Construction method of rapid repairing material prepared from concrete waste in expansion joint anchoring area

Abstract

The invention discloses a construction method of a quick repair material prepared from concrete waste in an expansion joint anchoring area, which comprises the following steps: firstly, preparing powder and crushing concrete chiseled off on site by using a crusher to obtain fine waste with the particle size of less than or equal to 2.36 mm and 2.36 mlt; the particle size of the coarse waste is smaller than or equal to 25 mm; uniformly mixing the powder with a certain amount of fine waste and water-borne epoxy resin modified graphene oxide, adding a curing agent and water, uniformly mixing, and pouring into the chiseled working surface of the anchoring area of the expansion joint to fill the hole; uniformly mixing the powder with a certain amount of coarse waste and waterborne epoxy resin modified graphene oxide, adding a curing agent, the powder and water, uniformly mixing, pouring into a working surface, vibrating, finishing the surface, and performing microwave curing for 40-60 minutes. According to the construction method of the rapid repairing material, the plugging material and the concrete in the anchoring area are formed respectively, so that the cracking resistance and the impact resistance of the rapid repairing material are improved, the interface bonding strength and toughness of the rapid repairing material and the anchoring area of the bridge expansion joint to be repaired are improved, and the maintenance time is short.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of rapid repair material, and particularly relates to a construction method of rapid repair material prepared by using concrete waste in an anchoring area of expansion joint. BACKGROUND

[0002] The concrete in the anchoring area of expansion joint of a bridge is prone to damage phenomena such as cracking, net cracking, peeling and the like due to long-term exposure to air, a harsh use environment and repeated impact of load, and peeling of the concrete from the main beam structure and the bridge deck pavement layer. In addition, the repair time is relatively long, and repeated damage often occurs after repair. Therefore, the repair of the concrete in the anchoring area of expansion joint of a bridge has been a difficult problem to be solved.

[0003] At present, common repair technologies for the anchoring area of expansion joint of a bridge mainly include ordinary concrete repair, fast-hardening cement concrete repair and modified asphalt mixture repair. The ordinary concrete has a long maintenance period, so that the repair of the expansion joint of a bridge is slow, which not only prolongs the road closure period, but also affects vehicle traffic, and has a negative impact on highway operation. The fast-hardening cement concrete has excellent early strength, but has deficiencies in late strength, durability, elasticity and impact resistance and the like, and is prone to secondary cracking and damage after repair in a short period. The modified asphalt mixture has a complex construction process and needs to use high-temperature mixing equipment, and thus is not suitable for rapid road repair tasks. The epoxy resin concrete has fast early strength growth, good elasticity and impact resistance, but has high price and poor aging resistance. Therefore, the daily maintenance and repair work of the anchoring area of expansion joint of a bridge has become a big problem faced by a traffic construction management department.

[0004] Therefore, it is an inevitable trend to solve the defects such as slow opening of traffic, long maintenance time, easy cracking and poor durability of the existing repair material, and to solve the problem of on-site concrete waste. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a construction method of repair material with short maintenance time, anti-cracking, strong impact resistance and high interface bonding strength with the anchoring area of expansion joint of a bridge to be repaired.

[0006] The construction method of rapid repair material prepared by using concrete waste in the anchoring area of expansion joint, and the construction method comprises the following steps:

[0007] (1) preparing a powder: uniformly mixing portland cement, sulphoaluminate cement, finely ground sand, an additive, steel fiber, quartz sand and an additional functional agent for use;

[0008] (2) Preparation of waste materials: the on-site chiseled concrete is crushed by a crusher to obtain fine waste materials with a particle size of ≤2.36 mm and coarse waste materials with a particle size of 2.36 mm≤particle size≤25 mm;

