Seawater corrosion resistant concrete cover plate and preparation method and application thereof

Abstract

The invention belongs to the technical field of building materials, and particularly relates to a seawater corrosion resistant concrete cover plate and a preparation method and application thereof. The raw materials of the cover plate include, by weight, 200-250 parts of silicate cement, 40-80 parts of water, 180-220 parts of river sand, 150-180 parts of crushed stone, 50-70 parts of diatomaceous earth, 5-10 parts of sodium dodecyl sulfate, 20-30 parts of polyacrylamide, 8-14 parts of methacrylate, 20-30 parts of nano silicon dioxide, 30-40 parts of basalt fiber and 6-8 parts of retarder. In the preparation process of the cover plate, polyacrylamide and methacrylate in the raw materials form a hydrophobic associating polymer, and the seawater corrosion resistance of the cover plate is effectively improved under the synergistic effect of sodium dodecyl sulfate and basalt fiber.

Description

Technical Field

[0001] The invention belongs to the technical field of building materials, and particularly relates to a seawater corrosion resistant concrete cover plate and a preparation method and application thereof. Background Art

[0002] As human society expands into the ocean, marine infrastructure construction continues to grow rapidly, and there are more and more buildings on the seashore. A large amount of data and cases show that the problem of seawater corrosion of cement concrete is very prominent and needs to be solved urgently.

[0003] The marine environment is recognized as the harshest service environment for materials due to the combination of multiple complex factors such as salt, climate, and biology. This is especially true for cement concrete, the main material used in the construction of marine infrastructure. The average salt content in seawater is 3.5%, mainly Na + Mg 2+ , Cl - 、SO 4 2- On the one hand, these salts in seawater can react chemically with the main components of cement hardening body, such as Mg 2+ It reacts with the CSH(Ⅱ) gel in the cement hardening body, turning it into MSH with weak or even no gelling property. On the other hand, long-term immersion in seawater causes the relatively soluble components in the cement hardening body, such as calcium hydroxide Ca(OH) 2 Dissolution occurs, resulting in a decrease in the alkalinity of the hardened body and damage to the dense structure. These are the chemical corrosion of the marine environment on cement concrete.

[0004] The corrosion problem of marine engineering structures is a global problem. Marine structures all over the world have suffered serious losses due to marine corrosion. Summary of the invention

[0005] The purpose of the present invention is to overcome the above-mentioned shortcomings and provide a seawater corrosion-resistant concrete cover plate and its application.

[0006] Another object of the present invention is to provide a method for preparing a seawater corrosion resistant concrete cover plate.

[0007] The objective of the present invention is achieved through the following technical solutions:

[0008] A seawater corrosion-resistant concrete cover plate comprises a plurality of cover plate bodies 1, wherein two adjacent cover plate bodies 1 are connected by an I-shaped connector 2; the cover plate body 1 is a rectangular parallelepiped; a mounting groove 5 is provided in the middle of the two long sides of the cover plate body 1; two pairs of positioning grooves 6 are symmetrically provided on the upper and lower surfaces of the two long sides of the cover plate body 1, and the two pairs of positioning grooves 6 are arranged at the same interval on both sides of the mounting groove 5; two adjacent cover plate bodies 1 are connected to form a group of cover plates by the I-shaped connector 2 and the positioning grooves 6.

[0009] Furthermore, an anti-slip strip 3 is provided on the upper surface of the cover body 1 , and a groove 4 is provided on the lower surface of the cover body 1 .

[0010] Furthermore, the I-shaped connector 2 includes a first connector 21 and a second connector 22; the first connector 21 and the second connector 22 are both T-shaped, and a connecting hole 23 is opened in the middle of the first connector 21 and the second connector 22, and the first connector 21 and the second connector 22 are connected by a fixing member passing through the connecting hole 23 to form the I-shaped connector 2.

[0011] Furthermore, the fixing member is a triangular bolt 7, and the first connecting member 21 and the second connecting member 22 are connected by the triangular bolt 7 and a matching hexagonal nut to form the I-shaped connecting member 2.

[0012] Furthermore, two ends of the fixing member are sunk into the connecting holes 23 of the first connecting member 21 and the second connecting member 22 .

[0013] Furthermore, the positioning grooves 6 corresponding to the two adjacent cover plate bodies 1 are respectively clamped in the grooves 4 on both sides of the I-shaped connector 2 .

[0014] Furthermore, the four corners of the cover body 1 are chamfered.

