CN114804731B - Large-volume concrete and preparation method thereof - Google Patents
Large-volume concrete and preparation method thereof Download PDFInfo
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- CN114804731B CN114804731B CN202210268964.9A CN202210268964A CN114804731B CN 114804731 B CN114804731 B CN 114804731B CN 202210268964 A CN202210268964 A CN 202210268964A CN 114804731 B CN114804731 B CN 114804731B
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B14/00—Use of inorganic materials as fillers, e.g. pigments, for mortars, concrete or artificial stone; Treatment of inorganic materials specially adapted to enhance their filling properties in mortars, concrete or artificial stone
- C04B14/02—Granular materials, e.g. microballoons
- C04B14/04—Silica-rich materials; Silicates
- C04B14/06—Quartz; Sand
- C04B14/062—Microsilica, e.g. colloïdal silica
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B22/00—Use of inorganic materials as active ingredients for mortars, concrete or artificial stone, e.g. accelerators, shrinkage compensating agents
- C04B22/08—Acids or salts thereof
- C04B22/10—Acids or salts thereof containing carbon in the anion
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B22/00—Use of inorganic materials as active ingredients for mortars, concrete or artificial stone, e.g. accelerators, shrinkage compensating agents
- C04B22/08—Acids or salts thereof
- C04B22/14—Acids or salts thereof containing sulfur in the anion, e.g. sulfides
- C04B22/142—Sulfates
- C04B22/147—Alkali-metal sulfates; Ammonium sulfate
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
- Y02W30/91—Use of waste materials as fillers for mortars or concrete
Abstract
The application relates to the field of concrete preparation technology, and particularly discloses mass concrete and a preparation method thereof. A mass concrete comprising the following components: cement, machine-made sand, broken stone, fly ash, mineral powder, a water reducing agent, heat-conducting silica gel powder, a crystallization solution, water, ammonium bicarbonate powder and sepiolite fiber; the preparation method comprises the following steps: s1: mixing cement, machine-made sand, broken stone, fly ash, mineral powder, heat-conducting silica gel powder and water, and stirring for 30-60s to obtain a pre-mixed mixture; s2: and mixing the water reducing agent, the crystallization solution and the premixed mixture, and stirring for 60-90s to obtain the mass concrete. The utility model provides a bulky concrete can be fast with the heat transfer to the concrete outward appearance of the inside production of concrete to reduce the inside and outside difference in temperature of concrete, and then reduce the concrete and produce cracked problem easily because of temperature stress.
Description
Technical Field
The application relates to the field of concrete preparation technology, in particular to mass concrete and a preparation method thereof.
Background
The bulk concrete refers to a mass concrete with a minimum geometric dimension of a concrete structure body not less than 1m, or a concrete which is expected to cause harmful crack generation due to temperature change and shrinkage caused by hydration of a cementing material in the concrete. The large-volume concrete is commonly used for the construction of high-rise building foundations, large equipment foundations, water conservancy dams and the like.
The related art, for example, application document 200910025167.2 discloses a C50 mass concrete, which comprises the following raw materials in parts by weight: 300 parts of cement, 1100 parts of crushed stone, 620 parts of sand, 180 parts of water, 200 parts of ground slag and 7 parts of admixture SPA. The prepared concrete has better construction performance.
In view of the above related technologies, the inventor believes that after the mass concrete is poured, a large amount of heat is released in a short time when cement in the concrete structure is hydrated, so that the internal temperature of the concrete rises rapidly and generally reaches 60-70 ℃, and the general structure size of the mass concrete structure is large, so that the internal part of the concrete cannot be conducted out in time, a large temperature difference is generated between the internal part of the concrete and the surface, and temperature cracks are generated and developed on the surface of the mass concrete structure after the temperature stress caused by the temperature exceeds the corresponding ultimate tensile strength of the age of the concrete.
Disclosure of Invention
In order to reduce the problem that the large-volume concrete is easy to crack, the application provides the large-volume concrete and a preparation method thereof.
In a first aspect, the present application provides a mass concrete, which adopts the following technical scheme:
the bulk concrete is prepared from the following raw materials in parts by weight:
270-320 parts of cement;
850-920 parts of machine-made sand;
900-950 parts of macadam;
100-120 parts of fly ash;
30-50 parts of mineral powder;
8-10 parts of a water reducing agent;
20-25 parts of heat-conducting silica gel powder;
15-20 parts of a crystallization solution;
150-180 parts of water.
