CN107299577A - A kind of method for blocking cement concrete pavement of aerodrome crack - Google Patents

Abstract

The invention discloses a method for sealing the cracks on the cement concrete pavement of an airport. Firstly, liquid nitrogen is slowly injected into the cracks along the expanding direction of the cracks until the cracks are filled, and the cracks are cleaned by gasification of the liquid nitrogen; The covering device is bonded to the cement concrete pavement of the airport where the crack is located, and the solid granular material is sent into the crack by means of the pneumatic conveying process. After the solid granular material fills the crack, water is injected into the crack by fine water mist. After ‑200min, it will expand and solidify, use a concrete grinder to smooth the cement concrete pavement of the airport and engrave anti-skid lines, that is, a crack will be sealed. Tested by practical application, the method of the present invention can realize all-round sealing of the cracks on the cement concrete pavement of the airport, can complete the repair of tiny cracks, has a better sealing effect, and the crack sealing rate has increased by more than 50%, ensuring that the aircraft Take off and land safely, prolong the service life of airport pavement by 30%‑50%, and have wide practicability.

Description

A method for sealing cracks in airport cement concrete pavement

technical field

The invention relates to a method for sealing cracks, in particular to a method for sealing cracks on airport cement concrete pavement.

Background technique

The pavement structure of Chinese airport runways is relatively simple, and the cement concrete pavement structure accounts for about 95%. The normal use of the airport runway mainly depends on its structural performance. With the continuous increase of air traffic volume, the continuous increase of aircraft load, and the continuous increase of aircraft daily flight sorties, the load effect on the airport runway is also increasing. In addition, the temperature factor Due to the coupling effect of the airport runway cement concrete pavement, internal cracks develop, resulting in various forms of damage, which are mainly manifested as: cracks, deformation, joint damage and surface damage. In order to ensure the safety of aircraft take-off and landing and prolong the service life of the airport runway, it is necessary to reinforce or restore the function of the cement concrete pavement structure to improve the performance of the pavement.

At present, there are mainly three types of methods commonly used at home and abroad to seal the cracks on the cement concrete pavement of airports: ① use inorganic materials to seal the cracks, the main body of which is cement, which is a kind of cementitious material in essence. Therefore, the mechanism of action of inorganic repairing materials on cracks mainly depends on the bonding and penetration of cement hydration products, so that cement paste and old concrete are bonded together to seal and repair cracks; inorganic repairing materials also have a lot of Defects, such as insufficient bonding strength, are prone to cracking under large impact forces; after repair, the pavement will be raised and affect the smoothness of the pavement; in terms of groutability, it is still different from other types of repair materials. There is a certain gap. Generally, it can only be injected into the gap or crack with a diameter or width greater than 0.2mm, and it is impossible to complete the repair of tiny cracks between 0.1mm-0.2mm. ② Use organic polymer materials to seal the cracks. After the organic polymer materials are poured into the cracks of the pavement through polymers, polymerization reactions occur during the curing process, and the concrete aggregates are bonded together by chemical bonds or van der Waals forces to achieve filling. 1. The purpose of plugging concrete cracks; the initial viscosity of organic materials is low, but the problem is that the shrinkage rate after curing is also large, generally around 20%, and it is easy to separate from the repair matrix concrete or produce a large Internal stress makes the repair fail. ③A polymer material compounded with organic materials and inorganic materials is used to seal the cracks, in which a layer of cross-linked polymer network can be formed in the cement-based material, which adheres to the mortar, thereby preventing the expansion of micro-cracks; polymer particles can be filled Some of the larger pores in the cement mortar have changed the pore structure and enhanced the adhesion between the cementitious material slurry and the old mortar and concrete, but it still cannot effectively seal the tiny cracks, which bury safety hazards for aircraft take-off and landing .

Contents of the invention

In view of the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a method for sealing the cracks in the airport cement concrete pavement, which has good bonding strength and can complete the repair of tiny cracks; the shrinkage rate after solidification is low, and the airport can be realized. The all-round sealing of cracks in cement concrete pavement ensures the safety of aircraft taking off and landing.

In order to achieve the above object, the technical solution adopted in the present invention is: a method for plugging the cracks in the airport cement concrete pavement, comprising the steps:

(1) Use a crack width detector to comprehensively investigate the cracks on the airport cement concrete pavement, slowly inject liquid nitrogen along the direction of crack expansion until the cracks are filled, and clean the cracks through liquid nitrogen gasification;

(2) After injecting water into the cracks of the airport cement concrete pavement by spraying, let it stand still;

(3) Use adhesive glue to bond the covering device to the airport cement concrete pavement where the crack is located to form a relatively airtight space where the crack is blocked, and use the pneumatic conveying process to send the solid granular material into the crack until the solid granular material full of cracks;

(4) Remove the covering device of this section, and inject water into the crack position by means of fine water mist until the water no longer seeps down;

(5) The solid particle material will expand and solidify after 180min-200min, use a concrete grinder to smooth the cement concrete pavement of the airport and engrave anti-skid lines to achieve the purpose of sealing the cracks in the cement concrete pavement of the airport;

(6) According to the distribution of cracks on the airport cement concrete pavement, repeat steps (3)-(5) until all cracks are sealed.

