Slipform agent for concrete construction using slipform machine and preparation method thereof

Abstract

The present invention provides a slipform agent for slipform machine construction concrete and a preparation method thereof. The slipform agent comprises, by weight, 58 to 100 parts of a slurry extracting agent, 40 to 62 parts of a drag reducing agent, 2 to 8 parts of a water retaining agent, and 830 to 900 parts of water. The preparation method is to put water into a compounding tank, then put in a water retaining agent and stir evenly, then put in a drag reducing agent and a slurry extracting agent in sequence, and stir to obtain the product. The slipform agent prepared by the present invention can realize pouring, vibrating, and plastering at one time, has good integrity, guaranteed quality, and excellent appearance quality. The slipform agent can be widely used in concrete for slipform construction of highway crash barriers, large shoulders, small shoulders, large cover plate ditches, special-shaped ditches, gap-type drainage ditches, etc., and the construction speed is improved, which greatly improves the construction progress and work efficiency, reduces the project cost, and has significant social and economic benefits.

Description

Technical Field

[0001] The invention belongs to the technical field of concrete admixtures, and specifically relates to a slipform agent for slipform machine concrete construction and a preparation method thereof. Background Art

[0002] Slipform agent is a special concrete admixture used in the construction of cement concrete multifunctional slipform machine. It is mainly used to improve the construction performance of concrete used in slipform construction, improve the efficiency of slipform construction, and meet the requirements of one-time completion of concrete pouring, vibration and plastering in slipform construction.

[0003] The slipform construction method was first used in the construction of high bridge piers. Due to its template-saving, fast progress and simple operation, it has been promoted and applied to the construction of concrete cable towers. In recent years, with the technical optimization and upgrading of slipform construction, it has been widely used in large-scale cover ditches, super-large canals, crack-type drainage ditches, sloped river embankment slopes, dam slopes, embankment reinforcement and other projects. Traditional casting of ditch side walls, curbs, sloped river embankments, etc. requires manual formwork, manual mixing of concrete, manual warehousing, manual vibration, low construction efficiency, and only a few hundred meters can be constructed at a time. The built river embankments and ditches generally have problems such as loose vibration, uneven slopes, low quality standards, and poor flood control capabilities. Slipform construction only requires cement concrete, staff and slipform machines to complete the construction. Compared with manual formwork casting, it has the characteristics of fast construction and long construction sections at a time, eliminating the process of template installation and removal. Streamlined construction improves production efficiency and reduces labor costs. At the same time, the waste soil generated during the excavation process at the construction site is directly transported away by dump trucks, which reduces the impact on the surrounding environment. There is no need to install formwork at the construction site, which reduces the accumulation of materials. The construction process is carried out in a continuous flow, and materials are cleared when people leave. There is no need for separate site cleaning, which can meet environmental protection requirements and has obvious social and economic benefits.

[0004] The concrete used in slipform machines is different from the index requirements of pumped concrete. Pumped concrete requires good fluidity, and the pumping slump is generally not less than 180mm. It has good workability and slump retention, meets the requirements of long-distance transportation and can be transported by concrete pumps through pipelines. The concrete used in slipform construction of roads, canals, cover ditches, etc. generally requires a concrete slump of 40-60mm, does not require water reduction and slump retention, but requires good concrete slurry, softness, and a construction speed of 10m per minute. After the construction is completed, the concrete surface is shiny and smooth, and no manual finishing is required. At present, there are no manufacturers specializing in slipform agents in the market, and no slipform agents are added during on-site construction, resulting in insufficient concrete strength, rough and rough surfaces, and the need for manual finishing and smoothing, which is labor-intensive and of varying quality. Summary of the invention

[0005] The purpose of the present invention is to provide a slipform agent for slipform machine construction concrete and a preparation method thereof, wherein the slipform agent can improve the construction performance of slipform construction concrete, increase construction progress and work efficiency, and realize pouring, vibrating and plastering in one step.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A slipform agent for concrete construction by slipform machine comprises, by weight, 58 to 100 parts of a slurry extracting agent, 40 to 62 parts of a drag reducing agent, 2 to 8 parts of a water retaining agent, and 830 to 900 parts of water.