Through adopting above-mentioned technical scheme, add heat conduction silica gel powder in concrete raw materials, inside heat conduction silica gel powder can evenly spread in the concrete, because heat conduction silica gel powder has good heat conductivity and stability, consequently be favorable to strengthening the holistic heat conductivity of concrete, thereby be convenient for make the inside heat of concrete in time transmit to the concrete outward appearance, thereby reduce the inside difference in temperature with the surface of concrete, thereby reduce the problem that produces the large volume concrete and produce the crack easily. Through adding the crystallization solution, when cement inside the concrete hydrates and releases heat, the crystallization solution can separate out crystals due to temperature rise, the separated out crystals grow and develop by taking the heat-conducting silica gel powder as attachment points, so that the uniformly dispersed crystals are attached to the surface of the heat-conducting silica gel powder, the separated out crystals can connect the heat-conducting silica gel powder uniformly dispersed in the concrete, a three-dimensional heat-conducting network can be formed between the heat-conducting silica gel powder through the connection of the crystals, the heat generated inside the concrete is conveniently transferred to the appearance of the concrete due to better heat conductivity of the crystals, the temperature difference inside and outside the concrete can be reduced due to the existence of the three-dimensional heat-conducting network, and the problem that the concrete is easy to crack due to temperature stress is solved. After the hydration heat release process of the inside of concrete is finished, the temperature of the inside of concrete is gradually reduced, and in the process, the crystal is dissolved in water again, so that the influence on the internal structure and the hardening process of the concrete is avoided, and the concrete is favorable for keeping good construction performance.
Optionally, the crystallization solution includes at least one of a lithium carbonate solution and a lithium sulfate solution.
Through adopting above-mentioned technical scheme, the crystallization solution selects to be lithium carbonate solution or lithium sulfate solution, the solubility and the temperature of lithium carbonate or lithium sulfate solution are the inverse ratio, and the solubility is comparatively obvious by the temperature influence, consequently be favorable to appearing fashioned crystal fast when the inside hydration of concrete is exothermic, and lithium carbonate crystal or lithium sulfate crystal have better heat conductivity, thereby be convenient for the inside heat that produces of conduction concrete, on the other hand lithium carbonate solution or lithium sulfate solution have the lubrication action to heat conduction silica gel powder, thereby be favorable to making heat conduction silica gel powder inside the concrete disperse evenly, and then be favorable to forming even stable three-dimensional heat conduction network, even three-dimensional heat conduction network can shorten thermal transfer route, thereby be convenient for with the inside heat transfer of concrete to the concrete surface fast, can reduce the inside and outside difference in temperature of concrete, and then reduce the problem that the concrete produces the crack because of temperature stress.
Optionally, the crystallization solution is a saturated solution.
By adopting the technical scheme, the crystallization solution is selected to be a saturated solution, when the heat in the concrete is slightly increased, the crystallization solution can quickly separate out crystals, the crystals grow rapidly along with the continuous increase of the temperature, so that the adjacent heat-conducting silica gel powder is connected to form a stable three-dimensional heat-conducting network, the selection of the saturated crystallization solution is favorable for enhancing the sensitivity of the crystallization solution to the temperature, the heat in the concrete is conveniently and rapidly conducted out, and the problem that the concrete cracks due to the temperature stress is reduced.
Optionally, the particle size of the heat-conducting silica gel powder is 20-50um.
Through adopting above-mentioned technical scheme, the heat conduction silica gel powder of above-mentioned particle diameter can exist at concrete internal stability, reduce the problem that heat conduction silica gel powder removed the diffusion in concrete internal portion, thereby be convenient for improve three-dimensional heat conduction network's stability, and the heat conduction silica gel powder of above-mentioned particle diameter scope is convenient for provide good attachment point to the growth development of crystal, the growth shaping of crystal fast and stable of being convenient for, thereby can link together adjacent heat conduction silica gel powder fast, be favorable to carrying out the heat conduction of concrete inside fast, thereby reduce the concrete and produce cracked problem because of temperature stress.