As a preferred solution of the present invention, the water supply pressure injected into the cracks of the airport cement concrete pavement by spraying in the step (2) is 0.4MPa-0.8MPa, and the standing time after water injection is 15min-20min. Using this parameter can ensure more sufficient contact between water and fracture surface after water injection.

Preferably, the device used for the pneumatic conveying in the step (3) is a solid particle material conveying pipe, one end of the solid particle material conveying pipe leads into the covering device, and the other end is externally connected to the solid particle conveying device. Opening the external solid particle conveying device, the solid particle material can be conveyed to the covering device through the solid particle material conveying pipe.

The covering device in step (3) can be a stainless steel cover or other covers with a certain weight and strength, which can confine the solid granular material therein, prevent the solid granular material from flying into the air, ensure the sealing efficiency and reduce waste. Preferably, the covering device of the step (3) is a transparent rubber cover, and the surface of the transparent rubber cover is soft, which is easy to bond with the cement concrete pavement of the airport where the crack is located, and the solid surface can also be observed through the transparent rubber cover. The progress of the granular material filling.

Preferably, in order to ensure the atomization effect, the device used in the fine water mist method in step (4) is a water atomizer.

Preferably, the solid granular material in the step (3) includes: 36-40 parts by mass of PO52.5 grade cement, 15-19 parts by mass of superabsorbent resin, 10-15 parts by mass of epoxy resin curing agent, 8-12 parts by mass of methyl cellulose thickener, 6-8 parts by mass of calcium sulfoaluminate concrete expansion agent, 6-8 parts by mass of polycarboxylate high-performance water reducer, 4-8 parts by mass of potassium aluminate accelerator 6 parts by mass and 3-5 parts by mass of blast furnace slag. The solid particle material has a short setting time and a water absorption rate of more than 150 times, which can be fully integrated with water, which is conducive to the full contact between the solid particle material and the surface of the airport cement concrete crack; the natural expansion rate is greater than 15%, which avoids shrinkage after curing. Repairing the detachment between the matrix concrete or the large internal stress makes the repair fail, and the plugging material expands in the relatively closed crack space, which produces a pressure effect in the crack space, which can greatly enhance the compactness of the plugging material after expansion It has strong cohesive force, and the compressive strength is greater than 70MPa, the flexural strength is greater than 9MPa, and the shear strength is greater than 6MPa, which makes it have a higher comprehensive strength after the final repair.

Preferably, in order to ensure that the solid granular material can enter tiny cracks and successfully realize the repair of tiny cracks between 0.1 mm and 0.2 mm, the particle size of the solid granular material is 180 mesh to 250 mesh.

Preferably, the flow rate of the water mist injection in the step (4) is 50L/min-100L/min, and the working pressure is 1.4MPa-1.9MPa. The appropriate flow rate and working pressure can ensure that the water and solid particle materials The full contact makes the solid granular material can quickly absorb water and swell and solidify.

The liquid nitrogen gasification process of the present invention helps to remove the dust on the surface of the fissures, and enhances the bonding force between the sealing material and the surface of the fissures; before the fissures are sealed, water is injected into the fissures by spraying to ensure that the water and the surface of the fissures are fully Contact is more conducive to the full contact between the solid particle material and the surface of the airport cement concrete crack; the solid particle material enters the crack by pneumatically transporting the solid particle material into the crack, and can enter the extremely small crack, complete the sealing of the crack in all directions, and effectively improve the crack sealing rate. Successfully achieve the repair of tiny cracks between 0.1mm-0.2mm. After the solid granular material is blocked, water is injected in the form of fine water mist, which is convenient for the solid granular material to fully absorb water, and the crack sealing effect is better. The solid granular material used has moderate expansion, which avoids separation from the matrix caused by curing shrinkage.

Tested by practical application, the present invention can realize all-round sealing of the cracks on the cement concrete pavement of the airport, can complete the repair of tiny cracks, has a better sealing effect, and the sealing rate of the cracks has increased by more than 50%, ensuring that the aircraft takes off and lands It is safe, prolongs the service life of airport pavement by 30%-50%, and has wide practicability.

Description of drawings

Fig. 1 is the schematic diagram of plugging the crack of cement concrete pavement according to the present invention.

