand / polymer dispersion: polymer dispersion mainly composed of styrene butadiene copolymer resin (manufactured by Taiheiyo Materials Co., Ltd., commercial product, non-volatile component: water = 36: 64 mass proportion polymer dispersion)
・ Additional water: tap water (Sakura city water), water added at the time of polymer cement mortar production ・ Repair mortar containing powder resin for commercial products: Polymer cement mortar for iron coating mixed with polyacrylic ester powder polymer (commercial product)

(Test method)
1) complies with the fluidity test Civil Engineers standards JSCE-F 541-2010 "Test Method of Flowability for Filling Mortar", was measured efflux time with J ₁₄ funnel immediately after kneading.
2) Flow test JIS R 5201 “Physical test method of cement” Using the flow cone defined in the flow test, the flow value after removal of the flow cone (no drop motion) was measured.
3) Material separation resistance test The prepared grout was put into a 2 liter poly beaker, and it was judged by checking whether or not aggregates were accumulated in the bottom part of the poly beaker by tactile sensation by hand. The material with fine aggregate settled and collected at the bottom of the poly beaker was designated as “Material Separation: X”, and the material with no aggregate accumulated was designated as “Good: ○”.
4) Compressive strength Based on JIS A 1171 "Test method of polymer cement mortar", the compressive strength (compressive strength) at the age of 28 days was measured.
5) Adhesive strength In accordance with JIS A 1171 “Testing method for polymer cement mortar”, the adhesive strength (adhesive strength) at the age of 28 days was measured.
6) Rate of change in length Based on JIS A 1171 “Testing method for polymer cement mortar”, the rate of change in length on the 28th day after the base length was measured.
7) Depth of neutralization According to JIS A 1171 “Test method for polymer cement mortar”, after pre-curing for 28 days, humidity 30 ± 2 ° C., relative humidity 60 ± 10%, carbon dioxide concentration 5.0 % Neutralization depth after standing in a carbon dioxide environment tank for 28 days.
8) Chloride ion penetration depth According to JIS A 1171 “Testing method for polymer cement mortar”, after pre-curing for 28 days, JIS A 6205 Annex 1 (Reinforcing salt water immersion test method) The chloride ion penetration depth after immersion in a salt solution specified in 2.1 (salt solution) for 28 days was measured.

  As can be seen from Table 1, none of the polymer cement grout materials according to the examples of the present invention exhibited high fluidity without clogging in the fluidity test without material separation. Further, as can be seen from Table 2, the polymer cement grout materials according to the examples of the present invention all have a neutralization depth and a chloride ion penetration depth of 0.0 mm, and deterioration factors (carbon dioxide and chloride ions). It did not penetrate to the extent that it could be measured and had high resistance to degradation factors. In addition, the increase in the amount of polymer dispersion added improved the adhesion strength and increased the rate of change in length (ie, reduced shrinkage). Since the polymer cement grout material according to the embodiment of the present invention has sufficiently high adhesion strength and compressive strength and a large rate of change in length (ie, small shrinkage), it has the performance as a repair mortar for submarine tunnel repair. It had enough performance as a grout material for repair.

[Example 2]
Except that the amount of the water reducing agent was changed as shown in Table 3, the experiment No. A grout composition was prepared in the same manner as in 1-4, 49 parts by mass of polymer dispersion and 17 parts by mass of water were added, and fluidity, flow, and material separation resistance were evaluated. The ambient temperature (test room temperature and material temperature before kneading) was 20 ° C. The test results are shown in Experiment No. 1 of Example 1. The results are shown in Table 3 together with 1-4.

As can be seen from Table 3, none of the polymer cement grout materials according to the examples of the present invention exhibited a high fluidity without being clogged in the fluidity test without being separated. Further, by increasing the addition amount of the water-reducing agent, although J ₁₄ funnel flow time is increased, and the material separated the amount of the water reducing agent with respect to 100 parts by weight cement exceeds 2.0 parts by weight.

  The submarine tunnel repair polymer cement grout material and the submarine tunnel repair method of the present invention can be suitably applied to repair of concrete submarine tunnels.

Claims (5)

1.0 to 2.0 parts by mass of water reducing agent, 10 to 22 parts by mass of non-volatile component, and 45 to 60 parts by mass of water and fine bone with respect to 100 parts by mass of early cement Polymer cement grout material for repairing submarine tunnels that contains wood.   The polymer cement grout material for repairing a submarine tunnel according to claim 1, comprising 80 to 350 parts by mass of fine aggregate with respect to 100 parts by mass of early strong cement.   The polymer cement grout material for repairing a submarine tunnel according to claim 1 or 2, wherein the polymer dispersion is a liquid polymer dispersion stabilized by emulsifying the polymer in water. (A) The process of removing the deteriorated concrete in the submarine tunnel and exposing the healthy concrete,
(B) a step of installing a formwork on the front surface of the concrete surface exposed in the step (A),
as well as,
(C) Repair of a submarine tunnel including a step of filling a polymer cement grout material for repairing a submarine tunnel according to any one of claims 1 to 3 between a formwork and a concrete surface installed in the step (B). Method. Furthermore,
(D) A step of applying a chloride ion penetration preventing material to the concrete surface exposed in the step (A),
And / or
(E) The step of applying a rust inhibitor to the concrete surface exposed in the step (A) and / or the reinforcing bar exposed in the step (A) is performed before the step (C). Item 5. Repair method for submarine tunnel according to item 4.