阅读说明：本技术 铁路桥梁弹性体伸缩装置斜面分段浇筑工艺 (Railway bridge elastomer expansion device inclined plane sectional pouring process ) 是由 孙天磊 申佳鹏 刘训翔 姜源 于 2021-08-31 设计创作，主要内容包括：本发明公开了一种铁路桥梁弹性体伸缩装置斜面分段浇筑工艺,解决了由于桥面人字坡斜度要求,使得模底到挡水台顶部的高度不一,中间高两头低,而液体浇注时,弹性体在浇注成型后是自流平的,弹性体的浇注高度只能与桥面最低点持平,在横桥向截面上看,桥梁两侧的弹性体已经浇满,但桥梁中部仍有较大空腔无法填满,容易造成缝内积水、应力集中导致开裂、薄厚不均匀的问题。该分段工艺通过平行设置浇注模腔,插入分隔板进行分段浇注,并且通过调节B组分中催化剂的加入,来控制浇注弹性体的流动性,实现斜面浇注,避免缝内积水,应力集中导致开裂、薄厚不均匀的问题,实现提升产品质量和使用寿命,降低成本的效果。(The invention discloses a railway bridge elastic body telescopic device inclined plane sectional pouring process, which solves the problems that the height from the bottom of a mold to the top of a water retaining table is different due to the requirement of the inclination of a herringbone slope of a bridge deck, the middle of the herringbone slope is high, the two ends of the herringbone slope are low, the elastic body is self-leveling after being poured and molded during liquid pouring, the pouring height of the elastic body can only be equal to the lowest point of the bridge deck, the elastic bodies on the two sides of the bridge are fully poured when viewed from the transverse bridge cross section, but the middle of the bridge is still large and cannot be fully filled, water accumulation in a seam and stress concentration are easy to cause cracking and uneven thickness. According to the sectional process, the casting mold cavities are arranged in parallel, the partition plates are inserted for sectional casting, the addition of the catalyst in the component B is adjusted to control the flowability of the cast elastomer, inclined plane casting is realized, the problems of cracking and uneven thickness caused by water accumulation in seams and stress concentration are avoided, the product quality is improved, the service life is prolonged, and the cost is reduced.)

1. The sectional pouring process for the inclined plane of the elastic body telescopic device of the railway bridge is characterized by comprising the following steps of:

1) bridge seam inspection and base layer treatment;

2) installing a pouring mold cavity, wherein the pouring mold cavity is parallel to the surface of the beam body;

3) constructing a primer, then uniformly filling a gap filler at the junction of the pouring die cavity and the cement, and filling a gap at the joint part of the pouring die cavity and the cement;

4) inserting the partition plate; the shape of the partition plate is matched with the upper top surface of the pouring mold cavity, so that the partition plate can be clamped in the gap along with the mold;

5) elastomer casting: mixing the polyurethane elastomer A component and the polyurethane elastomer B component, and pouring;

the polyurethane elastomer A component and the polyurethane elastomer B component are selected from AB two-component polyurethane elastomers of railway building research institute of China railway science research institute;

before the two components are mixed, a catalyst is added into the polyurethane elastomer B component, and the addition amount of the catalyst is 1-5 (wt)% per thousand of that of the polyurethane elastomer B component;

6) taking out the partition plate

7) Defoaming/surface coating construction

8) And (5) comprehensive self-checking/maintenance.

2. The process of claim 1, wherein the casting cavity is a cavity having a semi-circular, semi-elliptical, triangular or trapezoidal cross-section.

3. The process of claim 2, wherein in step 2), the casting mold cavity is a cavity with a semicircular or semi-elliptical cross section.

4. The process of claim 3, wherein in step 2), the casting mold cavity is a cavity with a semicircular cross section.

5. The railway bridge elastomer expansion device slope surface subsection casting process of claim 1, wherein in step 4), the distance between the partition plates is 0.5-2.5 meters; preferably, the distance between the partition plates is 1-2 meters, and more preferably, the distance between the partition plates is 2 meters.

6. The process of claim 1, wherein the step of pouring the resilient means of railroad bridges comprises the step of pouring the resilient means of railroad bridges,

in the step 5), the addition amount of the catalyst is 2-4 (wt)% of the component B of the polyurethane elastomer.

7. The process of claim 6, wherein the step of pouring the resilient means of railroad bridges comprises the step of pouring the resilient means of railroad bridges,

the addition amount of the catalyst is 3 (wt)% of the component B of the polyurethane elastomer.

