Rapid repairing material suitable for tropical island reef airport runway and preparation method

Abstract

The invention discloses a rapid repairing material suitable for tropical island reef airport runways. The rapid repairing material comprises the following components in parts by weight: 45-55 parts of slag, 45-55 parts of metakaolin, 20-30 parts of cement, 160-175 parts of sea sand, 25-30 parts of seawater, 5-10 parts of sodium hydroxide, 35-45 parts of water glass, 2-4 parts of PE fibers, 1-2 parts of a retarder and 1-2 parts of a water reducing agent. By adding the retarder, the working time of the mortar can be prolonged, so that a constructor has enough time to lay and level, and defects such as cracking and nonuniformity caused by rapid solidification are reduced; and the retarder also helps the mortar to maintain proper fluidity, so that the mortar can be uniformly distributed in large-area construction, and the construction quality and the final durability are improved.

Description

Technical Field

[0001] The invention relates to a rapid repair material suitable for a tropical island reef airport runway and a preparation method thereof, and belongs to the technical field of airport runway material repair. Background Art

[0002] Due to its special geographical location, the island airport is subject to harsh environments such as high temperature, high humidity, and salt spray corrosion all year round. The durability and stability of pavement materials have become important considerations in airport operation and maintenance. Traditional cement-based repair materials are prone to cracking and falling off under these conditions. Therefore, finding a more durable and environmentally friendly repair material has become an inevitable choice.

[0003] In the special environment of island airports, alkali-activated repair mortar has shown significant advantages. First, it has extremely strong corrosion resistance. The abundant chloride ions in the marine environment have serious corrosive effects on pavement materials, and the aluminosilicate gel formed in the alkali-activated material can effectively resist the erosion of chloride ions and significantly extend the service life of the pavement. Secondly, alkali-activated mortar has the characteristics of rapid hardening, and the chloride ions carried by seawater and sea sand themselves also promote the hydration reaction of the material on this basis. In the case of emergency repairs during wartime, the compressive strength of the repair mortar can exceed 40MPA within two hours, allowing the airport runway to resume operation, thereby improving the airport's operating efficiency. This rapid repair capability is particularly suitable for island airport runways that need emergency repairs.

[0004] In addition, considering the surrounding environment of tropical islands and reefs and the emergency environment during wartime, the cost of obtaining and transporting fresh water is extremely high. Seawater, as a local ready-made resource, can reduce the demand for transporting a large amount of fresh water, thereby reducing the overall construction cost and project cycle. The use of seawater mixing simplifies water resource management during construction and avoids the complexity of setting up a special freshwater reserve system. Under the harsh conditions of the island, mortar or concrete mixed with seawater, after reasonable formula design and the addition of preservatives, may be more adapted to such environmental conditions and reduce the secondary damage to the material caused by external seawater erosion.

[0005] At present, due to the harsh environment of tropical islands and reefs and the lack of raw materials for traditional repair mortar, there is no corresponding material that can be used for the repair of airport runways. To this end, we propose a rapid repair material suitable for tropical island reef airport runways and its preparation method to solve the problem. Summary of the invention

[0006] Purpose of the invention: In order to overcome the deficiencies in the prior art, the present invention provides a rapid repair material and preparation method suitable for tropical island reef airport runways, which has the effect of quickly repairing airport runways and restoring normal operations.

[0007] Technical solution: In order to solve the above technical problems, the present invention is a rapid repair material suitable for tropical island reef airport runways, which includes the following components by weight: 45-55 parts of slag, 45-55 parts of metakaolin, 20-30 parts of cement, 160-175 parts of sea sand, 25-30 parts of seawater, 5-10 parts of sodium hydroxide, 35-45 parts of water glass, 2-4 parts of PE fiber, 1-2 parts of retarder, 1-2 parts of water reducer, and 1-2 parts of polymer emulsion.

[0008] Preferably, the slag has a size of 100-150 mesh.

[0009] Preferably, the cement is PO42.5 ordinary Portland cement.

[0010] Preferably, the water glass is of model SP50, with a modulus of 2.4 and a solid content of 50.

[0011] Preferably, the retarder is borax or tartaric acid.

[0012] Preferably, the PE fibers are cut short PE fibers with a length of 12 mm.