[0009] (3) Preparation of plugging material: the prepared powder and fine waste materials are weighed in a mass ratio of (1-1.2):1, water-based epoxy resin modified graphene oxide accounting for 2.5%-4% of the total mass of the powder and fine waste materials is added for mixing, a curing agent accounting for 1%-1.5% of the water-based epoxy resin is added, and water accounting for 7%-8% of the total mass of the powder and fine waste materials is added, and after uniform mixing, the mixture is poured into the chiseled expansion joint anchoring area working surface to fill the holes;

[0010] (4) Preparation of anchoring area concrete: the prepared powder and coarse waste materials are weighed in a mass ratio of (1.5-1.8):1, water-based epoxy resin modified graphene oxide accounting for 2.5%-4% of the total mass of the powder and coarse waste materials is added for mixing, a curing agent accounting for 1%-1.5% of the water-based epoxy resin is added, and water accounting for 9%-10% of the total mass of the powder and coarse waste materials is added, and after uniform mixing, the mixture is poured into the working surface, vibrated, leveled, and microwave cured for 40-60 min.

[0011] Based on the chiseled bridge expansion joint anchoring area concrete, the present application forms fine waste materials and coarse waste materials by crushing, and forms main repair materials composed of coarse waste materials and powder, and plugging materials composed of fine waste materials and powder, and uses water-based epoxy resin wrapped modified graphene oxide in both, which realizes the uniform dispersion of the graphene oxide in the main repair materials and the plugging materials by the water-based epoxy resin, and at the same time, the microwave wave absorption and heating effect of the graphene oxide promotes the hydration reaction rate of the repair materials, promotes the coagulation of the repair materials, promotes the curing of the water-based epoxy resin, improves the bonding strength of the repair materials, and improves the bonding strength and toughness of the repair materials with the bridge expansion joint anchoring area concrete and asphalt, and improves the anti-cracking and impact resistance.

[0012] In addition, based on the water-based epoxy resin wrapped modified graphene oxide, the present application can improve the strength by adding a small amount of water-based epoxy resin, which reduces the cost, and improves the strength of the repair materials by the graphene oxide, which makes up for the strength damage caused by the aging of the water-based epoxy resin.

[0013] Further, in step (1) of the construction method of the rapid repair material, the silicate cement is 7-9 parts, the sulphoaluminate cement is 41 parts-46 parts, the ground sand is 13 parts-16 parts, the additive is 0.12 parts-0.15 parts, the steel fiber is 4 parts-7 parts, the quartz sand is 20 parts-24 parts, and the functional additive is 3 parts-5 parts.

[0014] Furthermore, in step (3) of the construction method of the rapid repair material of the present invention, the waterborne epoxy resin modified graphene oxide is prepared by the following steps: adding graphene oxide into the waterborne epoxy resin and stirring to disperse it evenly; the amount of graphene oxide added is 10%-12% of the mass of the waterborne epoxy resin.

[0015] Preferably, the silicate cement used in the construction method of the rapid repair material of the present invention has a strength grade of not less than 52.5, and the sulfoaluminate cement is a 42.5 grade low-alkalinity sulfoaluminate cement. The fine sand is made by grinding concrete waste to a specific surface area ≥ 300 m². 2 / kg of waste. The admixture is a mixture of polycarboxylate superplasticizer and tartaric acid in a mass ratio of (1-2):1. Or the admixture is a mixture of polycarboxylate superplasticizer and boric acid in a mass ratio of (1-2):1. Functional admixtures include 18-22 parts calcium formate, 50-60 parts sodium sulfate, and 8-12 parts calcium stearate. The curing agent is selected from ethylenediamine, diethylenetriamine, or m-phenylenediamine.

[0016] Beneficial effects: Compared with the prior art, the significant advantages of the present invention are: the construction method of the rapid repair material improves its crack resistance and impact resistance by forming sealing material and anchorage zone concrete separately, while improving the interface bonding strength and toughness with the anchorage zone of the bridge expansion joint to be repaired, and the curing time is short, only 40min-60min. Detailed Implementation

[0017] The technical solution of the present invention will be further described in detail below with reference to the embodiments.

