CN114349424A - Low-shrinkage anti-cracking concrete - Google Patents

Low-shrinkage anti-cracking concrete Download PDF

Info

Publication number
CN114349424A
CN114349424A CN202210003906.3A CN202210003906A CN114349424A CN 114349424 A CN114349424 A CN 114349424A CN 202210003906 A CN202210003906 A CN 202210003906A CN 114349424 A CN114349424 A CN 114349424A
Authority
CN
China
Prior art keywords
concrete
cement
shrinkage
water
reducing agent
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202210003906.3A
Other languages
Chinese (zh)
Inventor
荣志红
高卫东
张三鹏
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shanxi Lixintai Concrete Co ltd
Original Assignee
Shanxi Lixintai Concrete Co ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shanxi Lixintai Concrete Co ltd filed Critical Shanxi Lixintai Concrete Co ltd
Priority to CN202210003906.3A priority Critical patent/CN114349424A/en
Publication of CN114349424A publication Critical patent/CN114349424A/en
Pending legal-status Critical Current

Links

Classifications

    • 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
    • C04B28/02—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 containing hydraulic cements other than calcium sulfates
    • C04B28/04—Portland cements
    • 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
    • C04B12/00—Cements not provided for in groups C04B7/00 - C04B11/00
    • C04B12/04—Alkali metal or ammonium silicate cements ; Alkyl silicate cements; Silica sol cements; Soluble silicate cements
    • 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
    • C04B22/148—Aluminium-sulfate
    • 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
    • C04B24/00—Use of organic materials as active ingredients for mortars, concrete or artificial stone, e.g. plasticisers
    • C04B24/24—Macromolecular compounds
    • 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
    • C04B2103/00—Function or property of ingredients for mortars, concrete or artificial stone
    • C04B2103/30—Water reducers, plasticisers, air-entrainers, flow improvers
    • C04B2103/302—Water reducers
    • 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
    • C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
    • C04B2111/34—Non-shrinking or non-cracking materials
    • C04B2111/343—Crack resistant materials
    • 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
    • C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
    • C04B2111/34—Non-shrinking or non-cracking materials
    • C04B2111/346—Materials exhibiting reduced plastic shrinkage cracking
    • 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
    • C04B2201/00—Mortars, concrete or artificial stone characterised by specific physical values
    • C04B2201/50—Mortars, concrete or artificial stone characterised by specific physical values for the mechanical strength

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Materials Engineering (AREA)
  • Structural Engineering (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Curing Cements, Concrete, And Artificial Stone (AREA)

Abstract

The invention discloses low-shrinkage anti-cracking concrete, which belongs to the technical field of building materials, and has the technical scheme that the concrete comprises, by weight, 610 parts of a cementing material 580-one, 880 parts of machine-made sand 780-one, 940 parts of broken stone 900-one, 25-35 parts of an additive and 160 parts of water 130-one, wherein the cementing material comprises cement, fly ash, mineral powder and slag, and the cement comprises the following components in parts by weight: fly ash: mineral powder: 5, slag: (1.6-2.1): (1.2-1.7): (0.9-1.3) to reduce the shrinkage of concrete.