Optionally, the raw material also comprises 10-13 parts by weight of ammonium bicarbonate powder.
Through adopting above-mentioned technical scheme, when the inside cement hydration of concrete is exothermic, ammonium bicarbonate powder decomposes and can produce ammonia and carbon dioxide, ammonia and carbon dioxide form big or small homogeneity inside the concrete, the pore structure of dispersion uniformity can reduce and cause hindrance and suppression to crystal growth, thereby be convenient for crystal rapid stabilization's growth shaping, be favorable to connecting adjacent heat conduction silica gel powder fast, thereby be favorable to going out the heat conduction inside the concrete fast, absorb more heat when ammonium bicarbonate decomposes simultaneously, further reduce the inside temperature of concrete, and then reduce the concrete and produce cracked problem because of temperature stress.
Optionally, the raw material also comprises 15-20 parts by weight of sepiolite fibers.
Through adopting above-mentioned technical scheme, the sepiolite fibre has better elasticity and hardness, and self has better heat conductivility, the sepiolite fibre can evenly disperse in the concrete slurry at the concrete mixing in-process, can effectively improve the cohesive force of cementitious material and other aggregate, reduce the problem of concrete shrinkage cracking in the hardening process, and because self better heat conductivity, can accelerate the heat in the concrete and outwards conduct, thereby reduce the inside and outside difference in temperature of concrete, reduce the temperature stress because of the difference in temperature leads to, thereby reduce the concrete and produce cracked problem easily.
Optionally, the particle size of the ammonium bicarbonate powder is 300-500nm.
By adopting the technical scheme, the ammonium bicarbonate powder within the particle size range is beneficial to forming pores with proper size and uniform distribution in the concrete during decomposition, thereby facilitating the growth and development of crystals and avoiding generating larger pores to influence the working performance of the concrete.
In a second aspect, the present application provides a method for preparing a mass concrete, which adopts the following technical scheme: a preparation method of mass concrete comprises the following preparation steps: s1: mixing cement, machine-made sand, broken stone, fly ash, mineral powder, heat-conducting silica gel powder and water, and stirring for 30-60s to obtain a pre-mixed mixture;
s2: and mixing the water reducing agent, the crystallization solution and the premixed mixture, and stirring for 60-90s to obtain the mass concrete.
By adopting the technical scheme, the preparation method is simple, quick and easy to operate, the prepared mass concrete can quickly conduct the heat inside the concrete to the surface of the concrete in the cement hydration process, so that the small temperature difference between the inside and the outside of the concrete is kept, and the problem that the surface of the concrete is deformed in a stretching way to generate cracks can be reduced.
Optionally, ammonium bicarbonate powder and/or sepiolite fibers are also added in the step S1.
In summary, the present application has the following beneficial effects:
1. heating heat conduction silica gel powder and devitrification solution in this application raw materials, heat conduction silica gel powder has better heat conductivility, consequently, be favorable to strengthening the holistic heat conductivity of concrete, thereby be convenient for make the inside heat of concrete in time transmit to the concrete outward appearance, thereby reduce the inside and surperficial difference in temperature of concrete, thereby reduce the problem that produces the easy crack of bulky concrete, when the cement hydration of concrete inside is exothermic, devitrification solution can precipitate the crystal owing to the temperature rise, the crystal of appearing uses heat conduction silica gel powder to grow and develop as the attachment point, can make to form three-dimensional heat conduction network between the heat conduction silica gel powder through the connection of crystal, because the heat conductivity of crystal is better, thereby be convenient for transmit the inside heat that produces of concrete to the concrete outward appearance, because the existence of three-dimensional heat conduction network, can reduce the inside and outside difference in temperature of concrete, thereby reduce the concrete and produce cracked problem easily because of temperature stress.
2. Preferentially adopt lithium carbonate solution or lithium sulfate solution as the solution of devitrifying in this application, on the one hand because lithium carbonate crystal or lithium sulfate crystal have better heat conductivity, thereby be convenient for the inside heat that produces of conduction concrete, on the other hand lithium carbonate solution or lithium sulfate solution have the lubrication action to heat conduction silica gel powder, thereby be favorable to making heat conduction silica gel powder at the inside dispersion of concrete even, and then be favorable to forming even stable three-dimensional heat conduction network, even three-dimensional heat conduction network can shorten thermal transfer route, thereby be convenient for with the inside heat transfer of concrete to the concrete surface fast, can reduce the inside and outside difference in temperature of concrete, and then reduce the problem that the concrete produced the crack because of temperature stress.
