CN114644486A - Bridge pier erosion wear resistant repair segment and preparation method thereof - Google Patents

Abstract

The invention discloses a bridge pier erosion wear resistant repair segment and a preparation method thereof, wherein the repair segment comprises the following raw materials in parts by weight: 480 parts of water 381-. The repair segment for resisting the erosion and wear of the pier has the advantages of strong tensile strength and compressive strength, excellent toughness, capability of being still connected together after being damaged by impact, no fragmentation, high bonding strength, high erosion resistance and capability of more effectively resisting the erosion and wear of the pier.

Description

A repaired segment for resisting erosion and wear of bridge piers and preparation method thereof

technical field

The invention relates to the technical field of building materials, in particular to a repaired segment with resistance to erosion and wear of bridge piers and a preparation method thereof.

Background technique

In my country's rivers, the sediment content is generally large. There are more than 40 rivers with an annual sediment transport capacity of more than 10 million tons. Other rivers also have different degrees of sediment transport. The erosion and wear of hydraulic concrete structures or bridge piers caused by sediment carried by water flow is inevitable. Once the erosion and wear damage of bridge piers occurs, the internal defects of concrete will be exposed and enlarged. The natural environment where bridge piers are located is generally harsh. After exposure, other environmental factors such as chloride attack, sulfate attack, dissolution, freeze-thaw cycles, etc. will be more likely to damage it.

Therefore, the erosion and wear of hydraulic concrete structures or bridge piers has always been a difficult problem in engineering, and the erosion and wear of concrete structures or bridge piers is difficult and expensive to repair. In the past, ultra-low water-to-binder ratio engineering cement-based composite materials (polypropylene fibers) were used to repair the piers after erosion, but the toughness can be further improved; the jacket method (underwater pier fiber sleeve protection system) was used to repair the piers. Putting a permanent protective jacket on the column body can reduce the cost. However, the jacket is often repaired when the pier is submerged in water, and it is dangerous to need divers to go into the water to inspect and clean the damaged pier; using a small set of box cofferdams The method can leave a suitable working space, and increase the section of reinforced concrete within the scope of the pier column disease, but it will increase the self-weight of the structure, which will have a certain impact on the safety and integrity of the entire structure. After repairing the pier column The erosion resistance has not improved. Therefore, concrete materials with good erosion resistance are urgently needed as repair materials, and repair technologies such as fast, convenient, reliable performance and controllable cost are used to achieve the repair of pier erosion and wear damage.

SUMMARY OF THE INVENTION

In order to solve the above-mentioned technical problems, the purpose of the present invention is to provide a repaired segment with resistance to erosion and wear of bridge piers and a preparation method thereof, so as to solve the problem of poor erosion resistance of existing concrete materials.

The technical solution of the present invention to solve the above-mentioned technical problems is as follows: providing a repair segment with resistance to erosion and wear of bridge piers, comprising the following raw materials in parts by weight: 381-480 parts of water, 826-1080 parts of cement, 60-191 parts of silica fume, 120-254 parts of beads, 432-457 parts of fine aggregate, 15-22 parts of water reducing agent and 25-28 parts of PVA fiber.

The beneficial effects of the present invention are as follows: the repaired segment of the present invention that resists erosion and wear of bridge piers not only has strong tensile and compressive strengths, but also has excellent toughness, and is still connected together after being damaged by impact without breaking. It has high bonding strength and high erosion resistance, can more effectively resist the erosion and wear of bridge piers, and is suitable for the repair of concrete bridge piers when they are subjected to erosion and wear.

The raw material of the repairing segment for anti-erosion and wear of bridge piers of the present invention is composed of adding PVA fiber, silica fume, microbeads and admixtures to some components of traditional concrete. Silica fume can improve the strength and compactness of concrete; microbeads can reduce the viscosity of concrete, reduce water consumption and mixing time. The addition of a certain proportion of silica fume and microbeads can improve the strength of traditional ordinary concrete, and can be better combined with PVA fibers; PVA fibers have the effect of strengthening, toughening and cracking resistance. When micro-cracks are formed inside the repaired segment, PVA fiber can prevent the development of cracks. When the angle between the impact direction and the surface of the repaired segment that resists erosion and wear of bridge pier is small, the surface of the repaired segment that resists erosion and wear of bridge pier is mainly affected by the cutting action of sand along the surface of the test block. When the surface material of the repaired segment worn by the erosion and wear of the bridge pier is about to be detached, the restraint of the PVA fiber prevents it from peeling off from the matrix, that is, the peeling of the material needs to consume more energy. Therefore, adding PVA fiber to concrete mixed with a certain amount of silica fume and microbeads can significantly improve the erosion resistance of the repaired segment against erosion wear of bridge piers.

On the basis of above-mentioned technical scheme, the present invention can also do following improvement:

Further, the above-mentioned repairing segment includes the following raw materials by weight: 381 parts of water, 826 parts of cement, 191 parts of silica fume, 254 parts of microbeads, 457 parts of fine aggregate, 19 parts of water reducing agent and 26 parts of PVA fibers.

