C100 concrete filled steel tube added with activated and modified machine-made sandstone powder and preparation method of C100 concrete filled steel tube

Abstract

The invention relates to the technical field of building materials, in particular to a C100 concrete filled steel tube added with activated and modified machine-made sandstone powder and a preparation method of the C100 concrete filled steel tube added with activated and modified machine-made sandstone powder. The concrete is prepared from the following raw material components in parts by weight: 900 to 1100 parts of gravel, 450 to 560 parts of machine-made sand, 70 to 145 parts of high-strength pottery sand, 448 to 517 parts of cement, 97 to 121 parts of activated and modified machine-made sandstone powder, 65 to 75 parts of silica fume, 55 to 61 parts of an efficient composite expansion component, 126 to 145 parts of mixing water, 30 to 50 parts of steel fiber, 5 to 8 parts of temperature shrinkage fiber and 9 to 12 parts of a viscosity reduction type hyperdispersant. The problems that in practical application of an existing ultrahigh-strength steel pipe concrete technology, natural sand resources are deficient, the utilization rate of machine-made sand and stone powder is low, consequently, the construction performance of concrete is degraded, and traditional mineral admixtures such as fly ash are short in supply, and the requirement of high-performance concrete is difficult to meet are solved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of building materials, and particularly relates to C100 steel pipe concrete added with activated modified mechanism sand and stone powder and a preparation method. BACKGROUND

[0002] The construction of bridges, high-rise buildings and other infrastructures in western mountainous areas is increasing. In such projects, ultra-high strength steel pipe concrete can significantly improve the bearing capacity, ductility and durability of the structure due to the sheathing effect of the core concrete and the outer steel pipe, perfectly adapts to the complex and harsh construction conditions in western mountainous areas, and has become a key leading material. Traditional preparation of ultra-high strength concrete usually relies on high-quality natural sand as fine aggregate, and needs to be mixed with a large amount of fly ash, mineral powder and other active mineral admixtures to improve the workability and mechanical properties.

[0003] However, the above-mentioned traditional technical route faces severe challenges in the application in western regions: first, the natural sand resources are scarce in western regions, the long-distance transportation cost is high, and the exploitation of natural sand is strictly limited due to environmental protection policies, so that the replacement of natural sand with mechanism sand becomes an inevitable choice; but a large amount of stone powder is generated in the production process of mechanism sand, and the high content of the stone powder can lead to the increase of the viscosity of concrete, the deterioration of the fluidity, the instability of the air content, the serious deterioration of the construction performance, and the difficulty in meeting the requirements of ultra-high strength self-compacting concrete. Secondly, the scale of thermal power generation is limited, which leads to the significant decline of the yield and quality of high-quality fly ash, mineral powder and other traditional admixtures, and even in many areas, there is no material available, which cannot meet the huge demand of high-performance concrete for mineral admixtures, and seriously restricts the progress of the project.

[0004] Therefore, it is necessary to invent a C100 steel pipe concrete added with activated modified mechanism sand and stone powder and a preparation method to solve the above-mentioned problems. SUMMARY

[0005] The application provides a C100 steel pipe concrete added with activated modified mechanism sand and stone powder and a preparation method to solve the problems that the existing ultra-high strength steel pipe concrete technology has the problems of scarcity of natural sand resources, low utilization rate of mechanism sand and stone powder, deterioration of the construction performance of concrete, and shortage of traditional mineral admixtures such as fly ash, which cannot meet the demand of high-performance concrete.

[0006] The application is implemented by adopting the following technical scheme:

[0007] A C100 steel pipe concrete with added activated modified manufactured sand and gravel powder, comprising the following raw material components by weight: 900-1100 parts crushed stone, 450-560 parts manufactured sand, 70-145 parts high-strength ceramic sand, 448-517 parts cement, 97-121 parts activated modified manufactured sand and gravel powder, 65-75 parts silica fume, 55-61 parts high-efficiency composite expansion component, 126-145 parts mixing water, 30-50 parts steel fiber, 5-8 parts thermal shrinkage fiber, and 9-12 parts viscosity-reducing superdispersant.

[0008] Further, the preparation method of the activated modified manufactured sand and gravel powder includes the following steps: CSH nucleation activator emulsion, manufactured sand and gravel powder, polycrystalline silicon slag powder, calcined metakaolin, high-efficiency grinding aid and grinding water are mixed into a slurry at a mass ratio of 0.8-1:750-800:100-125:100-110:0.03-0.05:485-515, ball-milled at 150 r / min for 2 h, and then dried, dispersed and sieved in sequence to obtain activated modified manufactured sand and gravel powder.

[0009] Furthermore, the median particle size of the activated modified machine-made sand and gravel powder Its thickness is 7.5-7.8 μm, and its specific surface area is 620-680 m². 2 / kg.

[0010] Furthermore, the preparation method of the CSH nucleation activator emulsion includes the following steps: mixing the nucleation activator, deionized water and zeolite powder in a mass ratio of 20-25: 75-80: 5-8, stirring at 120 r / min for 10-15 min at a temperature of 40°C, to obtain the CSH nucleation activator emulsion.