3. The utility model provides add ammonium bicarbonate powder in the raw materials, when the inside cement hydration of concrete is exothermic, ammonium bicarbonate powder decomposes and can produce ammonia and carbon dioxide, ammonia and carbon dioxide form the size homogeneous inside the concrete, the pore structure that the dispersion is even can reduce and lead to the fact hindrance and suppression to crystal growth, thereby be convenient for crystal fast and stable's growth shaping, be favorable to connecting adjacent heat conduction silica gel powder fast, thereby be favorable to fast going out the heat conduction inside the concrete, absorb more heat when ammonium bicarbonate decomposes simultaneously, further reduce the inside temperature of concrete, and then reduce the problem that the concrete produced the crack because of temperature stress.
Detailed Description
The present application will be described in further detail with reference to examples.
The specifications of the materials used in the preparation examples, examples and comparative examples are as follows:
the heat-conducting silica gel powder is purchased from Xuancheng crystal-like Rui New Material Co., ltd;
sepiolite fiber was purchased from processing factory of mineral products of the skipper county;
lithium carbonate powder is purchased from Beijing Mino sincere science and technology Limited, and the purity is 99.9 percent;
lithium sulfate powder was purchased from Nanjing Sitaibao trade company, inc. and had a purity of 99.9%.
Examples
Example 1
The mass concrete is prepared from the following raw materials in parts by weight:
27kg of cement, 85kg of machine-made sand, 95kg of broken stone, 12kg of fly ash, 5.0kg of mineral powder, 1.0kg of water reducing agent, 2.0kg of heat-conducting silica gel powder, 1.5kg of lithium carbonate solution and 15kg of water; the particle size of the heat-conducting silica gel powder is 20um; the lithium carbonate solution is a saturated solution at the temperature of 25 ℃, and the mass fraction of the lithium carbonate solution is 25.7%.
The mass concrete is prepared by the following steps:
s1: mixing cement, machine-made sand, broken stone, fly ash, mineral powder, heat-conducting silica gel powder and water, and stirring for 30 seconds to obtain a pre-mixed mixture;
s2: and mixing the water reducing agent, the lithium carbonate solution and the premixed mixture, and stirring for 90 seconds to obtain the mass concrete.
Example 2
The mass concrete is prepared from the following raw materials in parts by weight:
30kg of cement, 89kg of machine-made sand, 93kg of broken stone, 11kg of fly ash, 4.0kg of mineral powder, 0.9kg of water reducing agent, 2.3kg of heat-conducting silica gel powder, 1.8kg of lithium sulfate solution and 16kg of water; the particle size of the heat-conducting silica gel powder is 35um; the lithium sulfate solution is a saturated solution at the temperature of 25 ℃, and the mass fraction of the lithium sulfate solution is 25.7%.
The mass concrete is prepared by the following steps:
s1: mixing cement, machine-made sand, broken stone, fly ash, mineral powder, heat-conducting silica gel powder and water, and stirring for 45 seconds to obtain a pre-mixed mixture;
s2: and mixing the water reducing agent, the lithium sulfate solution and the premixed mixture, and stirring for 80s to obtain the mass concrete.
Example 3
The mass concrete is prepared from the following raw materials in parts by weight:
32kg of cement, 92kg of machine-made sand, 90kg of broken stone, 10kg of fly ash, 3.0kg of mineral powder, 0.8kg of water reducing agent, 2.5kg of heat-conducting silica gel powder, 2.0kg of lithium carbonate solution and 18kg of water; the particle size of the heat-conducting silica gel powder is 50um; the lithium carbonate solution is a saturated solution at the temperature of 25 ℃, and the mass fraction of the lithium carbonate solution is 25.7%.
The mass concrete is prepared by the following steps:
s1: mixing cement, machine-made sand, broken stone, fly ash, mineral powder, heat-conducting silica gel powder and water, and stirring for 60s to obtain a pre-mixed mixture;
s2: and mixing the water reducing agent, the lithium carbonate solution and the premixed mixture, and stirring for 60s to obtain the mass concrete.