[0008] Preferably, the slurry extracting agent is prepared by solution polymerization of 90-110 parts of methacrylic acid, 84-125 parts of hydroxypropyl acrylate, 5-12 parts of linear alkylbenzene sodium sulfonate, 5-12 parts of alkylphenol polyoxyethylene ether, 5-12 parts of alkylphenol polyoxyethylene ether sodium carboxylate, 5-12 parts of dodecyl diphenyl ether sodium disulfonate, 5-12 parts of disodium octadecyl sulfosuccinamide, 5-12 parts of alkyl polyglycoside, 1-3 parts of diethanolamine, 1-3 parts of triethanolamine, 4-8 parts of diethanol monoisopropanolamine, 3-8 parts of ammonium persulfate, 0.6-2.8 parts of dodecanethiol, 0.2-2 parts of ferrous sulfate and 666-786 parts of water.

[0009] The synthesis steps of the slurry extracting agent include: adding water into a reaction kettle, starting stirring, and then sequentially adding methacrylic acid, hydroxypropyl acrylate, sodium linear alkylbenzene sulfonate, alkylphenol polyoxyethylene ether, sodium alkylphenol polyoxyethylene ether carboxylate, sodium dodecyl diphenyl ether disulfonate, disodium octadecyl sulfosuccinamide, alkyl polyglycoside, diethanolamine, triethanolamine, diethanol monoisopropanolamine, and continuing stirring for 10 minutes after adding the materials. Then, ammonium persulfate, dodecanethiol, and ferrous sulfate are sequentially added, and after adding, continuing stirring for 20 to 30 minutes and standing for 2 hours, to obtain the slurry extracting agent.

[0010] Preferably, the drag reducer is prepared by bulk polymerization of 114-172 parts of allyl polyethylene glycol ether APEG-1000 with a molecular weight of 1000, 40-60 parts of fumaric acid, 7-11 parts of styrene, 5.7-10 parts of butyl acrylate, 1.4-2.2 parts of sodium allyl sulfonate, 1.6-2.5 parts of azobisisobutyronitrile, and 3-5 parts of toluene.

[0011] The synthesis steps of the drag reducer include: stirring styrene and butyl acrylate evenly as No. 1 dropping material, dissolving azobisisobutyronitrile in toluene as No. 2 dropping material; adding APEG-1000 into a reactor, heating it to 60-70°C to completely melt it, starting stirring after melting, and then adding fumaric acid and sodium allyl sulfonate; simultaneously starting to drop materials No. 1 and No. 2, and controlling the dropping time to be completed within 3-4 hours; after dropping for 30 minutes, lowering the temperature to 40°C, and stopping heating after dropping for 1 hour; after the reaction is completed, continuing to keep warm for 1 hour, and then diluting with water to obtain a drag reducer with a solid content of 60%.

[0012] Preferably, the water-retaining agent includes one or more of pullulan, sodium carboxymethyl starch, hydroxypropyl starch ether, and dispersible latex powder.

[0013] A method for preparing a slipform agent for slipform machine construction concrete comprises the following steps: putting water into a compounding tank, then putting in a water retaining agent and stirring evenly, then putting in a drag reducing agent and a slurry extracting agent in sequence, and stirring for 30 minutes to obtain the slipform agent.

[0014] Mechanism of the present invention:

[0015] The performance requirements of concrete for strip structure slipform construction are different from those of ordinary concrete. Concrete for strip structure slipform construction requires that the slump should not be greater than 80mm, the concrete surface should be smooth and bright, and there should be no pores. The concrete demoulding strength is best at 0.2-1MPa. The slipform agent prepared by the present invention is compounded by a slurry raising agent, a drag reducing agent, a water retaining agent, and water. The slump of the slipform construction concrete is small, and no water reducing agent is used. The density of the concrete is improved by continuous vibration of the concrete by a vibrator. The slurry raising agent can increase the volume of the concrete slurry and the overall homogeneity of the cement mortar. Traditionally, air entraining agents can also improve the concrete slurry, but for small slump concrete, it is difficult for air entraining agents to form a large number of tiny, closed and stable bubbles in the concrete.