[0011] Furthermore, the high-efficiency grinding aid is diethanol monoisopropanolamine, or a composite grinding aid composed of diethylene glycol and triisopropanolamine in a mass ratio of 1:1.

[0012] Furthermore, the preparation method of the high-efficiency composite expansion component includes the following steps: mixing oyster shells, phosphogypsum, and bauxite in a mass ratio of 105:73:32, and calcining at 1350℃ for 40 min to obtain Ca-based expanded clinker; calcining periclase at 1200℃ for 1 h to obtain Mg-based expanded clinker; mixing the Ca-based expanded clinker, Mg-based expanded clinker, and gypsum in a mass ratio of 63:29:8, and grinding them to a particle size ≤80 μm to obtain the high-efficiency composite expansion component.

[0013] Further, the preparation method of the viscosity-reducing hyperdispersant comprises the following steps: ingredients are prepared according to the mass ratio of 47-51:5-6:10-11:0.2-0.3:125-135:16-18:16-20 of polyethylene glycol monoacrylate, sodium thiosulfate methacrylate, acrylic acid, methyl methacrylate, reaction medium water, ammonium persulfate solution and mercaptoethanol solution, wherein the ammonium persulfate solution is a 10% aqueous solution by mass fraction, and the mercaptoethanol solution is a 5% aqueous solution by mass fraction; the polyethylene glycol monoacrylate, sodium thiosulfate methacrylate, acrylic acid, methyl methacrylate and reaction medium water are mixed to obtain a monomer reaction solution; the ammonium persulfate solution is used as an initiator, and the mercaptoethanol solution is used as a transfer agent, which are added dropwise into the monomer reaction solution to perform a polymerization reaction; the initiator and the transfer agent are added dropwise within 2-2.5 h, and the reaction temperature is 90±5 DEG C; after the reaction is completed, a 35% sodium hydroxide solution by mass fraction is added to adjust the pH of the system to 6.0-7.0 to obtain the viscosity-reducing hyperdispersant.

[0014] A preparation method of C100 steel pipe concrete added with activated modified machine-made sand and stone powder, the preparation method is used for preparing the C100 steel pipe concrete added with activated modified machine-made sand and stone powder, and comprises the following steps:

[0015] S1: the gravel, the machine-made sand and the high-strength ceramic sand are mixed, and after stirring for 0.5-1 min, a mixed aggregate is obtained;

[0016] S2: the cement, the activated modified machine-made sand and stone powder, the silica fume and the high-efficiency composite expansion component are added into the mixed aggregate, and after stirring for 0.5-1 min, a uniform mixture is obtained;

[0017] S3: the mixing water and the viscosity-reducing hyperdispersant are added into the uniform mixture, the adding amount of the mixing water and the viscosity-reducing hyperdispersant is 2 / 3 of the total mass of the mixing water and the viscosity-reducing hyperdispersant respectively, and after stirring for 1-2 min, a flowable concrete rheological body is obtained;

[0018] S4: the steel fiber and the temperature shrinkage fiber are added into the concrete rheological body by using a vibrating screen, and then the remaining mixing water and the viscosity-reducing hyperdispersant are added, and after stirring for 1-1.5 min, the C100 steel pipe concrete added with the activated modified machine-made sand and stone powder is obtained.

[0019] Further, the high-strength ceramic sand is subjected to pre-wetting treatment before the mixed aggregate is prepared, and the pre-wetting treatment cycle is 24 h.

[0020] Further, the pre-wetting treatment method comprises the following steps: the high-strength ceramic sand is placed in a treatment pool, pre-wetting water is added to completely immerse the high-strength ceramic sand, the water temperature is controlled to be 20-25 DEG C, and the high-strength ceramic sand is placed for 24 h; then the pre-wetting water is discharged, the high-strength ceramic sand is taken out, and is laid flat to air dry in a ventilated environment for 1-2 h until the high-strength ceramic sand is in a surface-dry state.

[0021] Compared with the prior art, the present application has the following remarkable beneficial effects:

[0022] 1、The present application adopts the method of mechanical activation to activate and modify the machine-made sand stone powder, under the action of mechanical force, the particle morphology and crystal structure of the machine-made sand stone powder are optimized, the particle size is significantly reduced, the specific surface area is increased, and micro defects and active sites are generated, this process not only improves the particle size distribution from the physical level, but also excites its potential cementing activity from the chemical level, so that it is transformed into a high-performance mineral admixture. Therefore, the prepared activated modified stone powder not only has high activity, can improve the early strength and working performance of concrete, and realize the preparation requirements of C100 ultra-high strength self-compacting steel pipe concrete, but also can replace a large amount of cement, fly ash and slag powder, significantly reduce the cost of concrete, realize the high-value resource utilization of solid waste, solve the problem of concrete construction performance degradation caused by the lack of natural sand resources and low utilization rate of machine-made sand stone powder in the western region, and overcome the difficulty of shortage of high-quality admixture supply. In addition, the process does not need high-temperature calcination, and the energy consumption is greatly reduced compared with the traditional activation method, which is more green and low-carbon.