Example 4
A bulk concrete, differing from example 3 in that: in the embodiment, 1.0kg of ammonium bicarbonate powder with the particle size of 300nm is also added into the raw materials; ammonium bicarbonate powder is added in step S1.
Example 5
A bulk concrete, differing from example 3 in that: in the embodiment, 1.1kg of ammonium bicarbonate powder with the particle size of 400nm is also added into the raw materials; ammonium bicarbonate powder is added in step S1.
Example 6
A bulk concrete differing from example 3 in that: in the embodiment, 1.3kg of ammonium bicarbonate powder with the particle size of 500nm is also added into the raw materials; ammonium bicarbonate powder is added in step S1.
Example 7
A bulk concrete, differing from example 5 in that: in the embodiment, 1.5kg of sepiolite fibers are also added into the raw materials; adding sepiolite fibers in the step S1; the sepiolite fiber had a diameter of 50 μm and a cut length of 5mm.
Example 8
A bulk concrete differing from example 5 in that: in the embodiment, 1.7kg of sepiolite fibers are also added into the raw materials; adding sepiolite fibers in the step S1; the sepiolite fiber had a diameter of 50 μm and a cut length of 5mm.
Example 9
A bulk concrete, differing from example 5 in that: in the embodiment, 2.0kg of sepiolite fibers are also added into the raw materials; adding sepiolite fibers in the step S1; the sepiolite fiber diameter was 50 μm and the cut length was 5mm.
Example 10
A bulk concrete, which differs from example 9 in that: in the embodiment, a sodium chloride solution is adopted to replace a lithium carbonate solution, and the mass fraction of the sodium chloride solution is 35.9%.
Example 11
A bulk concrete, which differs from example 9 in that: in this example, a calcium chloride solution is used instead of a lithium carbonate solution, and the mass fraction of the sodium chloride solution is 35.9%.
Example 12
A bulk concrete, which differs from example 9 in that: the mass fraction of the lithium carbonate solution used in this example was 10.0%.
Comparative example
Comparative example 1
The C50 mass concrete is prepared from the following raw materials in parts by weight:
300kg of cement, 1100kg of broken stone, 620kg of sand, 180kg of water, 200kg of ground slag and 7kg of admixture.
The C50 mass concrete is prepared by the following steps:
s1: mixing cement, broken stone, sand, ground slag, an additive and water, and stirring for 120s to obtain the uniformly stirred concrete.
Comparative example 2
A bulk concrete, which differs from example 9 in that: in this embodiment, no heat conductive silica gel powder is added.
Comparative example 3
A bulk concrete, which differs from example 9 in that: in this embodiment, the same amount of graphite powder is used instead of the heat-conducting silica powder.
Comparative example 4
A bulk concrete, which differs from example 9 in that: in this example, an equal amount of water was used instead of the lithium carbonate solution.
Performance test
1. Crack observation experiment
Test samples: pouring the concrete obtained in the examples 1 to 12 into steel moulds of 150mm × 150mm × 150mm, vibrating for 30min, standing for 3h, curing for 24h by using a plastic film, curing for 10h by using steam at 55 ℃, and demolding to obtain molded cubic test samples 1 to 12; the concrete obtained in comparative examples 1 to 4 was treated and formed in the same manner to obtain comparative samples 1 to 4, respectively.
The test method comprises the following steps: and respectively taking three groups of test samples 1-12 and three groups of control samples 1-4, respectively monitoring the cracking condition of the control samples 1-14 of each test sample 1-10 in real time by a Supereye crack observer, and taking an average value to record and analyze.
And (3) test results: as shown in table 1.
TABLE 1 test results for test samples 1-12 and control samples 1-4
As can be seen from Table 1, when comparing the test samples 1 to 3 with the control sample 1, the number of cracks per unit area and the total area of cracks in the mass concrete provided by the present application were smaller than those in the mass concrete of comparative example 1, and the number of cracks per unit area in the examples 1 to 3 of the present application was 6.2 pieces/m on average 2 The total area of cracks per unit area was found to be 132mm on average 2 /m 2 The reduction in the number of cracks per unit area by 76.4% and the reduction in the area of cracks per unit area by 73.7% compared to control sample 1 thus demonstrates that the bulk concrete provided herein generates less temperature stress and therefore less cracks during cement hydration.