[0015] The raw materials of the cover plate include the following components by weight: 200-250 parts of silicate cement, 40-80 parts of water, 180-220 parts of river sand, 150-180 parts of crushed stone, 50-70 parts of diatomaceous earth, 5-10 parts of sodium dodecyl sulfate, 20-30 parts of polyacrylamide, 8-14 parts of methacrylate, 20-30 parts of nano silicon dioxide, 30-40 parts of basalt fiber, and 6-8 parts of retarder.

[0016] Furthermore, the raw materials of the cover plate include the following components by weight: 220-230 parts of silicate cement, 50-60 parts of water, 200-220 parts of river sand, 150-160 parts of crushed stone, 60 parts of diatomaceous earth, 7 parts of sodium dodecyl sulfate, 20 parts of polyacrylamide, 14 parts of methacrylate, 30 parts of nano-silicon dioxide, 30 parts of basalt fiber, and 8 parts of retarder.

[0017] Furthermore, the particle size of the crushed stone does not exceed 15 mm.

[0018] Furthermore, the length of the basalt fiber is 12-15 mm.

[0019] A method for preparing a seawater corrosion-resistant concrete cover plate comprises the following steps:

[0020] S1. Weigh the raw materials of the seawater corrosion resistant concrete cover according to any one of claims 1 to 4;

[0021] S2. The silicate cement, water, river sand, gravel and retarder are mixed and stirred to obtain a concrete slurry;

[0022] S3. Add the polyacrylamide and methacrylate to the concrete slurry and stir at high speed for 15-20 min;

[0023] S4. Continue to sequentially add sodium dodecyl sulfate, diatomaceous earth, nano-silica and basalt fiber to the concrete slurry and stir well;

[0024] S5. Pour the concrete slurry into a prefabricated cover plate mold, demould it after curing, and obtain the concrete cover plate.

[0025] Furthermore, in step S3, the stirring speed is 40-50 rpm.

[0026] Furthermore, in step S5, the curing is natural curing for 14-16 days.

[0027] The present invention also provides an application of a seawater corrosion resistant concrete cover plate in coastal engineering or submarine engineering.

[0028] The components of the seawater corrosion-resistant concrete cover plate provided by the present invention include polyacrylamide and methacrylate. The polyacrylamide has good water solubility, while the methacrylate is a hydrophobic monomer. The two can undergo a certain degree of copolymerization during high-speed stirring to form a hydrophobic associating polymer. Due to the interaction of the hydrophobic groups in the polymer, the macromolecular chains undergo intermolecular or intramolecular association to form a physical network structure, so that seawater is not easy to corrode the interior of the hardened concrete, thereby making the concrete show a certain salt resistance. At the same time, during the hydration process of the concrete, the hydrophilic side of the hydrophobic associating polymer is located in the concrete due to the adsorption of calcium silicate gel, while the hydrophobic side is exposed on the surface of the concrete, thereby blocking the entry of salt in the seawater and further improving the anti-permeability of the concrete.

[0029] As a conventional admixture, sodium dodecyl sulfate not only has its original antifreeze and dispersing properties, but can also be used as a further supplement to the hydrophobic associating polymer of polyacrylamide to improve the resistance to salt penetration.

[0030] Diatomaceous earth contains substances such as silicon dioxide and aluminum oxide, which produce secondary hydration reaction with nano-silicon dioxide to form a dense gel, which improves the pore structure of concrete and thus improves the concrete's impermeability. In addition, nano-silicon dioxide can also be used as a filler and has a certain reinforcing effect. It can also fill the capillary structure in concrete, enhance density, and improve the concrete's corrosion resistance.

[0031] As a conventional reinforcing fiber, basalt fiber can be entangled and cross-linked with the network structure formed by the hydrophobic associating polymer of polyacrylamide in the present invention, further improving the complexity of the three-dimensional structure in the concrete, and can simultaneously improve the strength and anti-penetration ability of the concrete.

[0032] The beneficial effects of the present invention are:

[0033] The concrete cover plate provided by the present invention has a small concrete water-to-cement ratio, high compactness, strong anti-seepage performance, and various components cooperate with each other. It has strong seawater corrosion resistance and is suitable for coastal projects or submarine projects. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A bottom view of the cover plate body structure prepared by the present invention;

[0035] Figure 2 A top view of the cover plate body structure prepared by the present invention;

[0036] Figure 3 For the present invention Figure 1 AA section view;

[0037] Figure 4 For the present invention Figure 1 BB cross-sectional view;

[0038] Figure 5 For the present invention Figure 1 CC section view;

[0039] Figure 6 It is a front view of a T-shaped connector of the present invention;

[0040] Figure 7 A top view of a T-shaped connector of the present invention;

[0041] Figure 8 A bottom view of a T-shaped connector of the present invention;

[0042] Fig. 9It is a schematic diagram of the connection of several cover plate bodies of the present invention;

[0043] Fig.10 for Fig. 9 A magnified view of the local structure.