[0023] 2、The present application adopts high-efficiency composite expansion components with solid waste as raw materials, which not only ensures the micro-expansion volume stability of the steel pipe concrete, avoids the shrinkage in the later period, and improves the durability, but also the Ca series expansion agent uses biological solid waste and industrial solid waste as raw materials, which has positive protection significance to the environment.

[0024] 3、The present application effectively improves the rheological property of concrete by using a viscosity-reducing type super dispersant, and reduces segregation and bleeding.

[0025] In summary, the overall process of the present application is energy-saving and environment-friendly, conforms to the concept of green and low-carbon development, and provides a reliable and sustainable material solution for high-performance concrete engineering in the western region. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a shrinkage performance comparison diagram of the concrete prepared by example 1 and comparative examples 4-6 in the present application. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be described below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0028] Example 1

[0029] A method for preparing C100 steel-tube concrete with added activated modified manufactured sand and gravel powder includes the following steps:

[0030] S1: Weigh the following raw materials by mass: 960 parts crushed stone, 505 parts manufactured sand, 109 parts high-strength ceramic sand, 486 parts cement, 109 parts activated and modified manufactured sand powder, 72.5 parts silica fume, 58 parts high-efficiency composite expansion component, 145 parts mixing water, 40 parts steel fiber, 6 parts thermal shrinkage fiber, and 10.5 parts viscosity-reducing superdispersant; the crushed stone has a particle size of 5-16mm in continuous gradation and an apparent density ≥1600 kg / m³. 3 The parent rock has a compressive strength greater than or equal to 125 MPa, and the equivalent calcium oxide (CaO) content is not less than 46.10% high-calcium limestone crushed stone; the manufactured sand is manufactured sand corresponding to the crushed stone; the cement is PO 52.5 type silicate cement; the high-strength ceramic sand is coal gangue ceramic sand with micro-interconnected pores, and its bulk density is 875 kg / m³. 3 The apparent density is 1600 kg / m³. 3 The weighed high-strength ceramic sand is pre-wetted. The pre-wetting treatment method includes the following steps: the high-strength ceramic sand is placed in a treatment tank, pre-wetting water is added until it is completely submerged, the water temperature is controlled at 20℃, and it is left to stand for 24 hours; then the pre-wetting water is drained, the high-strength ceramic sand is taken out, and it is spread out to dry in a ventilated environment for 2 hours until it is surface dry, thus obtaining the pre-wetted high-strength ceramic sand. It is then mixed with crushed stone and manufactured sand, and stirred at a speed of 48r / min for 1 minute to obtain mixed aggregate.

[0031] S2: Add cement, activated modified manufactured sand and gravel powder, silica fume and high-efficiency composite expansion component to the mixed aggregate, and stir at 48 r / min for 1 min to obtain a uniform mixture.

[0032] The preparation method of the activated modified manufactured sand and gravel powder includes the following steps: CSH nucleation activator emulsion, manufactured sand and gravel powder with a calcium oxide (CaO) content of not less than 46.10%, polycrystalline silicon slag powder, calcined metakaolin, high-efficiency grinding aid, and grinding water are mixed in a mass ratio of 0.9:775:110:105:0.04:500 to form a slurry. This slurry is poured into a ball mill jar with prepared grinding balls. The slurry volume does not exceed 3 / 4 of the effective volume of the ball mill jar. In this embodiment, the slurry volume is 2 / 3 of the effective volume of the ball mill jar, and the ball-to-material ratio is 1.6:1. The mixture is ball-milled at 150 r / min for 2 hours. After ball milling, the grinding balls are removed, and the mixture is then dried, vibrated and dispersed, and sieved to obtain activated modified manufactured sand and gravel powder. The median particle size of the activated modified manufactured sand and gravel powder is [not specified in the original text]. It has a thickness of 7.6 μm and a specific surface area of ​​650 m². 2 / kg.

[0033] The preparation method of the C-S-H crystal nucleus active agent emulsion comprises the following steps: mixing the crystal nucleus active agent, deionized water and zeolite powder according to a mass ratio of 22:78:6, stirring at a speed of 120 r / min for 10 min under a temperature condition of 40℃, and obtaining the C-S-H crystal nucleus active agent emulsion.

[0034] The high-efficiency grinding aid is diethanol monoisopropanolamine (DEIPA).

[0035] The preparation method of the high-efficiency composite expansion component comprises the following steps: mixing oyster shell, phosphogypsum and bauxite according to a mass ratio of 105:73:32, calcining at a temperature of 1350℃ for 40 min to obtain Ca-based expansion clinker; calcining periclase at a temperature of 1200℃ for 1 h to obtain Mg-based expansion clinker; mixing the Ca-based expansion clinker, the Mg-based expansion clinker and gypsum according to a mass ratio of 63:29:8, and grinding to a particle size of ≤80 μm to obtain the high-efficiency composite expansion component.

[0036] S3: adding mixing water and viscosity-reducing hyperdispersant to the uniform mixture, the adding amount of the mixing water and the viscosity-reducing hyperdispersant being 2 / 3 of the total mass of each, stirring for 2 min, and obtaining a flowable concrete rheological body.