8. The process for the sectional pouring of the inclined plane of the elastic expansion device of the railroad bridge as claimed in claim 1, wherein the weight ratio of the polyurethane elastomer A component to the polyurethane elastomer B component is (90-105) to 100,

preferably, the weight ratio of polyurethane elastomer A component to polyurethane elastomer B component is 92: 100.

9. The process of claim 1, wherein the step of pouring the resilient means of railroad bridges comprises the step of pouring the resilient means of railroad bridges,

in the step 5), the catalyst is lead isooctanoate and/or phenylmercuric acetate.

10. The process of claim 1, wherein the step of pouring the resilient means of railroad bridges comprises the step of pouring the resilient means of railroad bridges,

in the step 6), the time for taking out the partition board is 10-30min after pouring, and as a preferred technical scheme, the time for taking out the partition board is 15-20min after pouring.

Technical Field

The invention belongs to the field of railway bridge construction, and particularly relates to a railway bridge elastomer telescopic device inclined plane sectional pouring process.

Background

Expansion devices are required to be installed between various simply supported beams and continuous beams of railways and between bridges and abutment platforms, and the elastic body beam end expansion device is a new polyurethane material waterproof expansion device emerging in recent years. The elastic body beam end waterproof device is formed by mixing and casting a polyurethane material A, B component on site, is molded by using a liner template, is filled at the joint of the beam end of the railway bridge, is solidified into a telescopic device with a set size and shape, and is used for bridge floor waterproofing and meeting the requirements of thermal expansion and cold contraction of a beam body.

In practice, it has been found that the traditional casting process relies on the levelness of the beam-end water retaining platform, and when the water retaining platform is not level, it is difficult for the liquid material before solidification to fill the entire mold cavity. In addition, in order to meet the drainage requirement, the common beam body structure is provided with herringbone slopes with 2% slopes in the transverse bridge direction, so that the heights from the bottom of the mold to the top of the water retaining table are different, and the middle of the common beam body structure is high, and the two ends of the common beam body structure are low. The elastic bodies are self-leveling after being cast and molded, the casting height of the elastic bodies can only be equal to the lowest point of the bridge floor, and according to the traditional construction process, the elastic bodies on two sides of the bridge are fully cast when viewed from the cross-bridge section, but the middle part of the bridge still has a large cavity which cannot be filled, so that the problems of water accumulation in the joints, cracking caused by stress concentration, uneven thickness and the like are easily caused.

In view of the above problems, it is necessary to develop a novel pouring process to meet the requirement of pouring the inclined plane between the expansion joints of the bridge, so as to solve the above problems.

Disclosure of Invention

(1) Technical problem to be solved

Aiming at the current situation that the railway bridge elastomer beam end expansion device in the prior art can only be horizontally poured during construction and cannot meet the requirement of inclined plane pouring, the invention aims to provide a novel railway bridge elastomer expansion device inclined plane sectional pouring process, so that the whole die cavity is filled with an elastomer material, and the bonding surface is uniform. The problem of among the prior art, because bridge floor herringbone slope inclination requires for the height of mould bottom to manger plate bench top differs, middle high both ends are low, and during the liquid pouring, the elastomer is self-leveling after the casting moulding, and the pouring height of elastomer can only keep level with the bridge floor minimum, looks at on the horizontal bridge is to the cross-section, and the elastomer of bridge both sides has been watered, but the bridge middle part still has great cavity can't be filled up, causes easy that the seam is ponding, stress concentration leads to the fracture, thickness inhomogeneous is solved.

(2) Technical scheme

In order to solve the technical problem, the invention provides a railway bridge elastomer expansion device inclined plane sectional pouring process, which comprises the following specific scheme:

a railway bridge elastic body telescopic device inclined plane sectional pouring process comprises the following steps:

1) bridge seam inspection and base layer treatment;

2) installing a pouring mold cavity, wherein the pouring mold cavity is parallel to the surface of the beam body; the installation thickness is ensured to be uniform, and the influence of installation tolerance on the material consumption is eliminated.

3) Constructing a primer, then uniformly filling foaming glue or other materials at the junction of the pouring mold cavity and the cement, and filling the gap of the connecting part of the pouring mold cavity and the cement;

the primer is the conventional primer in the field, the construction method is also the conventional construction method, and in order to seal the cement gap, the adhesion performance between the cement and the elastomer can be improved; filling a gap filler such as foaming adhesive and the like uniformly at the junction of the pouring mold cavity and the cement, wherein the gap of the joint part of the pouring mold cavity and the cement is filled in order to fill the gap between the pouring mold cavity and the cement;

4) inserting the partition plate; the shape of the partition plate is matched with the upper top surface of the pouring mold cavity, so that the partition plate can be clamped in a gap along with the mold to separate the space and realize sectional pouring. See fig. 10-13.

