CN111003994A - Application of concrete material in pile foundation reinforcement cage - Google Patents

Abstract

The invention discloses an application of a concrete material in a pile foundation reinforcement cage, and belongs to the technical field of building materials. The invention relates to a concrete material for shortening final setting time, which comprises cement, starch and sand, wherein the concrete material comprises the following components in parts by weight: 90-100 parts of cement, 5-10 parts of starch and 200-250 parts of sand; wherein: the cement and the starch are uniformly mixed by water and then dried by a vacuum freeze drying process for use. The invention fully utilizes the plasticity in the initial setting stage, mixes the plasticity with starch and stirs the mixture with water, excites the active part of the cement, and then carries out the vacuum freeze drying process, wherein the vacuum freeze drying process has the function of keeping the activity, and after the ice crystals are sublimated and dried, a large amount of fine gaps are generated to form a structure of grey-white honeycomb-shaped thin and crisp blocks, and the structure lays a good foundation for the fineness of crushing to micron because the structure has small water content and bulkiness.

Description

Application of concrete material in pile foundation reinforcement cage

The invention is a divisional application, a parent application number: 2016104719319, respectively; name of mother case: a concrete material for shortening final setting time and a preparation method and application thereof; application date of the parent: 2016-06-27.

Technical Field

The invention belongs to the technical field of building materials, and particularly relates to a concrete material capable of shortening final setting time, and a preparation method and application thereof.

Background

The national standard stipulates that: the initial setting time of six types of portland cement such as portland cement, ordinary portland cement, portland slag cement, fly ash portland cement, pozzolana portland cement, composite portland cement and the like cannot be earlier than 45min, and is generally 1-3 h; the final setting time is not later than 6.5 hours except for silicate cement, the final setting time of other cement is not later than 10 hours, generally 5-8 hours, and the cement is a waste product when the initial setting time does not meet the specification, and the cement is an unqualified product when the final setting time does not meet the specification.

In general, when the concrete is allowed to reach final setting, the shorter the setting time, the better the setting time, and the shorter the construction time. After the cement reaches the final setting, the various strengths of the cement are formed and cannot be increased, so that the shortening of the final setting period is a research direction which is considered by technical personnel under the premise of ensuring the hardness of the concrete.

And after the main frame of the building is constructed, construction workers need to spray water to the building, because water evaporates quickly when the weather is dry and hot, the water evaporates before the cement is completely solidified, the chemical reaction between the cement and water and air stops, the cement cannot be completely solidified, and the hardness of the cement cannot meet the design requirement. Therefore, when the cement is in water shortage, water needs to be supplemented in time to ensure that the cement is completely solidified.

Chinese patent application No.: 201510656866.2, publication date: patent document 2015-12-15 discloses a method for modifying a raw soil material with starch residues, comprising: (1) weighing raw soil and an inorganic cementing material according to a proportion and uniformly mixing; (2) drying and grinding the starch residue, weighing the starch residue according to a proportion, and adding water to boil the starch residue to obtain slurry; (3) weighing an additive according to a certain proportion, and uniformly mixing the additive with the starch residue slurry prepared in the step (2); (4) adding the mixed solution prepared in the step (3) into the mixture obtained in the step (1), strongly stirring uniformly, sending the mixture after wet mixing into a vacuum pug mill for pugging, and extruding and forming, wherein the mass of water is 22-30% of the total mass of solids; (5) and (4) naturally drying and maintaining the raw soil material extruded and molded in the step (4) for 28 days. The invention has simple preparation process, belongs to a novel environment-friendly building material with low cost, has wide sources of used raw materials, and greatly reduces the cost of raw materials and transportation. Although the invention uses starch residue, the invention only needs to reduce the cost.

Disclosure of Invention

1. Technical problem to be solved

Aiming at the problems that the final setting period of concrete is long, the construction period is influenced and the cement is completely solidified due to the influence of dry heat of air temperature in the prior art, the invention provides a concrete material for shortening the final setting time and a preparation method and application thereof. The concrete curing agent can shorten the final setting period of concrete, can be completely cured in a short time without influencing the hardening quality, and has a heat preservation effect when being applied to an outer wall.

