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CN-116854433-B - Basalt fiber modified anti-freezing concrete and preparation method thereof

CN116854433BCN 116854433 BCN116854433 BCN 116854433BCN-116854433-B

Abstract

The application relates to the technical field of concrete, and particularly discloses basalt fiber modified anti-freezing concrete and a preparation method thereof. The basalt fiber modified antifreeze concrete is prepared by curing concrete mixture in a mold, wherein the components of the slurry modifier comprise ferric nitrate and calcium hydroxide, and the molar ratio of the ferric nitrate to the calcium hydroxide is 2 (2.1-3). By adding the slurry modifier in the concrete mixture, the degree of salt freezing damage can be reduced, and the service life of concrete structures such as concrete channels can be prolonged.

Inventors

  • Fu Gaozhong
  • CHEN YEHUI
  • WEI XIN
  • XU XINKAI
  • CAI CHANGFENG

Assignees

  • 南京南部路桥建设(集团)有限公司

Dates

Publication Date
20260512
Application Date
20230712

Claims (8)

  1. 1. The basalt fiber modified antifreeze concrete is characterized by being prepared by curing a concrete mixture in a mold, wherein the concrete mixture comprises, by weight, 980-1020 parts of coarse aggregate, 820-840 parts of fine aggregate, 60-80 parts of basalt anti-cracking fiber, 300-320 parts of cement, 60-80 parts of mineral admixture, 40-50 parts of slurry modifier, 146-150 parts of water and 3.8-4.2 parts of polycarboxylate water reducer, the mineral admixture comprises fly ash, the components of the slurry modifier comprise ferric nitrate and calcium hydroxide, and the molar ratio of the ferric nitrate to the calcium hydroxide is 2 (2.1-3); the slurry modifier is prepared according to the following method: (1) The components of the slurry modifier also comprise sodium tripolyphosphate, and the sodium tripolyphosphate is mixed with the carbide slag and the ferric nitrate together in the step; (2) Grinding the mixture to obtain the slurry modifier.
  2. 2. Basalt fiber modified antifreeze concrete according to claim 1, wherein the molar ratio of ferric nitrate to calcium hydroxide in the slurry modifier is 2:3.
  3. 3. The basalt fiber modified antifreeze concrete of claim 1, wherein the amount of said sodium tripolyphosphate is 0.01 to 0.1% of the sum of the weight of carbide slag and ferric nitrate.
  4. 4. The basalt fiber modified antifreeze concrete of claim 1, wherein said basalt anti-crack fiber is obtained by cutting a basalt fiber precursor.
  5. 5. The basalt fiber modified antifreeze concrete of claim 1, wherein said basalt anti-crack fiber is obtained by cutting a twisted yarn of basalt fiber.
  6. 6. The basalt fiber modified antifreeze concrete of claim 5, wherein said basalt fiber twisted yarn has a twist of 60 to 90 twists/m.
  7. 7. Basalt fiber modified antifreeze concrete according to claim 1, wherein the mineral admixture comprises metakaolin, and the weight ratio of the metakaolin in the mineral admixture is 8-16%.
  8. 8. The preparation method of the basalt fiber modified antifreeze concrete is characterized by comprising the following steps of: (1) Mixing coarse aggregate, fine aggregate, basalt anti-cracking fiber, cement and mineral admixture with the slurry modifier of any one of claims 1-7 to obtain dry materials; (2) Stirring the dry materials, adding the water reducing agent solution into the dry materials, mixing and stirring again to obtain a concrete mixture; (3) And (5) performing mold filling maintenance on the concrete mixture to obtain the basalt fiber modified antifreeze concrete.