The die cavity of the integral beam seam is divided into parts, and the elastomer solidification critical point can be controlled more accurately by means of sectional pouring.

5) Elastomer casting: mixing the polyurethane elastomer A component and the polyurethane elastomer B component, and pouring;

the polyurethane elastomer A component and the polyurethane elastomer B component are selected from AB two-component polyurethane elastomers of railway building research institute of China railway science research institute;

before the two components are mixed, a catalyst is added into the polyurethane elastomer B component, and the addition amount of the catalyst is 1-5 (wt)% per thousand of that of the polyurethane elastomer B component; a certain amount of catalyst is added into the component B of the polyurethane elastomer to accelerate the solidification, so that the solidification process of the elastomer is more controllable, and the solidification becomes possible in the inclined plane flowing process. Wherein the component A and the component B are in the prior art, for example:

the polyurethane elastomer A component is a semi-prepolymer liquid obtained by the semi-prepolymerization reaction of two polyether polyols and modified MDI, and adjusting the-NCO percentage under the conditions of specific temperature and vacuum degree to enable the-NCO percentage to meet the technical requirements; the component B is mainly chain extender, catalyst and various other assistants, and is dehydrated at a specific temperature, so that the total hydroxyl value of the component B meets the technical requirement, and the obtained uniform mixture liquid is obtained. A. And the component B is subjected to chain extension reaction between hydroxyl in the mixed polyether and-NCO in the modified MDI, and is gradually cured from a liquid state within a certain time to form an elastomer with certain strength and hardness, and the reaction process is controllable. The reaction equation is as follows:

6) and taking out the partition plate, combining with the addition of the catalyst, shortening the flowing distance of the elastomer during pouring of each section, enabling the solidification process of the elastomer to be more controllable, wherein each section is slightly stepped before the partition plate is disassembled, and the elastomer continues to flow to form an inclined plane after the partition plate is disassembled due to the control of the solidification of the elastomer.

7) Defoaming/surface coating construction

8) Comprehensive self-checking/maintenance

Further, the cross section of the pouring die cavity is small in upper portion and large in lower portion, so that the elastomer can be guaranteed to have sufficient contact area with a bridge after being filled, and specifically, the cross section of the pouring die cavity is a semicircular, semi-elliptical, triangular or trapezoidal cavity.

Further, in the step 2), the casting mold cavity is a cavity with a semicircular or semi-elliptical cross section.

Further, in step 2), the casting mold cavity is a cavity with a semicircular cross section.

Further, in the step 4), the distance between the partition plates is 0.5-2.5 meters; preferably, the distance between the partition plates is 1-2 meters, and more preferably, the distance between the partition plates is 2 meters.

Further, in the step 5), the addition amount of the catalyst is 2-4 (wt)% of the component B of the polyurethane elastomer.

Further, the addition amount of the catalyst is 3 (wt)% of the component B of the polyurethane elastomer.

Further, the weight ratio of the polyurethane elastomer A component to the polyurethane elastomer B component is (90-105) to 100,

as a preferred technical scheme, the weight ratio of the polyurethane elastomer A component to the polyurethane elastomer B component is 92: 100.

Further, in the step 5), the catalyst is lead isooctanoate and/or phenylmercuric acetate.

Further, in the step 6), the time for taking out the partition board is 10-30min after pouring, and as a preferred technical scheme, the time for taking out the partition board is 15-20min after pouring.

By controlling the time for taking out the partition plate and the adding amount of the catalyst, the elastomer is ensured to keep flowing to a certain degree after being dismantled, and the elastomer does not flow excessively, and is controlled to solidify in the process of flowing on the inclined surface, so that a relatively smooth slope is formed.

Advantageous effects

Compared with the prior art, the invention has the beneficial effects that:

the technical benefits are as follows: a mature novel inclined plane sectional pouring process of the elastomer beam end waterproof device is formed, so that the area of the bonding surface is uniformly distributed, the elastomer can fill the whole die cavity, stress concentration is avoided, the problem of accumulated water in the expansion joint is solved, the product quality is improved, and the service life is prolonged.

Economic benefits are as follows: the new construction process enables the consumption of raw materials to be accurate and controllable, the raw materials are saved as far as possible within the range of standard requirements, the most common expansion joint with the width of 10-14cm and the length of 11.88m is used for calculation, the raw materials can be saved by 18.45kg per expansion joint on average, and the cost is greatly saved.