2. Technical scheme

In order to achieve the purpose, the scheme of the invention is carried out in the following way:

the application of the concrete material in a pile foundation reinforcement cage comprises the following components in parts by weight: 100 parts of cement, 8 parts of starch and 250 parts of sand; the cement is pozzolanic portland cement; the preparation method of the concrete material comprises the following steps:

A. stirring after mixing: mixing cement and starch uniformly, adding water, and stirring uniformly to obtain an initial setting body;

B. thinning: rapidly spreading the initial condensate into a mold with the thickness of 3 cm;

C. quick-freezing: transferring to a quick-freezing warehouse for quick freezing; the freezing temperature is-20 ℃, and the quick-freezing time is 90 minutes.

D. Freeze-drying: transferring the mixture into a vacuum freeze drying bin, and freeze-drying the mixture to form an off-white honeycomb-shaped thin crisp block, wherein the curve of the vacuum freeze drying is as follows:

a. a temperature rise period: heating the plate temperature to 110 ℃ within 20 minutes, and vacuumizing to be within 200 Pa;

b. sublimation peak period: keeping the plate temperature at 110 ℃ for 1h, and keeping the vacuum at 160 +/-5 Pa;

c. in the medium temperature period: keeping the plate temperature at 85 ℃ for 3h, and keeping the vacuum at 60-80 Pa;

d. analyzing and drying period: keeping the plate temperature at 65 ℃ for 1h, and keeping the vacuum at 40-60 Pa;

e. a constant temperature period: the plate temperature is 55 ℃, the material temperature is 50 +/-1 ℃, the vacuum is kept at 40-50 Pa, the plate temperature and the material temperature are in two horizontal parallel lines and kept for 50min, and then the plate temperature and the material temperature are broken and discharged out of the bin;

E. crushing: crushing the thin and crisp blocks; the crushing mesh number is 300 meshes;

F. and (7) vacuum packaging.

Wherein, when the plate temperature is reduced in each step, cooling water is used for forcibly reducing the temperature;

the concrete material on the outer wall of the building comprises the following steps:

A. preparation of cement paste: after the powder material, the sand and the water are crushed, the powder material, the sand and the water are mixed and stirred to form a secondary initial condensate;

B. pouring: directly pouring the secondary primary condensate into a pile foundation reinforcement cage;

C. hardening: the final setting period can be used after the hardening is finished, and the final setting period is calculated to be less than 2 hours.

3. Advantageous effects

Compared with the prior art, the technical scheme provided by the invention has the following remarkable effects:

(1) the invention relates to a concrete material for shortening final setting time, starch and cement are freeze-dried and then crushed before the initial setting period is finished, the starch can fully utilize heat release in the concrete setting period to generate gelatinization jelly effect and is combined with sand to generate firm coating effect, the jelly heat transfer effect is poor, and the heat preservation effect can also be generated, the freeze-dried powder material with porous structure forms a moisture suction channel, the water suction is rapid, the water rapidly and the components in the concrete carry out physical and chemical reaction, the conglomeration effect of the cement is avoided due to the existence of the jelly starch, when the reaction is complete, the moisture channel can be closed, and at the moment, the water retention property of the jelly starch can continuously supply moisture to the cement which does not completely participate in the reaction, thus ensuring the completeness of hardening of the concrete and shortening the final setting period of the concrete, thereby shortening the construction period;

(2) according to the preparation method of the concrete material for shortening the final setting time, the thickness of the mould in the step B is 2-5 cm, so that the rapidity of quick freezing is guaranteed; in the step C, the quick-freezing temperature is-18 to-22 ℃, which is the condensation point of the mixture determined by the inventor so as to generate enough fine ice crystals and generate the largest ice crystal generation zone, the quick-freezing time is 40 to 120 minutes, and corresponding adjustment is carried out according to the thickness of the material;