Further, the diameter of the PVA fibers is 30-35 μm, and the aspect ratio is 340-400.

Further, the diameter of the PVA fibers was 32 μm, and the aspect ratio was 375.

Further, the particle size of the microbeads is 0.1-5 μm.

Further, the particle size of the beads was 0.3 μm.

Further, the fine aggregate is quartz sand or river sand; wherein, the hardness of the quartz sand is 5-7 degrees.

Further, the water reducing agent is a polycarboxylate water reducing agent, the water reducing rate is 28-32%, and the solid content is 25-30%.

Further, the water reducing agent is a polycarboxylate water reducing agent, the water reducing rate is 30%, and the solid content is 27%.

Further, the above-mentioned repair segment for anti-erosion and wear of bridge piers includes an arc-shaped prefabricated repair segment. One end of the arc-shaped prefabricated repair segment is provided with a left edge convex groove, the other end is provided with a right edge groove, and the left edge convex groove and the right edge are provided. grooves to match.

The beneficial effect of adopting the above-mentioned further technical scheme is: the arc-shaped prefabricated repair segment is sleeved on the bridge pier, and the horizontal connection is completed by engaging the left-edge convex groove and the right-edge groove, and a certain amount of coating can be applied on the surface of the right-edge groove The expansion mortar can make the process of clamping more relaxed. After clamping, the excess mortar is removed to form a pier protective sleeve to avoid erosion and wear of the pier. When the left edge convex groove and the right edge groove are engaged and fixed. When the vertical joint is located on the back surface of the pier, it can effectively avoid the erosion and wear of the pier.

Further, the number of arc-shaped prefabricated repair segments is at least two.

Further, the number of arc-shaped prefabricated repair segments is three.

The beneficial effects of adopting the above-mentioned further technical solutions are: when the number of arc-shaped prefabricated repair segments is greater than 3, there are many vertical joints, which will cause inconvenient installation and affect the effect of resisting erosion and wear of bridge piers; When the number of prefabricated repair segments is less than 3, the weight is heavy, which is inconvenient for workers to install. When the number of arc prefabricated repair segments is 3, the number is just moderate.

Further, the top of the arc-shaped prefabricated repairing segment is provided with an upper edge groove, and the bottom of the arc-shaped prefabricated repair segment is provided with a lower edge convex groove, and the upper edge groove and the lower edge convex groove are matched.

The beneficial effect of adopting the above-mentioned further technical solutions is: by engaging the upper groove of one arc-shaped prefabricated repair segment with the lower edge convex groove of another arc-shaped prefabricated repair segment, the vertical connection is completed, and the upper Apply a certain amount of expansion mortar along the surface of the groove, which can make the clamping process more relaxed. After clamping, the excess expansion mortar can be removed, so as to increase the resistance of the repair segment against erosion and wear of the bridge pier according to the height of the water level of the bridge pier. Height, which increases the vertical seam of the installed curved prefabricated repair segment aligned with the vertical seam of the bottom.

Further, the thickness of the arc-shaped prefabricated repair segment is 3-5 cm, and the height is 45-55 cm.

Further, the arc-shaped prefabricated repair segment is provided with a first transverse connection groove and a second transverse connection groove, the first transverse connection groove is provided near the left edge convex groove, and the second transverse connection groove is correspondingly provided near the right edge groove. .

The beneficial effects of adopting the above-mentioned further technical solutions are: connecting the first transverse connection groove and the second transverse connection groove located at the same height through matching I-shaped joints, which can make the transverse connection of the arc-shaped prefabricated repair segments more reliable, It is also possible to pour a certain amount of expansion mortar in the first transverse connection groove and the second transverse connection groove, and then use the I-shaped joint to connect, and then extrude the excess expansion mortar, so as to further improve the arc prefabricated repair segment. Lateral connections are more reliable.

When the arc-shaped prefabricated repair segment of the present invention is installed on the bridge pier, two narrow vertical joints will be formed on both sides of the water flow direction, and a wider vertical joint will be formed on the back flow direction of the bridge pier. The narrower vertical joints do not need to be treated, and their influence on the erosion and wear resistance of the piers can be ignored, while the wider vertical joints need to be sealed with expansion mortar to ensure efficient resistance to the erosion and wear of the bridge piers.

Further, the arc-shaped prefabricated repair segment is provided with a reserved hole for planting reinforcement.

The beneficial effects of adopting the above-mentioned further technical solutions are as follows: by implanting steel bars in the reserved holes for planting reinforcement, the repaired segment that resists erosion and wear of the bridge pier can be better connected to the pier column, and finally the expansion is poured in the reserved holes for planting reinforcement. The mortar can be closed.

Further, the number of reserved holes for planting bars is at least 4.

The present invention also provides a method for preparing the above-mentioned repairing segment with resistance to erosion and wear of bridge piers, comprising the following steps:

(1) Mix half the weight of cement, silica fume, microbeads and fine aggregate evenly, then add half the weight of PVA fiber while stirring, and then add the remaining cement, silica fume, microbeads and fine aggregate, After the mixing is uniform, the remaining PVA fibers are added while stirring, and finally the mixture of water reducing agent and water is added, and the mixing is uniform to obtain the polyvinyl alcohol concrete composite material;

(2) The polyvinyl alcohol concrete composite material is put into the mold of the repair segment that is resistant to erosion and wear of the bridge pier, and after 20-26 hours, it is demolded and cured to obtain an arc-shaped prefabricated repair segment, which is installed on the bridge pier and made into To obtain repaired segments that resist erosion and wear of bridge piers.