Social benefits are as follows: forms a mature new construction process and can be widely applied to the construction of similar elastic body expansion joint devices.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the technical solutions in the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained based on these drawings without creative efforts

FIG. 1 is a schematic cross-sectional view of a self-flowing smooth bridge after pouring of an elastomer material in a beam end in a traditional construction process;

FIG. 2 is a schematic cross-sectional view of the self-flow smooth bridge after the casting of the elastomer material in the beam end of the present invention;

FIG. 3 is a sectional pouring process flow diagram of the inclined plane of the elastic body telescopic device of the railroad bridge of the invention;

FIG. 4 is a construction site view (parallel installation of casting cavities);

FIG. 5 is a construction site diagram (the casting mold cavities are installed in parallel and then filled with the foaming glue);

FIG. 6 is a construction site view (filling of caulk after parallel installation of casting cavities);

FIG. 7 is a construction site view (casting process, also machine casting);

FIG. 8 is a construction site view (casting finish);

FIG. 9 is a construction site view (treatment of the casting finish);

FIG. 10 is a schematic view of a casting mold cavity being semi-circular;

FIG. 11 is a schematic view of a casting mold cavity of a semi-elliptical shape;

FIG. 12 is a schematic view of a casting mold cavity having a triangular shape;

FIG. 13 is a schematic view of a trapezoidal casting mold cavity.

Detailed Description

In order to make the technical means, the original characteristics, the achieved purposes and the effects of the invention easily understood and obvious, the technical solutions in the embodiments of the present invention are clearly and completely described below to further illustrate the invention, and obviously, the described embodiments are only a part of the embodiments of the present invention, but not all the embodiments.

A railway bridge elastic body telescopic device inclined plane sectional pouring process comprises the following steps: 1) bridge seam inspection and base layer treatment;

2) installing a pouring mold cavity, wherein the pouring mold cavity is semicircular in cross section (see fig. 10), and the pouring mold cavity is parallel to the surface of the beam body; the installation thickness is ensured to be uniform, and the influence of installation tolerance on the material consumption is eliminated.

In other embodiments, the casting cavity may also be a cavity with a semi-elliptical, triangular or trapezoidal cross-section, see fig. 11-13.

3) Constructing a primer, then uniformly filling a gap filler such as foaming adhesive at the junction of the pouring mold cavity and the cement, and filling the gap of the joint part of the pouring mold cavity and the cement;

the primer is the conventional primer in the field, the construction method is also the conventional construction method, and in order to seal the cement gap, the adhesion performance between the cement and the elastomer can be improved; filling a gap filler such as foaming adhesive and the like uniformly at the junction of the pouring mold cavity and the cement, wherein the gap of the joint part of the pouring mold cavity and the cement is filled in order to fill the gap between the pouring mold cavity and the cement;

4) inserting the partition plate; the distance between the partition plates is 0.5-2.5 m; the shape of the partition plate is matched with the upper top surface of the pouring mold cavity, so that the partition plate can be clamped in a gap along with the mold to separate the space and realize sectional pouring. The die cavity of the integral beam seam is divided into parts, and the elastomer solidification critical point can be controlled more accurately by means of sectional pouring.

In other embodiments, the distance between the partition plates is preferably 1-2 m, and further, the distance between the partition plates is 2 m.

5) Elastomer casting: mixing the polyurethane elastomer A component and the polyurethane elastomer B component, and pouring;

the polyurethane elastomer A component and the polyurethane elastomer B component are selected from AB two-component polyurethane elastomers of railway building research institute of China railway science research institute; wherein the polyurethane elastomer A component is a semi-prepolymer liquid obtained by the semi-prepolymerization reaction of two polyether polyols and modified MDI, and adjusting the-NCO percentage under the conditions of specific temperature and vacuum degree to enable the-NCO percentage to meet the technical requirements; the component B is mainly chain extender, catalyst and various other assistants, and is dehydrated at a specific temperature, so that the total hydroxyl value of the component B meets the technical requirement, and the obtained uniform mixture liquid is obtained. A. And the component B is subjected to chain extension reaction between hydroxyl in the mixed polyether and-NCO in the modified MDI, and is gradually cured from a liquid state within a certain time to form an elastomer with certain strength and hardness, and the reaction process is controllable. The reaction equation is as follows:

the weight ratio of the polyurethane elastomer A component to the polyurethane elastomer B component is (90-105) to 100. In some embodiments, the weight ratio of polyurethane elastomer A component to polyurethane elastomer B component is 90: 100, 95: 100, 100: 100, 92: 100, 105: 100.