Description

Low-shrinkage anti-cracking concrete
Technical Field
The invention relates to the field of building materials, in particular to low-shrinkage anti-cracking concrete.
Background
The problem of shrinkage cracking of concrete has become a common influence of the modern concrete world, and the normal use and the service life of a building engineering structure are seriously influenced.
The main reason for shrinkage cracking of concrete is that the moisture loss on the surface of concrete is too fast, the deformation is large, the moisture loss inside the concrete is slow, the deformation is small, the internal and external deformations of the concrete are different, and the large surface shrinkage deformation is restrained by the inside of the concrete, so that the crack is generated due to large tensile stress. At present, the most common measures for solving the problem of concrete dry shrinkage cracking are to add high water-absorbent resin into concrete, or to spray water, mist and the like on the surface of the concrete during concrete curing; although the shrinkage cracking problem of concrete can be solved by adding the super absorbent resin, the water-absorbent resin can leave a cavity in the concrete after releasing water, so that the mechanical property of the concrete is influenced; the concrete surface is only temporarily moistened by sprinkling and spraying, but moisture is not easy to enter the concrete, and the expected curing effect cannot be achieved.
Disclosure of Invention
In order to reduce the shrinkage rate of concrete, the invention provides low-shrinkage anti-cracking concrete.
The invention provides a low-shrinkage anti-cracking concrete which adopts the following technical scheme:
the low-shrinkage anti-cracking concrete comprises, by weight, 610 parts of a cementing material 580-: fly ash: mineral powder: 5, slag: (1.6-2.1): (1.2-1.7):(0.9-1.3).
Preferably, the weight ratio of water to cementitious material is between 0.23 and 0.25.
Preferably, the cement: fly ash: mineral powder: the weight ratio of the slag is 5: (1.7-2.1): (1.4-1.7):(1-1.3).
Preferably, the cement: fly ash: mineral powder: the weight ratio of the slag is 5: (1.7-1.9): (1.4-1.6):(1-1.3).
Through adopting above-mentioned technical scheme, because coal ash and powdered ore have form benefit, filling benefit and secondary hydration reaction in this application, make the closely knit degree of concrete increase, on the other hand, this application research finds that the concrete water consumption is compared and is further reduced in original water consumption behind the doping fly ash, powdered ore and slay to also increased the closely knit degree of concrete to a certain extent, made the inside dehydration resistance grow of concrete, the shrink reduces. Therefore, the compaction performance of the concrete is improved by controlling the water-cement ratio of the concrete and the proportion of cement, fly ash, mineral powder and slag in the cementing material, so that the shrinkage of the concrete is reduced, and the cracking resistance is improved.
In addition, the fly ash, the mineral powder and the slag are matched, so that a good matching between the micro-aggregate effect and the reactivity in the concrete can be formed, the pore structures of a hydration phase and a transition region are changed, an effective filling effect is achieved, the pore structure of the hydration phase is refined, the shrinkage of the concrete is further limited, and the anti-cracking effect is achieved.
Preferably, the admixture is a polycarboxylic acid water reducing agent.
Through adopting above-mentioned technical scheme, polycarboxylate water reducing agent has high dispersion to cement, and the slump that keeps the concrete that can be better can make the mobility of concrete mixture improve greatly, reduces the water consumption of concrete mixture by a wide margin under the circumstances that keeps good mobility simultaneously, and then improves the closely knit degree of concrete.
Preferably, the admixture comprises a polycarboxylic acid water reducing agent, an alkali activator and an expanding agent, and the polycarboxylic acid water reducing agent comprises the following components in percentage by weight: alkali activator: the swelling agent is 1: (0.2-0.6): (0.5-0.8).
Preferably, the admixture comprises a polycarboxylic acid water reducing agent, an alkali activator and an expanding agent, and the polycarboxylic acid water reducing agent comprises the following components in percentage by weight: alkali activator: the swelling agent is 1: (0.3-0.5): (0.6-0.8), and sodium silicate with fineness modulus of 2.1-2.3 is used as alkali activator.
By adopting the technical scheme, the polycarboxylate water reducing agent, the alkali activator and the expanding agent are matched for use, so that the partial shrinkage deformation of the concrete can be compensated, the probability of shrinkage cracking of the concrete is reduced, the gas forming amount of the concrete is adjusted, the pore structure of the concrete is further controlled, the compactness of the concrete is improved, and the shrinkage of the concrete is further reduced.
Preferably, the water absorption of the macadam is less than or equal to 2%, the content of needle-shaped particles is less than or equal to 5%, and the crushing index value is 4-5%.
By adopting the technical scheme, when the water absorption rate, the needle flake particle content and the compression index value of the macadam are limited in the range of the application, the shrinkage of the concrete can be further limited, and the purpose of reducing the shrinkage is achieved.