Further, after demoulding, the curing process is completed for 25-30 days under the conditions of 20±2° C. and relative humidity above 95%.

The present invention has the following beneficial effects:

1. The repaired segment with resistance to erosion and wear of bridge piers prepared by the present invention not only has strong tensile and compressive strengths, but also has high erosion resistance.

2. The repairing segment for anti-erosion and wear of bridge piers of the present invention has a simple structure, is convenient to install, and has high practicability, can effectively resist the erosion and wear of bridge piers, and solves the problem that honeycomb pitted surface and aggregates appear on the surface of existing bridge piers when they are eroded. Exposed, and even cause the bridge safety risk problem caused by the falling off of the protective layer, the exposed steel bar, and the reduction of the cross-sectional area.

Description of drawings

Fig. 1 is the overall schematic diagram of the repaired segment of the present invention that resists erosion and wear of bridge piers;

Fig. 2 is the front schematic diagram of the arc-shaped prefabricated repair segment of the present invention;

Fig. 3 is the reverse schematic diagram of the arc-shaped prefabricated repair segment of the present invention;

4 is a partial enlarged view of the convex groove along the left edge of the arc-shaped prefabricated repair segment of the present invention;

5 is a partial enlarged view of the groove at the right edge of the arc-shaped prefabricated repair segment of the present invention;

Fig. 6 is the top view of the repaired segment of the present invention that resists erosion and wear of bridge piers;

Fig. 7 is the I-shaped joint of the arc-shaped prefabricated repair segment of the present invention;

Fig. 8 is the compressive strength diagram of each arc-shaped prefabricated repair segment;

Fig. 9 is the mass loss diagram of each arc-shaped prefabricated repair segment when the impact angle is 90°;

Figure 10 is a graph of the mass loss of each arc-shaped prefabricated repair segment when the impact angle is 30°;

Figure 11 is a graph showing the relationship between mass loss and erosion time of the arc-shaped prefabricated repair segments obtained in Example 3 and Comparative Example 1;

12 is a graph showing the relationship between mass loss and erosion velocity of the arc-shaped prefabricated repair segments obtained in Example 3 and Comparative Example 1;

13 is a graph showing the relationship between mass loss and erosion sand content of the arc-shaped prefabricated repair segments prepared in Example 3 and Comparative Example 1.

Among them, 1. Arc-shaped prefabricated repair segment; 2. Left-edge convex groove; 3. Right-edge groove; 4. Bridge pier; 5. Upper-edge groove; 6. Lower-edge convex groove; 8. The second horizontal connection slot; 9. Narrower vertical seam; 10. Wider vertical seam; 11. Reserved holes for planting bars; 12. I-shaped joint.

Detailed ways

The principles and features of the present invention are described below with reference to the accompanying drawings. The examples are only used to explain the present invention, but not to limit the scope of the present invention. If the specific conditions are not indicated in the examples, it is carried out according to the conventional conditions or the conditions suggested by the manufacturer. The reagents or instruments used without the manufacturer's indication are conventional products that can be purchased from the market.

Example:

Please refer to Fig. 1-7 , a repair segment against erosion and wear of bridge piers, including an arc-shaped prefabricated repair segment 1, one end of the arc-shaped prefabricated repair segment 1 is provided with a left edge convex groove 2, and the other end is provided with a right edge The groove 3, the left edge convex groove 2 and the right edge groove 3 are matched; the arc-shaped prefabricated repair segment 1 is sleeved on the bridge pier 4. The arc-shaped prefabricated repair segment 1 is sleeved on the bridge pier 4, and the lateral connection is completed by engaging the left edge groove 2 and the right edge groove 3 to complete the horizontal connection. The clamping process is more relaxed. After clamping, the excess mortar is removed to form a protective cover for the bridge pier 4 to avoid erosion and wear of the bridge pier 4. When the left edge convex groove 2 and the right edge groove 3 are engaged and fixed, When the vertical joint is located on the backwater surface of the bridge pier 4, the erosion and wear of the bridge pier 4 can be more effectively avoided.

The quantity of the arc-shaped prefabricated repair segment 1 is 3. When the number of arc-shaped prefabricated repair segments 1 is greater than 3, there are many vertical joints, which will cause inconvenience in installation and affect the effect of resisting erosion and wear of bridge piers; when the number of arc-shaped prefabricated repair segments 1 is less than 3 When the number of arc-shaped prefabricated repair segments 1 is 3, the number is just moderate, and the left edge convex groove of one of the arc-shaped prefabricated repair segments 1 is installed. 2. Engage with the groove 3 on the right edge of another arc-shaped prefabricated repair segment 1, and then perform the above operations in sequence.