As can be seen from Table 1, when the test samples 4 to 6 were compared with the test sample 3, the number of cracks per unit area of the test samples 4 to 6 was 5.2 pieces/m on average 2 Sheet ofThe total area of cracks in the bit area was 97mm on average 2 /m 2 The number of cracks in the unit area and the total cracking area of the test samples 4-6 are smaller than those of the test sample 3, which shows that the problem of cracks easily generated in the mass concrete can be effectively reduced after the ammonium bicarbonate powder is added in the mass concrete preparation process.
As can be seen from Table 1, when test samples 7 to 9 were compared with test sample 5, the number of cracks per unit area of test samples 7 to 9 was 3.7 pieces/m on average 2 The total area of cracks per unit area was 68mm on average 2 /m 2 Compared with the test sample 5, the number of cracks in a unit area is reduced by 26%, the area of cracks in the unit area is reduced by 27%, and the problem that cracks are easily generated in large-volume concrete can be further solved after the sepiolite fibers are added during preparation of the large-volume concrete.
It can be known from table 1 that, comparing test sample 10 and test sample 9, the number of cracks per unit area and the total cracking area of test sample 10 are both greatly increased compared to test sample 9, which indicates that the problem that cracks are generated in concrete cannot be reduced by using sodium chloride as a crystallization solution, and originally, the problem may be that the solubility of sodium chloride is less affected by temperature, and when cement inside concrete is hydrated due to heat release, the solubility of sodium chloride is not greatly affected, so that crystals cannot be separated out from the sodium chloride solution, and therefore, the heat conducting silica gel powder cannot be connected, so that the heat inside concrete cannot be quickly conducted out, and the number of cracks and the total cracking area of concrete are increased.
As can be seen from table 1, comparing the test sample 11 with the test sample 9, the number of cracks per unit area and the total crack area of the test sample 11 are both greatly increased compared to the test sample 9, which indicates that the problem of cracks generated in concrete cannot be reduced by using calcium chloride as a crystallization solution, originally, the solubility of sodium chloride is directly proportional to the temperature, and when the cement inside the concrete is hydrated and releases heat, the solubility of calcium chloride is also increased, so the calcium chloride solution cannot separate out crystals, and thus the heat-conducting silica gel powder cannot be connected together, so that the heat inside the concrete cannot be rapidly conducted out, and thus the number of cracks and the total crack area of the concrete are increased.
As can be seen from table 1, comparing the test sample 12 with the test sample 9, the number of cracks per unit area and the total area of cracks in the test sample 11 are increased compared with the test sample 9, which may be because the unsaturated lithium carbonate solution is used for the test sample 12, and when the heat is released in the initial stage of hydration in the concrete, the lithium carbonate solution is still unsaturated, so crystals cannot be precipitated in the initial stage, and the solubility of lithium carbonate is greatly reduced after the heat is released in the middle and later stages of hydration, so that crystals can be precipitated, and thus a part of heat can be conducted, but the effect is far less good than that of the saturated lithium carbonate solution.
As can be seen from table 1, when comparing the control sample 1, the control sample 2 and the test sample 9, since the heat conductive silica gel powder is not added to the control sample 2, the heat conductive performance of the whole mass concrete prepared is not good, and the attachment point cannot be provided for the precipitation of the crystal, so that the heat conduction is not facilitated, and the number of cracks per unit area and the total cracking area of the control sample 2 are increased compared with the test sample 9. However, the number of cracks per unit area and the total cracking area of the comparative sample 2 are still reduced compared with those of the comparative sample 1, which shows that the cracking problem of the concrete can be reduced to a certain extent by using the lithium carbonate solution, and although the crystals precipitated due to the absence of the heat-conducting silica gel powder cannot exist stably, the crystals still have a certain heat conduction effect, so that the control sample 2 also has a certain beneficial effect on inhibiting the cracking problem of the concrete.
It can be known from table 1 that, compare control sample 3 and test sample 9, control sample 3 compares crack quantity and total crack area on the unit area of test sample 9 and all increases, show that graphite powder can not replace the effect of heat conduction silica gel powder in the concrete, because graphite powder also has better heat conductivility, graphite powder surface is comparatively smooth and level, be unfavorable for the crystal adhesion that precipitates, consequently, the inside three-dimensional heat conduction network that can't form of concrete, and then lead to the inside heat conduction of concrete slower, so the total crack area of the crack quantity of concrete increases.