[0044] In the figure: 1. Cover plate body; 2. I-shaped connecting piece; 21. First connecting piece; 22. Second connecting piece; 23. Connecting hole; 3. Anti-slip strip; 4. Groove; 5. Mounting groove; 6. Positioning groove; 7. Triangular bolt. DETAILED DESCRIPTION

[0045] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings, but the protection scope of the present invention is not limited to the following.

[0046] Example 1

[0047] like Figure 1-10 As shown, this embodiment provides a cable trench cover plate connection structure, including a plurality of cover plate bodies 1, two adjacent cover plate bodies 1 are connected by a connecting type connector 2; the cover plate body 1 is a rectangular parallelepiped; the upper and lower surfaces of the two long sides of the cover plate body 1 are symmetrically provided with two pairs of positioning grooves 6, and the two pairs of positioning grooves 6 are arranged at the same interval on both sides of the installation groove 5; the two adjacent cover plate bodies 1 are connected to form a group of cover plates through the connector and the positioning groove 6. As a preferred embodiment, the upper surface of the cover plate body 1 is provided with an anti-slip strip 3, and the lower surface of the cover plate body 1 is provided with a groove 4; the middle part of the two long sides of the cover plate body 1 is provided with an installation groove 5.

[0048] A cable trench cover plate connection structure, wherein the upper surface of the cover plate body 1 is provided with a raised anti-slip strip 3 to increase the friction of the upper surface of the cover plate body 1 and prevent workers from accidentally slipping; a groove 4 is provided on the lower surface of the cover plate body 1 to reduce the mass of the cover plate body 1 and improve the economic effect; the installation grooves 5 provided on the two long sides of the cover plate body 1 are convenient for lifting the cover plate body 1 by tools. Several cover plate bodies 1 are connected into a group of cover plates by an I-shaped connector 2. On the one hand, the stability of the installation of a single cover plate body 1 is prevented from being destroyed by external forces; on the other hand, several cover plate bodies 1 constitute a group of cover plates to prevent the loss of the cover plate body 1. The device has a simple structure, can improve the stability of the installation of the cover plate body 1, and has a certain cable theft prevention effect. As a preferred embodiment, the cover body 1 is a rectangular parallelepiped with a long side of 790 cm, a width of 490 cm, and a height of 25 cm. The lower surface of the cover body 1 is provided with 8 grooves 4 with a length of 220 cm, a width of 120 cm, and a depth of 13 cm, which are arranged in a matrix, and the middle of the rectangular parallelepiped is not provided with a groove 4. The height of the raised anti-slip strip 3 is 2 cm; the mounting groove 5 is rectangular, 300 cm long, 9 cm wide, and runs through the cover body 1; the positioning groove 6 is 40 cm long, 25 cm wide, and 4 cm deep, and is symmetrically arranged on the upper and lower surfaces; two pairs of positioning grooves 6 are arranged on both sides of the mounting groove 5 at a spacing of 77 cm. The groove 4, the anti-slip strip 3, the mounting groove 5, and the positioning groove 6 are all chamfered.

[0049] The I-shaped connector 2 includes a first connector 21 and a second connector 22; the first connector 21 and the second connector 22 are both T-shaped, and a connecting hole 23 is provided in the middle of the first connector 21 and the second connector 22, and the first connector 21 and the second connector 22 are connected through a fixing member through the connecting hole 23 to form the I-shaped connector 2. As a preferred embodiment, the first connector 21 and the second connector 22 have the same outer dimensions, and the connecting holes 23 provided in the two match the shape and size of the fixing member; specifically, the first connector 21 and the second connector 22 are two vertically arranged rectangular blocks arranged vertically up and down to form a T-shaped connector, the upper rectangular block is 58 cm long, 38 cm wide, and 5 cm high; the lower rectangular block is 38 cm long, 20 cm wide, and 9 cm high. The two T-shaped connectors are symmetrically arranged to form the I-shaped connector 2, and the four corners of the first connector 21 and the second connector 22 are chamfered.

[0050] Furthermore, the fixing member is a triangular bolt 7, and the first connecting member 21 and the second connecting member 22 are connected by the triangular bolt 7 and the matching hexagonal nut to form the I-shaped connecting member 2. As a preferred embodiment, the triangular bolt 7 is an anti-theft bolt with an outer circle and an inner triangle structure, which requires a specific matching triangular key to open, to prevent ordinary tools from opening it at will, resulting in the loss of the cable. It is worth noting that in the track engineering, the same type of triangular bolt 7 is used in a specific structure, so that this type of bolt is universal in the construction of the track engineering, and internal staff can use specific tools to carry out structural maintenance, replace parts and other projects, simplifying the workload of workers and ensuring the work efficiency of workers.