In order to increase the height of the repaired segment against erosion and wear of the bridge pier, the top of the arc-shaped prefabricated repair segment 1 is provided with an upper edge groove 5, the bottom of the arc-shaped prefabricated repair segment 1 is provided with a lower edge convex groove 6, and the upper edge is concave. The groove 5 is matched with the lower edge convex groove 6 . By engaging the upper edge groove 5 of one arc-shaped prefabricated repair segment 1 with the lower edge convex groove 6 of another arc-shaped prefabricated repair segment 1 to complete the vertical connection, the surface of the upper edge groove 5 can be coated with A certain amount of expansion mortar can make the clamping process more relaxed. After clamping, the excess expansion mortar can be removed, so that the height of the repair segment that resists erosion and wear of the bridge pier can be increased according to the height of the pier 4 water level. The vertical seam of the installed arc-shaped prefabricated repair segment 1 is aligned with the vertical seam of the bottom.

The thickness of the arc-shaped prefabricated repair segment 1 is 3-5 cm, and the height is 45-55 cm. In this way, it can not only effectively resist the erosion and wear of bridge piers, but also facilitate installation.

In order to make the lateral connection of the arc-shaped prefabricated repair segment 1 more reliable, the arc-shaped prefabricated repair segment 1 is provided with a first transverse connection slot 7 and a second transverse connection slot 8, and the first transverse connection slot 7 is arranged near the left edge. At the convex groove 2, the second transverse connecting groove 8 is correspondingly disposed near the groove 3 along the right edge. Connecting the first transverse connection groove 7 and the second transverse connection groove 8 at the same height through the matching I-shaped joint 12 can make the transverse connection of the arc-shaped prefabricated repair segment 1 more reliable, and can also be used in the first transverse connection. A certain amount of expansion mortar is poured into the transverse connection groove 7 and the second transverse connection groove 8, and then connected with the I-shaped joint 12, the excess expansion mortar is extruded, so as to further connect the arc-shaped prefabricated repair segment 1. more reliable. When the arc-shaped prefabricated repair segment 1 of the present invention is installed on the bridge pier 4, two narrow vertical joints 9 will be formed on both sides of the water flow direction, and a wider vertical joint 9 will be formed in the back water flow direction of the bridge pier 4. To the joint 10, the narrow vertical joint 9 does not need to be treated, and its impact on the erosion and wear of the bridge pier can be ignored, and the wider vertical joint 10 needs to be closed with expansion mortar to ensure efficient Resist erosion and wear of bridge piers.

In order to connect the eroded and worn repair segment of the bridge pier with the pier column, the arc-shaped prefabricated repair segment 1 is provided with reserved holes 11 for planting reinforcement, and the number of the reserved holes 11 for planting reinforcement is at least four. By implanting steel bars in the reserved holes for planting reinforcement, the repair segments that resist erosion and wear of the pier can be better connected to the pier column, and finally, the expansion mortar can be poured in the reserved holes for planting reinforcement to seal.

When the repairing segment of the present invention is used to resist erosion and wear of bridge piers for repair, it is specifically carried out according to the following methods:

1. Pretreatment of eroded bridge piers

Chisel off the failed surface layer of the erosion part of the concrete pier, clean the surface of the concrete pier, and smooth the surface with M15 grade expansion mortar. The mixing ratio of cement, river sand and water is 1:5.27:1.16, and the expansion agent is mixed The amount is 10%, and it is sealed and maintained with plastic film under normal construction conditions; if the steel bars in the bridge piers have been exposed due to erosion, the impurities between the steel bars need to be removed, and the surface of the steel bars should be derusted before pouring into the expanded concrete. The concrete label is the same as the concrete label of the original bridge pier, and its expansion agent dosage is 10%, and it is sealed and cured with plastic film under normal construction conditions;

2. Prepare an arc-shaped prefabricated repair segment according to the method of the present invention;

3. Install the arc-shaped prefabricated repair segment prepared by the present invention to the concrete bridge pier below the water level height, then insert the connecting steel bar into the reserved hole, and the connecting steel bar cannot leak outside the segment, and then pour expansive concrete to seal the reserved hole and The transverse connecting grooves between different segments of the same height and the vertical wide seams with a width of 4 cm.

The specific parameters of the raw materials used in the preparation of the repairing segment against erosion and wear of bridge piers in the present invention are as follows: the chemical composition of silica fume is shown in Table 1; the main chemical indexes of microbeads are shown in Table 2; the physical property indexes of quartz sand are shown in Table 3; The physical properties of the river sand are: medium sand, the fineness modulus is 2.81, the bulk density is 1460kg/m ³ , and the apparent density is 2500kg/m ³ ; the physical properties of the PVA fiber are shown in Table 4.