In conclusion, the invention has the following beneficial effects: this application is through the water-cement ratio of control concrete and the proportion of each component in the cementitious material, guarantee the required water consumption of hydration in the concrete, can also accelerate the speed of concrete hydration simultaneously, make the hydration product can effectively fill the inside hole of concrete in the system, improve the closely knit degree of concrete, water-reducing agent in the admixture in addition, alkali activator, the cooperation of inflation agent is used, make the concrete hydration speed faster, hydration degree is great, the hydration product of production can effectively fill the hole, make the pore structure become more compact, to so the shrink of concrete play certain limiting action.
Detailed Description
The present invention will be described in further detail with reference to examples.
The concrete drying mechanism is mainly caused by the loss of water of a cement structure, under a dry environment, water is evaporated from the surface of the concrete, namely free water in coarse holes and large capillary holes, the loss of the water cannot cause large-volume deformation of the concrete, water is absorbed in small capillary holes and pores among colloidal particles, the loss of the water can cause large-volume deformation, and finally, when combined water of strong crystal water and structural water is lost, the concrete structure begins to be broken. Therefore, the dry shrinkage and the cracking area of the concrete are tested by adjusting the water-cement ratio of the concrete, the proportion of each component in the cementing material and the proportion of each component in the admixture, and the influence of the water-cement ratio, the proportion of each component in the cementing material and the proportion of each component in the admixture on the flow property and the compressive strength of the concrete is tested, so that the concrete still has good construction performance and required compressive strength under the conditions of low shrinkage and low cracking area.
The raw materials are all sold in the market, and the specific description is as follows:
(1) the cement is P.O52.5 ordinary portland cement, the loss on ignition is 0.89%, the 28-day compressive strength is 60.6MPa, and the 28-day flexural strength is 9.6 MPa;
(2) the fly ash is I-grade fly ash, the activity index of 7 days is 88 percent, and the activity index of 28 days is 108 percent;
(3) the mineral powder is S95 grade mineral powder, the activity index in 7 days is 75%, and the activity index in 28 days is 100%;
(4) the solid content of the polycarboxylic acid water reducing agent is 40 percent, and the water reducing rate is 30 percent;
(5) the expanding agent is calcium sulphoaluminate-calcium oxide composite expanding agent;
(6) the alkali activator adopts sodium silicate, and the fineness modulus is 2.1-2.3.
(7) The chemical composition of the slag is shown in the following table
Figure BDA0003454705680000031
The concrete is prepared by adding a cementing material, machine-made sand, broken stone, an additive and water into a stirring tank, and uniformly mixing and stirring to obtain the low-shrinkage anti-cracking concrete.
Example 1
The low-shrinkage anti-cracking concrete comprises 580kg of cementing materials, 780kg of machine-made sand, 900kg of broken stone, 25kg of water reducing agent and 130kg of water;
the cementing material comprises cement, fly ash, mineral powder and slag, wherein the cement: fly ash: mineral powder: the weight ratio of the slag is 5:1.6:1.2: 0.9;
the water absorption of the macadam is 2%, the content of needle-like particles is 4%, and the crushing index value is 4-5%.
Examples 2 to 7
The difference between the concrete and the concrete in example 1 is that the water-cement ratio is changed, and the rest is unchanged, and the specific content is shown in Table 1.
Table 1 examples 1-7 concrete mix ratio table, units: kg of
Figure BDA0003454705680000032
Figure BDA0003454705680000041
Example 8
The low-shrinkage anti-cracking concrete is different from the concrete in example 5 in that the weight ratio of cement, fly ash, mineral powder and slag is 5:1.7:1.4:1, and the rest is the same as the concrete in example 5, and the specific proportion is shown in Table 2.
Example 9
The low-shrinkage anti-cracking concrete is different from the concrete in example 5 in that the weight ratio of cement, fly ash, mineral powder and slag is 5:1.8:1.6:1.1, and the rest is the same as the concrete in example 5, and the specific proportion is shown in Table 2.
Example 10
The low-shrinkage anti-cracking concrete is different from the concrete in example 5 in that the weight ratio of cement, fly ash, mineral powder and slag is 5:1.9:1.6:1.1, and the rest is the same as the concrete in example 5, and the specific proportion is shown in Table 2.
Example 11
The low-shrinkage anti-cracking concrete is different from the concrete in example 5 in that the weight ratio of cement, fly ash, mineral powder and slag is 5:1.8:1.7:1.1, and the rest is the same as the concrete in example 5, and the specific proportion is shown in Table 2.
Example 12
The low-shrinkage anti-cracking concrete is different from the concrete in example 5 in that the weight ratio of cement, fly ash, mineral powder and slag is 5:1.8:1.6:1.3, and the rest is the same as the concrete in example 5, and the specific proportion is shown in Table 2.
Example 13
The low-shrinkage anti-cracking concrete is different from the concrete in example 5 in that the weight ratio of cement, fly ash, mineral powder and slag is 5:2.1:1.7:1.3, and the rest is the same as the concrete in example 5, and the specific proportion is shown in Table 2.
Table 2 examples 8-13 concrete mix ratio table, units: kg of
Figure BDA0003454705680000042
Example 14
A low shrinkage crack resistant concrete, differing from example 9 in that: 820kg of machine-made sand, 920kg of crushed stone and 30kg of water reducing agent, and the content of the rest components is the same as that in the example 9.
Example 15
