CN103603236A - A crack control method for double-block ballastless track bed slab - Google Patents

Abstract

A method for controlling cracks of a double-block ballastless track bed plate comprises the steps of pouring concrete, and pouring the concrete back and forth between double-block sleepers according to a zigzag line; vibrating concrete, adopting a secondary vibrating process according to the slump and the initial setting time of the concrete in the process of pouring the concrete of the double-block type track bed slab, finishing and smoothing the surface, finishing rough smoothing by using wood after the concrete is filled into a mold, performing secondary smoothing after the concrete is filled into the mold for 2 hours, and performing third smoothing and smoothing after the concrete is filled into the mold for 4 hours; loosening the vertical screw rod adjuster, the fishplate and the fastener, loosening the vertical adjusting screw rod 4.5 hours after finishing concrete plastering, simultaneously loosening the fishplate from two sides of the initial pouring end, loosening the fastener by using a bolt fastening machine after loosening the bolts of the fishplate, and removing connection; and spraying the curing liquid. The problem of reduce ballastless track bed board crackle in the work progress is solved, provide safe, economic, the quick guarantee for the operation of train. The method has the characteristics of simple process, convenience in operation and easiness in construction, and improves the construction quality of the ballastless track bed plate.

Description

A crack control method for double-block ballastless track bed slab

technical field

The invention relates to a crack control method for a double-block ballastless track bed slab, in particular to a crack control method for a CRTS Ⅰ double-block ballastless track bed slab. the

Background technique

At present, during the period of rapid development of my country's high-speed rail, rapid passenger transport between provincial capitals and large and medium-sized cities, and the planned "four horizontal and four vertical" express rail channels are all under construction climax. The cracking of the track bed slab has brought inconvenience to the operation safety and maintenance. the

In the construction process of ballastless track bed slabs, the existing construction technology and process use pump trucks or hoppers for direct pouring of concrete, one-time vibration is completed, and the surface finishing is only performed once or twice. , and sprinkle water during lightening, improper lightening time and arbitrary lightening trowel. The sequence and timing of loosening the vertical screw adjuster, fish plate and fasteners are incorrect when using the rail-row frame method for construction. The maintenance process of the track bed slab is not correct, and the above construction methods and processes will cause cracks in the track bed slab to varying degrees. Violation of the acceptance requirements of the high-speed rail. the

The occurrence of cracks on the ballastless track of high-speed rail will seriously damage the ballast bed slab. Water entering the cracks will cause the reinforcement of the ballast slab to rust and expand, causing large-area cracks and damage to the ballast bed slab. Once the ballastless track bed slab is cracked, it is very difficult to repair, the cost is high and the time is long, so the train cannot run normally. At the same time, based on various factors such as economy and safety, the existing ballast slab crack control technology and process cannot meet the construction requirements. the

Contents of the invention

The purpose of the present invention is to provide a double-block ballastless track bed slab crack control method to solve the problem of reducing ballastless track bed slab cracks in the construction process and provide safe, economical and fast guarantee for the operation of trains. It has the characteristics of simple process, convenient operation and easy construction, and improves the construction quality of the ballastless track bed slab. the

Technical solutions adopted to achieve the above objectives, including steps

1) Concrete pouring

Moisten the supporting layer and sleepers before concrete pouring, pour back and forth between the double-block sleepers according to the zigzag route;

2) Concrete vibration

During the concrete pouring process of the double-block track bed slab, the secondary vibration process is adopted according to the slump and initial setting time of the concrete. The first time uses a Φ50 vibrator to vibrate between the sleepers, and the second time uses a Φ30 vibrator Vibrate around the sleeper, and the standard of vibrating compactness is that the concrete does not sink and the surface appears laitance;

3) Lighten and wipe the surface

After the concrete is put into the mold, use wooden trowel to complete the rough leveling, control the concrete elevation and surface flatness, and perform the second plastering 2 hours after the concrete is put into the mold. It is strictly forbidden to sprinkle water to moisten the surface, and perform the third plastering and calendering 4 hours after the concrete is put into the mold;

4) Loose vertical screw adjuster, fish plate, fasteners

After 4.5 hours of concrete plastering, start to loosen the vertical adjustment screw, use a wrench to turn the vertical screw 180 degrees in the upward direction, use the rail row to lower it uniformly by 0.5mm-1mm, and then loosen the fish tail from both sides of the pouring end at the same time After the plate and fish plate bolts are loosened, use the bolt fastening machine to loosen the fasteners in time and release the connection;

5) Curing solution spraying

After 4.5 hours of concrete pouring, the fine leveling and finishing quality meet the requirements. After passing the inspection, use a sprayer to spray the curing agent in time when it is not sticky to touch with your fingers. Use a soft brush to paint the bottom of the rails and rails. The amount of curing agent is 3.9m /5kg, the side formwork is sprayed with curing solution immediately after demoulding, and after each dismantled formwork is painted with curing solution, another formwork is removed, and the geotextile with two cloths and one film is used to cover it in time after the mold is formed.