Before the two components are mixed, a catalyst is added into the polyurethane elastomer B component, and the addition amount of the catalyst is 1-5 (wt)% per thousand of that of the polyurethane elastomer B component; a certain amount of catalyst is added into the component B of the polyurethane elastomer to accelerate the solidification, so that the solidification process of the elastomer is more controllable, and the solidification becomes possible in the inclined plane flowing process. The catalyst is lead isooctanoate, and in other embodiments, the catalyst is phenylmercuric acetate.

Preferably, in some embodiments, the catalyst is added in an amount of 2 to 4 parts per thousand of the B component of the polyurethane elastomer.

As a further preferred solution, in some embodiments, the amount of the catalyst added is 3 (wt)% of the B component of the polyurethane elastomer.

6) And after the elastomer is poured for 10-30min, taking out the partition plate, combining the determination of the addition amount of the catalyst, shortening the flowing distance of the elastomer during pouring of each section, enabling the solidification process of the elastomer to be more controllable, wherein each section is slightly stepped before the partition plate is removed, and the elastomer continues to flow to form an inclined plane after the partition plate is removed due to the control of the solidification of the elastomer.

As a preferable technical scheme, in some embodiments, the time for taking out the partition board is 15-20min after casting, such as 15min, 16min, 17min, 18min, 19min and 20 min.

Because the partition plates are cast in sections, after the partition plates are inserted and the elastomer is cast, actually, before the partition plates are taken out, the polyurethane is in a step shape, the time for taking out the partition plates and the adding amount of the catalyst are controlled, the elastomer can keep flowing to a certain degree after being dismantled, the elastomer can not flow excessively, and the elastomer is controlled to be solidified in the flowing process of the inclined surface, so that a relatively smooth slope is formed.

7) Defoaming/surface coating construction

8) Comprehensive self-checking/maintenance

Example 1

In Weilai railway engineering, the process is adopted as follows:

a railway bridge elastic body telescopic device inclined plane sectional pouring process comprises the following steps: 1) bridge seam inspection and base layer treatment;

2) installing a pouring die cavity, wherein the cross section of the pouring die cavity is semicircular, and the pouring die cavity is parallel to the surface of the beam body; the installation thickness is ensured to be uniform, and the influence of installation tolerance on the material consumption is eliminated.

3) Constructing a primer, then uniformly filling foaming glue at the junction of a pouring die cavity and cement, and filling a gap at the joint part of the pouring die cavity and the cement;

4) inserting the partition plate; the distance between the partition plates is 2 meters; the shape of the partition plate is matched with the upper top surface of the pouring mold cavity, so that the partition plate can be clamped in a gap along with the mold to separate the space and realize sectional pouring.

5) Elastomer casting (casting thickness 20 mm): adding a catalyst lead isooctoate into the polyurethane elastomer component B, wherein the addition amount of the catalyst lead isooctoate is 3 per mill (wt)% of the polyurethane elastomer component B; then mixing the polyurethane elastomer A component with the polyurethane elastomer B component added with the catalyst (wherein the weight ratio of the AB component is 92: 100), and pouring;

the polyurethane elastomer A component and the polyurethane elastomer B component are selected from the railway building institute of China railway science research institute;

the casting thickness is 20mm, which is the thickness at the thinnest point, i.e., 28mm above the highest point at the top of the casting cavity.

6) And (4) after the elastomer is cast for 15-20min, taking out the partition plate.

7) Defoaming/top coating construction.

8) And (5) comprehensive self-checking/maintenance.

Comparative example 1

The pouring mode adopts a traditional mode and a self-leveling mode for pouring, the steps of inserting the partition plate and taking out the partition plate are omitted, no catalyst is additionally added in the step 5), and the method is otherwise the same as that of the embodiment 1. The casting thickness is 28mm, which is the thickness at the thinnest point, i.e., 28mm above the highest point at the top of the casting cavity.

The elastomeric stretch materials of example 1 and comparative example 1 described above were subjected to performance tests, and the results are shown in tables 1 and 2 below.

TABLE 1 elastomer material mixing Performance Table (original construction thickness 28mm)

TABLE 2 elastomer material mixing Property statistics Table (inclined plane casting technique thickness 20mm)

In addition, in the project (embodiment 1), the width of the expansion joint is 14cm, the length of the expansion joint is 11.88m, and the raw materials of each expansion joint can be saved by 18.45kg on average, so that the cost is greatly saved.

Having thus described the principal technical features and basic principles of the invention, and the advantages associated therewith, it will be apparent to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, but is capable of other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Furthermore, it should be understood that although the present description is described in terms of various embodiments, not every embodiment includes only a single embodiment, and such descriptions are provided for clarity only, and those skilled in the art will recognize that the embodiments described herein can be combined as a whole to form other embodiments as would be understood by those skilled in the art.