[0037] The preparation method of the viscosity-reducing hyperdispersant comprises the following steps: dosing polyethylene glycol monoacrylate, sodium thiosulfonate methacrylate, acrylic acid, methyl methacrylate, reaction medium water, ammonium persulfate solution and mercaptoethanol solution according to a mass ratio of 50:5:10:0.3:130:16:18, wherein the ammonium persulfate solution is a 10% mass fraction aqueous solution, and the mercaptoethanol solution is a 5% mass fraction aqueous solution; mixing the polyethylene glycol monoacrylate, the sodium thiosulfonate methacrylate, the acrylic acid and the methyl methacrylate with the reaction medium water to obtain a monomer reaction solution; adding the monomer reaction solution dropwise for polymerization reaction with the ammonium persulfate solution as an initiator and the mercaptoethanol solution as a transfer agent, the initiator and the transfer agent being added dropwise within 2.5 h, and the reaction temperature being 90℃; after the reaction is completed, adding a 35% mass fraction sodium hydroxide solution to adjust the pH of the system to 6.0-7.0, and obtaining the viscosity-reducing hyperdispersant.

[0038] S4: adding steel fibers and temperature-shrinking fibers into the concrete rheological body using a vibrating screen, then adding the remaining mixing water and viscosity-reducing hyperdispersant, and stirring for 1.5 min to obtain the C100 steel pipe concrete of the high-calcium component added with the activated modified machine-made sandstone powder.

[0039] Example 2

[0040] The difference between the embodiment and embodiment 1 is that the mechanism sandstone powder adopts the mechanism sandstone powder with the equivalent calcium oxide (CaO) content lower than 46.10%; the rest of the raw material ratio, the preparation steps and the process parameters are the same as those of embodiment 1, and the C100 steel pipe concrete with the low calcium component and the activated modified mechanism sandstone powder is prepared.

[0041] Embodiment 3

[0042] The difference between the embodiment and embodiment 1 is that the mechanism sandstone powder adopts the mechanism sandstone powder with the equivalent calcium oxide (CaO) content lower than 46.10%; the rest of the raw material ratio, the preparation steps and the process parameters are the same as those of embodiment 1, and the C100 steel pipe concrete with the low calcium component and the activated modified mechanism sandstone powder is prepared.

[0043] Embodiment 4

[0044] The difference between the embodiment and embodiment 1 is that the mechanism sandstone powder adopts the mechanism sandstone powder with the equivalent calcium oxide (CaO) content lower than 46.10%; the rest of the raw material ratio, the preparation steps and the process parameters are the same as those of embodiment 1, and the C100 steel pipe concrete with the low calcium component and the activated modified mechanism sandstone powder is prepared.

[0045] Comparative example 1

[0046] The difference between the embodiment and embodiment 1 is that the mechanism sandstone powder adopts the mechanism sandstone powder with the equivalent calcium oxide (CaO) content lower than 46.10%; the rest of the raw material ratio, the preparation steps and the process parameters are the same as those of embodiment 1, and the C100 steel pipe concrete with the low calcium component and the activated modified mechanism sandstone powder is prepared.

[0047] Comparative example 2

[0048] The difference between the embodiment and embodiment 1 is that the mechanism sandstone powder adopts the mechanism sandstone powder with the equivalent calcium oxide (CaO) content lower than 46.10%; the rest of the raw material ratio, the preparation steps and the process parameters are the same as those of embodiment 1, and the C100 steel pipe concrete with the low calcium component and the activated modified mechanism sandstone powder is prepared.

[0049] Comparative example 3

[0050] The difference between the embodiment and embodiment 1 is that the mechanism sandstone powder adopts the mechanism sandstone powder with the equivalent calcium oxide (CaO) content lower than 46.10%; the rest of the raw material ratio, the preparation steps and the process parameters are the same as those of embodiment 1, and the C100 steel pipe concrete with the low calcium component and the activated modified mechanism sandstone powder is prepared.

[0051] Comparative example 4

[0052] The difference between the present embodiment and embodiment 1 is that: the same mass of alternative cement is used to replace the high-efficiency composite expansion component, and the rest of the raw material ratio, preparation steps and process parameters are the same as those of embodiment 1, and concrete is prepared.

[0053] Comparative example 5

[0054] The difference between the present embodiment and embodiment 1 is that: the same mass of alternative cement is used to replace the high-efficiency composite expansion component, and the rest of the raw material ratio, preparation steps and process parameters are the same as those of embodiment 1, and concrete is prepared.

[0055] Comparative example 6

[0056] The difference between the present embodiment and embodiment 1 is that: the same mass of alternative cement is used to replace the high-efficiency composite expansion component, and the rest of the raw material ratio, preparation steps and process parameters are the same as those of embodiment 1, and concrete is prepared.

[0057] Comparative example 7

[0058] The difference between the present embodiment and embodiment 1 is that: the same mass of alternative cement is used to replace the high-efficiency composite expansion component, and the rest of the raw material ratio, preparation steps and process parameters are the same as those of embodiment 1, and concrete is prepared.

