CN112456903A

CN112456903A - High-performance concrete based on antimony tailing waste stone and preparation method thereof

Info

Publication number: CN112456903A
Application number: CN202011359545.3A
Authority: CN
Inventors: 汪建群; 李隆; 李贝; 邓仁健; 周赛君; 王功勋; 周聪; 张龙威
Original assignee: Hunan University of Science and Technology
Current assignee: Hunan University of Science and Technology
Priority date: 2020-11-27
Filing date: 2020-11-27
Publication date: 2021-03-09

Abstract

The invention relates to high-performance concrete based on antimony tailing waste stone and a preparation method thereof, wherein the high-performance concrete comprises the following materials: coarse aggregate, machine-made sand, a water reducing agent and water; the coarse aggregate comprises cement and antimony tailing crushed stone; in per cubic meter of high-performance concrete, the mass ratio of the materials is cement: crushing antimony tailings: and (3) machining sand: water reducing agent: and (3) water is 442-485: 1047 to 1091: 724-758: 4.86-5.82: 160; the mineral component of the antimony tailing crushed stone is mainly quartz; SiO in quartz₂The content is 74.47-94.17%. The invention utilizes the combination of the broken stones made of the antimony tailing waste stones and the cement as the coarse aggregate to prepare the concrete, realizes the recycling comprehensive recycling of the antimony tailing waste stones, reduces the stacking field and the management cost, reduces the production cost of the concrete, and the concrete has high strength, frost resistance, crack resistance and resistanceGood permeability and durability, etc.

Description

High-performance concrete based on antimony tailing waste stone and preparation method thereof

Technical Field

The invention belongs to the technical field of solid waste resource utilization and concrete, and relates to high-performance concrete based on antimony tailing waste stone and a preparation method thereof.

Background

Concrete is the most widely used and most economical artificial civil engineering material in the world. The coarse aggregate is used as a framework of the concrete and is an important component of the high-performance concrete; in recent years, with the high-speed increase of the economy of China, the investment of the nation on the infrastructure is continuously increased, project construction needs a large amount of high-quality sandstone aggregates, a large amount of sandstone resources are consumed to produce concrete, the natural sandstone resources are increasingly exhausted, and excessive exploitation of the natural sandstone is forbidden for sustainable development, so that the problem that the price of the sandstone is all the way up and the supply is insufficient, and the shortage of the sandstone resources becomes a problem to be faced by project builders.

At present, the iron tailings, the copper tailings, the gold tailings, the zinc tailings, the molybdenum tailings and other metal tailings are applied to the concrete related research and cases, meanwhile, according to published data, the worldwide antimony detection reserve is 180 ten thousand tons, while China is the country with the most antimony resource reserve in the world and accounts for 52 percent of the global total amount; china is also a world large country for producing the first antimony, so a large amount of antimony tailings waste rocks cannot be generated inevitably in the processes of mining, mineral separation and production; the mineral component of the antimony tailing waste stone is mainly SiO₂Fe and Al₂O₃The treatment measures for antimony tailing waste stones at present mainly comprise the establishment of a special waste stone stacking field for centralized stacking, but the treatment mode not only occupies a large amount of land, but also wastes time and labor, the production cost of enterprises is increased invisibly, and if the treatment is improper, heavy metal pollution is extremely easy to cause to the surrounding environment. How to realize the waste of antimony tailings and how to solve the problem of antimony tailings wasteThe problem of comprehensive recycling of stones is a topic of concern.

Disclosure of Invention

The invention provides high-performance concrete based on antimony tailing waste stone and a preparation method thereof, aiming at the technical problems in the existing concrete sandstone resource and antimony tailing waste stone treatment.

In order to achieve the purpose, the invention adopts the technical scheme that:

a high-performance concrete based on antimony tailings waste rocks comprises the following materials: coarse aggregate, machine-made sand, a water reducing agent and water; the coarse aggregate comprises cement and antimony tailing crushed stone;

in per cubic meter of high-performance concrete, the mass ratio of the materials is cement: crushing antimony tailings: and (3) machining sand: water reducing agent: and (3) water is 442-485: 1047 to 1091: 724-758: 4.86-5.82: 160.

further, the mineral component of the antimony tailing crushed stone is mainly quartz; SiO in the quartz₂The content is 74.47% -94.17%.

