Non-shrinkage cementing material prepared from phosphogypsum, preparation method thereof and concrete
Technical Field
The invention relates to the technical field of comprehensive utilization of phosphogypsum, in particular to a non-shrinkage cementing material prepared from phosphogypsum, a preparation method thereof and concrete.
Background
The phosphogypsum is solid waste produced by preparing phosphoric acid from phosphate ore through sulfuric acid decomposition and filtration in the production process of wet-process phosphoric acid, and about 4-5 tons of phosphogypsum are discharged every 1 ton of wet-process phosphoric acid is produced. The phosphogypsum is powdery, the main phase component is calcium sulfate dihydrate and contains a small amount of quartz; the main chemical components are calcium oxide, sulfur trioxide, silicon dioxide, phosphorus pentoxide, fluorine ions and the like; the content of the calcium sulfate dihydrate in the phosphogypsum is generally more than 90 percent. According to the statistics of related data, the global phosphogypsum emission reaches 1.5 hundred million tons, while the national phosphogypsum emission exceeds 7000 million tons, and the stockpiling amount reaches 3 hundred million tons over the year. The huge yield of the phosphogypsum not only brings threat to the environment, but also causes a great deal of phosphogypsum resource waste; therefore, a large number of research schemes for comprehensive utilization of phosphogypsum appear in the prior art, but most of the research schemes are focused on producing bricks, preparing sulfuric acid and co-producing cement, sulphoaluminate cement, cement retarders, gypsum blocks and the like.
Therefore, the comprehensive utilization rate and the utilization value of the phosphogypsum are still low, so that the comprehensive utilization of the phosphogypsum is still a worldwide problem. In China, the southwest area is an important base for the characteristic industry of phosphorus chemical industry, and particularly the southwest area is low in phosphogypsum emission and utilization rate in Guizhou province. In order to accelerate the comprehensive utilization of phosphogypsum resources in Guizhou province and improve the comprehensive utilization rate and the utilization value of the phosphogypsum, the Ministry of Guizhou province issues an opinion on accelerating the comprehensive utilization of the phosphogypsum resources, and the opinion requires 'use of fixed production', namely, phosphogypsum discharge enterprises can consume and discharge only a certain amount of phosphogypsum. Therefore, the method is very important for comprehensive utilization of phosphogypsum resources. However, in the prior art, the comprehensive utilization value of the phosphogypsum resources is not high, so that the added value of the phosphogypsum resources is low, and the application situation is not good.
Based on this, there are researchers applying phosphogypsum to the preparation of cementitious materials used in the preparation of building materials, such as gypsum-based cementitious materials disclosed in patent application No. 201510207204.7, so that the cementitious materials react to form ettringite with expansion characteristics after mixing sulphoaluminate cement, portland cement and gypsum, and thus have the characteristics of quick setting, quick hardening and low shrinkage. For another example, the low-shrinkage early-strength mine filling cementing material with the patent application number of 201710062923.3 has the advantages of fast filling and setting, high strength and small shrinkage. However, in the prior art, due to improper use method of the phosphogypsum and improper control of the raw material mixing ratio in the cementing material, the performance of the obtained cementing material is poor, the shrinkage performance is not ideal, so that the quality of concrete products is poor when the cementing material is applied to the preparation process of products such as concrete and the like, and particularly the shrinkage deformation value is large.
Disclosure of Invention
In order to solve the technical problems in the prior art, the invention provides a non-shrinkage cementing material prepared from phosphogypsum, a preparation method thereof and concrete.
The method is realized by the following technical scheme:
one of the purposes of the invention is to provide a non-shrinkage cementing material prepared by ardealite, which is formed by mixing a mixed material and ordinary portland cement, wherein the mixed material is formed by mixing 5-20% of ardealite, 30-60% of fly ash or phosphorous slag, 15-30% of water-quenched slag and 10-20% of steel slag in percentage by weight; the mass ratio of the mixed material to the ordinary portland cement is 1-3: 7-9.