[0018] In the following embodiments of the present invention, the silicate cement used has a strength grade of not less than 52.5, and the sulfoaluminate cement is a 42.5 grade low-alkalinity sulfoaluminate cement. The fine sand is prepared by grinding concrete waste to a specific surface area ≥300 m². 2 / kg of waste.

[0019] In the following embodiments of the present invention, the waterborne epoxy resin modified graphene oxide is prepared by the following steps: adding graphene oxide to the waterborne epoxy resin and stirring to disperse it evenly; the amount of graphene oxide added is 10% of the mass of the waterborne epoxy resin.

[0020] Example 1

[0021] The component contents of the powder used in Example 1 are shown in Table 1 below. The functional additives include 20 parts calcium formate, 55 parts sodium sulfate, and 10 parts calcium stearate.

[0022] Table 1. Component content of the powder in Example 1

[0023]

[0024] This embodiment describes a construction method for a rapid repair material prepared from concrete waste in the expansion joint anchorage zone, comprising the following steps:

[0025] (1) Preparation of powder: Silicate cement, sulfoaluminate cement, fine sand, admixture, steel fiber, quartz sand and admixture functional agent are mixed evenly and set aside for use;

[0026] (2) Preparation of waste materials: The concrete removed on site is crushed by a crusher to obtain fine waste materials with a particle size ≤ 2.36 mm and coarse waste materials with a particle size ≤ 25 mm.

[0027] (3) Preparation of sealing material: Weigh the prepared powder and fine waste at a ratio of 1:1, add 3% waterborne epoxy resin modified graphene oxide of the total mass of powder and fine waste and mix evenly, then add 1% waterborne epoxy resin curing agent ethylenediamine and 7% water of the total mass of powder and fine waste, mix evenly and pour into the working surface of the excavated expansion joint anchoring area to fill the hole. The setting time is 12 minutes.

[0028] (4) Preparation of anchorage zone concrete: Weigh the prepared powder and coarse waste at a ratio of 1.5:1, add 3% water-based epoxy resin modified graphene oxide (based on the total mass of powder and coarse waste) and mix evenly, then add 1% ethylenediamine curing agent (based on the total mass of water-based epoxy resin) and 9% water (based on the total mass of powder and coarse waste), mix evenly and pour into the working surface, vibrate and finish, and then microwave cure for 50 minutes. The microwave power is 12kW / m. 2 .

[0029] Comparative Example 1

[0030] The basic raw materials and steps are the same as in Example 1. The difference is that, under the same conditions as in Example 1, graphene oxide and waterborne epoxy resin are added directly and independently to the sealing material and the concrete for the anchoring zone without prior modification.

[0031] Comparative Example 2

[0032] The basic raw materials and steps are the same as in Example 1, except that natural curing for 2 hours is used.

[0033] Example 2

[0034] The component contents of the powder used in Example 2 are shown in Table 2 below. The functional additives include 18 parts calcium formate, 50 parts sodium sulfate, and 8 parts calcium stearate.

[0035] Table 2. Component content of the powder in Example 2

[0036]

[0037] This embodiment describes a construction method for a rapid repair material prepared from concrete waste in the expansion joint anchorage zone, comprising the following steps:

[0038] (1) Preparation of powder: Silicate cement, sulfoaluminate cement, fine sand, admixture, fiber, quartz sand and admixture functional agent are mixed evenly and set aside for use;

[0039] (2) Preparation of waste materials: The concrete removed on site is crushed by a crusher to obtain fine waste materials with a particle size ≤ 2.36 mm and coarse waste materials with a particle size ≤ 25 mm.