[0016] The present invention utilizes active unsaturated carboxylic acids and unsaturated esters (methacrylic acid in the pulping agent is an unsaturated carboxylic acid, and hydroxypropyl acrylate is an unsaturated ester, which have high activity in free radical reactions. In free radical polymerization reactions, the Q value is usually used to represent the index of the difficulty of monomers participating in polymerization reactions and transforming into free radicals. Common unsaturated carboxylic acids, such as maleic anhydride, have a Q value of 0.23, acrylic acid has a Q value of 1.27, itaconic acid has a Q value of 0.76, and methacrylic acid has a Q value of 2.34. Common unsaturated esters, such as methyl acrylate, have a Q value of 0.42, ethyl acrylate has a Q value of 0.52, and butyl acrylate has a Q value of 0.38) in a static redox system. Polymerization and molecular chain entanglement occur, and linear sodium alkylbenzene sulfonate, alkylphenol polyoxyethylene ether, sodium alkylphenol polyoxyethylene ether carboxylate, sodium dodecyl diphenyl ether disulfonate, disodium octadecyl sulfosuccinamide, alkyl polyglycoside ammonium persulfate, diethanolamine, triethanolamine, and diethanol monoisopropanolamine are wrapped therein to form a entangled three-dimensional structure of molecular chains, which is helpful to introduce bubbles into small slump concrete, improve the foam stabilizing performance of the air entraining agent, improve the softness of the concrete, and promote the longitudinal dispersion of the cement paste; the diethanolamine, triethanolamine, and diethanol monoisopropanolamine wrapped therein can improve the demoulding strength of the concrete while helping to raise the slurry, ensuring that the strength of the concrete is sufficient to support its own weight.

[0017] Drag reducers can reduce the friction of concrete on the formwork, increase construction speed, and avoid cracking of the concrete surface caused by resistance. Drag reducer polymer molecules are long-chain molecules dominated by hydrophobic structures. This long-chain molecule has a small amount of adsorption on cement particles, and most of it penetrates between particles, playing a lubricating and barrier effect; on the other hand, hydrophilic monomers are introduced into the molecules to compress the thickness of the water film layer on the surface of cement particles to a certain extent, release free water, and reduce the interaction between cement particles; in addition, low-molecular-weight and low-activity APEG is used, and the molecular main chain is small, which can be quickly adsorbed on cement particles and act faster in small slump concrete. Small molecular weight polymers cannot provide water reduction rate through steric hindrance effect.

[0018] Water retaining agent can adjust the cohesiveness of concrete, play a role in thickening and retaining water, and effectively improve the concrete paste, especially for concrete with less adhesive. Branched starch, sodium carboxymethyl starch, hydroxypropyl starch ether, and dispersible latex powder have good stability, water solubility, and water retention. They can significantly improve the small slump concrete paste, improve cement dispersibility, and avoid locking of slurry.

[0019] Beneficial effects of the present invention:

[0020] (1) The slipform agent prepared by the present invention can realize pouring, vibrating and plastering in one step, has good integrity, guaranteed quality and excellent appearance quality.

[0021] (2) The slipform agent prepared by the present invention can be widely used in slipform construction concrete such as highway crash barriers, large shoulders, small shoulders, large cover ditches, special-shaped ditches, and gap-type drainage ditches. The construction speed can be increased from the original 4m / min to 10m / min, which greatly improves the construction progress and work efficiency, reduces the project cost, and has obvious social and economic benefits. DETAILED DESCRIPTION

[0022] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments, but the present invention is not limited to the following technical solution.