Preferably, the mixed material is prepared by mixing 15% of phosphogypsum, 50% of fly ash or phosphorous slag, 25% of water-quenched slag and 10% of steel slag in percentage by weight.
Preferably, the mass ratio of the mixed material to the ordinary portland cement is 1: 4.
Preferably, SO in the phosphogypsum is3The content is more than 40 percent.
The invention also provides a preparation method of the non-shrinkage cementing material prepared by the phosphogypsum, which comprises the steps of drying the phosphogypsum to constant weight, mixing and grinding the dried phosphogypsum with fly ash or phosphorus slag, water-quenched slag and steel slag to obtain a mixed material, and adding ordinary portland cement to stir and mix uniformly to obtain the non-shrinkage cementing material.
Preferably, the specific surface area of the mixed material is more than or equal to 420m2/kg。
The invention also aims to provide the application of the non-shrinkage cementing material in the preparation of concrete.
The invention provides non-shrinkage high-performance concrete, which is prepared by uniformly mixing and stirring a non-shrinkage cementing material, broken stones, sand, water and a surfactant, and performing pouring, vibrating and curing.
Specifically, the method comprises the following steps: the mixture ratio of the non-shrinkage cementing material, the broken stone, the sand, the water and the surfactant is designed according to the standard JGJ55-2011 'design rule for the mixture ratio of common concrete'; the volume weight of the non-shrinkage high-performance concrete is 2450-2500 kg/m3(ii) a The total amount of the non-shrinkage cementing material is 400-600 kg/m3The water-gel ratio is 25-38%, the sand rate is 30-40%, and the dosage of the surfactant is 1-2% of the total amount of the non-shrinkable cementing material.
Compared with the prior art, the invention has the technical effects that:
the phosphogypsum, the fly ash or the phosphorus slag, the water-quenched slag and the steel slag are compounded to prepare a mixed material, and the common silicate cement is added to prepare the cementing material, so that the phosphogypsum is comprehensively utilized with high value, and the phosphogypsum in the non-shrinkage cementing material, the fly ash, the phosphorus slag, the water-quenched slag, the steel slag and Al in the cement are ensured to be not shrunk2O3Cement hydration products Ca (OH)2The reaction is carried out to form ettringite AFt, fill and block capillary gaps in the concrete, and the quality percentage control of the raw material components is combined, so that the performance of the cementing material is improved, the compactness of the concrete is improved after the material is applied to the concrete, and the volume expansion can be generated, so that the cement hydration heat is reduced while the non-shrinkage high-performance concrete is obtained, the cement consumption is saved, and the production cost of the concrete is reduced.
The cementing material created by the invention is an organic composite of an aerogel cementing material and a hydraulic cementing material, so that the property of large shrinkage of the traditional hydraulic cementing material is improved, and the value of comprehensive utilization of resources of phosphogypsum in the field of building materials is improved.
In the building field, compared with common concrete, the high-performance concrete has the characteristics of higher strength, durability and the like, so that the high-performance concrete is more difficult to prepare, and simultaneously has higher requirements on raw materials. Therefore, the invention makes full use of the ardealite which is a bulk industrial solid waste to prepare the non-shrinkage cementing material, and prepares the non-shrinkage high-performance concrete by using the obtained non-shrinkage cementing material and crushed stones, sand and/or surfactant, wherein the dosage of the ardealite is between 5 and 20 percent, and the ardealite completely meets the national relevant standard regulation and sustainable development requirements on the comprehensive utilization of ardealite resources.