Table 1 Silica fume chemical composition

Element SiO₂ CaO MgO Fe₂O₃ Al₂O₃ Loss Content (mt%) 91.27 0.45 0.92 0.45 0.17 2.88

Table 2 Main chemical indicators of microbeads

Element SiO₂ CaO MgO Al₂O₃ Fe₂O₃ Na₂O K₂O SO₃ Loss Content (mt%) 56.5 4.8 1.3 26.5 5.3 1.4 3.3 0.7 <1

Table 3 Physical properties index of quartz sand

Table 4 Physical properties of PVA fiber

Example 1

A repair segment with resistance to erosion and wear of bridge piers, comprising the following raw materials in parts by weight: 381 parts of water, 1080 parts of ordinary Portland cement, 64 parts of silica fume, 127 parts of microbeads, 457 parts of quartz sand, and polycarboxylate water reducing Among them, the particle size of microbeads is 0.17 μm; the hardness of quartz sand is 57 degrees; the water reducing rate of polycarboxylate water reducing agent is 287%, and the solid content is 257%; The diameter is 30 μm and the aspect ratio is 340.

A method for preparing a repair segment with resistance to erosion and wear of a bridge pier, comprising the following steps:

(1) Mix the ordinary Portland cement, silica fume, microbeads and quartz sand with half the weight evenly, then add half the weight of PVA fiber while stirring, and then add the remaining ordinary Portland cement, silica fume, After the microbeads and the quartz sand are mixed evenly, the remaining PVA fibers are added while stirring, and finally the mixture of polycarboxylate water reducing agent and water is added, and the mixture is evenly mixed to obtain the polyvinyl alcohol concrete composite material;

(2) The polyvinyl alcohol concrete composite material is put into the mold of the repair segment for the erosion and wear resistance of the bridge pier, and the mold is demolded after 24 hours. After the repair segment is installed on the bridge pier, the repair segment resistant to erosion and wear of the bridge pier is obtained.

Example 2:

A repair segment with resistance to erosion and wear of bridge piers, comprising the following raw materials in parts by weight: 381 parts of water, 953 parts of ordinary Portland cement, 127 parts of silica fume, 191 parts of microbeads, 457 parts of river sand, and polycarboxylate water reducing 19 parts of additives and 26 parts of PVA fibers; the particle size of microbeads is 5 μm; the hardness of quartz sand is 7 degrees; the water reducing rate of polycarboxylate water reducing agent is 32%, and the solid content is 30%; the diameter of PVA fibers is 35 μm, and the aspect ratio is 400.

A method for preparing a repair segment with resistance to erosion and wear of a bridge pier, comprising the following steps:

(1) Mix the ordinary Portland cement, silica fume, microbeads and quartz sand with half the weight evenly, then add half the weight of PVA fiber while stirring, and then add the remaining ordinary Portland cement, silica fume, After the microbeads and the quartz sand are mixed evenly, the remaining PVA fibers are added while stirring, and finally the mixture of polycarboxylate water reducing agent and water is added, and the mixture is evenly mixed to obtain the polyvinyl alcohol concrete composite material;

(2) The polyvinyl alcohol concrete composite material is put into the mold of the repair segment for the erosion and wear resistance of the bridge pier, and the mold is demolded after 24 hours. After the repair segment is installed on the bridge pier, the repair segment resistant to erosion and wear of the bridge pier is obtained.

Example 3:

A repair segment with resistance to erosion and wear of bridge piers, comprising the following raw materials in parts by weight: 381 parts of water, 826 parts of ordinary Portland cement, 191 parts of silica fume, 254 parts of microbeads, 457 parts of quartz sand, and polycarboxylate water-reduced Among them, the particle size of microbeads is 0.3 μm; the hardness of quartz sand is 6 degrees; the water reducing rate of polycarboxylate water reducing agent is 30%, and the solid content is 27%; The diameter is 32 μm and the aspect ratio is 375.

A method for preparing a repair segment with resistance to erosion and wear of a bridge pier, comprising the following steps:

(1) Mix the ordinary Portland cement, silica fume, microbeads and quartz sand with half the weight evenly, then add half the weight of PVA fiber while stirring, and then add the remaining ordinary Portland cement, silica fume, After the microbeads and the quartz sand are mixed evenly, the remaining PVA fibers are added while stirring, and finally the mixture of polycarboxylate water reducing agent and water is added, and the mixture is evenly mixed to obtain the polyvinyl alcohol concrete composite material;

(2) The polyvinyl alcohol concrete composite material is put into the mold of the repair segment for the erosion and wear resistance of the bridge pier, and the mold is demolded after 24 hours. After the repaired segment is installed on the bridge pier, the repaired segment with resistance to erosion and wear of the bridge pier is obtained, with a thickness of 4 cm and a height of 50 cm.

Example 4:

A repair segment with resistance to erosion and wear of bridge piers, comprising the following raw materials in parts by weight: 432 parts of water, 987 parts of ordinary Portland cement, 62 parts of silica fume, 185 parts of microbeads, 444 parts of quartz sand, and polycarboxylate water-reduced Among them, the particle size of microbeads is 0.3 μm; the hardness of quartz sand is 6 degrees; the water reducing rate of polycarboxylate water reducing agent is 29%, and the solid content is 26%; The diameter is 33 μm and the aspect ratio is 350.