In the figure, 1. Airport cement concrete pavement, 2. Crack, 3. Covering device, 4. Solid granular material, 5. Solid granular material delivery pipe.

detailed description

The present invention is described in further detail below in conjunction with embodiment.

Example 1

The method for plugging up the crack of airport cement concrete pavement comprises the following steps:

(1) Use the crack width detector to comprehensively investigate the crack 2 of the airport cement concrete pavement 1, and guide the formulation of the crack 2 plugging scheme. Slowly inject liquid nitrogen along the expansion direction of the crack 2 until it fills the crack, and complete the cleaning of the crack by gasification of liquid nitrogen;

(2) Water is injected into the crack 2 of the airport cement concrete pavement 1 by means of spraying. The hydraulic pressure of the spraying process to the crack 2 of the airport cement concrete pavement 1 is 0.4MPa, and the standing time is 15min;

(3) Use high-strength natural curing adhesive to bond the covering device 3 on the airport cement concrete pavement 1 where the crack 2 is located to form a relatively closed space blocked by the crack 2, and place the solid particle material delivery pipe 5 at one end into the covering device 3, the other end is externally connected to the solid particle conveying device, and the solid particle material 4 is sent into the crack by means of pneumatic conveying until the solid particle material 4 fills the crack 2; the covering device 3 used is a transparent rubber cover, through The progress of the solid granular material 4 filling can be observed through the transparent rubber cover.

(4) Remove the crack plugging device 3 in this section, and use a water atomizer to inject water into the crack 2. The water injection flow rate of the water atomizer is 50L/min, and the working pressure is 1.4MPa until the water no longer seeps down to ensure that Adequate fusion of water and solid particulate material 4;

(5) The solid particle material 4 expands and solidifies after 180min, and the cement concrete pavement 1 of the airport is engraved with anti-skid lines with a concrete grinder, so as to achieve the purpose of blocking the crack 2 of the cement concrete pavement 1 of the airport;

(6) According to the distribution of cracks 2, repeat steps (3)-(5) until all the cracks are blocked.

Tested by practical application, the present invention can realize all-round sealing of the cracks on the cement concrete pavement of the airport, the sealing effect is good, the crack sealing rate is increased by 50%, the safety of aircraft take-off and landing is ensured, and the service life of the airport pavement is extended by 30%. Has wide applicability.

Example 2

The method for plugging up the crack of airport cement concrete pavement comprises the following steps:

(1) Use the crack width detector to comprehensively investigate the crack 2 of the airport cement concrete pavement 1, and guide the formulation of the crack 2 plugging scheme. Slowly inject liquid nitrogen along the expansion direction of the crack 2 until it fills the crack, and complete the cleaning of the crack by gasification of liquid nitrogen;

(2) Water injection is carried out in the crack 2 of the airport cement concrete pavement 1 by means of spraying. The hydraulic pressure of the water injection in the crack 2 of the airport cement concrete pavement 1 during the spraying process is 0.8MPa, and the standing time is 20min;

(3) Use high-strength natural curing adhesive to bond the covering device 3 on the airport cement concrete pavement 1 where the crack 2 is located to form a relatively closed space blocked by the crack 2, and place the solid particle material delivery pipe 5 at one end Connected to the covering device 3, the other end is connected to the solid particle conveying device, and the solid particle material 4 is sent into the crack by means of pneumatic conveying until the solid particle material 4 fills the crack 2; the covering device 3 used is a stainless steel cover.

(4) Remove the fissure plugging device 3 in this section, and inject water into the fissure 2 in the form of fine water mist. The flow rate of water injection in the form of fine water mist is 100L/min, and the working pressure is 1.9MPa until the water no longer seeps down to ensure that Adequate fusion of water and solid particulate material 4;

(5) The solid particle material 4 expands and solidifies after 200min, and the cement concrete pavement 1 of the airport is engraved with anti-skid lines with a concrete grinder, so as to achieve the purpose of blocking the crack 2 of the cement concrete pavement 1 of the airport;

(6) According to the distribution of cracks 2, repeat steps (3)-(5) until all the cracks are blocked.

Tested by practical application, the present invention can realize all-round sealing of the cracks in the cement concrete pavement of the airport, the sealing effect is good, the sealing rate of cracks is increased by 60%, the safety of aircraft taking off and landing is ensured, and the service life of the airport pavement is extended by 50%. Has wide applicability.

In the above two examples, the solid granular materials used in Example 1 include: 36 parts by mass of P.O 52.5 grade cement, 15 parts by mass of superabsorbent resin, 10 parts by mass of epoxy resin curing agent, methyl cellulose 8 parts by mass of thickener, 6 parts by mass of calcium sulfoaluminate concrete expansion agent, 6 parts by mass of polycarboxylate high-performance water reducer, 4 parts by mass of potassium aluminate quick-setting agent and 3 parts by mass of blast furnace slag.