[0013] Preferably, the polymer emulsion is PVA emulsion.

[0014] Preferably, the base activator is preactivated.

[0015] Preferably, the repaired runway portion is subjected to surface treatment and maintenance.

[0016] A method for preparing a rapid repair material for a tropical island reef airport runway, specifically comprising the following preparation steps:

[0017] S1. Alkali activator preparation: weigh sodium hydroxide and water glass and stir evenly;

[0018] S2. Dry material preparation: Prepare the ingredients according to the weight of the dry materials. Prepare the cementitious materials and pre-treat the fibers according to the weight of the dry materials. Cut the fibers into appropriate lengths for dispersion.

[0019] S3. Slurry preparation: The weighed slag, metakaolin, cement, sea sand and fiber are stirred at a low speed to ensure that the fiber is evenly distributed in the entire mixture. The stirring speed is 100-150r / min and the stirring time is 3-5min. Then, seawater, alkali activator, retarder and water reducer are added to the dry material and stirred at a high speed. The seawater must be cooled in advance to slow down the setting speed of the mortar. The stirring temperature is 30-40℃ and the stirring time is 2-4min to make the slurry;

[0020] S4. Slurry pouring: pour the slurry quickly. If the repair area is large, pour it in layers. Use a vibrator to vibrate the mortar and level it.

[0021] S5. Spray curing: After pouring, immediately moisten and cure the mortar surface, using a sprayer to spray water regularly to prevent cracks caused by rapid drying.

[0022] In the present invention, by adopting the above technical solution, dissolved silicate and aluminate are polymerized to form aluminosilicate gel, with hydrated aluminosilicate as the main product. The chemical structure of this gel is similar to that of natural zeolite minerals, forming a stable three-dimensional network structure.

[0023] In the present invention, dissolved silicon and aluminum combine with alkaline ions to gradually form a cross-linked silicon-oxygen and aluminum-oxygen network, which significantly improves the density and stability of the structure, forming the basis for the mechanical properties and durability of the alkali-activated material. As the reaction proceeds, the gel gradually polymerizes and forms a solid structure, which further condenses and hardens. This stage is accompanied by the formation of a small amount of crystalline phases, such as calcium silicate hydrate and calcium aluminum silicate hydrate, which act as reinforcements in the gel, further improving the mechanical strength and stability of the material. It also fills the micropores inside the material to a certain extent, making the material more superior in terms of impermeability resistance and durability.

[0024] In the present invention, by adopting the above technical solution and adding a retarder, the working time of the mortar can be extended, so that construction workers have enough time to lay and level, reducing defects caused by rapid solidification, such as cracking and unevenness; the retarder also helps the mortar maintain appropriate fluidity, ensuring that it can be evenly distributed in large-area construction, improving construction quality and ultimate durability.

[0025] In the present invention, by adopting the above technical scheme, the water consumption is reduced while maintaining or improving the fluidity and workability of the mortar. The polycarboxylate water reducer has good dispersibility and can effectively disperse the particles in the alkali-activated material to make the slurry more uniform. This uniformity helps to achieve more adequate contact between the reactants, thereby accelerating the hydration reaction and promoting the formation of early hydration products, especially calcium silicate hydrates and calcium aluminate hydrates. In addition, the polycarboxylate water reducer can significantly reduce the water-cement ratio in the slurry, and under the condition of low water-cement ratio, the density of the hydration product is higher and the porosity is lower, further improving the early strength of the mortar. At the same time, the polycarboxylate water reducer has a strong water retention capacity and can maintain the moisture in the slurry during the reaction process to prevent the premature evaporation of moisture, thereby ensuring the continuous progress of the hydration reaction, which is particularly important for the development of the early strength of the alkali-activated mortar.

[0026] In the present invention, the present invention is further configured as follows: the slag is preferably S105 grade blast furnace slag.

[0027] In the present invention, by adopting the above technical solution, the strength of the mortar is improved, its shrinkage is reduced and environmental benefits are achieved.

[0028] In the present invention, the present invention is further configured as follows: the cement is PO42.5 silicate cement.

[0029] In the present invention, by adopting the above technical solution, PO42.5 silicate cement dissolves in an alkaline environment to release silicate and calcium ions. The alkaline activator reacts with these components to form a high-strength gel structure, thereby enhancing the strength and durability of the mortar.

