CN107162562A - A kind of subway tunnel concrete rapid restoring material and its preparation method and application - Google Patents

Abstract

The invention relates to a subway tunnel concrete rapid repair material and its preparation method and application. The rapid repair material comprises the following components in parts by mass: 100 parts of phosphate cement, 1-20 parts of aluminosilicate minerals, boric acid 1-10 parts, 0.01-0.04 parts of admixture, the rapid repair material can be used after adding water and stirring, the recommended water-binder ratio is 0.15-0.18, and its comprehensive performance is obviously better than ordinary sulphoaluminate cement-based repair materials, especially The early strength and bond strength of the material are more excellent. In addition, the material performance matching between the emergency repair material of the present invention and ordinary cement concrete is high, and it does not require special maintenance (such as watering, moisturizing, heating, etc.) after pouring, and can quickly open up subway traffic, which is conducive to popularization and application .

Description

A kind of subway tunnel concrete rapid repair material and its preparation method and application

technical field

The invention relates to the field of building special materials, in particular to a subway tunnel concrete rapid repair material and its preparation method and application.

Background technique

With the rapid development of my country's economy, the acceleration of urbanization, the large increase of urban population, the increasing popularity of various means of transportation, the structural defects of urban roads and the problems of inefficient allocation and utilization of road resources are constantly emerging, and the problem of traffic congestion is becoming more and more serious. For these problems, turning traffic engineering underground has become the preferred solution. Because the subway is not affected by weather conditions and has the characteristics of safe and fast transportation, it has become the backbone of the public passenger transportation network in many big cities. Since the first subway in London was built in the 1860s, urban rail transit in many countries has developed vigorously. The construction of urban rail transit in my country began with the Beijing subway in the 1960s. With the continuous growth of the national economy and the continuous expansion of the city scale, more than ten cities such as Beijing, Shanghai, and Guangzhou have successively built subways and light rail lines. Practice has proved that the operation of the subway plays a huge role in alleviating the traffic pressure in the city. Therefore, in recent years, more than 20 cities in my country will build rail transit lines.

Due to the particularity of the project, the concrete of the subway tunnel is in a humid and groundwater environment, not only facing a more serious carbonation environment than the ground and the pressure penetration of groundwater, but also being eroded by various corrosive media in groundwater. At the same time, it is also affected by load, train vibration, stray current, etc., which greatly intensifies the erosion of concrete. Therefore, compared with other construction projects, the durability degradation of subway tunnel concrete due to erosion is particularly prominent, and is directly related to the safety and service life of subway concrete structures.

The subway project is a national key project. The so-called subway is a century-old project, which means that the design service life of the subway civil structure engineering is 100 years. After several years of operation, due to various erosions, the concrete damage of the subway shield tunnel has become more and more serious, seriously affecting the normal operation and safety of the subway. Therefore, the repair of the concrete damage of the subway shield tunnel has become an urgent problem.

In view of the characteristics of the subway, the repair of subway concrete defects can only be carried out at night, and the maintenance time given every day is very short, and the entire repair procedure is usually completed within 4 hours. 1-2 hours after the construction is completed, the strength can meet the minimum requirements for resuming subway operation, so as not to affect the normal operation of vehicles. In addition, when repairing the defects on the top of the subway, it is particularly required that the bonding strength between the repairing material and the subway segment concrete is high and develops quickly, so as to avoid falling off and affecting the safe operation of the train.

At present, the most commonly used rapid repair materials for subways include inorganic materials such as sulphoaluminate cement and modified Portland cement, and organic polymer materials such as epoxy resin and acrylic acid. Traditional organic polymer materials have fast setting and hardening and high bond strength, but the elastic modulus and thermal expansion coefficient of the subway segment concrete are greatly different and do not match, and fatigue cracking and falling off of the bonding interface are easy to occur; inorganic rapid repair materials The properties are just the opposite. The present invention is proposed in order to overcome the shortcoming of fast repairing materials and integrate the advantages of organic and inorganic materials.