When the non-shrinkage cementing material is used for preparing non-shrinkage high-performance concrete, the proportion of the broken stone, the sand, the water and the surfactant can be designed according to the industry standard JGJ55-2011 'design rule for mixing proportion of common concrete'. The content of sulfur trioxide in the phosphogypsum in the preparation of the non-shrinkage cementing material is more than 40 percent; the quality of the fly ash meets GB/T1596 fly ash for cement and concrete; the quality of the phosphorus slag meets JC/T317 'phosphorus slag powder for a granulated electric furnace for concrete'; the quality of the water-quenched slag meets GB/T18046 granulated blast furnace slag powder used in cement and concrete; the steel slag meets the requirements of GB/T20491 steel slag powder used in cement and concrete; the quality of the ordinary silica cement meets the requirements of GB175 Universal Portland cement 42.5 or 52.5 grade ordinary silica cement. In the preparation of the non-shrinkage high-performance concrete, the broken stone meets the standard requirements of GB/T14685-2011 construction pebbles and broken stones, and the maximum particle size is less than or equal to 25 mm; the sand meets the quality requirement of standard artificial sand of GB/T14684-2011 construction sand; the quality of the surfactant meets the standard requirements of JG/T223 polycarboxylic acid high-performance water reducing agent, namely the polycarboxylic acid high-performance water reducing agent is adopted as the surfactant.
After the non-shrinkage cementing material is applied to concrete preparation, the slump of the prepared concrete can be 18-25 cm, the compressive strength is 50-80MPa after natural curing for 28 days, the electric flux is less than or equal to 1000cc, and the free shrinkage deformation value is-0.2/ten thousand-0.4/ten thousand.
Detailed Description
The technical solution of the present invention is further defined below with reference to the specific embodiments, but the scope of the claims is not limited to the description.
The preparation method of the non-shrinkage cementing material comprises the steps of drying the phosphogypsum to constant weight, mixing and grinding the phosphogypsum, the fly ash or the phosphorus slag, the water-quenched slag and the steel slag until the specific surface area is more than or equal to 420m2The mixed material powder is obtained by the step of/kg, and then the ordinary portland cement is added to be stirred and mixed uniformly, so that the non-shrinkage cementing material is obtained; SO in phosphogypsum3The content is more than 40 percent. In the preparation process, the specific proportion of the raw material components is as follows:
example 1
The cementing material is formed by mixing a mixed material and ordinary portland cement, wherein the mixed material is formed by mixing 5% by weight of phosphogypsum, 60% by weight of a mixture of fly ash and phosphorus slag, 15% by weight of water-quenched slag and 20% by weight of steel slag; the mass ratio of the mixed material to 42.5 ordinary portland cement is 1: 7.
Example 2
The cementing material is formed by mixing a mixed material and ordinary portland cement, wherein the mixed material is formed by mixing 20% of phosphogypsum, 30% of phosphorus slag, 30% of water-quenched slag and 20% of steel slag in percentage by weight; the mass ratio of the mixed material to the 52.5 ordinary portland cement is 1: 9.
Example 3
The cementing material is formed by mixing a mixed material and ordinary portland cement, wherein the mixed material is formed by mixing 20% of phosphogypsum, 40% of fly ash, 30% of water-quenched slag and 10% of steel slag in percentage by weight; the mass ratio of the mixed material to 42.5 ordinary portland cement is 3: 7.
Example 4
The cementing material is formed by mixing a mixed material and ordinary portland cement, wherein the mixed material is formed by mixing 15% by weight of phosphogypsum, 50% by weight of a mixture of fly ash and phosphorus slag, 20% by weight of water-quenched slag and 15% by weight of steel slag; the mass ratio of the mixed material to the 52.5 ordinary portland cement is 1: 3.
Example 5
The cementing material is formed by mixing a mixed material and ordinary portland cement, wherein the mixed material is formed by mixing 5% of phosphogypsum, 50% of phosphorus slag, 25% of water-quenched slag and 20% of steel slag in percentage by weight; the mass ratio of the mixed material to 42.5 ordinary portland cement is 1: 4.
Test 1: non-shrinking cementitious Material addition test
Preparation of concrete samples: mixing and stirring broken stone, sand, a non-shrinkable cementing material and water uniformly, wherein the mixture ratio of various materials can be designed according to the industrial standard JGJ55-2011 'design rule for the mixture ratio of common concrete', and the mixing amount is as follows: adding 400kg of cementing material into per cubic meter, wherein the water-to-gel ratio is 25%, the volume weight of the concrete is 2500%, the sand rate is 30%, and the mixing amount of the surfactant is 1.5%, mixing and stirring uniformly, and pouring, vibrating and curing to obtain the concrete; the cements used were the non-shrinking cements obtained in examples 1 to 5, respectively.