[0023] Example 1

[0024] Add 724.3 parts of water into the reactor, start stirring, then add 90 parts of methacrylic acid, 125 parts of hydroxypropyl acrylate, 5 parts of linear alkylbenzene sulfonate sodium, 8 parts of alkylphenol polyoxyethylene ether, 5 parts of alkylphenol polyoxyethylene ether sodium carboxylate, 12 parts of sodium dodecyl diphenyl ether disulfonate, 12 parts of disodium octadecyl sulfosuccinamide, 5 parts of alkyl polyglycoside, 3 parts of diethanolamine, 3 parts of triethanolamine, 6 parts of diethanol monoisopropanolamine in sequence, continue stirring for 10 minutes after adding the materials, then add 3 parts of ammonium persulfate, 1.7 parts of dodecanethiol, and 2 parts of ferrous sulfate in sequence, continue stirring for 30 minutes after adding, and let stand for 2 hours to obtain the slurry agent.

[0025] Mix 7 parts of styrene and 10 parts of butyl acrylate evenly as drop material No. 1, and dissolve 2 parts of azobisisobutyronitrile in 4 parts of toluene as drop material No. 2. Add 172 parts of APEG-1000 to the reactor, heat it to 60°C to melt it completely, start stirring after melting, and then add 40 parts of fumaric acid and 2.2 parts of sodium allyl sulfonate. At the same time, start dripping materials No. 1 and No. 2, and the dripping time is 3.5h and 4h respectively. After 30 minutes of dripping, reduce the temperature to 40°C, and stop heating after 1h of dripping. After the reaction is completed, continue to keep warm for 1h, then dilute with water to obtain a drag reducer with a solid content of 60%.

[0026] Put 855 parts of water into the compounding tank, then add 5 parts of sodium carboxymethyl starch and stir evenly, then add 40 parts of drag reducer and 100 parts of slurry extracting agent in sequence, and stir for 30 minutes to obtain the slip agent.

[0027] Example 2

[0028] Add 719 parts of water into the reactor, start stirring, then add 110 parts of methacrylic acid, 104 parts of hydroxypropyl acrylate, 12 parts of linear alkylbenzene sulfonate sodium, 5 parts of alkylphenol polyoxyethylene ether, 8 parts of alkylphenol polyoxyethylene ether sodium carboxylate, 5 parts of sodium dodecyl diphenyl ether disulfonate, 8 parts of disodium octadecyl sulfosuccinamide, 12 parts of alkyl polyglycoside, 1 part of diethanolamine, 1.5 parts of triethanolamine, 8 parts of diethanol monoisopropanolamine in sequence, continue stirring for 10 minutes after adding the materials, then add 6 parts of ammonium persulfate, 0.6 parts of dodecanethiol, and 0.2 parts of ferrous sulfate in sequence, continue stirring for 20 minutes after adding, and let stand for 2 hours to obtain the slurry agent.

[0029] Mix 9 parts of styrene and 5.7 parts of butyl acrylate evenly as drop material No. 1, and dissolve 2.5 parts of azobisisobutyronitrile in 5 parts of toluene as drop material No. 2. Add 114 parts of APEG-1000 to the reactor, heat it to 60°C to melt it completely, start stirring after melting, and then add 60 parts of fumaric acid and 1.8 parts of sodium allyl sulfonate. At the same time, start dripping materials No. 1 and No. 2, and the dripping time is 3h and 3.5h respectively. After 30 minutes of dripping, reduce the temperature to 40°C, and stop heating after 1h of dripping. After the reaction is completed, continue to keep warm for 1h, then dilute with water to obtain a drag reducer with a solid content of 60%.

[0030] Put 857 parts of water into the compounding tank, then add 2 parts of branched starch and stir evenly, then add 62 parts of drag reducer and 79 parts of pulping agent in sequence, and stir for 30 minutes to obtain the slip agent.

[0031] Example 3

[0032] Add 743.7 parts of water into the reaction kettle, start stirring, then add 100 parts of methacrylic acid, 84 parts of hydroxypropyl acrylate, 9 parts of linear alkylbenzene sulfonate sodium, 12 parts of alkylphenol polyoxyethylene ether, 5 parts of alkylphenol polyoxyethylene ether sodium carboxylate, 9 parts of dodecyl diphenyl ether disulfonate sodium, 5 parts of octadecyl sulfosuccinamide disodium, 12 parts of alkyl polyglycoside, 1.5 parts of diethanolamine, 3 parts of triethanolamine, 4 parts of diethanol monoisopropanolamine in sequence, continue stirring for 10 minutes after adding the materials, then add 8 parts of ammonium persulfate, 2.8 parts of dodecanethiol, and 1 part of ferrous sulfate in sequence, continue stirring for 25 minutes after adding, and let stand for 2 hours to obtain the slurry agent.