Contents of the invention

The purpose of the present invention is to provide a subway tunnel concrete rapid repair material and its preparation method and application in order to overcome the above-mentioned defects in the prior art.

The purpose of the present invention can be achieved through the following technical solutions:

The invention relates to a quick repair material for subway tunnel concrete, which comprises the following components in parts by mass: 100 parts of phosphate cement, 1-20 parts of aluminosilicate minerals, 1-10 parts of boric acid, and 0.01-0.04 parts of admixture.

As a preferred embodiment, the phosphate cement is magnesium ammonium phosphate cement, which is directly purchased from Hangzhou Luxiuren Technology Co., Ltd., and is used to prepare the phosphate cement used in the restoration king mortar ZG01 product.

As a preferred embodiment, the aluminosilicate mineral is one or a combination of metakaolin and slag powder. The specific surface area of the aluminosilicate mineral is 300-500m ² /kg.

As a preferred embodiment, the boric acid is a powder product with a purity of ≥95%.

As a preferred embodiment, the additive is tea saponin.

The preparation method of the concrete rapid repair material for subway tunnels comprises the following specific steps: weighing phosphate cement, aluminosilicate minerals, boric acid and admixtures in proportion, placing them in a mixer and mixing them to obtain the target product.

Concrete rapid repair materials for subway tunnels are used to repair subway diseases.

As a preferred embodiment, its application method is specifically:

(1) Take quick repair materials, mix them with water and sand and gravel, and make them into emergency repair materials;

(2) Before repairing the subway damage, clean the damaged concrete layer. It is not necessary to spray and wet the surface, and then apply the emergency repair material prepared in step (1). After the construction, no special maintenance such as watering is required And heating, etc., according to the needs of the project, after standing still for about 1 hour, the restoration will be completed, and the subway operation will be opened.

As a more preferred embodiment of the above, the mass ratio of the rapid repair material to water in step (1) is 1: (0.1-0.18).

Compared with the prior art, the emergency repair material of the present invention has the following advantages:

(1) High strength, rapid development, and the strength will continue to grow in the later stage;

(2) High bonding strength with subway segment concrete;

(3) Match with cement concrete material properties such as thermal expansion coefficient, elastic modulus, etc.;

(4) The subway traffic can be quickly opened;

(5) High volume stability and small drying shrinkage;

(6) Excellent durability, such as good resistance to stress fatigue and protection of steel bars from corrosion.

(7) The present invention overcomes the shortcomings of traditional rapid repair materials and integrates the advantages of organic and inorganic materials, thereby providing a fast, efficient and durable repair material for rapid repair of subway diseases. This patent will provide new technical means for the treatment of existing subway seam diseases, and has great social significance and significant economic benefits.

detailed description

The present invention will be described in detail below in conjunction with specific embodiments.

In each of the following examples 1-4, the phosphate cement used is magnesium ammonium phosphate cement, and the aluminosilicate mineral is a composite of metakaolin and slag powder at a mass ratio of 9:1, and its specific surface area is 300 to 500 m ² / kg. Boric acid is a powder product with a purity of ≥95%. The additive is tea saponin.

When the rapid repair material made by each of the following embodiments is used for repairing subway defects, the following specific steps are adopted for construction: (1) get the rapid repair material, stir fully with water and sand, and make it into a repair material; Before the repair of the disease, the damaged concrete layer should be cleaned up. It is not necessary to spray and wet the surface, and then apply the emergency repair material prepared in step (1). After the construction, no special maintenance such as watering and heating is required. According to the needs of the project, after standing still for about 1 hour, the restoration will be completed, so that the subway can be opened for operation.

Example 1:

When the repair material: water: sand = 1:0.12:1, the performance index of the repair material is shown in Table 1.