Further, the main components and contents of the antimony tailing crushed stone in the coarse aggregate are as follows: SiO2₂86.53-93.64 percent of Al₂O₃The content is 2.57-4.12%; the CaO content is 0.177 to 2.04 percent; fe₂O₃The content is 0.638 to 1.275 percent; k₂The content of O is 0.337 to 0.565 percent; the FeO content is 0.219 to 0.364 percent; TiO 2₂The content is 0.143 percent to 0.176 percent; the MgO content is 0.103-0.14%; the MnO content is 0.026% -0.034%; p₂O₅The content of Na is 0.029 to 0.045 percent₂The content of O is 0.013-0.024%.

Further, the particle size of the coarse aggregate is 5 mm-20 mm of continuous gradation; all properties of the coarse aggregate meet the requirements of II-class indexes of the coarse aggregate in JTG/T F50-2011 Highway and bridge construction technical Specification.

Further, the cement is P.O 42.5.

Further, the fineness modulus of the machine-made sand is 2.9-2.6 of medium sand; all the performances of the machine-made sand can meet the standard requirements of GB/T14684 plus 2011 construction sand.

Further, the water reducing agent is a HT-HPC polycarboxylic acid high-strength water reducing agent.

A preparation method of high-performance concrete based on antimony tailing waste stones comprises the following steps:

1) washing the antimony tailing waste stone until no residue is on the surface, and drying, crushing and screening to obtain antimony tailing crushed stone for later use;

2) weighing cement and machine-made sand according to the mass ratio of claim 1, adding the cement and the machine-made sand into a stirrer, and stirring for 20-40 s;

3) continuously adding water into the stirrer in the step 2), stirring for 15-25 s, and then adding the antimony tailing crushed stone in the step 1);

4) dissolving the water reducing agent in water, adding into a stirrer, continuously stirring for 120-180 s, and discharging.

The invention has the beneficial effects that:

1. the high-performance concrete provided by the invention comprises the following materials: coarse aggregate, machine-made sand, a water reducing agent and water; the coarse aggregate comprises cement and antimony tailing crushed stone; according to the invention, the antimony tailing waste stone and the cement form the coarse aggregate, then the coarse aggregate is further prepared into the concrete, and the antimony tailing waste stone is solidified in the concrete, so that the consumption of natural resources in the concrete is reduced, the stacking place and the management cost of the antimony tailing waste stone are reduced, the comprehensive utilization of solid waste resources is realized, the production cost of the concrete is reduced, and the energy-saving and environment-friendly effects are achieved.

2. In the invention, the mineral components of the antimony tailing crushed stone are mainly quartz, and SiO in the quartz₂The content is 74.47% -94.17%; the grain size of the coarse aggregate is 5 mm-20 mm; the coarse aggregate has various properties meeting the requirements of II-class indexes of the coarse aggregate in JTG/T F50-2011 Highway bridge and culvert construction technical Specification, the cement is P.O 42.5, and the machine is used for preparing the coarse aggregatePreparing medium sand with fineness modulus of 2.9-2.6; the water reducing agent is HT-HPC polycarboxylic acid high-strength water reducing agent, and by utilizing the materials and through reasonable grading distribution, the prepared concrete has the advantages of high strength, good freezing resistance, cracking resistance, impermeability and durability, and the like, particularly has high strength and good cracking resistance, is very suitable for the upper structure of a bridge, ensures the structural safety and obviously improves the durability of the structure.

3. The invention firstly stirs and mixes the cement and the machine-made sand, and then adds water, processes the obtained antimony tailing crushed stone and the water reducing agent to form the high-performance concrete, and has simple production process and low production cost.

Drawings

FIG. 1 is a graph of concrete compressive strength as a function of age for various embodiments of the present invention;

FIG. 2 is a graph of concrete split tensile strength as a function of age for various embodiments of the present invention;

FIG. 3 is a graph of the change in elastic modulus with age for different embodiments of the present invention;

FIG. 4 is a graph of concrete carbonation depth as a function of carbonation time for various embodiments of the present invention.