Description

Basalt fiber modified anti-freezing concrete and preparation method thereof Technical Field The application relates to the technical field of concrete, in particular to basalt fiber modified anti-freezing concrete and a preparation method thereof. Background The ditch is an important component of the road, can bear the drainage effect in rainy seasons, and is helpful for reducing the water immersion of the road surface. At present, the canal in road engineering is generally formed by pouring concrete, and the tensile property of the concrete is poorer than that of the concrete, so that the concrete canal is easy to crack under the action of tensile stress under the severe conditions of dry and wet circulation, freeze injury and the like, and the service life of the canal is shortened. The related art comprises 980-1020 parts of coarse aggregate, 820-840 parts of fine aggregate, 60-80 parts of basalt anti-cracking fiber, 300-320 parts of cement, 60-80 parts of mineral admixture, 146-150 parts of water and 3.8-4.2 parts of polycarboxylate water reducer. In view of the above-mentioned related art, the inventors believe that the basalt anti-cracking fiber added in the related art can play a certain role in protecting frost heaving cracking, but when ice salt is removed from snow road surface in winter, the produced salt water flows into the canal at the roadside and permeates into the concrete canal. In this case, once the air temperature drops further below the freezing point of brine, the concrete raceway is susceptible to brine damage. The influence caused by salt freezing damage is more serious than that caused by simple frost heaving cracking, and is difficult to fully prevent by only doping basalt anti-cracking fibers, so that the long-term service of the concrete canal is not facilitated. Disclosure of Invention After ice salt is removed from snow covered pavement, brine can flow into the concrete canal, and then once the air temperature is further reduced below the freezing point of the brine, the concrete canal is easy to be damaged by brine freezing, and the influence caused by brine freezing damage is more serious than that caused by simple frost heaving cracking. Under such a situation, according to the scheme in the related art (only basalt anti-cracking fiber is doped), salt freeze damage is difficult to sufficiently prevent, and long-term service of the concrete canal is not facilitated. In order to overcome the defect, the application provides basalt fiber modified antifreeze concrete and a preparation method thereof. In a first aspect, the application provides basalt fiber modified antifreeze concrete, which adopts the following technical scheme: The basalt fiber modified antifreeze concrete is prepared by curing a concrete mixture in a mold, wherein the concrete mixture comprises, by weight, 980-1020 parts of coarse aggregate, 820-840 parts of fine aggregate, 60-80 parts of basalt anti-cracking fiber, 300-320 parts of cement, 60-80 parts of mineral admixture, 40-50 parts of slurry modifier, 146-150 parts of water, 3.8-4.2 parts of polycarboxylate superplasticizer, the mineral admixture comprises fly ash, the components of the slurry modifier comprise ferric nitrate and calcium hydroxide, and the molar ratio of the ferric nitrate to the calcium hydroxide is 2 (2.1-3). By adopting the technical scheme, the application adds the slurry modifier into the concrete mixture. In the concrete mixture, ferric nitrate can react with calcium hydroxide to form calcium nitrate and ferric hydroxide, and the generated ferric hydroxide is in a gel state, so that the total gel content in the cement paste is increased, the reduction of pores in the concrete is facilitated, the compactness of the concrete structure is improved, and the invasion of a salt solution is prevented. And when the salt solution invades the concrete structure, calcium nitrate is dissolved into the salt solution, so that the total concentration of inorganic salt in the salt solution is improved, the freezing point of the salt solution is further reduced, and the salt freezing damage is delayed. Therefore, by adding the slurry modifier of the application into the concrete mixture, the degree of salt freeze damage can be reduced, and the service life of concrete structures such as concrete channels can be prolonged. Preferably, in the slurry modifier, the molar ratio of ferric nitrate to calcium hydroxide is 2:3. By adopting the technical scheme, the molar ratio of ferric nitrate to calcium hydroxide in the exact reaction is 2:3, and on the basis, when the addition amount of the calcium hydroxide is relatively reduced, the ferric nitrate can consume part of calcium hydroxide generated by cement hydration, so that the cement paste does not have enough calcium hydroxide to fully excite the hydration activity of the mineral admixture, and the total gel product amount in the concrete mixture is not beneficial to being fully improved. Thus, when t