A low shrinkage crack resistant concrete, differing from example 9 in that: 880kg of machine-made sand, 940kg of broken stone and 35kg of water reducing agent, and the content of the other components is the same as that in example 9.
Example 16
The low-shrinkage crack-resistant concrete is different from the concrete in example 14 in that the admixture comprises a water reducing agent, water glass and an expanding agent, and the water reducing agent comprises the following components in percentage by weight: water glass: the specific content of the swelling agent was 1:0.2:0.5, and the other components were the same as those in example 14, as shown in table 3.
Comparative example 16-1
A low shrinkage cracking resistant concrete, which is different from that in example 16 in that the admixture comprises a water reducing agent and an expanding agent, wherein the water reducing agent comprises the following components in percentage by weight: the specific content of the swelling agent was 1:0.5, and the other components were the same as those in example 16, as shown in Table 3.
Comparative example 16-2
A low shrinkage cracking resistant concrete, which is different from that in example 16 in that the admixture comprises a water reducing agent and an expanding agent, wherein the water reducing agent comprises the following components in percentage by weight: the ratio of water glass to water glass was 1:0.2, and the specific content is shown in Table 3, and the other components were the same as those in example 16.
Example 17
The low-shrinkage crack-resistant concrete is different from the concrete in example 14 in that the admixture comprises a water reducing agent, water glass and an expanding agent, and the water reducing agent comprises the following components in percentage by weight: water glass: the specific content of the swelling agent was 1:0.4:0.6, and the other components were the same as those in example 14, as shown in table 3.
Example 18
The low-shrinkage crack-resistant concrete is different from the concrete in example 14 in that the admixture comprises a water reducing agent, water glass and an expanding agent, and the water reducing agent comprises the following components in percentage by weight: water glass: the specific content of the swelling agent was 1:0.6:0.8, and the other components were the same as those in example 14, as shown in table 3.
Table 3 mixing additive proportioning table for examples 16 to 18, comparative examples, unit: kg of
Figure BDA0003454705680000051
Comparative examples 1 to 3
A low shrinkage cracking resistant concrete, which is different from that of example 5 in that no slag or no mineral powder or no fly ash is contained in the cementitious material, as shown in Table 4, and the rest of the components and contents are the same as those of example 5.
Comparative example 4
A low shrinkage crack resistant concrete, differing from example 5 in that the cement in the cementitious material: fly ash: mineral powder: the slag weight ratio was 5:1.5:1.8:0.7, the specific contents are shown in Table 4, and the contents of the remaining components are the same as in example 5.
Comparative example 5
A low shrinkage crack resistant concrete, differing from example 5 in that the cement in the cementitious material: fly ash: mineral powder: the slag weight ratio was 5:2.3:1.0:0.5, the specific contents are shown in Table 4, and the contents of the remaining components are the same as in example 5.
Table 4 gel material ratios in comparative examples 1-3, unit: kg of
Figure BDA0003454705680000061
Comparative example 6
A low shrinkage crack resistant concrete, which differs from example 5 in that the amount of water is 170kg, i.e. the water to cement ratio is: 0.283, and the content of the rest components is the same as that of the example 5.
Performance detection
The low shrinkage cracking-resistant concrete obtained in the examples, comparative examples and comparative examples of the present application were subjected to a general mechanical property test, a concrete shrinkage test and an early cracking test, and the test results are shown in the following table.
The concrete common performance test is carried out according to the regulation of GB/T50081-2002 concrete common mechanical property test method, the size of a strength test piece is 100 multiplied by 100mm, and the detection result is shown in Table 5;
the concrete shrinkage and crack resistance tests are carried out according to the regulations in GB/T50082-2009 test method for long-term performance and durability of common concrete, the dimension of a shrinkage part is 100 multiplied by 515mm, and the dimension of a crack resistance part is 800 multiplied by 600 multiplied by 100 mm.
TABLE 5 working and mechanical Properties of concrete test results Table
Figure BDA0003454705680000062
Figure BDA0003454705680000071
As can be seen from table 5:
in examples 1-7, the slump when the concrete is taken out of the machine is more than 200mm, and the slump of the concrete after 2h is about 200mm, so that the concrete has good fluidity, and the application proves that the water-cement ratio of the concrete can meet the construction requirement of C60 concrete when the water-cement ratio is between 0.224 and 0.262, and the compressive strength of the concrete in examples 1-7 for 28 days is more than 64MPa, and also meets the strength requirement of C60 concrete.
In examples 8 to 18, comparative example 16 to 1 and comparative example 16 to 2, it can be seen that when the cement, fly ash, mineral powder and slag, the ratio of the machine-made sand, crushed stone and water reducing agent and the ratio of the admixture are changed under the condition that the water-cement ratio is the same as that in example 5, the fluidity and compressive strength of the concrete are not greatly different from those in example 5, which indicates that the fluidity and compressive strength of the concrete can be effectively ensured and the compressive strength of the concrete can be improved when the ratio of the cement, fly ash, mineral powder and slag, the ratio of the machine-made sand, crushed stone and water reducing agent and the ratio of the admixture are within the range defined in the application.