Example 2:

When repair materials: water: sand = 1:0.12:1, its performance indicators are shown in Table 1.

Example 3:

When repair materials: water: sand = 1:0.12:1, its performance indicators are shown in Table 1.

Example 4:

When repair materials: water: sand = 1:0.12:1, its performance indicators are shown in Table 1.

Table 1

Note:

(1) The comparison sample is a commonly used sulphoaluminate cement-based emergency repair material, and its mix ratio is sulphoaluminate cement: water: sand=1:0.40:1.0;

(2) The size of the test piece is 4cm×4cm×16cm;

(3) The bonding strength is the bonding flexural strength between the emergency repair material and the cement concrete, and the flexural strength of the concrete itself is 9.1MPa;

(4) "≥" means that when the bond strength is measured, the fracture position of the bonded specimen is in the concrete body material, that is, the bond strength is greater than the flexural strength of the concrete itself.

From Table 1, it can be clearly seen that compared with the traditional sulphoaluminate cement-based emergency repair material (comparative sample), the comprehensive performance of the emergency repair material of the present invention is obviously better, especially the early strength before 1d, and the The bond strength between salt cement concrete is particularly outstanding.

The performance of the emergency repair material of the present invention can be obviously improved by optimizing the ratio of the materials. By adding boric acid, because it can react with MgO particles in phosphate cement, a thin layer of magnesium borate salt is formed on its surface, thereby hindering the reaction of phosphate and MgO, so the repairability of the repair material of the present invention can be significantly increased. operating time, but reduces its early strength, and has little effect on the strength after 7 days; adding an appropriate amount of aluminosilicate minerals, because the active Si and Al components contained in it can participate in the coagulation hardening reaction, can increase the content of cementing minerals , so it is beneficial to improve the strength and bonding performance of the emergency repair material of the present invention, and can reduce its production cost; adding an appropriate amount of admixture, because it can introduce a large number of tiny spherical bubbles in the slurry, reduce the viscosity and density of the slurry , so it can significantly improve the construction performance of emergency repair materials and reduce the flow and detachment of repair slurry from the repair facade, but its compressive strength will be reduced to a certain extent. Therefore, according to the actual requirements of the site engineering, these material parameters can be adjusted to obtain the most cost-effective emergency repair materials.

Example 5

A rapid repair material for subway tunnel concrete, comprising the following components in parts by mass: 100 parts of phosphate cement, 1 part of aluminosilicate mineral, 1 part of boric acid and 0.04 part of admixture. The phosphate cement is magnesium ammonium phosphate cement. The aluminosilicate mineral is metakaolin with a specific surface area of 300-500m ² /kg. The boric acid is a powder product with a purity of ≥95%. The admixture is tea saponin, which is a substance extracted from the residual tea dregs of camellia oleifera enterprises.

When the rapid repair material made according to the above formula is used for repairing subway defects, it is the same as ordinary repair cement, and the rapid repair material, water and sand are mixed according to the mass ratio of 1:0.1:1. For other methods, refer to the previous application methods.

Example 6

A rapid repair material for subway tunnel concrete, comprising the following components in parts by mass: 100 parts of phosphate cement, 20 parts of aluminosilicate minerals, 10 parts of boric acid and 0.04 parts of admixture. The phosphate cement is magnesium ammonium phosphate cement. The aluminosilicate mineral is slag powder, and its specific surface area is 300-500m ² /kg. The boric acid is a powder product with a purity of ≥95%. The admixture is tea saponin, which is a substance extracted from the residual tea dregs of camellia oleifera enterprises.

When the rapid repair material made according to the above formula is used for repairing subway defects, it is the same as ordinary repair cement, and the rapid repair material, water and sand are mixed according to the mass ratio of 1:0.18:1. For other methods, refer to the previous application methods.