[0040] (3) Preparation of sealing material: Weigh the prepared powder and fine waste at a ratio of 1.2:1, add 2.5% waterborne epoxy resin modified graphene oxide of the total mass of powder and fine waste and mix evenly, then add 1.5% curing agent ethylenediamine of waterborne epoxy resin and 8% water of the total mass of powder and fine waste, mix evenly and pour into the working surface of the excavated expansion joint anchoring area to fill the hole. The setting time is 10 minutes.

[0041] (4) Preparation of anchorage zone concrete: Weigh the prepared powder and coarse waste at a ratio of 1.8:1, add 2.5% water-based epoxy resin modified graphene oxide (based on the total mass of powder and coarse waste) and mix evenly, then add 1.5% ethylenediamine curing agent (based on the total mass of water-based epoxy resin) and 10% water (based on the total mass of powder and coarse waste), mix evenly and pour into the working surface, vibrate and finish, and then microwave cure for 40 minutes. The microwave power is 15kW / m. 2 .

[0042] Comparative Example 3

[0043] The basic raw materials and steps are the same as in Example 2. The difference is that, under the same conditions as in Example 2, graphene oxide and waterborne epoxy resin are added directly and independently to the sealing material and the concrete for the anchoring zone without prior modification.

[0044] Comparative Example 4

[0045] The basic raw materials and steps are the same as in Example 2, except that natural curing for 2 hours is used.

[0046] Example 3

[0047] The component contents of the powder used in Example 3 are shown in Table 3 below. The functional additives include 22 parts calcium formate, 60 parts sodium sulfate, and 12 parts calcium stearate.

[0048] Table 3. Component content of the powder in Example 3

[0049]

[0050] This embodiment describes a construction method for a rapid repair material prepared from concrete waste in the expansion joint anchorage zone, comprising the following steps:

[0051] (1) Preparation of powder: Silicate cement, sulfoaluminate cement, fine sand, admixture, fiber, quartz sand and admixture functional agent are mixed evenly and set aside for use;

[0052] (2) Preparation of waste materials: The concrete removed on site is crushed by a crusher to obtain fine waste materials with a particle size ≤ 2.36 mm and coarse waste materials with a particle size ≤ 25 mm.

[0053] (3) Preparation of sealing material: Weigh the prepared powder and fine waste at a ratio of 1.1:1, add 4% waterborne epoxy resin modified graphene oxide of the total mass of powder and fine waste, mix evenly, add 1.5% curing agent ethylenediamine of waterborne epoxy resin and 8% water of the total mass of powder and fine waste, mix evenly and pour into the working surface of the excavated expansion joint anchoring area, solidify to fill the hole, solidification time is 15min;

[0054] (4) Preparation of anchorage zone concrete: Weigh the prepared powder and coarse waste at a ratio of 1.7:1, add 4% water-based epoxy resin modified graphene oxide (based on the total mass of powder and coarse waste) and mix evenly, then add 1.5% ethylenediamine curing agent (based on the total mass of water-based epoxy resin) and 10% water (based on the total mass of powder and coarse waste), mix evenly and pour into the working surface, vibrate and finish, and then microwave cure for 60 minutes. The microwave power is 10kW / m. 2 .

[0055] Performance testing

[0056] The repair materials of Examples 1-3 and Comparative Examples 1-4 were prepared into test specimens to determine the flexural strength and compressive strength of the specimens. The test specimens were also prepared by combining the repair materials with the concrete in the anchorage zone to determine the bond strength between the sealing repair materials and the concrete. The results are shown in Table 4 below.

[0057] Table 4 Performance test data of Examples 1-3 and Comparative Examples 1-4

[0058]

[0059] As shown in Table 4, compared to Comparative Examples 2 and 4, the repair material of the present invention, utilizing microwaves, can effectively shorten the curing time. Furthermore, compared to Comparative Examples 1 and 3, the repair material of the present invention, by pre-modifying graphene oxide with water-based epoxy resin, achieves uniform dispersion of graphene oxide in the main repair material and sealing material. Simultaneously, the microwave absorption and heating effect of graphene oxide promotes the hydration reaction rate of the uniformly dispersed graphene oxide surrounding the repair material, thus accelerating the overall hydration reaction rate of the repair material. It also promotes the curing of the water-based epoxy resin surrounding the uniformly dispersed graphene oxide. This results in higher flexural and compressive strength, as well as higher bonding strength with the concrete and asphalt in the anchoring area to be repaired, under the same curing time conditions, achieving early strength under short curing conditions.