Compared with the example 5, when any one of slag, mineral powder and fly ash is absent in the cementing material, the fluidity of the concrete is reduced, and the compressive strength of the concrete for 7 days and 28 days is reduced, which shows that the cooperative use of cement, fly ash, mineral powder and slag in the cementing material not only can ensure the fluidity of the concrete, but also is beneficial to improving the compressive strength of the concrete.
Comparative examples 4-5 compared with example 5, when the cement, fly ash, ore powder and slag ratio in the cementitious material were outside the range of the present application when the water-cement ratio was the same, the fluidity and compressive strength of the concrete were both lower than those of example 5 of the present application, indicating that when the cement, fly ash, ore powder and slag ratio were within the range defined in the present application, the fluidity and compressive strength of the concrete were improved.
Table 6 test results of concrete drying shrinkage
Figure BDA0003454705680000072
Figure BDA0003454705680000081
As can be seen from table 6:
the dry shrinkage of the concrete in examples 1-5 is gradually reduced along with the increase of the water-cement ratio, and the dry shrinkage reaches the lowest in example 5, and the dry shrinkage in examples 6-7 is basically close to but shows an increasing trend compared with the dry shrinkage in example 5, and the main reasons are that when the water-cement ratio is small, the internal pore diameter of the concrete is reduced, the ratio of capillary pores and fine pores is increased, at the moment, the disappearance of free moisture causes great shrinkage stress, when the water-cement ratio is large, the internal moisture content of the concrete is high and exists in larger gaps, and as the cement hydration reaction continues, the cement stone structure is further densified, the moisture in the large gaps is gradually lost, and large capillary tension cannot be generated, so the shrinkage of the concrete is also small.
In addition, in examples 1 to 7, the time for the concrete to crack was gradually increased, the total cracking area was decreased first and then increased in 24 hours, and in example 5, the number of cracks and the total cracking area were minimized, indicating that the crack resistance of the concrete was also superior when the water-cement ratio was 0.25.
In examples 8 to 13, when the cement-to-cement ratio was the same as that of example 5, the shrinkage rates of the concretes in examples 8 to 13 were all lower than that of the concrete in example 5, and the crack resistance of the concrete in examples 8 to 13 was also superior to that of example 5, indicating that the cracking resistance of the concrete was limited when the cement, fly ash, powdered ore and slag were in this range.
In examples 14 to 15, when the water-cement ratio and the proportions of cement, fly ash, ore powder and slag were the same as in example 9, the shrinkage rate was decreased by changing the contents of the machine-made sand, crushed stone and water-reducing agent, and the time for cracking of the concrete was later than that in example 9, but when the contents of the machine-made sand, crushed stone and water-reducing agent reached the maximum values defined in the present application, the shrinkage rate in example 15 was lower than that in example 9 but higher than that in example 14, and the cracking resistance area in example 15 was also larger than that in example 13, indicating that when the contents of the machine-made sand, crushed stone and water-reducing agent were the same as in example 14, the drying shrinkage rate and cracking resistance of the concrete were superior.
In examples 16 to 18, after the water reducing agent, the water glass and the expanding agent are used as the admixture, the shrinkage rate and the cracking area of the concrete are both reduced, which indicates that the hydration speed and the hydration degree of the concrete are higher due to the matched use of the water glass, the expanding agent and the water reducing agent, so that the hydration products in the concrete system fill the pores, the pore structure becomes more compact, the shrinkage rate is reduced, and the cracking area is also reduced.
Compared with the example 16, in the comparative examples 16-1 and 16-2, when the admixture is composed of the water reducing agent and the expanding agent or the water reducing agent and the water glass, the dry shrinkage and the cracking area of the concrete are lower than those of the water reducing agent alone but higher than those of the water reducing agent alone, which shows that when the water reducing agent, the water glass and the expanding agent are used together, the good flowing property of the concrete can be ensured, and the shrinkage and the cracking area of the concrete can be reduced.
As can be seen in comparative examples 1-6, the dry shrinkage and the cracking area of the concrete in comparative examples 1-6 are higher than those of the concrete in example 5 of the present application, and it can be shown that the dry shrinkage and the cracking area of the concrete can be effectively reduced only by the interaction and the coordination of the components in the present application.
The embodiments of the present invention are preferred embodiments of the present invention, and the scope of the present invention is not limited by these embodiments, so: all equivalent changes made according to the structure, shape and principle of the invention are covered by the protection scope of the invention.

Claims (8)

1. A low-shrinkage anti-cracking concrete is characterized in that: the concrete comprises, by weight, 610 parts of a cementing material 580-containing sand, 880 parts of machine-made sand, 940 parts of crushed stone 900-containing sand, 25-35 parts of an admixture and 160 parts of water 130-containing sand, wherein the cementing material comprises cement, fly ash, mineral powder and slag, and the cement comprises the following components in parts by weight: fly ash: mineral powder: 5, slag: (1.6-2.1): (1.2-1.7):(0.9-1.3).
2. The low shrinkage crack resistant concrete according to claim 1, wherein: the weight ratio of the water to the cementing material is 0.23-0.25.
3. The low shrinkage crack resistant concrete according to claim 1, wherein: the cement is as follows: fly ash: mineral powder: the weight ratio of the slag is 5: (1.7-2.1): (1.4-1.7): (1-1.3).
4. The low shrinkage crack resistant concrete according to claim 2, wherein: the cement is as follows: fly ash: mineral powder: the weight ratio of the slag is 5: (1.7-1.9): (1.4-1.6): (1-1.3).
5. The low shrinkage crack resistant concrete according to claim 1, wherein: the additive is a polycarboxylic acid water reducing agent.
6. The low shrinkage crack resistant concrete according to claim 1, wherein: the admixture comprises a polycarboxylic acid water reducing agent, an alkali activator and an expanding agent, and the polycarboxylic acid water reducing agent comprises the following components in percentage by weight: alkali activator: the swelling agent is 1: (0.2-0.6): (0.5-0.8).
7. The low shrinkage crack resistant concrete according to claim 6, wherein: the admixture comprises a polycarboxylic acid water reducing agent, an alkali activator and an expanding agent, and the polycarboxylic acid water reducing agent comprises the following components in percentage by weight: alkali activator: the swelling agent is 1: (0.3-0.5): (0.6-0.8).
8. The low shrinkage crack resistant concrete according to claim 1, wherein: the water absorption of the macadam is less than or equal to 2 percent, the content of needle-shaped and sheet-shaped particles is less than or equal to 5 percent, and the crushing index value is 4-5 percent.
CN202210003906.3A 2022-01-04 2022-01-04 Low-shrinkage anti-cracking concrete Pending CN114349424A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210003906.3A CN114349424A (en) 2022-01-04 2022-01-04 Low-shrinkage anti-cracking concrete