(3) according to the preparation method of the concrete material for shortening the final setting time, the curve of vacuum freeze drying is a result of comprehensive consideration of the material condensation point, the material thickness and the material heating rate in the freeze-drying process, so that the prepared gray honeycomb-shaped thin and crisp block keeps the activity of the gray honeycomb-shaped thin and crisp block, and avoids the influence of excessive gelatinization of internal starch on the absorption of water during use as much as possible;

(4) according to the concrete material for shortening the final setting time, the crushing mesh number is 200-400 meshes, the smaller the fineness is, the shorter the final setting period is, the corresponding adjustment can be carried out as required, and the gray honeycomb-shaped thin and crisp blocks lay a good foundation for uniform fineness distribution; in a drying curve, the temperature of the material is not more than 52 ℃, and excessive gelatinization of starch in a bin is avoided;

(5) the concrete material capable of shortening the final setting time is applied to paving concrete ground, and has the advantages that the final setting time is short, the ground maintenance period is short, the concrete material can pass in a short time, is completely hardened and has high hardness, and due to the existence of starch colloid, the concrete material can also generate the effects of absorbing water and discharging water, can keep the ground water for a long time, and reduces the generation of cracks caused by excessive change of ground stress;

(6) the application of the concrete material for shortening the final setting time in the pile foundation reinforcement cage has simple working procedures, does not need to repeatedly spray water to supplement water, has the effect of heat preservation, and can also avoid cracks caused by excessive change of wall stress;

(7) the application of the concrete material for shortening the final setting time in the pile foundation reinforcement cage has the advantages that the existence of the starch colloid and the combination degree of the reinforcement are high, and the damage to the whole pile foundation caused by the separation of the concrete from the reinforcement is avoided.

Detailed Description

For a further understanding of the contents of the present invention, reference will now be made in detail to the following examples.

Example 1

The concrete material for shortening the final setting time comprises cement, starch and sand, and comprises the following components in parts by weight: 90 parts of cement, 5 parts of starch and 200 parts of sand; the cement is fly ash portland cement;

the preparation method of the concrete material for shortening the final setting time of the embodiment comprises the following steps:

A. stirring after mixing: mixing cement and starch uniformly, adding water, and stirring uniformly to obtain an initial setting body;

B. thinning: rapidly spreading the initial condensate into a mold with the thickness of 2 cm;

C. quick-freezing: transferring to a quick-freezing warehouse for quick freezing; the freezing temperature is-18 ℃, and the quick-freezing time is 40 minutes.

D. Freeze-drying: transferring the mixture into a vacuum freeze drying bin, and freeze-drying the mixture to form an off-white honeycomb-shaped thin crisp block, wherein the curve of the vacuum freeze drying is as follows:

a. a temperature rise period: raising the temperature of the plate to 100 ℃ within 15 minutes, and vacuumizing to be within 200 Pa;

b. sublimation peak period: keeping the plate temperature at 100 ℃ for 0.5h, and keeping the vacuum at 160 +/-5 Pa;

c. in the medium temperature period: keeping the plate temperature at 90 ℃ for 2h, and keeping the vacuum at 60-80 Pa;

d. analyzing and drying period: keeping the plate temperature at 70 ℃ for 2h, and keeping the vacuum at 40-60 Pa;

e. a constant temperature period: the plate temperature is 55 ℃, the material temperature is 50 +/-1 ℃, the vacuum is kept at 40-50 Pa, the plate temperature and the material temperature are in two horizontal parallel lines and kept for 60min, and then the plate temperature and the material temperature are broken and discharged out of the bin;

E. crushing: crushing the thin and crisp blocks; the crushing mesh number is 200 meshes;

F. and (7) vacuum packaging.

The concrete material for shortening the final setting time is applied to concrete ground pavement, and the application steps are as follows:

A. preparation of cement paste: after the powder material, the sand and the water are crushed, the powder material, the sand and the water are mixed and stirred to form a secondary initial condensate;

B. laying: directly paving the secondary primary condensate to a paved ground;

C. hardening: the final setting period can be used after the hardening is finished, and the final setting period is calculated to be less than 3 hours.