[0030] In the present invention, the present invention is further configured as follows: the retarder is preferably borax or tartaric acid.

[0031] In the present invention, by adopting the above technical solution, the borate ions released by borax form calcium borate precipitation with calcium ions in the solution, and this precipitation forms a protective film on the surface of the active mineral particles, slowing down the dissolution rate of the particle surface and the polymerization rate of the aluminosilicate gel. Tartaric acid exists in the form of tartrate ions in an alkaline solution, and these ions can combine with calcium ions to form a calcium tartrate complex. This complex will form a protective film in the mortar, hindering the reaction of calcium ions with silicate or aluminate ions, thereby slowing down the formation of gel.

[0032] In the present invention, the present invention is further configured as follows: the PE fiber is a cut short PE fiber with a length of 12 mm.

[0033] In the present invention, by adopting the above technical solution, PE fiber disperses stress by forming a three-dimensional structure in the repair mortar, greatly reduces the occurrence of cracks, and improves the flexibility and durability of the mortar. It also fills the pores, reduces the penetration of water and salt, and its high ductility also improves the impact resistance of the mortar.

[0034] In the present invention, the present invention is further configured as follows: the polymer emulsion is a PVA emulsion.

[0035] In the present invention, by adopting the above technical solution, the polymer structure of PVA emulsion can penetrate into the concrete surface and form strong physical and chemical bonding with it. This bonding ability enables the newly added repair mortar to be tightly combined with the original concrete, avoiding the problem of delamination or falling off at the interface.

[0036] In the present invention, the present invention is further configured as follows: the alkali activator is pre-activated before preparing the mortar.

[0037] In the present invention, by adopting the above technical solution, the alkali activator is preheated and the temperature is controlled between 60-120 degrees Celsius. The preactivation process increases the reaction speed of the alkali activator, so that it reacts with the cement-based material in a shorter time, thereby forming more hydration products, thereby improving the early strength and density of the mortar.

[0038] In the present invention, the present invention is further configured as follows: a silicone coating is brushed on the surface of the repair mortar and then maintained.

[0039] In the present invention, by adopting the above technical solution, the silicone coating can effectively block water penetration, prevent moisture from appearing inside the concrete or repair mortar, thereby reducing the risk of corrosion and damage caused by water. In addition, it can also effectively block the intrusion of salt and slow down the corrosion process, thereby reducing the frequency of maintenance and repair. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0041] The present invention will be further described below in conjunction with the accompanying drawings.

[0042] Example 1 is an alkali-activated repair mortar and a preparation method thereof disclosed in the present invention. The alkali-activated repair mortar comprises the following components in parts by weight:

[0043] The base activator modulus is 0.9;

[0044] Components Weight Components Weight cement 25 Sodium hydroxide 10 slag 50 Water Glass 40 Metakaolin 50 Retarder 1 Sea sand 168 Water reducing agent 1 seawater 25 PE fiber 2

[0045] like Figure 1 As shown, the preparation method of alkali-activated repair mortar specifically includes the following steps:

[0046] S1. Alkali activator preparation: weigh sodium hydroxide and water glass and stir evenly;

[0047] S2. Dry material configuration: Mix the dry materials according to their weight, mix the cementitious materials according to their weight, and pre-treat the aggregates and fibers, and cut the fibers into appropriate lengths for dispersion;

[0048] S3. Slurry preparation: Stir the weighed slag, metakaolin, cement, sea sand and fiber at a low speed (add specific speed) of 100-150r / min for 3-5min to ensure that the fiber is evenly distributed throughout the mixture. Add seawater, alkali activator, retarder and water reducer to the dry material and stir at a high speed (add specific speed) at a temperature of 30-40℃, a speed of 150-200r / min for 2-4min to make slurry;

[0049] S4. Slurry pouring: pour the slurry quickly. If the repair area is large, pour it in layers. Use a vibrator to vibrate the mortar and level it to ensure that it is evenly filled and remove bubbles;

[0050] S5. Spray curing: After pouring, immediately moisten and cure the mortar surface. Use a sprayer to spray moisture regularly to prevent cracks caused by rapid drying.