[0051] Furthermore, the two ends of the fixing member are sunk into the connecting holes 23 of the first connecting member 21 and the second connecting member 22 to avoid the two ends of the fixing member being exposed to the outside, which ensures the flatness of the installation of the cover body 1 on the one hand, and on the other hand, avoids the two ends of the fixing member being outside, which makes it easy to open the fixing member and causes the loss of the internal cables. It is worth noting that the connecting holes 23 on the first connecting member 21 and the second connecting member 22 match the properties of the triangular bolt 7. The first connecting member 21 is provided with a circular stepped through hole, so that the head of the triangular bolt 7 is sunk into the hole; the second connecting member 22 is provided with a stepped through hole that is a combination of a regular hexagon and a circle, so that the hexagonal nut is sunk into the hole.

[0052] Furthermore, the positioning grooves 6 corresponding to the two adjacent cover bodies 1 are respectively clamped in the grooves 4 on both sides of the I-shaped connector 2, and the size of the I-shaped connector 2 matches the size of the groove 4, ensuring that the I-shaped connector 2 can stably connect each cover body 1.

[0053] Furthermore, the four corners of the cover body 1 are chamfered, and the size of the chamfer is 4 cm.

[0054] Furthermore, the thickness of the cover body 1 is 2-3 cm, preferably 2.5 cm.

[0055] A method for preparing a seawater corrosion-resistant concrete cover plate comprises the following steps:

[0056] S1. Weigh 220 parts of Portland cement, 60 parts of water, 200 parts of river sand, 150 parts of crushed stone, 60 parts of diatomaceous earth, 7 parts of sodium dodecyl sulfate, 20 parts of polyacrylamide, 14 parts of methacrylate, 30 parts of nano-silica, 30 parts of basalt fiber, and 8 parts of retarder;

[0057] S2. The silicate cement, water, river sand, gravel and retarder are mixed and stirred to obtain a concrete slurry;

[0058] S3. Add the polyacrylamide and methacrylate to the concrete slurry and stir at 50 rpm for 20 min;

[0059] S4. Continue to sequentially add the sodium dodecyl sulfate, diatomaceous earth, nano-silica and basalt fiber to the concrete slurry and stir well;

[0060] S5. Pour the concrete slurry into a prefabricated cover plate mold, and demould after natural curing for 14 days to obtain the concrete cover plate.

[0061] Example 2

[0062] The structure and size of the cover plate prepared in this embodiment are the same as those in Embodiment 1.

[0063] A method for preparing a seawater corrosion-resistant concrete cover plate comprises the following steps:

[0064] S1. 250 parts of Portland cement, 40 parts of water, 180 parts of river sand, 180 parts of crushed stone, 70 parts of diatomaceous earth, 5 parts of sodium dodecyl sulfate, 20 parts of polyacrylamide, 8 parts of methacrylate, 20 parts of nano-silica, 30 parts of basalt fiber, and 8 parts of retarder;

[0065] S2. The silicate cement, water, river sand, gravel and retarder are mixed and stirred to obtain a concrete slurry;

[0066] S3. Add the polyacrylamide and methacrylate to the concrete slurry and stir at 50 rpm for 20 min;

[0067] S4. Continue to sequentially add the sodium dodecyl sulfate, diatomaceous earth, nano-silica and basalt fiber to the concrete slurry and stir well;

[0068] S5. Pour the concrete slurry into a prefabricated cover plate mold, and demould after natural curing for 14 days to obtain the concrete cover plate.

[0069] Comparative Example 1

[0070] The only difference between Comparative Example 1 and Example 1 is that the concrete cover plate component prepared in Comparative Example 1 does not contain polyacrylamide and methacrylate.

[0071] Comparative Example 2

[0072] The only difference between Comparative Example 2 and Example 1 is that the concrete cover plate component prepared in Comparative Example 2 does not contain sodium dodecyl sulfate.

[0073] Comparative Example 3

[0074] The only difference between Comparative Example 3 and Example 1 is that the concrete cover plate component prepared in Comparative Example 3 does not contain polyacrylamide, methacrylate and sodium dodecyl sulfonate.

[0075] Comparative Example 4

[0076] The only difference between Comparative Example 4 and Example 1 is that the concrete cover plate component prepared in Comparative Example 4 does not contain nano-silicon dioxide.

[0077] Comparative Example 5

[0078] The only difference between Comparative Example 5 and Example 1 is that the concrete cover plate component prepared in Comparative Example 5 does not contain basalt fiber.