Through measurement and calculation, the final setting period of the fly ash portland cement is about 4.5 hours, and the concrete material for shortening the final setting time shortens the period by at least 50%.

Example 2

The concrete material for shortening the final setting time comprises cement, starch and sand, and comprises the following components in parts by weight: 100 parts of cement, 10 parts of starch and 250 parts of sand; the cement is 42.5-grade ordinary portland cement;

the preparation method of the concrete material for shortening the final setting time of the embodiment comprises the following steps:

A. stirring after mixing: mixing cement and starch uniformly, adding water, and stirring uniformly to obtain an initial setting body;

B. thinning: rapidly spreading the initial condensate into a mold with the thickness of 5 cm;

C. quick-freezing: transferring to a quick-freezing warehouse for quick freezing; the freezing temperature is-22 ℃, and the quick-freezing time is 120 minutes.

D. Freeze-drying: transferring the mixture into a vacuum freeze drying bin, and freeze-drying the mixture to form an off-white honeycomb-shaped thin crisp block, wherein the curve of the vacuum freeze drying is as follows:

a. a temperature rise period: heating the plate temperature to 110 ℃ within 20 minutes, and vacuumizing to be within 200 Pa;

b. sublimation peak period: keeping the plate temperature at 110 ℃ for 2h, and keeping the vacuum at 160 +/-5 Pa;

c. in the medium temperature period: keeping the plate temperature at 80 ℃ for 2h, and keeping the vacuum at 60-80 Pa;

d. analyzing and drying period: keeping the plate temperature at 60 ℃ for 1h, and keeping the vacuum at 40-60 Pa;

e. a constant temperature period: the plate temperature is 55 ℃, the material temperature is 50 +/-1 ℃, the vacuum is kept at 40-50 Pa, the plate temperature and the material temperature are in two horizontal parallel lines and kept for 50min, and then the plate temperature and the material temperature are broken and discharged out of the bin;

E. crushing: crushing the thin and crisp blocks; the crushing mesh number is 400 meshes;

F. and (7) vacuum packaging.

The concrete material for shortening the final setting time is applied to an outer wall of a building, and the application steps are as follows:

A. preparation of cement paste: after the powder material, the sand and the water are crushed, the powder material, the sand and the water are mixed and stirred to form a secondary initial condensate;

B. laying: directly troweling the secondary initial set to the outer wall of the building;

C. hardening: the final setting period can be used after the hardening is finished, and the final setting period is calculated to be less than 2 hours.

Through calculation, the final setting period of the 42.5-grade ordinary portland cement is 6-10 hours, and the concrete material for shortening the final setting time shortens the period by at least 200%.

Example 3

The concrete material for shortening the final setting time comprises cement, starch and sand, and comprises the following components in parts by weight: 100 parts of cement, 8 parts of starch and 250 parts of sand; the cement is pozzolanic portland cement;

the preparation method of the concrete material for shortening the final setting time of the embodiment comprises the following steps:

A. stirring after mixing: mixing cement and starch uniformly, adding water, and stirring uniformly to obtain an initial setting body;

B. thinning: rapidly spreading the initial condensate into a mold with the thickness of 3 cm;

C. quick-freezing: transferring to a quick-freezing warehouse for quick freezing; the freezing temperature is-20 ℃, and the quick-freezing time is 90 minutes.