[0051] Example 2 is an alkali-activated repair mortar and a preparation method thereof disclosed in the present invention. The alkali-activated repair mortar comprises the following components in parts by weight:

[0052]

[0053]

[0054] The base activator modulus is 0.9;

[0055] The preparation method of the alkali-activated repair mortar is the same as that in Example 1.

[0056] Example 3 is an alkali-activated repair mortar and a preparation method thereof disclosed in the present invention. The alkali-activated repair mortar comprises the following components in parts by weight:

[0057] Components Weight Components Weight cement 27 Sodium hydroxide 14 slag 54 Water Glass 36 Metakaolin 44 Retarder 1 Sea sand 175 Water reducing agent 2 seawater 35 PE fiber 3

[0058] The base activator modulus is 0.9;

[0059] The preparation method of the alkali-activated repair mortar is the same as that in Example 1.

[0060] Example 4 is different from Example 1 in that the base activator modulus is 1.0.

[0061] Example 5 is different from Example 1 in that the base activator modulus is 1.1.

[0062] Example 6, which differs from Example 1 in that the base activator modulus is 1.2

[0063] Comparative Example 1 is an alkali-activated repair mortar and a preparation method thereof disclosed in the present invention. The alkali-activated repair mortar comprises the following components in parts by weight:

[0064] The base activator modulus is 0.9;

[0065] Components Weight Components Weight cement 22 Sodium hydroxide 10 slag 44 Water Glass 40 Metakaolin 44 Retarder 1 Sea sand 181 Water reducing agent 1 seawater 25 PE fiber 2

[0066] The preparation method of alkali-activated repair mortar specifically comprises the following steps:

[0067] The preparation methods of S1, S2, S4 and S5 are the same as those of Example 1;

[0068] The difference between S3 and Example 1 is that the alkaline activator is aged for 24 hours in advance.

[0069] Comparative Example 2 is an alkali-activated repair mortar and a preparation method thereof disclosed in the present invention. The alkali-activated repair mortar comprises the following components in parts by weight:

[0070] Components Weight Components Weight cement 19 Sodium hydroxide 10 slag 38 Water Glass 40 Metakaolin 38 Retarder 1 Sea sand 195 Water reducing agent 1 seawater 25

[0071] The base activator modulus is 0.9;

[0072] The preparation method of alkali-activated repair mortar specifically comprises the following steps:

[0073] The preparation methods of S1, S2, S4 and S5 are the same as those of Example 1;

[0074] S3 differs from Example 1 in that the PE fibers are removed.

[0075] Comparative Example 3 is an alkali-activated repair mortar and a preparation method thereof disclosed in the present invention. The alkali-activated repair mortar comprises the following components in parts by weight:

[0076] Components Weight Components Weight cement 14.5 Sodium hydroxide 10 slag 29 Water Glass 40 Metakaolin 29 Retarder 1 Sea sand 218 PE fiber 2 seawater 25

[0077] The base activator modulus is 0.9;

[0078] The preparation method of alkali-activated repair mortar specifically comprises the following steps:

[0079] The preparation methods of S1, S2, S4 and S5 are the same as those of Example 1;

[0080] S3 differs from Example 1 in that the water reducing agent is removed.

[0081] Comparative Example 4 is an alkali-activated repair mortar and a preparation method thereof disclosed in the present invention. The alkali-activated repair mortar comprises the following components in parts by weight:

[0082] Components Weight Components Weight cement 14.5 Sodium hydroxide 10 slag 29 Water Glass 40 Metakaolin 29 Retarder 1 river sand 218 Water reducing agent 1 freshwater 25 PE fiber 2

[0083] The base activator modulus is 0.9;

[0084] The preparation method of alkali-activated repair mortar specifically comprises the following steps:

[0085] The preparation methods of S1, S3-S5 are the same as those of Example 1;

[0086] The difference between S2 and Example 1 is that seawater and sea sand are replaced with fresh water and river sand.

[0087] Performance testing

[0088] The alkali-activated repair mortars prepared in Examples 1-6 and Comparative Examples 1-4 were sampled, and the following performance tests were performed on the samples.

[0089] Compressive strength test: The 2h compressive strength and 2d flexural strength of the samples in Examples 1-7 and Comparative Examples 4-8 were tested according to JTGE30-2005.