[0033] Stir 11 parts of styrene and 10 parts of butyl acrylate evenly as drop material No. 1, and dissolve 1.6 parts of azobisisobutyronitrile in 3 parts of toluene as drop material No. 2. Add 143 parts of APEG-1000 to the reactor, heat it to 60°C to melt it completely, start stirring after melting, and then add 60 parts of fumaric acid and 1.4 parts of sodium allyl sulfonate. At the same time, start dripping materials No. 1 and No. 2, and the dripping time is 3h and 3h respectively. After 30 minutes of dripping, reduce the temperature to 40°C, and stop heating after 1h of dripping. After the reaction is completed, continue to keep warm for 1h, then dilute with water to obtain a drag reducer with a solid content of 60%.

[0034] Put 883 parts of water into the compounding tank, then add 5 parts of dispersible latex powder and 3 parts of sodium carboxymethyl starch and stir evenly, then add 51 parts of drag reducer and 58 parts of slurry extracting agent in sequence, and stir for 30 minutes to obtain the slip agent.

[0035] Example 4

[0036] Add 699.3 parts of water into the reaction kettle, start stirring, and then add 110 parts of methacrylic acid, 125 parts of hydroxypropyl acrylate, 5 parts of linear alkylbenzene sulfonate sodium, 5 parts of alkylphenol polyoxyethylene ether, 12 parts of alkylphenol polyoxyethylene ether sodium carboxylate, 12 parts of dodecyl diphenyl ether disulfonate sodium, 5 parts of octadecyl sulfosuccinamide disodium, 8 parts of alkyl polyglycoside, 3 parts of diethanolamine, 1 part of triethanolamine, 6 parts of diethanol monoisopropanolamine in sequence, continue stirring for 10 minutes after adding the materials, then add 6 parts of ammonium persulfate, 1.7 parts of dodecanethiol, and 1 part of ferrous sulfate in sequence, continue stirring for 25 minutes after adding, and let stand for 2 hours to obtain the slurry agent.

[0037] Mix 7 parts of styrene and 8 parts of butyl acrylate evenly as drop material No. 1, and dissolve 2.5 parts of azobisisobutyronitrile in 3 parts of toluene as drop material No. 2. Add 172 parts of APEG-1000 to the reactor, heat it to 60°C to melt it completely, start stirring after melting, and then add 50 parts of fumaric acid and 1.4 parts of sodium allyl sulfonate. At the same time, start dripping materials No. 1 and No. 2, and the dripping time is 4h and 4h respectively. After 30 minutes of dripping, reduce the temperature to 40°C, and stop heating after 1h of dripping. After the reaction is completed, continue to keep warm for 1h, then dilute with water to obtain a drag reducer with a solid content of 60%.

[0038] 833 parts of water were added into the compounding tank, and then 5 parts of hydroxypropyl starch ether were added and stirred evenly, and then 62 parts of drag reducer and 100 parts of pulping agent were added in sequence, and the slip agent was obtained after stirring for 30 minutes.

[0039] The cement used for the performance verification of the slipform agent for slipform construction concrete is Dongjun PO 425 ordinary Portland cement, the fineness modulus of the machine-made sand is 3.0, the water-cement ratio is 0.6, the sand rate is 52%, and the water consumption is 170kg / m 3 .

[0040] Table 1 Comparison of slip agent properties

[0041]

[0042] The results show that the slipform construction speed of the slipform agent of Examples 1-4 is faster than that of the slipform agent not used, and the surface is smooth and shiny, no manual finishing is required, the work efficiency is improved, the labor cost is reduced, and the early strength is higher than the benchmark. This is mainly because the benchmark concrete only uses water as a lubricant, the slurry is small, the concrete state is poor, and the slurry is not dense enough after being vibrated by the slipform machine, so the surface is not smooth and bubbles appear. After the slipform agent is used, more free water is released, the density of the slurry is improved, and after vibration, the surface is smoother, the resistance is smaller, and the construction speed is faster.

