Non-shrink concrete

A concrete and fly ash technology, applied in the field of building concrete, can solve the problems of affecting the construction progress, concrete cracking, brittleness, etc., and achieve the effect of slowing down the heat generation speed, slowing down the hydration reaction speed, and increasing the limited expansion rate

Inactive Publication Date: 2017-05-31
HUNAN CITY UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] Existing large-scale construction requires the use of concrete. After the concrete is poured, the cement in it will generate a large amount of hydration heat during the hydration process, which will increase the temperature of the concrete and cause volume thermal expansion; after the heat is dissipated, the temperature will rise again When the shrinkage stress is reduced, the temperature shrinkage stress will be generated. When the shrinkage stress exceeds the ultimate tensile strength of the concrete, the concrete will crack and seriously affect the quality of the project
[0003] In order to prevent the shrinkage and cracking of the concrete structure, it is necessary to set the post-casting belt, but the increase of the post-casting belt will increase the complexity of the construction and affect the construction progress. Therefore, a shrinkage-compensating concrete technology has been developed. The reinforcement ratio is 0.2% - Under 0.8%, shrinkage-compensated concrete is used, but the existing shrinkage-compensated concrete is only added with expansion agent, and because the concrete has the characteristics of high early strength, high brittleness, and poor stress, the expansion force is inconsistent with the stress release speed of the concrete. Leads to unsatisfactory compensation for shrinkage

Method used

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Embodiment 1

[0013] First prepare the expansion agent, take 190kg of anhydrite, 60kg of magnesium oxide, 70kg of calcium oxide, 20kg of tartaric acid, 40kg of sodium silicate, 70kg of sodium tripolyphosphate, 60kg of sodium gluconate, and 10kg of sodium citrate. 270 mesh sieve, take powder, and mix each powder material evenly to obtain expansion agent.

[0014] To prepare shrinkage-resistant concrete, take 3,500kg of sulphoaluminate cement, 25,000kg of medium sand, 16,000kg of fly ash, 750kg of methyl cellulose, and 50kg of aluminum nitride powder and mix them evenly, and add 250kg of expansion agent to obtain shrinkage-resistant concrete.

[0015] When preparing mortar, stir in three steps, ① firstly mix sulphoaluminate cement, medium sand, fly ash, methyl cellulose, aluminum nitride powder evenly, ② add 2500kg water and stir repeatedly, ③ then add The expansion agent is stirred and mixed evenly to obtain shrinkage-resistant concrete mortar; then pouring construction is carried out.

Embodiment 2

[0017] To prepare shrinkage-resistant concrete, take 3500kg of sulphoaluminate cement, 2500kg of medium sand, 1540kg of fly ash, 75kg of methyl cellulose, 5kg of aluminum nitride powder, and 40kg of quartz powder, and mix them evenly. Shrinkage resistant concrete.

[0018] When preparing the mortar, stir in three steps, ① first mix sulfoaluminate cement, medium sand, fly ash, methyl cellulose, aluminum nitride powder, and quartz powder evenly, ② add 2500kg of water and stir repeatedly, ③Then add expansion agent and mix well to obtain shrinkage-resistant concrete mortar.

Embodiment 3

[0020] First prepare the expansion agent, take 200kg of anhydrite, 65kg of magnesium oxide, 75kg of calcium oxide, 25kg of tartaric acid, 45kg of sodium silicate, 75kg of sodium tripolyphosphate, 65kg of sodium gluconate, and 15kg of sodium citrate. 270 mesh sieve, take powder, and mix each powder material evenly to obtain expansion agent.

[0021] Then prepare anti-shrinkage concrete, take 3800kg of sulphoaluminate cement, 2700kg of medium sand, 1800kg of fly ash, 100kg of methyl cellulose, 7kg of aluminum nitride powder and mix well, and add 275kg of expansion agent to obtain anti-shrinkage concrete.

[0022] When preparing the mortar, stir in three steps, ① first mix the sulphoaluminate cement, medium sand, fly ash, methyl cellulose, aluminum nitride powder evenly, ② add 2700kg of water and stir repeatedly, ③ then add The expansion agent is stirred and mixed evenly to obtain shrinkage-resistant concrete mortar; then pouring construction is carried out.

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Abstract

The invention discloses a non-shrink concrete, and belongs to the technical field of building concrete. The non-shrink concrete is prepared from sulphate aluminum cement, medium sand, flyash, methylcellulose, aluminum nitride powder and an expanding agent. The non-shrink concrete has the beneficial effects that sodium gluconate and sodium citrate are added to the expanding agent, so that concrete condensation can be slowly retarded; methylcellulose is added to the concrete, so that water can be slowly released, the hydration reaction rate is reduced and the heat generation speed is reduced; the aluminum nitride powder or quartz powder is added to the concrete, so that heat release can be accelerated; the methylcellulose and aluminum nitride are cooled and heated synergistically, the expanding rate is improved and shrinkage is automatically reduced to achieve the non-shrink target.

Description

technical field [0001] The invention belongs to the technical field of building concrete, in particular to a shrink-resistant concrete capable of preventing the shrinkage of concrete structures. Background technique [0002] Existing large-scale construction requires the use of concrete. After the concrete is poured, the cement in it will generate a large amount of hydration heat during the hydration process, which will increase the temperature of the concrete and cause volume thermal expansion; after the heat is dissipated, the temperature will rise again If the temperature is reduced, the temperature shrinkage stress will be generated. When the shrinkage stress exceeds the ultimate tensile strength of the concrete, the concrete will crack and seriously affect the quality of the project. [0003] In order to prevent the shrinkage and cracking of the concrete structure, it is necessary to set the post-casting belt, but the increase of the post-casting belt will increase the ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B24/10C04B28/06
Inventor 袁启良
Owner HUNAN CITY UNIV
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