[0090] The compressive strength test data of the samples in Examples 1-6 and Comparative Examples 1-3 are shown in Table 1 below:

[0091] Table 1 2h compressive strength / MPa 2h flexural strength / MPa Example 1 48.6 5.1 Example 2 46.4 4.8 Example 3 47.2 4.9 Example 4 45 5.2 Example 5 44.5 5.3 Example 6 43.7 5.1 Comparative Example 1 24.2 3.9 Comparative Example 2 24.7 4.2 Comparative Example 3 25.8 4.3 Comparative Example 4 24.9 4.1

[0092] According to the sample test data of Examples 1-3 in Table 1, it can be seen that changing the addition amount of each component within a suitable range has little effect on the compressive strength of the alkali-activated repair mortar.

[0093] According to the sample test data of Example 1 and Examples 4-6 in Table 1, it can be seen that the lower the modulus of the alkali activator is, the higher the two-hour compressive strength of the alkali-activated repair mortar is. The modulus of the alkali activator has a greater influence on the two-hour compressive strength of the alkali-activated repair mortar. As the modulus of the alkali activator gradually decreases, the 2h compressive strength of the alkali-activated repair mortar does not increase linearly. When the modulus of the activator decreases to 0.8, the compressive strength begins to decrease.

[0094] According to the sample test data of Example 1 and Comparative Example 1 in Table 1, it can be seen that the unaged alkali activator has a promoting effect on improving the compressive strength of the alkali-activated repair mortar.

[0095] According to the sample test data of Example 1 and Comparative Example 2 in Table 1, it can be seen that PE fiber has little effect on the compressive strength of the alkali-activated repair mortar, but has a promoting effect on the improvement of its flexural strength.

[0096] According to the sample test data of Example 1 and Comparative Example 3 in Table 1, it can be known that the water reducing agent has a promoting effect on the fluidity and compressive strength of the alkali-activated repair mortar.

[0097] According to the sample test data of the embodiment and comparative example 4 in Table 1, it can be known that the compressive strength of the alkali-activated freshwater river sand mortar is slightly lower than that of the alkali-activated seawater sand mortar.

[0098] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A rapid repair material for tropical island reef airport runways, comprising the following components by weight: 45-55 parts of slag, 45-55 parts of metakaolin, 20-30 parts of cement, 160-175 parts of sea sand, 25-30 parts of seawater, 5-10 parts of sodium hydroxide, 35-45 parts of water glass, 2-4 parts of PE fiber, 1-2 parts of retarder, and 1-2 parts of water reducer.

2. The rapid repair material for tropical island reef airport runways according to claim 1 is characterized in that: The specification of the slag is 100-150 mesh.

3. The rapid repair material for tropical island reef airport runways according to claim 1 is characterized in that: The cement is PO42.5 ordinary Portland cement.

4. The rapid repair material for tropical island airport runways according to claim 1 is characterized by: The model of the water glass is SP50, the modulus is 2.4, and the solid content is 50.

5. The rapid repair material for tropical island reef airport runways according to claim 1 is characterized by: The retarder is borax or tartaric acid.

6. A method for preparing a rapid repair material for tropical island reef airport runway according to any one of claims 1 to 5, comprising the following preparation steps: S1. Alkali activator preparation: weigh sodium hydroxide and water glass and stir evenly; S2. Dry material preparation: Prepare the ingredients according to the weight of the dry materials. Prepare the cementitious materials and pre-treat the fibers according to the weight of the dry materials. Cut the fibers into appropriate lengths for dispersion. S3. Slurry preparation: The weighed slag, metakaolin, cement, sea sand and fiber are stirred at a low speed to ensure that the fiber is evenly distributed in the entire mixture. The stirring speed is 100-150r / min and the stirring time is 3-5min. Then, seawater, alkali activator, retarder and water reducer are added to the dry material and stirred at a high speed. The seawater must be cooled in advance to slow down the setting speed of the mortar. The stirring temperature is 30-40℃, the stirring speed is 150-200r / min, and the stirring time is 2-4min to make a slurry; S4. Slurry pouring: pour the slurry quickly. If the repair area is large, pour it in layers. Use a vibrator to vibrate the mortar and level it. S5. Spray curing: After pouring, immediately moisten and cure the mortar surface, using a sprayer to spray water regularly to prevent cracks caused by rapid drying.

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