The solid granular materials used in Example 2 include: 40 parts by mass of P.O 52.5 grade cement, 19 parts by mass of superabsorbent resin, 15 parts by mass of epoxy resin curing agent, 12 parts by mass of methyl cellulose thickener, sulfur 8 parts by mass of calcium aluminate concrete expansion agent, 8 parts by mass of polycarboxylate high-performance water reducer, 6 parts by mass of potassium aluminate accelerator and 5 parts by mass of blast furnace slag.

Carry out performance measurement to the solid granular material of embodiment 1,2. After mixing the components thoroughly, place them in a molding tool, add sufficient water, and record the initial volume and coagulation time. After the sample is molded and demoulded, it is placed in a standard curing room for standard curing. The conditions are: temperature 20°C ± 2°C, relative humidity above 95%, and curing for 28 days. Calculate the natural expansion rate, grind the specimen into a cube of 100mm×100mm×100mm, and then conduct the mechanical performance test. The relevant performance test results are shown in Table 1.

Table 1 Determination of properties of solid granular materials

As can be seen from Table 1, the plugging material of the present invention has a short setting time and can meet the needs of rapid repair of airport cement concrete pavement; the natural expansion rate is greater than 15%, which avoids the separation or generation of shrinkage after curing and the restoration matrix concrete. The large internal stress makes the repair fail, and the plugging material expands in the relatively closed fracture space, which produces a pressure effect in the fracture space, which can greatly enhance the compactness of the plugging material after expansion, effectively plug micro-cracks, and seal The plugging effect is better; after curing, it has good shear strength, flexural strength, compressive strength and tensile strength, and has good bonding strength, which can meet the mechanical and mechanical requirements of the plugging of airport cement concrete pavement cracks. Repair needs.

Claims (8)

1. a kind of method for blocking cement concrete pavement of aerodrome crack, it is characterised in that comprise the following steps：

(1) cement concrete pavement of aerodrome crack situation is investigated using fracture width detector comprehensively, along crack propagation direction Liquid nitrogen is slowly injected into until full of crack, the cleaning to crack is completed by liquid nitrogen gasification；

(2) after water filling, stood into cement concrete pavement of aerodrome crack using spray regime；

(3) cladding system is bonded in cement concrete pavement of aerodrome residing for crack using adhesive glue, forms crack closure Relatively closed space, is sent into solid particulate materials in crack using process of pneumatic transmission, until solid particulate materials are full of Crack；

(4) this section of cladding system is removed, using water mists mode to the water filling of crack position, until water no longer oozes down；

(5) solid particulate materials expansion curing after 180min-200min, airport cement concrete is polished with concrete sanding machine Anti-slip veins are simultaneously scribed in road face, reach the purpose in closure cement concrete pavement of aerodrome crack；

(6) according to cement concrete pavement of aerodrome fractured zones situation, repeat step (3)-(5), until having blocked all cracks.

2. the method in closure cement concrete pavement of aerodrome crack according to claim 1, it is characterised in that the step (2) water supply pressure that spray regime is injected into cement concrete pavement of aerodrome crack in is 0.4MPa-0.8MPa, quiet after water filling The time is put for 15min-20min.

3. the method in closure cement concrete pavement of aerodrome crack according to claim 1, it is characterised in that the step (3) device that Geldart-D particle is used is solid particulate materials delivery pipe, and solid particulate materials delivery pipe one end is passed through covering dress In putting, the external solid particle conveying device of the other end.

4. the method in closure cement concrete pavement of aerodrome crack according to claim 1, it is characterised in that the step (3) cladding system is transparent rubber lid.

5. the method in closure cement concrete pavement of aerodrome crack according to claim 1, it is characterised in that the step (4) device that water mists mode is used is water atomizer(-iser).

6. the method in closure cement concrete pavement of aerodrome crack according to claim 1, it is characterised in that the step (3) solid particulate materials in include：The class g cement 36-40 mass parts of PO 52.5, super absorbent resin 15-19 mass parts, ring Oxygen resin curing agent 10-15 mass parts, methylcellulose thickener 8-12 mass parts, calcium sulphoaluminate class cement expansive material 6-8 Mass parts, polycarboxylate high performance water-reducing agent 6-8 mass parts, potassium aluminate accelerator 4-6 mass parts and blast-furnace cinder 3-5 mass Part.

7. the method in closure cement concrete pavement of aerodrome crack according to claim 1, it is characterised in that the solid Granular materials particle diameter is the mesh of 180 mesh -250.

8. the method in closure cement concrete pavement of aerodrome crack according to claim 1, it is characterised in that the step (4) flow of water mists mode water filling is 50L/min-100L/min, and operating pressure is 1.4MPa-1.9MPa.