[0079] Performance Test:

[0080] Due to the lack of relevant standards, the present invention does not conduct corrosion resistance tests on the cover plates prepared in the above embodiments and comparative examples, but conducts performance tests on concrete specimens cast with the cover plates in the above embodiments and comparative examples, wherein the flexural strength is tested in accordance with GB / T17671-1999 "Test Method for Strength of Cement Mortar", the water seepage height is tested in accordance with "GB / T50082-2009 Standard for Test Methods for Long-term Performance and Durability of Ordinary Concrete", and the compressive strength is tested in accordance with GB / T50081 "Standard for Test Methods for Physical and Mechanical Properties of Concrete".

[0081] Before the compressive strength and flexural strength tests, the concrete specimens were cast and cured, and then placed in seawater prepared with artificial sea salt and continuously immersed.

[0082] Table 1 below shows the test results.

[0083] Table 1

[0084]

[0085] It can be seen from the above results that the concrete cast with the raw material ratio of the present invention still has strong compressive and flexural strength after being soaked in seawater, and has a low average water seepage height and strong density, which indicates that the cover plate prepared by the present invention has seawater corrosion resistance and is suitable for coastal projects or submarine projects.

[0086] The above is only a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art shall not deviate from the spirit and scope of the present invention, and shall be within the scope of protection of the claims attached to the present invention.

Claims

1. A seawater corrosion resistant concrete cover plate, characterized in that: The invention comprises a plurality of cover plate bodies (1), wherein two adjacent cover plate bodies (1) are connected by an I-shaped connecting piece (2); the cover plate body (1) is a rectangular parallelepiped; a mounting groove (5) is provided in the middle of two long sides of the cover plate body (1); two pairs of positioning grooves (6) are symmetrically provided on the upper and lower surfaces of the two long sides of the cover plate body (1), and the two pairs of positioning grooves (6) are arranged at the same interval on both sides of the mounting groove (5); the adjacent two cover plate bodies (1) are connected to form a set of cover plates by the I-shaped connecting piece (2) and the positioning grooves (6); The raw materials of the cover plate include the following components by weight: 200-250 parts of silicate cement, 40-80 parts of water, 180-220 parts of river sand, 150-180 parts of crushed stone, 50-70 parts of diatomaceous earth, 5-10 parts of sodium dodecyl sulfate, 20-30 parts of polyacrylamide, 8-14 parts of methacrylate, 20-30 parts of nano silicon dioxide, 30-40 parts of basalt fiber, and 6-8 parts of retarder; The polyacrylamide and methacrylate undergo copolymerization during high-speed stirring to form a hydrophobic associating polymer.

2. The seawater corrosion resistant concrete cover plate according to claim 1, characterized in that: The raw materials of the cover plate include the following components by weight: 220-230 parts of silicate cement, 50-60 parts of water, 200-220 parts of river sand, 150-160 parts of crushed stone, 60 parts of diatomaceous earth, 7 parts of sodium dodecyl sulfate, 20 parts of polyacrylamide, 14 parts of methacrylate, 30 parts of nano-silicon dioxide, 30 parts of basalt fiber, and 8 parts of retarder.

3. The seawater corrosion resistant concrete cover plate according to claim 1, characterized in that: The particle size of the crushed stone does not exceed 15 mm.

4. The seawater corrosion resistant concrete cover plate according to claim 1, characterized in that: The length of the basalt fiber is 12-15 mm.

5. A method for preparing a seawater corrosion resistant concrete cover plate, characterized in that: The following steps are involved: S1. Weigh the raw materials of the seawater corrosion resistant concrete cover according to any one of claims 1 to 4; S2. The silicate cement, water, river sand, gravel and retarder are mixed and stirred to obtain a concrete slurry; S3. Add the polyacrylamide and methacrylate to the concrete slurry and stir at high speed for 15-20 min; S4. Continue to sequentially add sodium dodecyl sulfate, diatomaceous earth, nano-silica and basalt fiber to the concrete slurry and stir well; S5. Pour the concrete slurry into a prefabricated cover plate mold, demould it after curing, and obtain the concrete cover plate.

6. The method for preparing a seawater corrosion resistant concrete cover plate according to claim 5, characterized in that: In step S3, the stirring speed is 40-50 rpm.

7. The method for preparing a seawater corrosion resistant concrete cover plate according to claim 5, characterized in that: In step S5, the curing is natural curing for 14-16 days.

8. Use of the seawater corrosion resistant concrete cover plate according to any one of claims 1 to 4 in coastal engineering or submarine engineering.

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