Detailed Description

The present invention will now be described in detail with reference to the accompanying drawings and examples.

Example 1

The high-performance concrete based on the antimony tailing waste rock provided by the embodiment comprises the following materials: coarse aggregate, machine-made sand, a water reducing agent and water; the coarse aggregate comprises cement and antimony tailing crushed stone. The mass ratio of each material in each cubic meter of high-performance concrete is cement: crushing antimony tailings: and (3) machining sand: water reducing agent: 482 parts of water: 1085: 724: 5.30: 160.

in the embodiment, the mineral component of the antimony tailing crushed stone is mainly quartz; the SiO2 content in the quartz was 74.47%.

In this example, the cement was ordinary cement having a strength of 42.5MPa and P.O 42.5.

In this example, the coarse aggregate comprises the following main components in percentage by weight: SiO2₂The content is 86.53 percent，Al₂O₃The content is 4.12%; the CaO content is 0.177%; fe₂O₃The content is 0.638%; k₂The O content is 0.565%; the FeO content is 0.364%; TiO 2₂The content is 0.176%; MgO content is 0.103%; the MnO content is 0.034%; p₂O₅The content is 0.045%; na (Na)₂The O content was 0.013%.

In this example, the coarse aggregate had a continuous gradation with a particle size of 5 mm; the properties of the coarse aggregate all meet the requirements of II-class indexes of the coarse aggregate in JTG/T F50-2011 Highway bridge and culvert construction technical Specification.

In this example, the fineness modulus of the machine-made sand is medium sand of 2.8; all the performances of the machine-made sand can meet the standard requirements of GB/T14684 plus 2011 construction sand. The fineness modulus is an index for representing the fineness degree and the category of the particle size of the natural sand, and the larger the fineness modulus is, the thicker the sand is. The fineness modulus of the common sand for concrete is within 3.7-1.6, and medium sand is suitable.

In the embodiment, the water reducing agent is HT-HPC polycarboxylic acid high-strength water reducing agent. The water reducing agent is a concrete admixture which can reduce the mixing water consumption under the condition of keeping the slump constant of concrete basically, has a dispersing effect on cement particles, can improve the workability, reduce the unit water consumption and improve the fluidity of the concrete admixture; or the unit cement consumption is reduced, and the cement is saved.

The preparation method of the high-performance concrete based on the antimony tailing waste rock, provided by the embodiment, comprises the following steps:

2) weighing 482 parts of cement and 724 parts of machine-made sand according to the mass ratio, adding into a stirrer, and stirring for 30 s;

3) adding 100 parts of water into the stirrer in the step 2), stirring for 20s, and adding 1085 parts of antimony tailing crushed stones in the step 1);

4) and (3) dissolving 5.30 parts of water reducing agent in 60 parts of water, adding into the stirrer, continuously stirring for 120s, and discharging to obtain the concrete with the volume of 1 cubic meter.

In the embodiment, the antimony tailing waste rock is mainly stripped in the open-pit mining process, and is waste rock generated in the processes of prospecting, mining, exploitation, beneficiation and cutting of an underground mine.

Example 2

The difference from example 1 is:

the mass ratio of each material in each cubic meter of high-performance concrete is cement: crushing antimony tailings: and (3) machining sand: water reducing agent: the water is 442: 1091: 758: 4.86: 160.

in the embodiment, the mineral component of the antimony tailing crushed stone is mainly quartz; SiO in quartz₂The content was 94.17%.

In this example, the coarse aggregate comprises the following main components in percentage by weight: SiO2₂90.44% of Al₂O₃The content is 3.58%; the CaO content is 1.05 percent; fe₂O₃The content is 0.972%; k₂The O content is 0.441%; the FeO content is 0.309%; TiO 2₂The content is 0.152%; the MgO content is 0.12%; the MnO content is 0.030%; p₂O₅The content is 0.038%; na (Na)₂The O content was 0.017%. The coarse aggregate has a continuous gradation of 10mm particle size.

In this example, the fineness modulus of the machine-made sand was medium sand of 2.9.