[0060] In addition to the above embodiments, the construction steps and defined parameters of the repair material of the present invention can achieve the above-mentioned technical effects, so no specific tests are required to verify them.

Claims

1. A method of constructing a rapid repair material made from concrete waste of a joint anchorage zone, characterized in that, It comprises the following steps: (1) preparing powder: mixing silicate cement, sulphoaluminate cement, finely ground sand, additive, steel fiber, quartz sand and functional additive uniformly for use; (2) preparing waste material: the on-site chiseled concrete is crushed by a crusher to obtain fine waste material with a particle size of ≤2.36 mm and coarse waste material with a particle size of 2.36 mm≤particle size≤25 mm; (3) preparing plugging material: the prepared powder and fine waste material are weighed in a mass ratio of (1-1.2):1, 2.5%-4% of water-based epoxy resin modified graphene oxide is added to the powder and fine waste material, and then mixed uniformly, 1%-1.5% of a curing agent is added to the water-based epoxy resin, and 7%-8% of water is added to the total mass of the powder and fine waste material, and then mixed uniformly, and then poured into the chiseled expansion joint anchoring area working surface to fill the holes; (4) preparing anchoring area concrete: the prepared powder and coarse waste material are weighed in a mass ratio of (1.5-1.8):1, 2.5%-4% of water-based epoxy resin modified graphene oxide is added to the powder and coarse waste material, and then mixed uniformly, 1%-1.5% of a curing agent is added to the water-based epoxy resin, and 9%-10% of water is added to the total mass of the powder and coarse waste material, and then mixed uniformly, and then poured into the working surface, vibrated, and then leveled, and then microwave cured for 40 min-60 min.

2. The construction method of the rapid repair material according to claim 1, characterized by, In step (1), the silicate cement is 7-9 parts, the sulphoaluminate cement is 41-46 parts, the finely ground sand is 13-16 parts, the additive is 0.12-0.15 parts, the steel fiber is 4-7 parts, the quartz sand is 20-24 parts, and the functional additive is 3-5 parts.

3. The method of claim 1, wherein the quick repair material is applied by spraying. In step (3), the water-based epoxy resin modified graphene oxide is prepared by the following steps: adding graphene oxide to water-based epoxy resin, and then stirring and dispersing uniformly; the addition amount of graphene oxide is 10-12% of the mass of water-based epoxy resin.

4. The method of claim 1, wherein the quick repair material is applied by spraying. The strength grade of the silicate cement is not less than 52.5 grade, and the sulphoaluminate cement is 42.5 grade low alkalinity sulphoaluminate cement.

5. The method of claim 1, wherein the quick repair material is applied by spraying. The ground sand is waste material chipped from concrete ground to a specific surface area of > 300 m 2 / kg.

6. The construction method of the rapid repair material according to claim 1 or 2, characterized by, The additive is a mixture of polycarboxylic acid water reducer and tartaric acid in a mass ratio of (1-2):

1.

7. The construction method of the rapid repair material according to claim 1 or 2, characterized by, The additive is a mixture of polycarboxylic acid water reducer and boric acid in a mass ratio of (1-2):

1.

8. The construction method of the rapid repair material according to claim 1 or 2, characterized by, The functional additive comprises calcium formate 18-22 parts, sodium sulfate 50-60 parts, and calcium stearate 8-12 parts.

9. The method of applying the rapid repair material of claim 1, wherein, The curing agent is selected from ethylenediamine, diethylenetriamine or m-phenylenediamine.

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