Compared with the prior art, the present invention has the following advantages. the

1. The present invention greatly improves the occurrence of cracks in the ballastless track bed slab, and greatly improves the construction quality of the ballastless track bed slab;

2. The present invention is not restricted by the environment of the construction site, and can control the occurrence of cracks with the same input of manpower, financial resources, material resources and equipment, and the process is simple and easy to construct;

3. It greatly reduces the rework rate, saves costs, and has obvious social and economic benefits.

Description of drawings

Below in conjunction with accompanying drawing, the present invention is described in further detail. the

Fig. 1 is a schematic diagram of the sequence of pouring the road bed slabs of the present invention. the

Fig. 2 is a schematic diagram of pouring and vibrating a road bed slab according to the present invention. the

In the figure, 1 is the pouring point, 2 is the pouring sequence, 3 is the Φ50 vibrating rod, and 4 is the Φ30 vibrating rod. the

Detailed ways

include steps

1) Concrete pouring

Wet the supporting layer and sleepers before concrete pouring, and pour back and forth between the double-block sleepers according to the zigzag route, as shown in Figure 1;

2) Concrete vibration

During the concrete pouring process of the double-block track bed slab, the secondary vibration process is adopted according to the slump and initial setting time of the concrete. The first time uses a Φ50 vibrator to vibrate between the sleepers, and the second time uses a Φ30 vibrator Vibrate around the sleeper, and the standard of vibration compaction is that the concrete does not sink and the surface appears laitance, as shown in Figure 2;

3) Lighten and wipe the surface

After the concrete is put into the mould, finish the rough leveling with a wooden trowel, control the concrete elevation and surface smoothness, and carry out the second plastering 2 hours after the concrete is put into the mold. It is strictly forbidden to sprinkle water to moisten the surface, and perform the third plastering and calendering 4 hours after the concrete is put into the mold;

4) Loose vertical screw adjuster, fish plate, fasteners

After 4.5 hours of concrete plastering, start to loosen the vertical adjustment screw, use a wrench to turn the vertical screw 180 degrees in the upward direction, use the rail row to lower it uniformly by 0.5mm-1mm, and then loosen the fish tail from both sides of the pouring end at the same time After the plate and fish plate bolts are loosened, use the bolt fastening machine to loosen the fasteners in time and release the connection;

5) Curing solution spraying

After 4.5 hours of concrete pouring, the fine leveling and finishing quality meet the requirements. After passing the inspection, use a sprayer to spray the curing agent in time when it is not sticky to touch with your fingers. Use a soft brush to paint the bottom of the rails and rails. The amount of curing agent is 3.9m /5kg, the side formwork is sprayed with curing solution immediately after demoulding, and after each dismantled formwork is painted with curing solution, another formwork is removed, and the geotextile with two cloths and one film is used to cover it in time after the mold is formed.

Technical scheme of the present invention proceeds as follows:

Before pouring, the surface of the supporting layer and the sleeper should be wet, the surface of the supporting layer should be sprinkled with water, and the surrounding and bottom of the sleeper should be sprayed several times with a sprayer. In order to reduce excessive vibration, the concrete of the track bed slab should not be poured at one point, and the vibrator should be used to drive the material, but should be poured back and forth between the double-block sleepers in a zigzag route. The concrete of the track bed slab should be vibrated twice. For the first time, Φ50 vibrating rods are used to vibrate between the sleepers, and for the second time, Φ30 vibrating rods are used to vibrate around the sleepers to strengthen the bond between the newly poured concrete and the sleepers. and the compactness of the concrete at the bottom of the sleeper. The concrete of the road bed slab should be plastered 3-5 times before initial setting, and watering is strictly prohibited during the plastering process. When cleaning the sleeper during the plastering process, it should be cleaned with a brush or a dry rag, and water should not be used for cleaning. After spraying the curing agent on the concrete of the track bed slab, the fishplate bolts of the tool rails at the outermost ends of the front and rear mileages of the newly poured concrete should be loosened in time to avoid the influence of the temperature deformation of the front and rear tool rails on the newly poured concrete; the bolts of the tool rail fasteners should be The concrete loosens near the final setting time. The concrete of the road bed slab should adopt the measures of windproof, thermal insulation and moisture preservation by spraying curing agent and covering geotextile, plastic film and quilt. The spraying of curing agent should be carried out immediately after the last plastering. It should be combined with spraying and rolling, and brushing should not be used. The construction quality of the curing agent should be checked around the sleeper, and the leakage of spray and paint should be dealt with in time. Maintenance and construction should be carried out immediately after the formwork on both sides is removed. The curing agent is strictly forbidden to contact with water before film formation, so as to avoid affecting the quality of film formation.

Example

1. Concrete pouring technology

Before concrete pouring, the supporting layer and sleepers should be moistened to ensure that the supporting layer and sleepers are completely wet, and there should be no obvious water accumulation. If the concrete is not wetted with water, the concrete will lose water at the contact position between the concrete and the supporting layer and the sleeper, resulting in inconsistent shrinkage of the concrete in the early stage. Cracks occur. In order to reduce excessive vibration, the concrete of the track bed slab cannot be poured at one point, and the vibrator is used to drive the material, but should be poured back and forth between the double-block sleepers in a zigzag route, otherwise the concrete on the surface of the track bed slab after pouring will segregate and appear laitance , resulting in inconsistent shrinkage and cracks.