2) 442 parts of cement and 758 parts of machine-made sand are weighed according to the mass ratio and added into a stirrer to be stirred for 40 s;

3) continuously adding 110 parts of water into the stirrer in the step 2), stirring for 15s, and then adding 1091 parts of the antimony tailing crushed stone in the step 1);

4) dissolving 4.86 parts of water reducing agent in 50 parts of water, adding into a stirrer, continuously stirring for 180s, and discharging to obtain the concrete with the volume of 1 cubic meter.

Example 3

Different from the embodiment 2, in the embodiment, the mass ratio of each material in each cubic meter of the high-performance concrete is cement: crushing antimony tailings: and (3) machining sand: water reducing agent: water is 485: 1047: 758: 5.82: 160.

In this example, the coarse aggregate comprises the following main components in percentage by weight: SiO2₂93.64% of Al₂O₃The content is 2.57%; the CaO content is 2.04 percent; fe₂O₃The content is 1.275 percent; k₂The O content is 0.337%; the FeO content is 0.219%; TiO 2₂The content is 0.143%; the MgO content is 0.14%; the MnO content is 0.026%; p₂O₅The content is 0.029%; na (Na)₂The O content is 0.024%. The coarse aggregate has a continuous gradation of 20mm particle size.

In this example, the fineness modulus of the machine-made sand was medium sand of 2.6.

2) 485 parts of cement and 758 parts of machine-made sand are weighed according to the mass ratio and added into a stirrer to be stirred for 20 s;

3) continuously adding 80 parts of water into the stirrer in the step 2), stirring for 25s, and then adding 1085 parts of the antimony tailing crushed stones in the step 1);

4) and (3) dissolving 5.82 parts of water reducing agent in 80 parts of water, adding into the stirrer, continuously stirring for 150 seconds, and discharging to obtain the concrete with the volume of 1 cubic meter.

In order to further illustrate the superiority of the invention for preparing concrete by using antimony tailing waste stones, the performance of the prepared concrete is further tested and verified.

Verification test 1 working performance and mechanical properties of concrete

Test groups: concrete prepared in example 1, example 2 and example 3

The test process comprises the following steps:

(1) respectively measuring the compressive strengths of the three groups of concrete in the test group by adopting a concrete compressive strength test method (GB/T11837-2009) for the concrete pipe; the results are shown in table 1 and fig. 1.

(2) The three groups of concrete of the test group are respectively measured by adopting a direct tension method for splitting tensile strength, the test piece is a 150mm multiplied by 550mm prism test piece which is formed by casting through a steel die, and two ends of the test piece are provided with centering ribbed steel bars (the diameter is 6mm) with the embedded depth of 125mm for applying axial tension. The results are shown in table 1 and fig. 2;

(3) the elastic modulus of the concrete in three groups of test groups is respectively measured by adopting a concrete elastic modulus test method in the standard GB/T50081-2002 of common concrete mechanical property test methods; the results are shown in table 1 and fig. 3.

TABLE 1 workability and mechanical Properties of the concretes

Referring to table 1, fig. 1-3, it can be seen that:

(1) the compressive strength of the concrete prepared in the embodiment 1, the embodiment 2 and the embodiment 3 is 50.5 MPa, 51.8 MPa and 52.6MPa respectively after 7 days; the 28-day compressive strength is respectively 59.5 MPa, 62.6 MPa and 64.5 MPa;

(2) the concrete prepared in the embodiment 1, the embodiment 2 and the embodiment 3 has the splitting tensile strength of 3.41, 3.47 and 3.51MPa respectively after 7 days; the 28-day splitting tensile strength is respectively 3.85 MPa, 3.94 MPa and 4.17 MPa;

(3) the concrete prepared in the example 1, the example 2 and the example 3 of the invention has the elastic modulus of 3.29 multiplied by 10 in 7 days⁴、3.31×10⁴And 3.35X 10⁴MPa; the elastic modulus of the alloy is respectively 3.97 multiplied by 10 in 28 days⁴、4.06×10⁴And 4.11X 10⁴MPa。

According to the specification GBT 50107-2010 concrete strength test evaluation standard, JTG 3362-2018 highway reinforced concrete and prestressed concrete bridge and culvert design specification, and C50 concrete 28d age compressive strength needs to meet 1.15f_cu，kNamely 57.5Mpa, and the 28d splitting tensile strength of the concrete is 2.65 Mpa; the 28d age elastic modulus of the concrete needs to reach 3.45 multiplied by 10⁴Therefore, the invention adopts the antimony tailing waste rock to prepare the concrete, which meets the standard requirements, has good working performance and mechanical property, and is high-strength concrete.