As can be seen from table 1, comparing the comparison sample 4 with the test sample 9, the number of cracks per unit area and the total cracking area of the comparison sample 4 are increased compared with the test sample 9, and since no crystallization solution is added (i.e. an equivalent amount of water is used to replace the lithium carbonate solution), crystals cannot be precipitated inside the concrete to connect the heat-conducting silica gel powder, a three-dimensional heat-conducting network cannot be formed inside the concrete, and further, the heat conduction inside the concrete is slow, so the total cracking area of the number of cracks of the concrete is increased.
The present embodiment is only for explaining the present application, and it is not limited to the present application, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present application.
Claims (5)
1. The mass concrete is characterized by being prepared from the following raw materials in parts by weight:
270-320 parts of cement;
850-920 parts of machine-made sand;
900-950 parts of macadam;
100-120 parts of fly ash;
30-50 parts of mineral powder;
8-10 parts of a water reducing agent;
20-25 parts of heat-conducting silica gel powder;
10-13 parts of ammonium bicarbonate powder;
15-20 parts of a crystallization solution;
150-180 parts of water;
the crystallization solution is a saturated solution;
the crystallization solution comprises at least one of a lithium carbonate solution and a lithium sulfate solution.
2. A bulk concrete according to claim 1, wherein: the particle size of the heat-conducting silica gel powder is 20-50um.
3. A bulk concrete according to claim 1, wherein: the raw material also comprises 15-20 parts of sepiolite fibers by weight.
4. A bulk concrete according to claim 1, wherein: the particle size of the ammonium bicarbonate powder is 300-500nm.
5. A method for preparing mass concrete according to claim 1, characterized in that: comprises the following preparation steps:
s1: mixing cement, machine-made sand, broken stone, fly ash, mineral powder, heat-conducting silica gel powder, ammonium bicarbonate powder and water, and stirring for 30-60s to obtain a premixed mixture;
s2: and mixing the water reducing agent, the crystallization solution and the premixed mixture, and stirring for 60-90s to obtain the mass concrete.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4277357A (en) * | 1980-01-31 | 1981-07-07 | Boardman Energy Systems Incorporated | Heat or cold storage composition containing a hydrated hydraulic cement |
| CN101712862A (en) * | 2009-11-27 | 2010-05-26 | 东南大学 | Heat-conducting fluid for reducing internal temperature rise of mass concrete and preparation method thereof |
| CN111732443A (en) * | 2020-06-28 | 2020-10-02 | 宁波新力建材科技有限公司 | Environment-friendly ceramsite concrete and preparation method thereof |
| CN113735507A (en) * | 2021-06-23 | 2021-12-03 | 陕西森右达环保建材有限公司 | Water-retaining heat-releasing anti-crack concrete and preparation method thereof |
| WO2022015958A1 (en) * | 2020-07-16 | 2022-01-20 | Rogers Corporation | Thermally conductive phase-change composition, methods of manufacture thereof, and articles including the composition |
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2022
- 2022-03-18 CN CN202210268964.9A patent/CN114804731B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4277357A (en) * | 1980-01-31 | 1981-07-07 | Boardman Energy Systems Incorporated | Heat or cold storage composition containing a hydrated hydraulic cement |
| CN101712862A (en) * | 2009-11-27 | 2010-05-26 | 东南大学 | Heat-conducting fluid for reducing internal temperature rise of mass concrete and preparation method thereof |
| CN111732443A (en) * | 2020-06-28 | 2020-10-02 | 宁波新力建材科技有限公司 | Environment-friendly ceramsite concrete and preparation method thereof |
| WO2022015958A1 (en) * | 2020-07-16 | 2022-01-20 | Rogers Corporation | Thermally conductive phase-change composition, methods of manufacture thereof, and articles including the composition |
| CN113735507A (en) * | 2021-06-23 | 2021-12-03 | 陕西森右达环保建材有限公司 | Water-retaining heat-releasing anti-crack concrete and preparation method thereof |
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| CN114804731A (en) | 2022-07-29 |
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