The concrete performance determination method comprises the following steps: according to the concrete slump and the compressive strength after natural curing for 28 days in the prior art; measuring the electric flux of the concrete according to GB/T50082 Standard test method for long-term performance and durability of common concrete; the free shrinkage deformation value of the concrete is measured according to GB/T50082 Standard test method for the long-term performance and durability of ordinary concrete.
The concrete indexes are as follows: the slump, compressive strength, electric flux and free shrinkage deformation values measured above were counted in table 1 below.
TABLE 1
As shown in the data in Table 1, the cementing material provided by the invention can be added into concrete preparation to greatly improve the comprehensive performance of the concrete and the quality of the concrete.
Test 2: concrete performance detection test with different raw material ratios
Sample preparation:
on the basis of the test 1, the mixture ratio of the concrete raw material components was adjusted as follows on the basis of the example 1, and test samples were prepared:
sample 1: mixing and stirring broken stone, sand, a non-shrinkable cementing material and water uniformly, wherein the mixture ratio of various materials can be designed according to the industrial standard JGJ55-2011 'design rule for the mixture ratio of common concrete', and the mixing amount is as follows: adding 600kg of cementing material into each cubic meter, mixing at a water-to-gel ratio of 38% and a sand ratio of 40%, uniformly mixing and stirring, casting, vibrating and maintaining to obtain the concrete mortar; the cements used were the non-shrinking cements obtained in example 1, respectively.
Sample 2: mixing and stirring broken stone, sand, a non-shrinkable cementing material and water uniformly, wherein the mixture ratio of various materials can be designed according to the industrial standard JGJ55-2011 'design rule for the mixture ratio of common concrete', and the mixing amount is as follows: adding 500kg of cementing material into each cubic meter, mixing at a water-to-gel ratio of 38% and a sand ratio of 40%, uniformly mixing and stirring, casting, vibrating and maintaining to obtain the concrete mortar; the cements used were the non-shrinking cements obtained in example 1, respectively.
Sample 3: mixing and stirring broken stone, sand, a non-shrinkable cementing material and water uniformly, wherein the mixture ratio of various materials can be designed according to the industrial standard JGJ55-2011 'design rule for the mixture ratio of common concrete', and the mixing amount is as follows: adding 480kg of cementing material into per cubic meter, mixing at a water-to-gel ratio of 38% and a sand rate of 40%, uniformly mixing and stirring, casting, vibrating and maintaining to obtain the concrete mortar; the cements used were the non-shrinking cements obtained in example 1, respectively.
Sample 4: on the basis of sample 1, a surfactant (e.g., Corjie Point-SS polycarboxylic acid-based high performance water reducing agent) is added in an amount of 1% by mass based on the non-shrinking cement.
Sample 5: on the basis of sample 1, a surfactant (e.g., Cojie Point-SS polycarboxylic acid-based high performance water reducing agent) was added in an amount of 2% by mass based on the non-shrinking cement.
And (3) sample performance determination:
the volume weight, slump, and the compressive strength, electric flux, and free shrinkage deformation values of the obtained sample after natural curing for 28 days were measured, and the results are shown in table 2 below:
TABLE 2
As shown by the data in Table 2, the addition ratio of the non-shrinkable cementing material to concrete prepared from sand, water and the like has little influence on the comprehensive performance of the concrete; in the addition process, the surfactant is added into the concrete, so that the comprehensive performance of the concrete is greatly influenced, and the electric flux and the shrinkage deformation value of the concrete are improved.
The present invention may be practiced in other ways without departing from the spirit and scope of the present invention, which should be determined from the contents of the conventional technical means, common general knowledge and prior art documents in the art.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.