Verification test 2 concrete anti-freezing property

Test groups: concrete prepared in example 1, example 2 and example 3

The test process comprises the following steps: the freezing and thawing cycle times, the mass loss rate after freezing and thawing and the relative dynamic elastic modulus after freezing and thawing of three groups of concrete in the test group were respectively measured by the method of carrying out the normal slow freezing method on the frost resistance of common concrete, so as to show the frost resistance of the concrete, and the results are shown in table 2.

TABLE 2 concrete quality and loss rate of the relative dynamic elastic modulus

Note: the negative sign of mass loss rate in the table represents a decrease in mass.

As can be seen from table 2:

the concrete prepared in example 1, example 2 and example 3 has mass loss rates of 1.99%, 1.93% and 1.90% after freeze-thaw respectively when the number of freeze-thaw cycles is 300, and relative dynamic elastic modulus of 81.9%, 84.7% and 85.8% after freeze-thaw respectively.

According to the specification GB/T50082-2009 test method standard for long-term performance and durability of common concrete, the concrete anti-freezing grade is regulated to meet the freezing-thawing times that the relative dynamic elastic modulus value is not less than 60% and the mass loss rate is not more than 5%. Therefore, the concrete prepared from the antimony tailing waste stones has the frost resistance meeting the index of F300, and is good in frost resistance.

Verification test 3 concrete crack resistance

Test groups: concrete prepared in example 1, example 2 and example 3

The test process comprises the following steps: the cracking resistance of three groups of concrete in the test group was measured by the method in GB/T50082-2009 Standard test methods for Long-term Performance and durability of ordinary concrete, and the results are shown in Table 3.

TABLE 3 evaluation index for crack resistance of concrete

Item	a/(mm²/piece)	b/(piece/m²)	c/(mm²/m²)
				Example 1	33.84	6.84	231.47
Example 2	34.15	7.13	243.49
				Example 3	35.28	7.26	256.13

As can be seen from table 3:

the concrete prepared in example 1, example 2 and example 3 has c values of 231.47, 243.49 and 256.13mm respectively²/m²。

According to the grade division of the early cracking resistance of the concrete in JGJ/T193-2009 concrete durability test evaluation Standard, when the thickness is 100mm²/m²≤c＜400mm²/m²The concrete cracking performance rating is L-IV; the c value of the concrete prepared by the invention is less than 400, and the concrete is good in crack resistance, so that the concrete prepared by antimony tailing waste rock is high in crack resistance level and good in durability.

Verification test 4 concrete impermeability

Test groups: concrete prepared in example 1, example 2 and example 3

The test process comprises the following steps: the impermeability, durability and carbonization depth of the three groups of concrete in the test group were measured by the method in GB/T50082-2009 Standard test methods for Long-term Performance and durability of ordinary concrete, and the results are shown in Table 4 and FIG. 4.

TABLE 4 durability of concrete

As can be seen from table 4 and fig. 4:

the electric flux Q of the concrete prepared in example 1, example 2 and example 3 is_SAt 794, 816 and 832c, respectively; the 14-day expansion rate is respectively 0.07%, 0.07% and 0.08%; the 28d carbonization depth was 5.07, 5.73 and 6.15mm, respectively.

The evaluation of the concrete impermeability performance is carried out according to GB-T50082-2009 test method standards for the long-term performance and the durability of common concrete by adopting the electric flux of a concrete test piece as an evaluation index, and when Q is more than or equal to 500c, the electric flux is used as an evaluation index_SWhen the temperature is less than 1000c, the grade of the impermeability of the concrete is evaluated as Q-IV, and the invention adoptsConcrete prepared from antimony tailings waste rock, Q_SThe values are all less than 1000, therefore, the concrete has good anti-permeability performance.