A method for preparing a repair segment with resistance to erosion and wear of a bridge pier, comprising the following steps:

(1) Mix the ordinary Portland cement, silica fume, microbeads and quartz sand with half the weight evenly, then add half the weight of PVA fiber while stirring, and then add the remaining ordinary Portland cement, silica fume, After the microbeads and the quartz sand are mixed evenly, the remaining PVA fibers are added while stirring, and finally the mixture of polycarboxylate water reducing agent and water is added, and the mixture is evenly mixed to obtain the polyvinyl alcohol concrete composite material;

(2) The polyvinyl alcohol concrete composite material is put into the mold of the repair segment for the erosion and wear resistance of the bridge pier, and the mold is demolded after 24 hours. After the repaired segment is installed on the bridge pier, the repaired segment with resistance to erosion and wear of the bridge pier is obtained, with a thickness of 4 cm and a height of 50 cm.

Example 5:

A repair segment with resistance to erosion and wear of bridge piers, comprising the following raw materials in parts by weight: 432 parts of water, 864 parts of ordinary Portland cement, 123 parts of silica fume, 247 parts of microbeads, 444 parts of quartz sand, and polycarboxylate water-reduced Among them, the particle size of microbeads is 0.4 μm; the hardness of quartz sand is 6 degrees; the water reducing rate of polycarboxylate water reducing agent is 31%, and the solid content is 28%; The diameter is 34 μm and the aspect ratio is 360.

A preparation method of a repair segment with resistance to erosion and wear of a bridge pier, comprising the following steps:

(1) Mix the ordinary Portland cement, silica fume, microbeads and quartz sand with half the weight evenly, then add half the weight of PVA fiber while stirring, and then add the remaining ordinary Portland cement, silica fume, After the microbeads and the quartz sand are mixed evenly, the remaining PVA fibers are added while stirring, and finally the mixture of polycarboxylate water reducing agent and water is added, and the mixture is evenly mixed to obtain the polyvinyl alcohol concrete composite material;

(2) The polyvinyl alcohol concrete composite material is put into the mold of the repair segment for the erosion and wear resistance of the bridge pier, and the mold is demolded after 24 hours. After the repaired segment is installed on the bridge pier, the repaired segment with resistance to erosion and wear of the bridge pier is obtained, with a thickness of 4 cm and a height of 50 cm.

Example 6:

A repair segment with resistance to erosion and wear of bridge piers, comprising the following raw materials in parts by weight: 432 parts of water, 925 parts of ordinary Portland cement, 185 parts of silica fume, 123 parts of microbeads, 444 parts of quartz sand, and polycarboxylate water-reduced 19 parts of agent and 26 parts of PVA fiber; among them, the particle size of microbeads is 2μm; the hardness of quartz sand is 5-7 degrees; the water reducing rate of polycarboxylate superplasticizer is 32%, and the solid content is 30%; PVA fiber The diameter is 35 μm and the aspect ratio is 400.

A preparation method of a repair segment with resistance to erosion and wear of a bridge pier, comprising the following steps:

(1) Mix the ordinary Portland cement, silica fume, microbeads and quartz sand with half the weight evenly, then add half the weight of PVA fiber while stirring, and then add the remaining ordinary Portland cement, silica fume, After the microbeads and the quartz sand are mixed evenly, the remaining PVA fibers are added while stirring, and finally the mixture of polycarboxylate water reducing agent and water is added, and the mixture is evenly mixed to obtain the polyvinyl alcohol concrete composite material;

(2) The polyvinyl alcohol concrete composite material is put into the mold of the repair segment for the erosion and wear resistance of the bridge pier, and the mold is demolded after 24 hours. After the repaired segment is installed on the bridge pier, the repaired segment with resistance to erosion and wear of the bridge pier is obtained, with a thickness of 4 cm and a height of 50 cm.

Example 7:

A repair segment with resistance to erosion and wear of bridge piers, comprising the following raw materials in parts by weight: 480 parts of water, 899 parts of ordinary Portland cement, 60 parts of silica fume, 240 parts of microbeads, 432 parts of quartz sand, and polycarboxylate water-reduced Among them, the particle size of microbeads is 4 μm; the hardness of quartz sand is 6 degrees; the water reducing rate of polycarboxylate water reducing agent is 32%, and the solid content is 27%; the diameter of PVA fiber is 35 μm, and the aspect ratio is 380.

A preparation method of a repair segment with resistance to erosion and wear of a bridge pier, comprising the following steps:

(1) Mix the ordinary Portland cement, silica fume, microbeads and quartz sand with half the weight evenly, then add half the weight of PVA fiber while stirring, and then add the remaining ordinary Portland cement, silica fume, After the microbeads and the quartz sand are mixed evenly, the remaining PVA fibers are added while stirring, and finally the mixture of polycarboxylate water reducing agent and water is added, and the mixture is evenly mixed to obtain the polyvinyl alcohol concrete composite material;

(2) The polyvinyl alcohol concrete composite material is put into the mold of the repair segment for the erosion and wear resistance of the bridge pier, and the mold is demolded after 24 hours. After the repair segment is installed on the bridge pier, the repair segment resistant to erosion and wear of the bridge pier is obtained.

Example 8:

A repair segment with resistance to erosion and wear of bridge piers, comprising the following raw materials in parts by weight: 381 parts of water, 826 parts of ordinary Portland cement, 191 parts of silica fume, 254 parts of microbeads, 457 parts of quartz sand, and polycarboxylate water-reduced Among them, the particle size of microbeads is 0.1-5 μm; the hardness of quartz sand is 5-7 degrees; the water reducing rate of polycarboxylate water reducing agent is 28-32%, and the solid content is 25 -30%; PVA fibers have a diameter of 30-35 μm and an aspect ratio of 340-400.

A preparation method of a repair segment with resistance to erosion and wear of a bridge pier, comprising the following steps:

(1) Mix the ordinary Portland cement, silica fume, microbeads and quartz sand with half the weight evenly, then add half the weight of PVA fiber while stirring, and then add the remaining ordinary Portland cement, silica fume, After the microbeads and the quartz sand are mixed evenly, the remaining PVA fibers are added while stirring, and finally the mixture of polycarboxylate water reducing agent and water is added, and the mixture is evenly mixed to obtain the polyvinyl alcohol concrete composite material;

(2) The polyvinyl alcohol concrete composite material is put into the mold of the repair segment for the erosion and wear resistance of the bridge pier, and the mold is demolded after 24 hours. After the repaired segment is installed on the bridge pier, the repaired segment with resistance to erosion and wear of the bridge pier is obtained, with a thickness of 4 cm and a height of 50 cm.

Example 9:

A repair segment with resistance to erosion and wear of bridge piers, comprising the following raw materials in parts by weight: 480 parts of water, 839 parts of ordinary Portland cement, 180 parts of silica fume, 180 parts of microbeads, 432 parts of quartz sand, and polycarboxylate water-reduced 18 parts of agent and 26 parts of PVA fiber; the particle size of microbeads is 3 μm; the hardness of quartz sand is 6 degrees; the water reducing rate of polycarboxylate water reducing agent is 30%, and the solid content is 28%; the diameter of PVA fiber is 31 μm, and the aspect ratio is 350.

A preparation method of a repair segment with resistance to erosion and wear of a bridge pier, comprising the following steps:

(1) Mix the ordinary Portland cement, silica fume, microbeads and quartz sand with half the weight evenly, then add half the weight of PVA fiber while stirring, and then add the remaining ordinary Portland cement, silica fume, After the microbeads and the quartz sand are mixed evenly, the remaining PVA fibers are added while stirring, and finally the mixture of polycarboxylate water reducing agent and water is added, and the mixture is evenly mixed to obtain the polyvinyl alcohol concrete composite material;

(2) The polyvinyl alcohol concrete composite material is put into the mold of the repair segment for the erosion and wear resistance of the bridge pier, and the mold is demolded after 24 hours. After the repaired segment is installed on the bridge pier, the repaired segment with resistance to erosion and wear of the bridge pier is obtained, with a thickness of 4 cm and a height of 50 cm.

Comparative Example 1:

A bridge pier repairing segment comprises the following raw materials in parts by weight: 160 parts of water, 533.33 parts of cement, and 1406.67 parts of mortar.

A method for preparing a bridge pier repair segment, comprising the following steps:

(1) Mix cement and sand uniformly, then add water while stirring, and mix uniformly to obtain a mixed material;

(2) Put the mixed material into the mold of the bridge pier repair segment, demold it after 24 hours, and seal it with plastic film for 28 days under normal construction conditions to obtain an arc-shaped prefabricated repair segment, which is installed on the bridge pier, A bridge pier repair segment was prepared with a thickness of 4 cm and a height of 50 cm.

Test example:

1. Detect the compressive strength and mass loss of the arc-shaped prefabricated repair segments obtained in Examples 1-9 and Comparative Example 1. The specific testing method for compressive strength is: according to the "Standard for Testing Method of Mechanical Properties of Ordinary Concrete" (GB/T50081-2019) Article 6 stipulates that the pressurization speed is 0.5MPA/s. The specific detection method for mass loss is: (1) The test block is saturated with water. Before the test, the test block is soaked in water for 24 hours, and the weight increase of two weighings is not more than 0.1g, indicating that the test block has reached water saturation; And take the average value of the three quality results; (2) put the weighed test block into the test block fixing device to carry out the erosion simulation test (the specific erosion conditions are: the sand content is 100Kg/m ³ , the impact velocity is 6.32 m/s, the sand particle size is 1mm, and the erosion time is 60min). After the test, take out the test block and wipe it dry and weigh it 3 times. amount of loss.

The test results of compressive strength are shown in Fig. 8. It can be seen from Fig. 8 that the compressive strengths of the arc-shaped prefabricated repair segments made by the present invention are all greater than those of the arc-shaped prefabricated repair segments made from ordinary mortar.

When the impact angle is 90°, the mass loss is shown in Fig. 9, and when the impact angle is 30°, the mass loss is shown in Fig. 10. It can be seen from Figs. Less than the mass loss of arc-shaped prefabricated repair segments made from ordinary mortar.

The compressive strength of the arc-shaped prefabricated repair segment prepared by the invention is 1.6 times that of the arc-shaped prefabricated repair segment prepared by ordinary mortar, and the mass loss is about 0.6 times that of the arc-shaped prefabricated repair segment prepared by ordinary mortar.