[0059] Comparative example 8

[0060] The difference between the present embodiment and embodiment 1 is that: the same mass of alternative cement is used to replace the high-efficiency composite expansion component, and the rest of the raw material ratio, preparation steps and process parameters are the same as those of embodiment 1, and concrete is prepared.

[0061] The concrete prepared in examples 1-4 and comparative examples 1-8 is tested for performance.

[0062] The concrete prepared in examples 1-4 and comparative examples 1-3 is poured into a standard mold and vibrated to form a 150mm x 150mm x 150mm cube standard sample; the poured and formed cube standard sample is placed in a 20℃ standard curing room, and 3d, 7d and 28d concrete standard test blocks are taken and tested according to the standard method in GB / T50081-2019 "Standard Test Methods for Physical and Mechanical Properties of Concrete", and the compressive strength of the concrete test blocks at 3d, 7d and 28d is measured, respectively. The specific results are shown in Table 1.

[0063] Table 1

[0064]

[0065] The concrete prepared in Example 1 and Comparative Examples 4-6 was vibrated and formed in a standard mold to obtain a concrete shrinkage test piece with a size of 100 mm x 100 mm x 515 mm, a reflective target was arranged at a distance of not less than 400 mm, and a non-contact concrete shrinkage tester was used to test the concrete shrinkage deformation of the test piece for 90 days. The specific results are shown in Table 1. Figure 1 .

[0066] The above Example 1, Examples 3 and 4, and Comparative Examples 2, 3, 7 and 8 were tested according to the standard method of GB / T50080-2016 "Standard Test Methods for Properties of Freshly Mixed Concrete", and the concrete expansion, 1h expansion loss and T500 test were tested, respectively. The specific results are shown in Table 2.

[0067] Table 2

[0068]

[0069] As shown in Table 1, the compressive strength of the concrete after 28 days of standard curing using the activated modified mechanism sand stone powder as a mineral admixture can fully meet and exceed C100. Whether the activated modified mechanism sand stone powder is of high calcium component or low calcium component, the contribution of the activated modified mechanism sand stone powder to the development of the strength of the concrete is equivalent to that of the Grade I fly ash, and the early strength of the two is higher. Therefore, using the activated modified mechanism sand stone powder as a mineral admixture, the configured concrete material can not only meet the strength requirement of C100 concrete, but also can achieve early strength to some extent.

[0070] As shown in Example 1 and Comparative Examples 4-6, neither the single-doped Ca-based expansive clinker nor the single-doped Mg-based expansive clinker as an expansive agent can meet the requirement of micro-expansion of the steel pipe concrete. The Ca-based expansive agent has fast early activity development, can realize expansion in the early hydration period of the concrete, but will have volume shrinkage in the later period. The Mg-based expansive agent has slow early development and obvious delayed expansion phenomenon. The high-efficiency composite expansive component of the present application has stable expansion effect, realizes early expansion, eliminates the generation of volume shrinkage phenomenon, converges within 28 days, and meets the requirement of volume stability of the steel pipe concrete.

[0071] It can be seen from the combination of Example 1 and Comparative Examples 2-3 that the slump and spread of the concrete prepared by Comparative Example 2 are better than those of the concrete prepared by Comparative Example 3, and the slump and spread of the concrete prepared by Example 1 are close to those of the concrete prepared by Comparative Example 2, and it can be further known that the activated and modified mechanism sand and stone powder can replace the Class I fly ash and Class II fly ash to a certain extent as an auxiliary cementitious material for application in concrete. It can be known from Comparative Examples 7-8 that when the amount of the ordinary high-performance concrete water reducer is reduced from 15 parts to 10.5 parts, although the bleeding condition of the concrete prepared thereby can be improved, the slump and spread are affected. In combination with Example 1, it can be known that the use of 10.5 parts of the viscosity-reducing superdispersant as the activated and modified mechanism sand and stone powder special additive for C100 steel pipe concrete can greatly improve the workability of the concrete, and compared with the ordinary high-performance concrete water reducer, the additive can realize large flow state of the concrete at a low dosage, effectively ensure the bleeding condition and flow rate of the concrete, and fully meet the requirements of JGJ / T283-2012 “Technical Specification for Application of Self-compacting Concrete”.

[0072] Example 5

[0073] In this example, a high-calcium component activated and modified mechanism sand and stone powder is prepared, and the raw material ratio, preparation steps and process parameters are the same as those of the activated and modified mechanism sand and stone powder in Example 1.

[0074] Example 6

[0075] The difference between this example and Example 5 is that the mechanism sand and stone powder is a mechanism sand and stone powder with a calcium oxide (CaO) conversion content of less than 46.10%, the high-efficiency grinding aid is a composite grinding aid DEG-TIPA compounded from diethylene glycol (DEG) and triisopropanolamine (TIPA) at a mass ratio of 1:1, and the rest of the raw material ratio, preparation steps and process parameters are the same as those of Example 5, to obtain a low-calcium component activated and modified mechanism sand and stone powder.

[0076] Example 7

[0077] The difference between this example and Example 5 is that the mass ratio of the C-S-H crystal nucleus active agent emulsion, the mechanism sand and stone powder, the polysilicon slag powder, the calcined metakaolin, the high-efficiency grinding aid and the grinding water is 0.8:750:125:105:0.04:500, and the rest of the raw material ratio, preparation steps and process parameters are the same as those of Example 5, to obtain a high-calcium component activated and modified mechanism sand and stone powder.

[0078] Example 8

[0079] The difference between the present embodiment and Example 5 is that the mass ratio of the C-S-H crystal nucleus activator emulsion, machine-made sandstone powder, polysilicon slag powder, calcined metakaolin, high-efficiency grinding aid and grinding water is 1:800:100:105:0.04:500; the rest of the raw material ratio, preparation steps and process parameters are the same as those of Example 5, and the activated modified machine-made sandstone powder of high calcium component is prepared.

[0080] Comparative Example 9

[0081] The difference between the present comparative example and Example 5 is that the high-efficiency grinding aid is a composite grinding aid DEG-TIPA compounded by diethylene glycol (DEG) and triisopropanolamine (TIPA) at a mass ratio of 1:1, and the rest of the raw material ratio, preparation steps and process parameters are the same as those of Example 5, and the activated modified machine-made sandstone powder of high calcium component is obtained.

[0082] Comparative Example 10

[0083] The difference between the present comparative example and Example 6 is that the high-efficiency grinding aid is diethanol monoisopropanolamine (DEIPA), and the rest of the raw material ratio, preparation steps and process parameters are the same as those of Example 6, and the activated modified machine-made sandstone powder of low calcium component is obtained.

[0084] The fineness of Examples 5-6 and Comparative Examples 9-10 is tested by a laser particle size analyzer, and the results are shown in Table 3.

[0085] Table 3

[0086]

[0087] Comparative Example 11

[0088] The difference between the present comparative example and Example 5 is that an equal amount of substitute cement is used to replace the activated modified machine-made sandstone powder.

[0089] Comparative Example 12

[0090] The difference between the present embodiment and Example 5 is that an equal amount of Grade I fly ash is used to replace the activated modified machine-made sandstone powder.

[0091] Comparative Example 13

[0092] The difference between the present embodiment and Example 5 is that an equal amount of Grade II fly ash is used to replace the activated modified machine-made sandstone powder.

[0093] According to GB / T35164-2017 "Limestone powder for use in cement, mortar and concrete", standard mortar tests are carried out on Examples 5-6 and Comparative Examples 9-13, and the results are shown in Table 4.

[0094] Table 4

[0095]

[0096] From Table 3 and Table 4, it can be seen that the effect of the grinding aid is closely related to the chemical composition of the machine-made sand and stone powder. For high calcium limestone machine-made sand and stone powder, that is, CaO content ≥ 46.10%, the use of DEIPA high-efficiency grinding aid can significantly improve its activity, and the 7d and 28d activity indexes reach 92.3% and 89.6% respectively, the activity level is comparable to that of the I-grade fly ash in Comparative Example 12, but the late activity shows a downward trend, and the fluidity ratio of the modified stone powder is maintained at 87.0%, showing good workability, which shows that the DEIPA high-efficiency grinding aid can effectively increase the active components of the high calcium stone powder and improve its cementing activity.

[0097] In contrast, the DEG-TIPA composite grinding aid has no significant effect in the high calcium system, that is, the application in Comparative Example 9, which shows that it has poor adaptability to the system, and for low calcium limestone machine-made sand and stone powder, the use of DEG-TIPA composite grinding aid, that is, the application in Example 6, can significantly improve its activity, and the 7d and 28d activity indexes reach 89.5% and 86.2% respectively, the overall activity is close to the I-grade fly ash level, and the fluidity ratio is 80.9%, showing good workability. On the contrary, the DEIPA high-efficiency grinding aid has limited effect on the activity improvement of the low calcium stone powder, that is, the application in Comparative Example 10.

[0098] The above results show that limestone machine-made sand and stone powder with different chemical compositions and mineral compositions need to be matched with different types of grinding aids to achieve the best activation effect: DEIPA high-efficiency grinding aid is suitable for high calcium systems, and DEG-TIPA composite grinding aid is suitable for low calcium systems.

[0099] Example 9

[0100] The difference between this example and Example 1 is that:

[0101] In step S1, the following raw materials are weighed in parts by mass: 900 parts of crushed stone, 560 parts of machine-made sand, 145 parts of high-strength ceramic sand, 448 parts of cement, 121 parts of activated and modified machine-made sand and stone powder, 75 parts of silica fume, 61 parts of high-efficiency composite expansion component, 126 parts of mixing water, 30 parts of steel fiber, 8 parts of temperature shrinkage fiber, and 12 parts of viscosity-reducing superdispersant; when the high-strength ceramic sand is pre-wetted, the water temperature in the treatment tank is 22℃, and the drying time of the high-strength ceramic sand is 1h; the pre-wetted high-strength ceramic sand is mixed and stirred with the crushed stone and machine-made sand for 0.5min.

[0102] The mixing time of the mixed aggregate, cement, activated modified mechanism sand and gravel powder, silica fume and high-efficiency composite expansion component in step S2 is 0.5 min. The mass ratio of the C-S-H crystal nucleus activator emulsion, mechanism sand and gravel powder, polysilicon slag powder, calcined metakaolin, high-efficiency grinding aid and grinding water is 0.8:750:100:100:0.03:485, and the median particle size of the activated modified mechanism sand and gravel powder is 7.5 μm. The specific surface area is 620 m 2 / kg. The mass ratio of the crystal nucleus activator, deionized water and zeolite powder is 20:75:5, and the stirring time is 12 min.

[0103] In step S3, the stirring time of the uniform mixture, 2 / 3 of the total mass of the added amount of mixing water and viscosity-reducing superdispersant is 1 min. The preparation method of the viscosity-reducing superdispersant comprises the following steps: the mass ratio of the polyethylene glycol monoacrylate, sodium thiosulfate methacrylate, acrylic acid, methyl methacrylate, reaction medium water, ammonium persulfate solution and mercaptoethanol solution is 47:5.5:10.5:0.2:125:17:16; the initiator and transfer agent are added dropwise within 2 h, and the reaction temperature of the polymerization reaction is 92℃.

[0104] In step S4, the stirring time of the steel fiber, temperature-shrinking fiber, concrete rheological body, remaining mixing water and viscosity-reducing superdispersant is 1 min.

[0105] The remaining raw material ratio, preparation steps and process parameters are the same as those of example 1, and a C100 steel pipe concrete added with activated modified mechanism sand and gravel powder is prepared.

[0106] Example 10

[0107] The difference between this example and example 1 is that:

[0108] In step S1, the following raw materials are weighed in mass parts: 1100 parts of crushed stone, 450 parts of mechanism sand, 70 parts of high-strength ceramic sand, 517 parts of cement, 97 parts of activated modified mechanism sand and gravel powder, 65 parts of silica fume, 55 parts of high-efficiency composite expansion component, 140 parts of mixing water, 50 parts of steel fiber, 5 parts of temperature-shrinking fiber and 9 parts of viscosity-reducing superdispersant. When the high-strength ceramic sand is pre-wetted, the water temperature in the treatment tank is 25℃, and the drying time of the high-strength ceramic sand is 1.5 h. The pre-wetted high-strength ceramic sand is mixed and stirred with the crushed stone and mechanism sand for 0.7 min.

[0109] The mixing time of the mixed aggregate, cement, activated modified mechanism sand and gravel powder, silica fume and high-efficiency composite expansion component in step S2 is 0.7 min. The mass ratio of the C-S-H crystal nucleus active agent emulsion, mechanism sand and gravel powder, polysilicon slag powder, calcined metakaolin, high-efficiency grinding aid and grinding water is 1:800:125:110:0.05:515, and the median particle size of the activated modified mechanism sand and gravel powder is 7.8 μm The specific surface area is 680 m 2 / kg. The mass ratio of the crystal nucleus active agent, deionized water and zeolite powder is 25:80:8, and the stirring time is 15 min.

[0110] The stirring time of the uniform mixture, 2 / 3 of the total mass of the mixture, mixing water and viscosity-reducing type super dispersant in step S3 is 1.5 min. The preparation method of the viscosity-reducing type super dispersant comprises the following steps: the mass ratio of the polyethylene glycol monoacrylate, sodium thiosulfate methacrylate, acrylic acid, methyl methacrylate, reaction medium water, ammonium persulfate solution and mercaptoethanol solution is 51:6:11:0.25:135:18:20; the initiator and the transfer agent are completely added dropwise within 2.2 h, and the reaction temperature of the polymerization reaction is 95℃.

[0111] The stirring time of the steel fiber, temperature shrinkage fiber, concrete rheological body, remaining mixing water and viscosity-reducing type super dispersant in step S4 is 1.2 min.

[0112] The remaining raw material ratio, preparation steps and process parameters are the same as those of example 1, and the C100 steel pipe concrete added with the activated modified mechanism sand and gravel powder is prepared.

[0113] In the specific implementation process, it should be noted that each raw material is 1 kg in mass fraction. In the above examples of preparing concrete, 1 m³ of concrete mixture can be prepared according to the corresponding ratio.

[0114] In the description of the present application, it should be understood that the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as a limitation on the present application. The indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0115] Although embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A C100 steel pipe concrete with activated modified mechanism sand and stone powder added, characterized in that: The raw material components include the following in mass fraction: 900-1100 parts of broken stone, 450-560 parts of machine-made sand, 70-145 parts of high-strength ceramic sand, 448-517 parts of cement, 97-121 parts of activated modified machine-made sandstone powder, 65-75 parts of silica fume, 55-61 parts of high-efficiency composite expansion component, 126-145 parts of mixed water, 30-50 parts of steel fiber, 5-8 parts of temperature shrinkage fiber, and 9-12 parts of viscosity-reducing type super dispersant.

2. A C100 steel pipe concrete with activated modified mechanism sand and stone powder according to claim 1, characterized in that: The preparation method of the activated modified machine-made sandstone powder comprises the following steps: mixing C-S-H crystal nucleus activator emulsion, machine-made sandstone powder, polysilicon slag powder, calcined metakaolin, high-efficiency grinding aid and grinding water in a mass ratio of 0.8-1:750-800:100-125:100-110:0.03-0.05:485-515 to form a slurry, ball milling the slurry at a rotating speed of 150 r / min for 2 h, and then sequentially drying, scattering and screening to obtain the activated modified machine-made sandstone powder.