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210003906.3A CN114349424A (en) 2022-01-04 2022-01-04 Low-shrinkage anti-cracking concrete

Publications (1)

Publication Number Publication Date
CN114349424A true CN114349424A (en) 2022-04-15

Family

ID=81108108

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210003906.3A Pending CN114349424A (en) 2022-01-04 2022-01-04 Low-shrinkage anti-cracking concrete

Country Status (1)

Country Link
CN (1) CN114349424A (en)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015124136A (en) * 2013-12-27 2015-07-06 住友大阪セメント株式会社 Concrete composition having initial-stage and long-term high strength developability and high crack resistance, and concrete body using the composition
CN105645894A (en) * 2015-12-29 2016-06-08 武汉武新新型建材股份有限公司 High-performance concrete with large mixing amount of mineral powder and manufacturing method of high-performance concrete
CN113651581A (en) * 2021-09-10 2021-11-16 杭州华杰商品混凝土有限公司 High-mineral-powder-doped concrete and preparation method thereof

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015124136A (en) * 2013-12-27 2015-07-06 住友大阪セメント株式会社 Concrete composition having initial-stage and long-term high strength developability and high crack resistance, and concrete body using the composition
CN105645894A (en) * 2015-12-29 2016-06-08 武汉武新新型建材股份有限公司 High-performance concrete with large mixing amount of mineral powder and manufacturing method of high-performance concrete
CN113651581A (en) * 2021-09-10 2021-11-16 杭州华杰商品混凝土有限公司 High-mineral-powder-doped concrete and preparation method thereof

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
徐友辉，李晓楼主编: "《建筑材料》", 31 March 2020, 北京理工大学出版社 *
李秋义，王亮著: "《固体废弃物在绿色建材中的应用》", 30 April 2019, 中国建材工业出版社 *

Similar Documents

Publication Publication Date Title
CN110256023B (en) Anti-freezing, anti-permeability and anti-cracking concrete and preparation method thereof
CN109678433B (en) Ultrahigh-strength self-compacting micro-expansion steel pipe concrete and preparation method thereof
Türkel et al. The effect of limestone powder, fly ash and silica fume on the properties of self-compacting repair mortars
NZ528311A (en) Low bulk density calcium silicate hydrate strength accelerant additive for curing cementitious products
CN110950604A (en) SAP-based machine-made sand ultra-high-performance concrete and preparation method and application thereof
CN111620624B (en) Self-compacting concrete and preparation method thereof
CN111848019A (en) Ultrahigh-lift pumping anti-cracking concrete suitable for cable tower structure and preparation method thereof
CN111847921B (en) Low clinker cement and preparation method and application thereof
CN111792889A (en) Natural tuff ultrahigh-performance concrete and preparation method thereof
CN113603388B (en) Concrete reinforced compact and temperature-adjustable anti-cracking agent and preparation method thereof
Tawfik et al. Hybrid effect of nanosilica and metakaolin on mechanical properties of cement mortar
El-Alfi et al. Effect of limestone fillers and silica fume pozzolana on the characteristics of sulfate resistant cement pastes
CN112851264A (en) High-temperature-resistant concrete based on iron tailings and steel slag powder
CN110451840B (en) Composite type compacting agent
EP0877007B1 (en) Hydraulic cement
CN112062521A (en) Large-volume concrete and preparation method thereof
CN115321924A (en) Durable self-compacting filling concrete material for underground structural engineering
CN114349424A (en) Low-shrinkage anti-cracking concrete
CN116409948A (en) Low-carbon composite cementing material based on regenerated micro powder, and preparation method and application thereof
Gulmez et al. Effects of iron powder on properties of geopolymers subjected to different curing regimes
CN113248201A (en) Early-strength micro-expansion ultra-high performance concrete and preparation method and application thereof
Sherif Utilization of metakaolin on sustainable concrete properties
Wu et al. Research on shrinkage inhibition technology of C50 steel shell immersed tube self-compacting concrete
CN115504754B (en) Steel pipe concrete based on solid waste expansion and preparation method thereof
CN109503084A (en) A kind of C45P6 subway concrete and preparation method thereof

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
RJ01 Rejection of invention patent application after publication
RJ01 Rejection of invention patent application after publication

Application publication date: 20220415