2. The mass loss and erosion time of the arc-shaped prefabricated repair segments obtained in Example 3 and Comparative Example 1 are plotted, and the results are shown in Figure 11. It can be seen from Figure 11 that the arc-shaped prefabricated repair segments obtained from ordinary mortar The quality damage fluctuation in each 10min time period is relatively large; the arc-shaped prefabricated repair segment material prepared by the present invention is relatively uniform, and the quality damage fluctuation per unit time is relatively small. With the increase of time, the quality of the unit time Damage is reduced.

3. The arc-shaped prefabricated repair segments obtained in Example 3 and Comparative Example 1 are used to detect the mass loss under different impact speeds according to the above-mentioned detection method for mass loss. The specific erosion conditions are: the sand content is 50Kg/m ³ , the sand particle size is 1mm, and the erosion time is 30min. The results are shown in Fig. 12. It can be seen from Fig. 12 that with the increase of the impact speed, the mass loss of the arc-shaped prefabricated repair segment obtained by the present invention and the arc-shaped prefabricated repair segment obtained by ordinary mortar concrete increased, but the The obtained arc-shaped prefabricated repair segment has a slower mass loss rate and a smaller mass loss.

4. The arc-shaped prefabricated repair segments obtained in Example 3 and Comparative Example 1 were used to detect the mass loss under the impact of different sand contents according to the above-mentioned quality loss detection method. The specific erosion conditions are: when the impact speed is 6.32 m /s, the sand particle size is 1mm, and the erosion time is 30min. The results are shown in Fig. 13. It can be seen from Fig. 13 that with the increase of the sand content, the mass loss rate of the arc-shaped prefabricated repair segment obtained by the present invention is fast at first and then slow, and the growth is relatively gentle; The rate of mass loss of prefabricated repair segments is accelerating, and the mass loss is relatively large.

The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection of the present invention. within the range.

Claims (10)

1. The repair segment capable of resisting erosion and abrasion of the pier is characterized by comprising the following raw materials in parts by weight: 480 parts of water 381-.

2. The bridge pier erosive wear-resistant repair segment as set forth in claim 1, comprising the following raw materials in parts by weight: 381 parts of water, 826 parts of cement, 191 parts of silica fume, 254 parts of micro-beads, 457 parts of fine aggregate, 19 parts of water reducing agent and 26 parts of PVA fiber.

3. The bridge pier erosive wear resistant prosthetic tube sheet according to claim 1 or 2, wherein the PVA fiber has a diameter of 30-35 μm and an aspect ratio of 340-400.

4. The bridge pier erosive wear resistant prosthetic segment according to claim 1 or 2, wherein the particle size of the microbeads is 0.1-5 μm.

5. The method for preparing a bridge pier erosive wear resistant repair segment according to any one of claims 1-4, characterized by comprising the steps of:

(1) uniformly mixing half of the cement, the silica fume, the microbeads and the fine aggregate, adding half of the PVA fiber while stirring, adding the rest of the cement, the silica fume, the microbeads and the fine aggregate, continuously adding the rest of the PVA fiber while stirring after uniformly mixing, and finally adding a mixture of a water reducing agent and water, and uniformly mixing to prepare the polyvinyl alcohol concrete composite material;

(2) and (3) putting the polyvinyl alcohol concrete composite material into a die of the bridge pier erosion abrasion resistant repair segment for molding, demolding after 20-26h, maintaining to obtain an arc prefabricated repair segment, and installing the arc prefabricated repair segment to the bridge pier to obtain the bridge pier erosion abrasion resistant repair segment.

6. The bridge pier erosion wear resistant repair segment according to any one of claims 1-4, which comprises an arc-shaped prefabricated repair segment (1), wherein one end of the arc-shaped prefabricated repair segment (1) is provided with a left edge convex groove (2), the other end of the arc-shaped prefabricated repair segment is provided with a right edge groove (3), and the left edge convex groove (2) is matched with the right edge groove (3).

7. The bridge pier erosive wear resistant repair segment according to claim 6, characterized in that the number of the arc-shaped prefabricated repair segments (1) is at least 2.

8. The bridge pier erosive wear resistant repair segment according to claim 6, characterized in that an upper edge groove (5) is arranged at the top of the arc-shaped prefabricated repair segment (1), a lower edge convex groove (6) is arranged at the bottom of the arc-shaped prefabricated repair segment (1), and the upper edge groove (5) is matched with the lower edge convex groove (6).

9. The bridge pier erosion wear resistant repair segment according to claim 6, wherein a first transverse connection groove (7) and a second transverse connection groove (8) are arranged on the arc-shaped prefabricated repair segment (1), the first transverse connection groove (7) is arranged close to the left edge convex groove (2), and the second transverse connection groove (8) is correspondingly arranged close to the right edge concave groove (3).

10. The bridge pier erosive wear resistant repair segment according to claim 6, characterized in that the arc-shaped prefabricated repair segment (1) is provided with a bar planting prepared hole (11).

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