Example 7

A rapid repair material for subway tunnel concrete, comprising the following components in parts by mass: 100 parts of phosphate cement, 12 parts of aluminosilicate minerals, 4 parts of boric acid and 0.025 parts of admixture. The phosphate cement is magnesium ammonium phosphate cement. The aluminosilicate mineral is a composite of metakaolin and slag powder at a mass ratio of 2:1, and its specific surface area is 300-500m ² /kg. The boric acid is a powder product with a purity of ≥95%. The admixture is tea saponin, which is a substance extracted from the residual tea dregs of camellia oleifera enterprises.

When the rapid repair material made according to the above formula is used for repairing subway defects, it is the same as ordinary repair cement, and the rapid repair material, water and sand are mixed according to the mass ratio of 1:0.12:1. For other methods, refer to the previous application methods.

Example 8

A rapid repair material for subway tunnel concrete, comprising the following components in parts by mass: 100 parts of phosphate cement, 8 parts of aluminosilicate minerals, 6 parts of boric acid and 0.03 parts of admixture. The phosphate cement is magnesium ammonium phosphate cement. The aluminosilicate mineral is a composite of metakaolin and slag powder at a mass ratio of 1:2, and its specific surface area is 300-500m ² /kg. The boric acid is a powder product with a purity of ≥95%. The admixture is tea saponin, which is a substance extracted from the residual tea dregs of camellia oleifera enterprises.

When the rapid repair material made according to the above formula is used for repairing subway defects, it is the same as ordinary repair cement, and the rapid repair material, water and sand are mixed according to the mass ratio of 1:0.11:1. For other methods, refer to the previous application methods.

The above descriptions of the embodiments are for those of ordinary skill in the art to understand and use the invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments, and apply the general principles described here to other embodiments without creative effort. Therefore, the present invention is not limited to the above-mentioned embodiments. Improvements and modifications made by those skilled in the art according to the disclosure of the present invention without departing from the scope of the present invention should fall within the protection scope of the present invention.

Claims (10)

1. a kind of subway tunnel concrete rapid restoring material, it is characterised in that include the component of following mass fraction：Phosphate 100 parts of cement, 1-20 parts of aluminosilicate mineral, 1-10 parts of boric acid, 0.01-0.04 parts of additive.

2. a kind of subway tunnel concrete rapid restoring material according to claim 1, it is characterised in that described phosphoric acid Salt cement is ammonium magnesium phosphate cement.

3. a kind of subway tunnel concrete rapid restoring material according to claim 1, it is characterised in that described sial Hydrochlorate mineral are the compound of one or both of metakaolin, slag powders.

4. a kind of subway tunnel concrete rapid restoring material according to claim 3, it is characterised in that described sial The specific surface area of hydrochlorate mineral is 300~500m²/kg。

5. a kind of subway tunnel concrete rapid restoring material according to claim 1, it is characterised in that described boric acid For powder product, its purity >=95%.

6. a kind of subway tunnel concrete rapid restoring material according to claim 1, it is characterised in that described is additional Agent is Tea Saponin.

7. the preparation method of the subway tunnel concrete rapid restoring material as described in claim 1-6 is any, it is characterised in that Including step in detail below：Phosphate cement, aluminosilicate mineral, boric acid and additive are weighed in proportion, are placed in batch mixer Mixing, that is, obtain purpose product.

8. the subway tunnel concrete rapid restoring material as described in claim 1-6 is any is used to repair subway disease.

9. the application of subway tunnel concrete rapid restoring material according to claim 8, it is characterised in that its application side Method is specially：

(1) rapid restoring material is taken, it is abundant with water, sandstone stirring, it is made into repairing material；

(2) subway disease is carried out before repairing construction, the concrete layer of damage is cleaned out, then smearing step (1) is made into Repairing material, stands, that is, completes to repair.

10. the application of subway tunnel concrete rapid restoring material according to claim 9, it is characterised in that step (1) The mass ratio of middle rapid restoring material and water is 1：(0.1-0.18).