According to the grading of the concrete carbonization resistance in JGJ/T193-2009 concrete durability test evaluation standard, when d is more than or equal to 0.1mm and less than 10mm, the concrete carbonization resistance is graded as T-IV, the 28d carbonization depth value of the concrete prepared by using the antimony tailing waste stone is less than 10mm, and therefore the concrete with good carbonization resistance is obtained.

The alkali-aggregate reaction of the concrete is also an important index for evaluating the durability of the concrete, according to the standard requirement of GB/T14685 plus 2011 construction pebble macadam, the expansion rate at the specified test age is less than 0.10 percent, the 14d expansion rate of the concrete prepared by antimony tailing waste stones is less than 0.10 percent, and the test piece has no phenomena of cracks, cracking, colloid overflow and the like, thereby meeting the standard requirement.

In conclusion, the concrete prepared by utilizing the antimony tailing waste stones has the characteristics that the tensile strength, the freezing resistance, the crack resistance, the impermeability and the durability can reach the characteristics of C50 high-strength concrete, but the machine-made sand is medium sand with the fineness modulus of 2.9-2.6, the sand with the fineness modulus meets the requirement of the fineness modulus of the sand for the ordinary concrete, but the antimony tailing waste stones are crushed to obtain antimony tailing crushed stones, the antimony tailing crushed stones and cement form coarse aggregate, the sand is combined with the machine-made sand and a water reducing agent to prepare the ordinary concrete, but the SiO contained in the antimony tailing waste stones₂、Al₂O₃、Fe₂O₃And FeO and the like, can improve the mechanical property and durability of the concrete, and ensure that the concrete meets the strength requirement of C50 high-strength concrete.

The invention can reduce the consumption of natural resources in concrete, reduce the stacking field and the management cost of antimony tailings waste rocks, and realize the comprehensive utilization of solid waste resources; the high-performance concrete is obtained, the production cost of the concrete is reduced, and the energy-saving and environment-friendly effects are achieved.

Claims

1. The high-performance concrete based on the antimony tailing waste stones is characterized by comprising the following materials: coarse aggregate, machine-made sand, a water reducing agent and water; the coarse aggregate comprises cement and antimony tailing crushed stone;

2. the high performance concrete based on antimony tailings waste stones according to claim 1, wherein the mineral component of the antimony tailings crushed stones is mainly quartz; SiO in the quartz₂The content is 74.47% -94.17%.

3. The high-performance concrete based on the antimony tailings waste stones as claimed in claim 2, wherein the antimony tailings crushed stones mainly comprise the following components in percentage by weight: SiO2₂86.53-93.64 percent of Al₂O₃The content is 2.57-4.12%; the CaO content is 0.177 to 2.04 percent; fe₂O₃The content is 0.638 to 1.275 percent; k₂The content of O is 0.337 to 0.565 percent; the FeO content is 0.219 to 0.364 percent; TiO 2₂The content is 0.143 percent to 0.176 percent; the MgO content is 0.103-0.14%; the MnO content is 0.026% -0.034%; p₂O₅The content of Na is 0.029 to 0.045 percent₂The content of O is 0.013-0.024%.

4. The high-performance concrete based on antimony tailing waste stones according to claim 3, characterized in that the particle size of the coarse aggregates is 5 mm-20 mm continuous gradation; all properties of the coarse aggregate meet the requirements of II-class indexes of the coarse aggregate in JTG/T F50-2011 Highway and bridge construction technical Specification.

5. The high-performance concrete based on antimony tailings waste stone according to claim 4, wherein the cement is P-O42.5.

6. The high-performance concrete based on antimony tailing waste stones according to claim 5, characterized in that the fineness modulus of the machine-made sand is 2.9-2.6 medium sand; all the performances of the machine-made sand can meet the standard requirements of GB/T14684 plus 2011 construction sand.

7. The high-performance concrete based on antimony tailings waste stones according to claim 6, wherein the water reducing agent is a HT-HPC polycarboxylic acid high-strength water reducing agent.

8. A method for preparing high-performance concrete based on antimony tailings waste stones according to any one of claims 1 to 7, wherein the method for preparing the high-performance concrete comprises the following steps: