C40 high-finished fair-faced concrete column and preparation process thereof

Abstract

The application relates to a C40 high-finished fair-faced concrete column and a preparation process thereof, and relates to the field of building materials. Raw materials used by the application include the following components in parts by weight: cement 300-315 parts; mineral powder 80-95 parts; fly ash 95-105 parts; sand 700-750 parts; broken stone 900-1000 parts; water 168.3-174 parts; additive 2.3-2.6 parts; the additive includes polycarboxylate water reducing agent, early slump retaining agent, middle slump retaining agent, air entraining agent, retarder and thickening agent in a weight ratio of (105-115):(45-55):(25-35):(0.35-0.45):(27-32):(65-75); the application has the effect of improving the anti-segregation and anti-syneresis performance of concrete slurry, thereby improving the strength of the C40 high-finished fair-faced concrete column.

Description

Technical Field

[0001] This application relates to the field of building materials, and in particular to a C40 high-polish fair-faced concrete column and its preparation process. Background Technology

[0002] Concrete columns are common structural components in building construction, used to bear and transfer loads from floors, walls, and roofs. Fair-faced concrete columns utilize the natural texture of the concrete after molding as their finish. Due to their high strength, good load-bearing capacity, aesthetic appeal, and ease of construction, they are widely used in the construction industry. Currently, fair-faced concrete columns are often poured using the high-throw method, which involves pouring directly from the upper floor slab or roof, resulting in convenient construction and lower costs.

[0003] However, during the high-throw method of construction, due to the high pouring height of the fair-faced concrete column, the impact force of the falling concrete slurry is relatively large, which makes the bottom layer of concrete slurry prone to segregation. Specifically, coarse aggregates sink while mortar and cementitious materials float, significantly affecting the homogeneity of the concrete slurry. Furthermore, the bottom layer of concrete slurry, in its plastic state, is easily subjected to the impact force of the falling upper layer of concrete slurry and its own weight, resulting in pressure bleeding. This leads to a reduction in the strength of the finished fair-faced concrete column and seriously affects the quality of the project. Summary of the Invention

[0004] To address the aforementioned technical problems, this application provides a C40 high-polish fair-faced concrete column and its preparation process.

[0005] Firstly, this application provides a C40 high-polish fair-faced concrete column, which adopts the following technical solution:

[0006] A C40 high-polish fair-faced concrete column, the raw materials used include the following components in parts by weight: 300-315 parts cement; 80-95 parts mineral powder; 95-105 parts fly ash; 700-750 parts sand; 900-1000 parts crushed stone; 168.3-174 parts water; and 2.3-2.6 parts admixtures.

[0007] The admixtures include polycarboxylate superplasticizer, early slump retainer, mid-term slump retainer, air-entraining agent, retarder and thickener in a weight ratio of (105-115):(45-55):(25-35):(0.35-0.45):(27-32):(65-75).

[0008] By adopting the above technical solution, this application utilizes the synergistic effect of various admixtures to reduce the water-cement ratio in concrete slurry, improve the water retention and stability of concrete slurry, reduce segregation and bleeding, thereby improving the strength of fair-faced concrete columns.

[0009] Among them, polycarboxylate superplasticizers have the characteristic of high water reduction rate. Using polycarboxylate superplasticizers can greatly reduce the water-cement ratio of concrete slurry, making the concrete slurry less prone to segregation and bleeding, thereby improving the strength of the concrete slurry after molding.

[0010] Early slump retainers are suitable for concrete slurry requiring 0.5-1.5 hours of slump retention, while mid-term slump retainers are suitable for 1.5-2 hours. Using them in combination can extend the time the concrete slurry retains its fluidity. Both early and mid-term slump retainers are polycarboxylate-based slump retainers; therefore, they possess slump retention properties as well as some water-reducing capabilities. Using them in conjunction with polycarboxylate-based water-reducing agents can better achieve the water-reducing effect, thereby further reducing the possibility of segregation and bleeding in the concrete slurry, and ultimately improving the strength of the concrete slurry after molding.

[0011] The addition of retarders extends the initial and final setting times of concrete slurry without affecting the later strength of fair-faced concrete columns. Retarders themselves have a certain water-reducing function. When combined with polycarboxylate superplasticizers, early slump retainers, and mid-term slump retainers, they can play a synergistic water-reducing role, further reducing the water-cement ratio of concrete slurry. This reduces the possibility of segregation and bleeding of concrete slurry, thereby improving the strength of concrete slurry after molding.

[0012] This application also adds an air-entraining agent to the concrete slurry, which improves the workability, fluidity and durability of the concrete slurry. In addition, the air-entraining agent also has a certain water-reducing effect. When used in combination with admixtures such as polycarboxylate superplasticizers, the synergistic water-reducing effect of each component can be fully utilized.

[0013] The thickener described in this application can increase the viscosity of concrete slurry, resulting in higher stability and reducing the likelihood of segregation and bleeding. The thickener, when used in combination with admixtures such as polycarboxylate superplasticizers, allows the concrete slurry to maintain high fluidity while also possessing high stability. Furthermore, it fully leverages the synergistic thickening effect of each component, resulting in a superior thickening effect.

[0014] In summary, this application uses a specific range of polycarboxylate superplasticizers, early slump retainers, mid-term slump retainers, air-entraining agents, retarders, and thickeners in a mixed combination, which allows the above-mentioned admixtures to fully exert their synergistic effects, thereby greatly reducing the possibility of segregation and bleeding of concrete slurry, and thus improving the strength of the concrete slurry after molding.

[0015] Preferably, the raw materials comprise the following combination by weight: 305 parts cement; 85 parts mineral powder; 100 parts fly ash; 726 parts sand; 1000 parts crushed stone; 171 parts water; and 2.5 parts admixture.

[0016] By adopting the above technical solution, this application optimizes the proportion between the components of the concrete slurry, further improves the anti-segregation and anti-bleeding properties of the concrete slurry, and thus further improves the strength of the concrete slurry after molding.

[0017] Preferably, the admixtures include a polycarboxylate superplasticizer, an early slump retainer, a mid-term slump retainer, an air-entraining agent, a retarder, and a thickener in a weight ratio of 110:50:30:0.4:30:70.

[0018] By adopting the above technical solution, this application optimizes the proportions of various admixtures, further promotes the synergistic effect among various admixtures, and thus further improves the anti-segregation and anti-bleeding properties of concrete slurry.

[0019] Optionally, the air-entraining agent comprises sodium rosinate and sodium dodecyl sulfonate in a weight ratio of (11-14):(2-3).

[0020] By adopting the above technical solution, this application can give full play to the synergistic air-entraining effect of sodium dodecyl sulfonate and sodium rosinate, enhance the air-entraining effect of the air-entraining agent, and the air-entraining agent of this application has little impact on the compactness of fair-faced concrete columns.

[0021] Optionally, the sodium rosinate is an alcohol-modified sodium rosinate.

[0022] Optionally, the alcohol-modified sodium rosinate is prepared by the following method:

[0023] I. At a temperature of 210-220℃, rosin powder and alcohol compounds in a weight ratio of (5-9):(3-5) are mixed and reacted at a pressure of 5.0-5.5MPa for 4.5-5.0h.

[0024] II. Mix a 30-40 wt% sodium hydroxide solution with the product obtained in step I, heat to 95-105℃ and keep the temperature for 1.5-2 hours. After cooling, obtain sodium rosinate modified with alcohol compounds, wherein the weight ratio of sodium hydroxide solution to the product obtained in step I is (9-12):(5-7).

[0025] By adopting the above technical solution, this application first uses alcohol compounds to esterify rosin powder to improve the chemical structure of rosin powder, and then performs a saponification reaction with sodium hydroxide, so that the modified sodium rosinate can better serve as the skeleton of the air-entraining agent molecule, thereby making the liquid film after bubble formation have sufficient viscosity and elasticity, and the formed bubbles are small and stable, with better air-entraining effect.

[0026] Optionally, the thickener is a sodium polyacrylate thickener modified with ester compounds.

[0027] Optionally, the ester-modified sodium polyacrylate thickener is prepared by the following method:

[0028] a. Mix an aqueous solution of an ester compound with a concentration of 18-23 wt% in a weight ratio of (4-7):(1-3) with sodium polyacrylate to obtain a mixture;

[0029] b. Heat the mixture to 40-45℃, add hydrogen peroxide, and keep it at this temperature for 10-15 minutes. Then add the initiator, chain transfer agent, and an aqueous solution of ester compound with a concentration of 18-23wt%. Mix and stir, and keep it at this temperature for 30-35 minutes to obtain an ester compound modified sodium polyacrylate thickener. The weight ratio of the mixture, hydrogen peroxide, initiator, chain transfer agent, and aqueous solution of ester compound is (6-15):(0.1-1):(0.3-1):(1-1.5):(4-6).

[0030] By adopting the above technical solution, the thickener of this application is sodium polyacrylate thickener, and the sodium polyacrylate thickener is modified with ester group, which can significantly improve the water retention and stability of concrete slurry while effectively reducing the competitive adsorption effect of the thickener on polycarboxylate superplasticizer. This results in the polycarboxylate superplasticizer having better initial adsorption capacity and initial dispersibility, and thus better exerting its water-reducing effect.

[0031] Optionally, the crushed stone includes crushed stone with a particle size of 5-25 mm and crushed stone with a particle size of 5-16 mm in a weight ratio of (15-17):(3-5).

[0032] By adopting the above technical solution, this application uses a mixture of crushed stone with different gradations and optimizes the proportions, so that the smaller-diameter crushed stone can be fully filled into the basic skeleton formed by the larger-diameter crushed stone, which significantly improves the stability of the concrete slurry, thereby reducing the possibility of segregation of the concrete slurry and improving the strength of the concrete slurry after molding.

[0033] Secondly, this application provides a process for preparing C40 high-polish fair-faced concrete columns, comprising the following steps:

[0034] S1. Mix all raw materials together for 60-90 seconds to obtain concrete slurry;

[0035] S2. Pour the concrete slurry into the formwork of the fair-faced concrete column and vibrate the concrete slurry in the formwork. The vibration frequency is 1.8-2 meters / time, and the vibration time is 2-3 minutes each time.

[0036] By adopting the above technical solution, the concrete slurry falling into the template is vibrated, which can increase the fluidity of the concrete slurry, eliminate air bubbles, and make the final fair-faced concrete column have a better fair-faced effect.

[0037] In summary, this application has the following beneficial technical effects:

[0038] 1. By utilizing the synergistic effect among polycarboxylate superplasticizer, early slump retainer, mid-term slump retainer, retarder, air-entraining agent and thickener, the water-cement ratio of concrete slurry is reduced, and the water retention and stability of concrete slurry are increased, thereby effectively reducing the possibility of segregation and bleeding of concrete slurry, and thus improving the strength of concrete slurry after molding.

[0039] 2. By using a compound air-entraining agent to improve the fluidity of concrete slurry, the air bubbles introduced by the compound air-entraining agent have good stability, which improves the air-entraining effect of the air-entraining agent, while having little impact on the compactness of fair-faced concrete columns.

[0040] 3. The modified sodium polyacrylate thickener exhibits lower competitive adsorption of polycarboxylate superplasticizer, resulting in better initial adsorption capacity and initial dispersibility for the polycarboxylate superplasticizer, thus enabling it to better exert its water-reducing effect. Detailed Implementation

[0041] Material source

[0042] Unless otherwise specified, all raw materials used in this application are commercially available products, specifically:

[0043] The cement was purchased from Tianjin Jinyu Zhenxing Environmental Protection Technology Co., Ltd., and its grade is P.O42.5.

[0044] The mineral powder was purchased from Tangshan Fengnan Hongye Furnace Materials Co., Ltd., model S95, with an activity coefficient of 104% after 28 days;

[0045] The fly ash was purchased from Tianjin Beijiang Environmental Protection Building Materials Co., Ltd., and is classified as Class F, Grade II, with a fineness of 18.2% and a 28-day mortar strength of 73%.

[0046] The sand is artificial sand, with MB < 1.4, stone powder content ≤ 5.0%, soundness ≤ 8%, and crushing value index < 30%;

[0047] The crushing value of the crushed stone is ≤10%, the content of needle-shaped and flaky particles is ≤8%, the mud content is ≤0.5%, and the soundness is ≤8%.

[0048] The polycarboxylate superplasticizer was TS-1 polycarboxylate superplasticizer purchased from Beijing Jinyu Cement Energy Saving Technology Co., Ltd.

[0049] The early slump retainer was TS-2 concrete slump retainer purchased from Beijing Jinyu Cement Energy Saving Technology Co., Ltd.

[0050] The mid-term slump retainer was TS-302 concrete slump retainer purchased from Beijing Jinyu Cement Energy Saving Technology Co., Ltd.

[0051] Sodium dodecyl sulfonate was purchased from Shandong Jinli Chemical Co., Ltd.

[0052] Sodium gluconate was purchased from Shandong Gushuo Biotechnology Co., Ltd.

[0053] The sorbate was purchased from Hebei Qiansheng Biotechnology Co., Ltd.

[0054] Sodium polyacrylate thickener was purchased from Shanghai Yuanye Biotechnology Co., Ltd., model number S25744;

[0055] Vitamin C was purchased from Hebei Pengyu Biotechnology Co., Ltd.

[0056] Thioglycolic acid, hydrogen peroxide, sodium hydroxide, and sodium polyacrylate were purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0057] The rosin powder was purchased from Wuhan Jiyesheng Chemical Products Co., Ltd.

[0058] The alcohol compounds in this application include, but are not limited to, the following substances: methanol, ethanol, ethylene glycol, glycerol, sorbitol, and pentaerythritol. Since the above alcohol compounds do not have a significant difference in their modification effect on sodium rosinate, ethylene glycol is used as an example in the preparation examples of this application. Ethylene glycol was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0059] The ester compounds in this application include, but are not limited to, the following substances: methyl hydroxyacrylate, ethyl hydroxyacrylate, butyl hydroxyacrylate, methyl hydroxymethyl acrylate, and ethyl hydroxymethyl acrylate. Since the above ester compounds do not have a significant difference in their modification effect on sodium polyacrylate thickener, methyl hydroxyacrylate is selected as an example in the preparation examples of this application. The methyl hydroxyacrylate was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0060] The formwork specifications for the fair-faced concrete columns used in this application are as follows: cross-section is 1.2×1.4m, and height is 11m.

[0061] Preparation Example 1

[0062] The preparation method of the air-entraining agent includes the following steps:

[0063] T1. A 30wt% sodium hydroxide solution and rosin powder were mixed in a weight ratio of 4:1 to obtain a mixture, wherein the 30wt% sodium hydroxide solution was 112g and the rosin powder was 28g. The mixture was placed in a 100℃ water bath and stirred and saponified for 1.5h to obtain sodium rosinate.

[0064] T2. Mix sodium rosinate and sodium dodecyl sulfonate in a weight ratio of 7:1, with 70g of sodium rosinate and 10g of sodium dodecyl sulfonate. Stir the mixture at 60r / min for 10min to obtain an air-entraining agent.

[0065] Preparation Example 2

[0066] The difference from Preparation Example 1 is that in step T2, the weight ratio of sodium rosinate to sodium dodecyl sulfonate is 11:3, wherein sodium rosinate is 62.86 g and sodium dodecyl sulfonate is 17.14 g.

[0067] Preparation Example 3

[0068] The difference from Preparation Example 1 is that in step T2, the weight ratio of sodium rosinate to sodium dodecyl sulfonate is 2:1, wherein sodium rosinate is 53.3g and sodium dodecyl sulfonate is 26.7g.

[0069] Preparation Example 4

[0070] The difference from Preparation Example 1 is that in step T2, the weight ratio of sodium rosinate to sodium dodecyl sulfonate is 5:1, wherein sodium rosinate is 66.7g and sodium dodecyl sulfonate is 13.3g.

[0071] Preparation Example 5

[0072] The difference from Preparation Example 1 is that in step T2, the sodium rosinate is ethylene glycol-modified sodium rosinate, and the specific preparation method includes the following steps:

[0073] I. Weigh rosin powder and ethylene glycol in a weight ratio of 1:1 at 210℃, with 17.5g of rosin powder and 17.5g of ethylene glycol, and mix them in a reaction vessel. React at a pressure of 5.0MPa for 5.0h.

[0074] II. Mix a 30wt% sodium hydroxide solution with the product obtained in step I at a weight ratio of 9:7, wherein the 30wt% sodium hydroxide solution is 45g and the product obtained in step I is 35g. Heat the mixture to 105℃ and keep it at that temperature for 2 hours. After cooling, ethylene glycol-modified sodium rosinate is obtained.

[0075] Preparation Example 6

[0076] The difference from Preparation Example 1 is that the sodium rosinate used is ethylene glycol-modified sodium rosinate, and the specific preparation method includes the following steps:

[0077] I. At a temperature of 220℃, weigh rosin powder and ethylene glycol in a weight ratio of 3:1, where the weight of rosin powder is 17.63g and the weight of ethylene glycol is 5.87g. Mix the two and put them into a reaction vessel, and react for 4.5h under a pressure of 5.5MPa.

[0078] II. Mix a 40wt% sodium hydroxide solution with the product obtained in step I at a weight ratio of 12:5, wherein the 40wt% sodium hydroxide solution is 56.5g and the product obtained in step I is 23.5g. Heat the mixture to 95℃ and keep it at that temperature for 1.5h. After cooling, ethylene glycol-modified sodium rosinate is obtained.

[0079] Preparation Example 7

[0080] The difference from Preparation Example 5 is that in step I, rosin powder and ethylene glycol are weighed in a weight ratio of 4:1, wherein the rosin powder is 28g and the ethylene glycol is 7g.

[0081] Preparation Example 8

[0082] The difference from Preparation Example 5 is that in step I, rosin powder and ethylene glycol are weighed in a weight ratio of 1:2, wherein the rosin powder is 11.7g and the ethylene glycol is 23.3g.

[0083] Preparation Example 9

[0084] The preparation method of hydroxymethyl acrylate modified sodium polyacrylate thickener includes the following steps:

[0085] a. Mix a 18wt% hydroxymethyl acrylate solution and sodium polyacrylate in a weight ratio of 4:3 to obtain a mixture, wherein the 18wt% hydroxymethyl acrylate solution contains 3.214 kg and the sodium polyacrylate contains 2.411 kg.

[0086] b. Heat the mixture to 40°C, add hydrogen peroxide, and maintain the temperature for 10 minutes. Then add the initiator, chain transfer agent, and 18 wt% methyl acrylate solution to the mixture, maintain the temperature, and stir at 60 r / min for 30 minutes to obtain methyl acrylate modified sodium polyacrylate thickener. The weight ratio of the mixture, hydrogen peroxide, initiator, chain transfer agent, and methyl acrylate solution is 6:1:0.3:1.5:4, with 5.625 kg of mixture, 0.938 kg of hydrogen peroxide, 0.281 kg of initiator, 1.406 kg of chain transfer agent, and 3.75 kg of 18 wt% methyl acrylate solution.

[0087] The initiator mentioned above is vitamin C, and the chain transfer agent is thioglycolic acid.

[0088] Preparation Example 10

[0089] The preparation method of hydroxymethyl acrylate modified sodium polyacrylate thickener includes the following steps:

[0090] a. Mix a 23wt% hydroxymethyl acrylate solution and sodium polyacrylate in a weight ratio of 7:1 to obtain a mixture, wherein the hydroxymethyl acrylate solution is 6.82kg and the sodium polyacrylate solution is 0.97kg.

[0091] b. Heat the mixture to 45°C, add hydrogen peroxide, and maintain the temperature for 15 minutes. Then add the initiator, chain transfer agent, and 23 wt% methyl acrylate solution to the mixture, maintain the temperature, and stir at 60 r / min for 35 minutes to obtain methyl acrylate modified sodium polyacrylate thickener. The weight ratio of the mixture, hydrogen peroxide, initiator, chain transfer agent, and methyl acrylate solution is 15:0.1:1:1:6, with 7.79 kg of mixture, 0.052 kg of hydrogen peroxide, 0.52 kg of initiator, 0.52 kg of chain transfer agent, and 3.12 kg of 23 wt% methyl acrylate solution.

[0092] The initiator mentioned above is vitamin C, and the chain transfer agent is thioglycolic acid.

[0093] Example 1

[0094] A C40 high-polish fair-faced concrete column, the preparation process of which includes the following steps:

[0095] S1. The following components are combined: 5400 kg cement, 1710 kg mineral powder, 1710 kg fly ash, 13500 kg manufactured sand, 3132 kg water, 16200 kg crushed stone (comprising crushed stone with a particle size of 5-25 mm and crushed stone with a particle size of 5-16 mm in a weight ratio of 17:3, of which 13770 kg is 5-25 mm crushed stone and 2430 kg is 5-16 mm crushed stone), and 41.4 kg admixture (comprising admixtures in a weight ratio of 105:55:25:0.45). TS-1 polycarboxylate superplasticizer, TS-2 concrete slump retainer, TS-302 concrete slump retainer, air-entraining agent, retarder, and thickener (27:75) were added to a mixer and mixed for 60 seconds to obtain concrete slurry.

[0096] S2. Pour the concrete slurry into the formwork of the fair-faced concrete column and vibrate the concrete slurry in the formwork. The vibration frequency is 1.8 meters / time, and the vibration time is 2 minutes each time. When vibrating the upper layer of concrete slurry, insert the vibrator into the lower layer of concrete slurry 50mm.

[0097] S3. After the pouring process is completed, the fair-faced concrete column will be cured by watering and covering with a film for 28 days.

[0098] The air-entraining agent is sodium dodecyl sulfonate, the thickener is gluten gel, and the retarder is sodium gluconate.

[0099] Example 2

[0100] A C40 high-polish fair-faced concrete column, the preparation process of which includes the following steps:

[0101] S1. The following components are combined: 5400 kg of cement, 1710 kg of mineral powder, 1710 kg of fly ash, 13500 kg of manufactured sand, 3132 kg of water, and 16200 kg of crushed stone. The crushed stone includes crushed stone with a particle size of 5-25 mm and crushed stone with a particle size of 5-16 mm in a weight ratio of 17:3, of which 13770 kg is crushed stone with a particle size of 5-25 mm and 2430 kg is crushed stone with a particle size of 5-16 mm. 41.4 kg of admixture is also included, with the admixture comprising components in a weight ratio of 115:45:35:0.35: TS-1 polycarboxylate superplasticizer, TS-2 concrete slump retainer, TS-302 concrete slump retainer, air-entraining agent, retarder, and thickener in a 32:65 ratio are added to a mixer. The mixture consists of 16.28 kg of TS-1 polycarboxylate superplasticizer, 6.37 kg of TS-2 concrete slump retainer, 4.96 kg of TS-302 concrete slump retainer, 0.05 kg of air-entraining agent, 4.53 kg of retarder, and 9.2 kg of thickener. The mixture is stirred for 90 seconds to obtain concrete slurry.

[0102] S2. Pour the concrete slurry into the formwork of the fair-faced concrete column and vibrate the concrete slurry in the formwork. The vibration frequency is 2.0 meters / time, and the vibration time is 3 minutes each time. When vibrating the upper layer of concrete slurry, insert the vibrator into the lower layer of concrete slurry 100mm.

[0103] S3. After the pouring process is completed, the fair-faced concrete column will be cured by watering and covering with a film for 28 days.

[0104] The air-entraining agent is sodium dodecyl sulfonate, the thickener is gluten gel, and the retarder is sodium gluconate.

[0105] Example 3

[0106] A C40 high-polish fair-faced concrete column, the preparation process of which includes the following steps:

[0107] S1. The following components are combined: 5670 kg cement, 1440 kg mineral powder, 1890 kg fly ash, 12600 kg manufactured sand, 3092.4 kg water, and 18000 kg crushed stone. The crushed stone includes crushed stone with a particle size of 5-25 mm and crushed stone with a particle size of 5-16 mm in a weight ratio of 17:3, of which 15300 kg is crushed stone with a particle size of 5-25 mm and 2700 kg is crushed stone with a particle size of 5-16 mm. An admixture of 46.8 kg is also included, with the admixture comprising components in a weight ratio of 115:45:35:0.35: TS-1 polycarboxylate superplasticizer, TS-2 concrete slump retainer, TS-302 concrete slump retainer, air-entraining agent, retarder, and thickener in a 32:65 ratio are added to a mixer. The mixture consists of 18.41 kg of TS-1 polycarboxylate superplasticizer, 7.20 kg of TS-2 concrete slump retainer, 5.60 kg of TS-302 concrete slump retainer, 0.056 kg of air-entraining agent, 5.12 kg of retarder, and 10.4 kg of thickener. The mixture is stirred for 60 seconds to obtain concrete slurry.

[0108] S2. Pour the concrete slurry into the formwork of the fair-faced concrete column and vibrate the concrete slurry in the formwork. The vibration frequency is 1.8 meters / time, and the vibration time is 2 minutes each time. When vibrating the upper layer of concrete slurry, insert the vibrator into the lower layer of concrete slurry 50mm.

[0109] S3. After the pouring process is completed, the fair-faced concrete column will be cured by watering and covering with a film for 28 days.

[0110] The air-entraining agent is sodium dodecyl sulfonate, the thickener is gluten gel, and the retarder is sodium gluconate.

[0111] Example 4

[0112] A C40 high-polish fair-faced concrete column, the preparation process of which includes the following steps:

[0113] S1. The following components are combined: 5670 kg cement, 1440 kg mineral powder, 1890 kg fly ash, 12600 kg manufactured sand, 3092.4 kg water, and 18000 kg crushed stone. The crushed stone includes crushed stone with a particle size of 5-25 mm and crushed stone with a particle size of 5-16 mm in a weight ratio of 17:3, of which 15300 kg is crushed stone with a particle size of 5-25 mm and 2700 kg is crushed stone with a particle size of 5-16 mm. An admixture of 46.8 kg is also included, with the admixture comprising components in a weight ratio of 105:55:25:0.45. The following components were added to a mixer in a 27:75 ratio: TS-1 polycarboxylate superplasticizer, TS-2 concrete slump retainer, TS-302 concrete slump retainer, air-entraining agent, retarder, and thickener. The amounts were: 17.1 kg of TS-1 polycarboxylate superplasticizer, 8.95 kg of TS-2 concrete slump retainer, 4.07 kg of TS-302 concrete slump retainer, 0.073 kg of air-entraining agent, 4.4 kg of retarder, and 12.21 kg of thickener. The mixture was stirred for 60 seconds to obtain the concrete slurry.

[0114] S2. Pour the concrete slurry into the formwork of the fair-faced concrete column and vibrate the concrete slurry in the formwork. The vibration frequency is 1.8 meters / time, and the vibration time is 2 minutes each time. When vibrating the upper layer of concrete slurry, insert the vibrator into the lower layer of concrete slurry 50mm.

[0115] S3. After the pouring process is completed, the fair-faced concrete column will be cured by watering and covering with a film for 28 days.

[0116] The air-entraining agent is sodium dodecyl sulfonate, the thickener is gluten gel, and the retarder is sodium gluconate.

[0117] Example 5

[0118] A C40 high-polish fair-faced concrete column differs from Example 1 in that, in step S1, the crushed stone includes crushed stone with a particle size of 5-25mm and crushed stone with a particle size of 5-16mm in a weight ratio of 3:1, wherein the crushed stone with a particle size of 5-25mm is 13500kg, the crushed stone with a particle size of 5-16mm is 4500kg, and the admixture is 46.8kg.

[0119] Example 6

[0120] A C40 high-polish fair-faced concrete column differs from Example 1 in that, in step S1, the following ingredients are used: 5490 kg of cement, 1530 kg of mineral powder, 1800 kg of fly ash, 13068 kg of manufactured sand, 3078 kg of water, and 18000 kg of crushed stone. The crushed stone comprises crushed stone with a particle size of 5-25 mm and crushed stone with a particle size of 5-16 mm in a weight ratio of 17:3, wherein 15300 kg is 5-25 mm crushed stone and 2700 kg is 5-16 mm crushed stone. 45 kg of admixture is also included. The additives include TS-1 polycarboxylate superplasticizer, TS-2 concrete slump retainer, TS-302 concrete slump retainer, air-entraining agent, retarder, and thickener in a weight ratio of 105:55:25:0.45:27:75. The weight ratio of TS-1 polycarboxylate superplasticizer is 16.44 kg, TS-2 concrete slump retainer is 8.61 kg, TS-302 concrete slump retainer is 3.91 kg, air-entraining agent is 0.07 kg, retarder is 4.23 kg, and thickener is 11.74 kg.

[0121] Example 7

[0122] A C40 high-polish fair-faced concrete column differs from Example 6 in that, in step S1, the admixtures include TS-1 polycarboxylate superplasticizer, TS-2 concrete slump retainer, TS-302 concrete slump retainer, air-entraining agent, retarder, and thickener in a weight ratio of 110:50:30:0.10:30:70, wherein TS-1 polycarboxylate superplasticizer is 17.05 kg, TS-2 concrete slump retainer is 7.74 kg, TS-302 concrete slump retainer is 4.65 kg, air-entraining agent is 0.06 kg, retarder is 4.65 kg, and thickener is 10.85 kg.

[0123] Example 8

[0124] A C40 high-polish fair-faced concrete column differs from Example 1 in that, in step S1, the air-entraining agent used is sodium rosinate obtained in step T1 of Preparation Example 1.

[0125] Example 9

[0126] A C40 high-polished fair-faced concrete column differs from Example 1 in that, in step S1, the air-entraining agent used is the same as that prepared in Example 1.

[0127] Example 10

[0128] A C40 high-polished fair-faced concrete column differs from Example 1 in that, in step S1, the air-entraining agent used is the air-entraining agent prepared in Preparation Example 2.

[0129] Example 11

[0130] A C40 high-polished fair-faced concrete column differs from Example 1 in that, in step S1, the air-entraining agent used is the air-entraining agent prepared in Preparation Example 3.

[0131] Example 12

[0132] A C40 high-polished fair-faced concrete column differs from Example 1 in that, in step S1, the air-entraining agent used is the air-entraining agent prepared in Preparation Example 4.

[0133] Example 13

[0134] A C40 high-polished fair-faced concrete column differs from Example 1 in that, in step S1, the air-entraining agent used is the ethylene glycol-modified air-entraining agent obtained in Preparation Example 5.

[0135] Example 14

[0136] A C40 high-polished fair-faced concrete column differs from Example 1 in that, in step S1, the air-entraining agent used is the ethylene glycol-modified air-entraining agent obtained in Preparation Example 6.

[0137] Example 15

[0138] A C40 high-polished fair-faced concrete column differs from Example 1 in that, in step S1, the air-entraining agent used is the ethylene glycol-modified air-entraining agent obtained in Preparation Example 7.

[0139] Example 16

[0140] A C40 high-polished fair-faced concrete column differs from Example 1 in that, in step S1, the air-entraining agent used is the ethylene glycol-modified air-entraining agent obtained in Preparation Example 8.

[0141] Example 17

[0142] A C40 high-polish fair-faced concrete column differs from Example 1 in that the thickener used is sodium polyacrylate thickener.

[0143] Example 18

[0144] A C40 high-polish fair-faced concrete column differs from Example 1 in that the thickener used is the sodium polyacrylate thickener modified with methyl acrylate obtained in Preparation Example 9.

[0145] Example 19

[0146] A C40 high-polish fair-faced concrete column differs from Example 1 in that the thickener used is the sodium polyacrylate thickener modified with methyl acrylate obtained in Preparation Example 10.

[0147] Example 20

[0148] A C40 high-polish fair-faced concrete column differs from Example 1 in that the crushed stone includes crushed stone with a particle size of 5-25mm and crushed stone with a particle size of 5-16mm in a weight ratio of 2:1, wherein the crushed stone with a particle size of 5-25mm is 10800kg and the crushed stone with a particle size of 5-16mm is 5400kg.

[0149] Example 21

[0150] A C40 high-polish fair-faced concrete column differs from Example 1 in that the crushed stone includes crushed stone with a particle size of 5-25mm and crushed stone with a particle size of 5-16mm in a weight ratio of 6:1, with 13886kg of crushed stone with a particle size of 5-25mm and 2314kg of crushed stone with a particle size of 5-16mm.

[0151] Comparative Example 1

[0152] The difference from Example 1 is that in step S1, the admixtures include TS-1 polycarboxylate superplasticizer, TS-2 concrete slump retainer, TS-302 concrete slump retainer, air-entraining agent, retarder, and thickener in a weight ratio of 120:60:20:0.5:25:80, wherein TS-1 polycarboxylate superplasticizer is 16.26 kg, TS-2 concrete slump retainer is 8.13 kg, TS-302 concrete slump retainer is 2.71 kg, air-entraining agent is 0.068 kg, retarder is 3.39 kg, and thickener is 10.84 kg.

[0153] Comparative Example 2

[0154] The difference from Example 1 is that in step S1, the admixtures include TS-1 polycarboxylate superplasticizer, TS-2 concrete slump retainer, TS-302 concrete slump retainer, air-entraining agent, retarder, and thickener in a weight ratio of 90:40:40:0.3:35:80, wherein TS-1 polycarboxylate superplasticizer is 13.06 kg, TS-2 concrete slump retainer is 5.8 kg, TS-302 concrete slump retainer is 5.8 kg, air-entraining agent is 0.044 kg, retarder is 5.08 kg, and thickener is 11.61 kg.

[0155] Comparative Example 3

[0156] The difference from Example 1 is that in step S1, the following ingredients are used: 5220 kg of cement, 1800 kg of mineral powder, 1620 kg of fly ash, 13680 kg of manufactured sand, 2880 kg of water, and 15300 kg of crushed stone. The crushed stone includes crushed stone with a particle size of 5-25 mm and crushed stone with a particle size of 5-16 mm in a weight ratio of 17:3, of which 13005 kg is crushed stone with a particle size of 5-25 mm and 2295 kg is crushed stone with a particle size of 5-16 mm. 32.4 kg of admixture is also included. The mixture comprises TS-1 polycarboxylate superplasticizer, TS-2 concrete slump retainer, TS-302 concrete slump retainer, air-entraining agent, retarder, and thickener in a ratio of 105:55:25:0.45:27:75. The content of TS-1 polycarboxylate superplasticizer is 11.84 kg, TS-2 concrete slump retainer is 6.2 kg, TS-302 concrete slump retainer is 2.82 kg, air-entraining agent is 0.051 kg, retarder is 3.04 kg, and thickener is 8.45 kg.

[0157] Comparative Example 4

[0158] The difference from Example 1 is that in step S1, the following ingredients are used: 5760 kg of cement, 1260 kg of mineral powder, 2160 kg of fly ash, 12240 kg of manufactured sand, 3240 kg of water, and 18180 kg of crushed stone. The crushed stone includes crushed stone with a particle size of 5-25 mm and crushed stone with a particle size of 5-16 mm in a weight ratio of 17:3. Specifically, 15453 kg of the 5-25 mm crushed stone and 2727 kg of the 5-16 mm crushed stone are used. 50 kg of admixture is also included. The admixture comprises... The composition is 105:55:25:0.45:27:75, consisting of TS-1 polycarboxylate superplasticizer, TS-2 concrete slump retainer, TS-302 concrete slump retainer, air-entraining agent, retarder, and thickener. The amounts are: TS-1 polycarboxylate superplasticizer (18.26 kg), TS-2 concrete slump retainer (9.57 kg), TS-302 concrete slump retainer (4.35 kg), air-entraining agent (0.078 kg), retarder (4.7 kg), and thickener (13.04 kg).

[0159] Comparative Example 5

[0160] The difference from Example 1 is that in step S1, the admixtures include TS-1 polycarboxylate superplasticizer, TS-2 concrete slump retainer, TS-302 concrete slump retainer, air-entraining agent, and retarder in a weight ratio of 105:55:25:0.45:27, wherein TS-1 polycarboxylate superplasticizer is 20.46 kg, TS-2 concrete slump retainer is 10.72 kg, TS-302 concrete slump retainer is 4.87 kg, air-entraining agent is 0.088 kg, and retarder is 5.26 kg.

[0161] Comparative Example 6

[0162] The difference from Example 1 is that in step S1, the admixtures include TS-1 polycarboxylate superplasticizer, TS-2 concrete slump retainer, air-entraining agent, retarder, and thickener in a weight ratio of 105:55:0.45:27:75, wherein TS-1 polycarboxylate superplasticizer is 16.56 kg, TS-2 concrete slump retainer is 8.67 kg, air-entraining agent is 0.071 kg, retarder is 4.26 kg, and thickener is 11.83 kg.

[0163] Performance testing

[0164] 1. The pressure bleeding rate and segregation rate of the concrete slurry prepared in step S1 of Examples 1-21 and Comparative Examples 1-6 were tested according to GB / T50080-2016.

[0165] 2. Take 8 kg of the concrete slurry prepared in step S1 of Examples 1-21 and Comparative Examples 1-6 respectively, and make cubes with a side length of 150 mm as concrete specimens. Cur the concrete specimens for 28 days. Test the 28-day compressive strength of the concrete specimens of Examples 1-21 and Comparative Examples 1-6 according to GB / T50081-2019.

[0166] In the 28-day compressive strength test, each group of concrete specimens consisted of 3 pieces, and the performance test result was the average value of the 3 specimens in each group.

[0167] The performance test results are shown in Table 1.

[0168] Table 1 Performance Test Results

[0169]

[0170]

[0171] 3. Take 8 kg of the concrete slurry prepared in step S1 of Examples 1 and 8-16 respectively, and make it into cubes with a side length of 150 mm as concrete specimens. Cur the concrete specimens for 28 days. Test the porosity of the concrete specimens of Examples 1 and 8-16 according to GB / T50082-2019. Each group of concrete specimens consists of 3 pieces, and the performance test results are the average of the 3 specimens in each group. The porosity test results are shown in Table 2.

[0172] Table 2 Porosity Detection Results

[0173]

[0174] As can be seen from Table 1, the 28-day compressive strength of Examples 1-4 of this application ranges from 55.8 MPa to 56.7 MPa, the segregation rate ranges from 7.3% to 7.6%, and the pressure bleeding rate ranges from 15.3% to 15.9%. This indicates that the proportions of each component in the concrete slurry and the proportions of each component in the admixture provided in this application have a good effect on improving the anti-segregation and anti-bleeding properties of the concrete slurry, thereby resulting in higher compressive strength of the concrete slurry after molding.

[0175] The 28-day compressive strength of Example 5 of this application is 56.1 MPa, the segregation rate is 7.5%, and the pressure bleeding rate is 15.6%. The 28-day compressive strength of Example 1 is 55.8 MPa, the segregation rate is 7.6%, and the pressure bleeding rate is 15.9%. This shows that the use of different gradations of crushed stone provided in this application can make the concrete slurry more stable, thereby improving the anti-segregation performance of the concrete slurry and thus improving the compressive strength of the concrete slurry after molding.

[0176] Compared with Example 1, Example 6 of this application has a higher 28-day compressive strength, a lower segregation rate, and a lower pressure bleeding rate. This indicates that the optimal proportion of cement, mineral powder, and other components in the concrete slurry provided by this application has a better effect on improving the anti-segregation and anti-bleeding properties of the concrete slurry, thereby further improving the compressive strength of the concrete slurry after molding.

[0177] Compared with Example 6, Example 7 of this application has a higher 28-day compressive strength, a lower segregation rate, and a lower pressure bleeding rate. This indicates that the preferred ratio of each component in the admixture of the concrete slurry provided by this application has a better effect on improving the anti-segregation and anti-bleeding performance of the concrete slurry, thereby further improving the compressive strength of the concrete slurry after molding.

[0178] As can be seen from Tables 1 and 2, Examples 1 and 8 of this application have lower 28-day compressive strength, higher porosity, segregation rate, and pressure bleeding rate compared to Examples 9 and 10. This indicates that the combined use of sodium rosinate and sodium dodecyl sulfonate has a lower impact on the density of fair-faced concrete columns than the use of either one alone, and at the same time has a better synergistic water-reducing effect with admixtures such as polycarboxylate superplasticizers.

[0179] Compared to Examples 9 and 10, Examples 11 and 12 of this application have lower 28-day compressive strength, higher porosity, segregation rate, and pressure bleeding rate, indicating that the air-entraining agent ratio provided in this application has a lower impact on the density of fair-faced concrete columns and has a better synergistic water-reducing effect with admixtures such as polycarboxylate superplasticizers.

[0180] Compared to Examples 11 and 12, Examples 13 and 14 of this application exhibit higher 28-day compressive strength, lower porosity, segregation rate, and pressure bleeding rate. This indicates that the ethylene glycol-modified air-entraining agent has a lower impact on the density of fair-faced concrete columns than the unmodified air-entraining agent, and also has a better synergistic water-reducing effect with admixtures such as polycarboxylate superplasticizers.

[0181] Compared with Examples 13 and 14, Examples 15 and 16 have higher porosity, segregation rate and pressure bleeding rate, and lower 28-day compressive strength, indicating that the ratio range of ethylene glycol to rosin powder provided in this application can enable the ethylene glycol-modified air-entraining agent to have a better effect.

[0182] As can be seen from Table 1, Example 17 of this application has a higher 28-day compressive strength and a lower segregation rate and pressure bleeding rate compared to Example 1, indicating that the sodium polyacrylate thickener has a better thickening effect than the PVC thickener, thus improving the water retention and stability of the concrete slurry. Examples 18 and 19 have a higher 28-day compressive strength and a lower segregation rate and pressure bleeding rate compared to Example 17, indicating that the methyl acrylate modified sodium polyacrylate thickener has a better thickening effect than the unmodified sodium polyacrylate thickener, further improving the water retention and stability of the concrete slurry and reducing the competitive adsorption effect with the polycarboxylate superplasticizer.

[0183] Compared to Example 1, Examples 20 and 21 of this application have slightly lower 28-day compressive strength and slightly higher segregation rate, indicating that the optimized mix ratio of different gradations of crushed stone has a good effect on improving the stability of concrete slurry, thereby improving the anti-segregation performance of concrete slurry and thus improving the compressive strength of concrete slurry after molding.

[0184] Compared to Example 1, Comparative Examples 1-2 of this application have lower 28-day compressive strength, higher segregation rate, and higher pressure bleeding rate, indicating that the proportion range of each component in the admixture provided in this application has a good effect on improving the anti-segregation and anti-bleeding performance of concrete slurry, thereby resulting in higher compressive strength of the concrete slurry after molding.

[0185] Compared with Example 1, Comparative Examples 3-4 of this application have lower 28-day compressive strength, higher segregation rate, and higher pressure bleeding rate. This indicates that the proportion of cement, mineral powder, fly ash, and other components in the concrete slurry provided by this application has a better effect on improving the segregation resistance and bleeding resistance of the concrete slurry, thereby resulting in higher compressive strength of the concrete slurry after molding.

[0186] Compared with Example 1, Comparative Examples 5-6 of this application have lower 28-day compressive strength, higher segregation rate, and higher pressure bleeding rate, indicating that the various admixtures provided in this application have a good synergistic effect, which has a good effect on improving the anti-segregation and anti-bleeding performance of concrete slurry, thereby resulting in higher compressive strength of the concrete slurry after molding.

Claims

1. A C40 high-finished fair-faced concrete column, characterized in that: The raw materials used include the following components in parts by weight: cement 300-315 parts; mineral powder 80-95 parts; fly ash 95-105 parts; sand 700-750 parts; crushed stone 900-1000 parts; water 168.3-174 parts; and admixtures 2.3-2.6 parts. The admixtures include polycarboxylate superplasticizer, early slump retainer, mid-term slump retainer, air-entraining agent, retarder and thickener in a weight ratio of (105-115):(45-55):(25-35):(0.35-0.45):(27-32):(65-75); The air-entraining agent comprises sodium rosinate and sodium dodecyl sulfonate in a weight ratio of (11-14):(2-3); The sodium rosinate is an alcohol-modified sodium rosinate; The alcohol-modified sodium rosinate was prepared by the following method: I. At a temperature of 210-220℃, rosin powder with an alcohol compound in a weight ratio of (5-9):(3-5) is mixed and reacted at a pressure of 5.0-5.5MPa for 4.5-5.0h. II. Mix a 30-40 wt% sodium hydroxide solution with the product obtained in step I, heat to 95-105℃ and keep the temperature for 1.5-2 hours. After cooling, obtain sodium rosinate modified with alcohol compounds, wherein the weight ratio of sodium hydroxide solution to the product obtained in step I is (9-12):(5-7). The thickener is an ester-modified sodium polyacrylate thickener; The ester-modified sodium polyacrylate thickener was prepared by the following method: a. Mix an aqueous solution of an ester compound with a concentration of 18-23 wt% in a weight ratio of (4-7):(1-3) with sodium polyacrylate to obtain a mixture; b. Heat the mixture to 40-45℃, add hydrogen peroxide, keep it warm for 10-15 min, then add initiator, chain transfer agent and ester compound aqueous solution with a concentration of 18-23wt%, mix and stir and keep it warm for 30-35 min to obtain ester compound modified sodium polyacrylate thickener; wherein, the weight ratio of the mixture, hydrogen peroxide, initiator, chain transfer agent and ester compound aqueous solution is (6-15):(0.1-1):(0.3-1):(1-1.5):(4-6).

2. The C40 high-finished fair-faced concrete column according to claim 1, characterized in that: The raw materials comprise the following components in parts by weight: 305 parts cement; 85 parts mineral powder; 100 parts fly ash; 726 parts sand; 1000 parts crushed stone; 171 parts water; and 2.5 parts admixture.

3. The C40 high-finished fair-faced concrete column according to claim 1 or 2, characterized in that: The admixtures include a polycarboxylate superplasticizer, an early slump retainer, a mid-term slump retainer, an air-entraining agent, a retarder, and a thickener in a weight ratio of 110:50:30:0.4:30:

70.

4. The C40 high-finished fair-faced concrete column according to claim 1 or 2, characterized in that: The crushed stone includes crushed stone with a particle size of 5-25 mm and crushed stone with a particle size of 5-16 mm in a weight ratio of (15-17):(3-5).

5. A process for the production of a C40 high-finished fair-faced concrete column according to any one of claims 1 to 4, characterized in that: Includes the following steps: S1. Mix all raw materials together for 60-90 seconds to obtain concrete slurry; S2. Pour the concrete slurry into the formwork of the fair-faced concrete column and vibrate the concrete slurry in the formwork. The vibration frequency is 1.8-2 meters / time, and the vibration time is 2-3 minutes each time.

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