3. A C100 steel pipe concrete with activated modified mechanism sand and stone powder according to claim 1, characterized in that: The median particle diameter of the activated modified machine-made sandstone powder is 7.5-7.8 μm, and the specific surface area is 620-680 m 2 / kg.

4. The C100 steel pipe concrete with added activated modified machine-made sand and stone powder according to claim 2, characterized in that: The preparation method of the C-S-H crystal nucleus activator emulsion comprises the following steps: mixing crystal nucleus activator, deionized water and zeolite powder in a mass ratio of 20-25:75-80:5-8, stirring at a rotating speed of 120 r / min at a temperature of 40℃ for 10-15 min to obtain the C-S-H crystal nucleus activator emulsion.

5. The C100 steel pipe concrete with added activated modified machine-made sand and stone powder according to claim 2, characterized in that: The high-efficiency grinding aid is diethanol monoisopropanolamine or a composite grinding aid compounded from diethylene glycol and triisopropanolamine in a mass ratio of 1:

1.

6. The C100 steel pipe concrete with added activated modified machine-made sand and stone powder according to claim 1, characterized in that: The preparation method of the high-efficiency composite expansion component comprises the following steps: mixing oyster shell, phosphogypsum and bauxite in a mass ratio of 105:73:32, calcining at a temperature of 1350℃ for 40 min to obtain Ca-based expansion clinker; calcining periclase at a temperature of 1200℃ for 1 h to obtain Mg-based expansion clinker; mixing the Ca-based expansion clinker, the Mg-based expansion clinker and gypsum in a mass ratio of 63:29:8, and grinding to a particle size of ≤80 μm to obtain the high-efficiency composite expansion component.

7. The C100 steel pipe concrete with added activated modified machine-made sand and stone powder according to claim 1, characterized in that: The preparation method of the viscosity-reducing type super dispersant comprises the following steps: dosing polyethylene glycol monoacrylate, sodium thiosulfonate methacrylate, acrylic acid, methyl methacrylate, reaction medium water, ammonium persulfate solution and mercaptoethanol solution in a mass ratio of 47-51:5-6:10-11:0.2-0.3:125-135:16-18:16-20, wherein the ammonium persulfate solution is a 10% mass fraction aqueous solution, and the mercaptoethanol solution is a 5% mass fraction aqueous solution; mixing the polyethylene glycol monoacrylate, the sodium thiosulfonate methacrylate, the acrylic acid and the methyl methacrylate with the reaction medium water to obtain a monomer reaction solution, dropping the monomer reaction solution into the solution as an initiator and a transfer agent to perform polymerization reaction, the initiator and the transfer agent being completely added within 2-2.5 h, and the reaction temperature being 90±5℃; after the reaction is completed, a 35% mass fraction sodium hydroxide solution is added to adjust the pH of the system to 6.0-7.0 to obtain the viscosity-reducing type super dispersant.

8. A method for producing a C100 steel pipe concrete added with an activated modified machine-made sand stone powder, which is used for producing the C100 steel pipe concrete added with the activated modified machine-made sand stone powder according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: S1: mixing the gravel, the machine-made sand and the high-strength ceramic sand, and stirring for 0.5-1 min to obtain a mixed aggregate; S2: adding cement, activated modified machine-made sand stone powder, silica fume and high-efficiency composite expansion components into the mixed aggregate, and stirring for 0.5-1 min to obtain a uniform mixture; S3: adding mixing water and a viscosity-reducing type hyperdispersant into the uniform mixture, wherein the adding amount of the mixing water and the viscosity-reducing type hyperdispersant is 2 / 3 of the total mass of the mixing water and the viscosity-reducing type hyperdispersant respectively, and stirring for 1-2 min to obtain a flowable concrete rheological body; S4: adding steel fibers and temperature-shrinking fibers into the concrete rheological body by using a vibrating screen, and then adding the remaining mixing water and viscosity-reducing type hyperdispersant, and stirring for 1-1.5 min to obtain C100 steel pipe concrete added with the activated modified machine-made sand stone powder.

9. The method according to claim 8, wherein the method is a method for producing C100 steel pipe concrete by adding activated modified machine-made sand and stone powder. The high-strength ceramic sand is subjected to pre-wetting treatment before the mixed aggregate is prepared, and the pre-wetting treatment cycle is 24 h.

10. The method for preparing C100 steel pipe concrete with added activated modified machine-made sand and stone powder according to claim 9, characterized in that: The pre-wetting treatment method comprises the following steps: placing the high-strength ceramic sand in a treatment pool, adding pre-wetting water to completely immerse the high-strength ceramic sand, controlling the water temperature to be 20-25 DEG C, and standing for 24 h; then discharging the pre-wetting water, taking out the high-strength ceramic sand, and laying and airing the high-strength ceramic sand in a ventilated environment for 1-2 h until the high-strength ceramic sand is in a surface-dry state.

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