D. Freeze-drying: transferring the mixture into a vacuum freeze drying bin, and freeze-drying the mixture to form an off-white honeycomb-shaped thin crisp block, wherein the curve of the vacuum freeze drying is as follows:

a. a temperature rise period: heating the plate temperature to 110 ℃ within 20 minutes, and vacuumizing to be within 200 Pa;

b. sublimation peak period: keeping the plate temperature at 110 ℃ for 1h, and keeping the vacuum at 160 +/-5 Pa;

c. in the medium temperature period: keeping the plate temperature at 85 ℃ for 3h, and keeping the vacuum at 60-80 Pa;

d. analyzing and drying period: keeping the plate temperature at 65 ℃ for 1h, and keeping the vacuum at 40-60 Pa;

e. a constant temperature period: the plate temperature is 55 ℃, the material temperature is 50 +/-1 ℃, the vacuum is kept at 40-50 Pa, the plate temperature and the material temperature are in two horizontal parallel lines and kept for 50min, and then the plate temperature and the material temperature are broken and discharged out of the bin;

E. crushing: crushing the thin and crisp blocks; the crushing mesh number is 300 meshes;

F. and (7) vacuum packaging.

Wherein, when the plate temperature is reduced in each step, the plate temperature is forcibly reduced by using cooling water.

The concrete material for shortening the final setting time is applied to a pile foundation reinforcement cage, and the application steps are as follows:

A. preparation of cement paste: after the powder material, the sand and the water are crushed, the powder material, the sand and the water are mixed and stirred to form a secondary initial condensate;

B. pouring: directly pouring the secondary primary condensate into a pile foundation reinforcement cage;

C. hardening: the final setting period can be used after the hardening is finished, and the final setting period is calculated to be less than 2 hours.

The final setting period of the pozzolanic portland cement is 4 to 6 hours according to measurement, and the period of the concrete material with the shortened final setting time of the embodiment is at least 100%.

The invention and its embodiments have been described above schematically and without limitation. Therefore, if a person skilled in the art receives the teachings of the present invention, without inventive design, a similar structure and an embodiment to the above technical solution should be covered by the protection scope of the present patent.

Claims (1)

1. The application of the concrete material in the pile foundation reinforcement cage is characterized in that the concrete material comprises cement, starch and sand, and the concrete material comprises the following components in parts by weight: 100 parts of cement, 8 parts of starch and 250 parts of sand; the cement is pozzolanic portland cement; the preparation method of the concrete material comprises the following steps:

A. stirring after mixing: mixing cement and starch uniformly, adding water, and stirring uniformly to obtain an initial setting body;

B. thinning: rapidly spreading the initial condensate into a mold with the thickness of 3 cm;

C. quick-freezing: transferring to a quick-freezing warehouse for quick freezing; the freezing temperature is-20 ℃, and the quick-freezing time is 90 minutes.

D. Freeze-drying: transferring the mixture into a vacuum freeze drying bin, and freeze-drying the mixture to form an off-white honeycomb-shaped thin crisp block, wherein the curve of the vacuum freeze drying is as follows:

a. a temperature rise period: heating the plate temperature to 110 ℃ within 20 minutes, and vacuumizing to be within 200 Pa;

b. sublimation peak period: keeping the plate temperature at 110 ℃ for 1h, and keeping the vacuum at 160 +/-5 Pa;

c. in the medium temperature period: keeping the plate temperature at 85 ℃ for 3h, and keeping the vacuum at 60-80 Pa;

d. analyzing and drying period: keeping the plate temperature at 65 ℃ for 1h, and keeping the vacuum at 40-60 Pa;

e. a constant temperature period: the plate temperature is 55 ℃, the material temperature is 50 +/-1 ℃, the vacuum is kept at 40-50 Pa, the plate temperature and the material temperature are in two horizontal parallel lines and kept for 50min, and then the plate temperature and the material temperature are broken and discharged out of the bin;

E. crushing: crushing the thin and crisp blocks; the crushing mesh number is 300 meshes;

F. and (7) vacuum packaging.

Wherein, when the plate temperature is reduced in each step, cooling water is used for forcibly reducing the temperature;

the concrete material on the outer wall of the building comprises the following steps:

A. preparation of cement paste: after the powder material, the sand and the water are crushed, the powder material, the sand and the water are mixed and stirred to form a secondary initial condensate;

B. pouring: directly pouring the secondary primary condensate into a pile foundation reinforcement cage;

C. hardening: can be used after the final setting stage and hardening.