2. Concrete vibration technology

During the concrete pouring process of the double-block track bed slab, in order to improve the compactness of the concrete and reduce cracks, the secondary vibration process was adopted according to the slump and initial setting time of the concrete. For the first time, a Φ50 vibrating rod was used to vibrate between sleepers. For the second time, use a Φ30 vibrating rod to vibrate around the sleeper to strengthen the bonding between the newly poured concrete and the sleeper and the compactness of the concrete at the bottom of the sleeper. The standard of vibration compactness is that the concrete does not sink and the surface appears laitance, so as to prevent over-vibration and vibration leakage. Otherwise, the vibration will not be compacted, and cracks will appear during the concrete solidification process.

3. Finishing and wiping technology

After the concrete is put into the mold, the rough leveling is completed with a wooden trowel, and the rough leveling uses a mold to control the concrete elevation and surface flatness. In order to prevent small cracks on the concrete surface due to water loss, the concrete should be plastered 2 hours after the concrete has been put into the mold. It is strictly forbidden to sprinkle water to moisten the surface, otherwise it will cause cracks in the surface concrete. In the process of plastering, attention should be paid to strengthening the construction of the parts below the rails and around the sleepers. Enter the mold for 4 hours to carry out the third plastering and calendering. During the plastering process, attention should be paid to strengthening the construction of the rails, the bottom of the joist, and around the sleeper. When plastering the surface around the sleeper, the trowel should be applied in the direction of the sleeper to avoid the early appearance of cracks around the sleeper and around the sleeper.

4. Loose vertical screw adjuster, fish plate, fastener time technology

About 4.5 hours after the completion of the concrete plastering, start to loosen the vertical adjustment screw, and use a wrench to turn the vertical screw 180 degrees in the upward direction, and use the rail row to lower it uniformly by 0.5mm-1mm to improve the compactness of the bed slab under the sleeper; then Loosen the fishplate at the same time from both sides of the pouring end. After the bolts of the fishplate are loosened, use the bolt fastening machine to loosen the fasteners in time to release the connection and release the stress, so that the concrete will not crack due to temperature rise, and the newly poured The concrete is in a free state and prevents the rails from heating and cooling to cause cracks in the newly poured concrete due to tensile stress.

5. Curing solution spraying technology

About 4.5 hours after the concrete is poured, the fine leveling and finishing quality meet the requirements. After passing the inspection, use a sprayer to spray the curing agent in time when the hands are not sticky when pressed lightly with your fingers. To prevent uneven spraying, use a roller brush to cooperate with the operation. For rails , Brush the bottom of the rail row with a soft brush to ensure that the curing agent is sprayed evenly and comprehensively. The amount of curing agent is 3.9m /5kg. Spray the curing liquid immediately after the side mold is demoulded. One template, and cover it with two geotextiles and one film in time after the mold is formed.

Claims (1)

1. a double-block ballastless track bed board crack controlling means, is characterized in that, comprises step

1) concreting

Solidifying soil is built and frontly supporting bed, sleeper is carried out moistening, between double-block type sleeper, by "the" shape route, pours into back and forth;

2) concrete vibrating

In double-block type railway roadbed board concrete casting process, according to concrete slump and initial setting time, adopt secondary vibration technique, adopt for the first time Φ 50 vibrating spears to vibrate between sleeper, adopt for the second time Φ 30 vibrating spears to vibrate at sleeper circumferential, the standard of vibratory compaction take concrete not sinking, surface presents laitance as degree;

3) receiving light wipes one's face

Concrete enters with wood, to have smeared after mould thick flatly, controls concrete absolute altitude and surface finish, enters mould after 2 hours, carry out quadric-plastering at concrete, forbids the profit face of sprinkling water while wiping one's face, and enters the mould press polish of wiping one's face for the third time for 4 hours;

4) the vertical screw regulator of pine, splice bar, fastener

Concrete coating finished after 4.5 hours, start loose vertical adjustment screw rod, the direction vertical screw rod first being made progress with spanner is rotated 180 degree, use the unified 0.5mm-1mm of reduction of the section of track, then from starting to build end both sides loose splice bar simultaneously, fish-bolt unclamps rear in time with the loosening fastener of Screw Tightening Machines, removes and connects;

5) curing fluid capable spraying

After concreting 4.5h, the gentle receipts light quality of essence reaches requirement, after passed examination, when tack-free with finger flicking, use in time atomizers spray curing agent, for rail, section of track below, with soft brushing, brush, curing agent consumption is 3.9m/5kg, and side form sprays immediately curing fluid capable after the demoulding, often tears open after a template brushing curing fluid capable, pull down again a template, and after Cheng Mo, adopt timely the geotextiles of two cloth one films to cover.

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