Claims

1. A slipform agent for concrete construction by slipform machine, characterized in that: The invention comprises, by weight, 58 to 100 parts of a pulping agent, 40 to 62 parts of a drag reducing agent, 2 to 8 parts of a water retaining agent, and 830 to 900 parts of water; the pulping agent is composed of 90 to 110 parts of methacrylic acid, 84 to 125 parts of hydroxypropyl acrylate, 5 to 12 parts of linear alkylbenzene sodium sulfonate, 5 to 12 parts of alkylphenol polyoxyethylene ether, 5 to 12 parts of alkylphenol polyoxyethylene ether sodium carboxylate, and 5 to 12 parts of sodium dodecyl diphenyl oxide disulfonate. , 5-12 parts of disodium octadecyl sulfosuccinamide, 5-12 parts of alkyl polyglycoside, 1-3 parts of diethanolamine, 1-3 parts of triethanolamine, 4-8 parts of diethanol monoisopropanolamine, 3-8 parts of ammonium persulfate, 0.6-2.8 parts of dodecanethiol, 0.2-2 parts of ferrous sulfate, and 666-786 parts of water; the drag reducer is formed by polymerizing 114-172 parts of allyl polyethylene glycol ether APEG-1000 with a molecular weight of 1000, 40-60 parts of fumaric acid, 7-11 parts of styrene, 5.7-10 parts of butyl acrylate, 1.4-2.2 parts of sodium allyl sulfonate, 1.6-2.5 parts of azobisisobutyronitrile, and 3-5 parts of toluene.

2. The slipform agent for concrete construction by slipform machine according to claim 1, characterized in that: The synthesis steps of the pulping agent include: adding water into a reaction kettle, starting stirring, and then sequentially adding methacrylic acid, hydroxypropyl acrylate, sodium linear alkylbenzene sulfonate, alkylphenol polyoxyethylene ether, sodium alkylphenol polyoxyethylene ether carboxylate, sodium dodecyl diphenyl ether disulfonate, disodium octadecyl sulfosuccinamide, alkyl polyglycoside, diethanolamine, triethanolamine, diethanol monoisopropanolamine, and continuing stirring for 10 minutes after adding the materials, and then sequentially adding ammonium persulfate, dodecanethiol, and ferrous sulfate, and continuing stirring for 20 to 30 minutes after adding the materials, and then standing for 2 hours to obtain the pulping agent.

3. The slipform agent for concrete construction by slipform machine according to claim 1, characterized in that: The synthesis steps of the drag reducer include: stirring styrene and butyl acrylate evenly as No. 1 drop material, dissolving azobisisobutyronitrile in toluene as No. 2 drop material; adding APEG-1000 into a reaction kettle, heating it to 60-70°C to completely melt it, stirring it after melting, and then adding fumaric acid and sodium allyl sulfonate; simultaneously starting to drop materials No. 1 and No. 2, and controlling the drop time to be completed within 3-4 hours; after dropping for 30 minutes, lowering the temperature to 40°C, and stopping heating after dropping for 1 hour; after the reaction is completed, continuing to keep warm for 1 hour, and then adding water to dilute it to obtain a drag reducer with a solid content of 60%.

4. The slipform agent for concrete construction by slipform machine according to claim 1, characterized in that: The water retaining agent comprises one or more of pullulan, sodium carboxymethyl starch, hydroxypropyl starch ether and dispersible latex powder.

5. A method for preparing a slipform agent for concrete construction by slipform machine according to claim 1, characterized in that: The method comprises the following steps: putting water into a compounding tank, then putting in a water retaining agent and stirring evenly, then putting in a drag reducing agent and a slurry extracting agent in sequence, and stirring for 30 minutes to obtain a slip agent.

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