A production method of non-residual slurry and pressure-free steamed C80 concrete pile

Abstract

The invention discloses a production method of a non-residue slurry-free pressure-steamed C80 concrete pile, which belongs to the technical field of concrete pipe piles. The method includes the following process steps: (1) Add medium sand, gravel, Portland cement clinker, mineral powder, silica fume, and sodium gluconate into the mixer, stir for 60-70 seconds, and finally add water and naphthalene-based high-efficiency reducing Water agent, stirring for 90-120s; (2) The concrete obtained in step (1) is placed, molded, and stretched for later use; (3) The pipe piles stretched in step (2) are centrifuged; (4 ) Put the centrifuged pipe pile into the steam curing pool for curing. The present invention uses Portland cement without gypsum and composite mineral powder and silica fume as the cementitious material, which avoids the introduction of sulfate ions, thereby preventing the delayed ettringite reaction from occurring when the concrete is maintained at 80-100°C. Improve pipe pile durability.

Description

technical field [0001] The invention relates to a preparation method of a concrete pile, in particular to a production method of a non-residue slurry-free pressure-steamed C80 concrete pile, which belongs to the field of concrete pipe piles. Background technique [0002] At present, after the high-strength concrete pipe pile is centrifugally formed, it is first cured by atmospheric pressure steam and undergoes four stages of static stop, temperature rise, constant temperature, and temperature drop. The temperature is 60°C to 70°C, and the time is 4 to 7 hours. Carry out autoclave curing again. Autoclave is used for autoclave curing. During curing, the steam pressure reaches 0.9MPa-1.0MPa, the temperature is around 180°C, and the curing time lasts for 7-10 hours. During the steam curing process of concrete, due to the rapid rise and fall of temperature, the temperature difference between the inside and outside of the pipe pile concrete is too large, and the pipe pile body is...

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Problems solved by technology

[0006] After searching, two patent documents related to the patent of the present invention were found: Publication No. CN104960086A provides a production method of no-residual slurry-free pressure-steamed concrete piles. The agent is prepared by adding diethylene glycol, triethanolamine and diffusing agent NNO to expanded perlite, and the preparation method is complicated and uneconomical; while the patent of publication number CN104742249A achieves pressure-free steaming by adding solid glass microspheres and 95 grade mineral powder purpose, but the cost is high and the shrinkage is large

[0007] The non-autoclaved concrete in the prior art often contains a certain amount of gypsum to retard the setting, but in the presence of gypsum, the C in the cement 3 The hydration products of A are AFt (calcium sulfoaluminate hydrate of trisulfide type) and AFm (calcium sulfoaluminate hydrate of monosulfide type). For steaming at atmospheric pressure, the presence of gypsum will delay the formation of ettringite. It is called the DEF phenomenon, and DEF is considered to be a potential destructive reaction that affects the durability of concrete. The DEF reaction in concrete refers to the normal temperature and humidity curing stage after steam curing. The low-stable low-sulfur sulfoaluminic acid The transformation of calcium (AFm) to ettringite (AFt)

Relevant studies have concluded that the best permissible curing temperature to effectively avoid DEF reaction is 65-70°C, but the strength of concrete can be improved in a short period of time and the construction period can be shortened. The curing temperature is too low, which is not conducive to industrialized large-scale production

[0008] To sum up, the pipe pile concrete in the prior art has the following problems: 1) The curing time is long and the cost is high; 2) The preparation method is complicated and the shrinkage is large; 3) The conventional curing will cause the volume of the pipe pile to be unstable and the durability is not good , the use of low temperature curing has the disadvantages of long construction period and high cost

4) The problem of residual slurry needs to be solved

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