CN114671639A - Blending agent for resisting concrete shrinkage cracks of bridge guardrail and preparation method thereof - Google Patents
Blending agent for resisting concrete shrinkage cracks of bridge guardrail and preparation method thereof Download PDFInfo
- Publication number
- CN114671639A CN114671639A CN202210407252.0A CN202210407252A CN114671639A CN 114671639 A CN114671639 A CN 114671639A CN 202210407252 A CN202210407252 A CN 202210407252A CN 114671639 A CN114671639 A CN 114671639A
- Authority
- CN
- China
- Prior art keywords
- parts
- agent
- water
- internal curing
- curing agent
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B40/00—Processes, in general, for influencing or modifying the properties of mortars, concrete or artificial stone compositions, e.g. their setting or hardening ability
- C04B40/0028—Aspects relating to the mixing step of the mortar preparation
- C04B40/0039—Premixtures of ingredients
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
- C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
- C08F220/04—Acids; Metal salts or ammonium salts thereof
- C08F220/06—Acrylic acid; Methacrylic acid; Metal salts or ammonium salts thereof
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F283/00—Macromolecular compounds obtained by polymerising monomers on to polymers provided for in subclass C08G
- C08F283/06—Macromolecular compounds obtained by polymerising monomers on to polymers provided for in subclass C08G on to polyethers, polyoxymethylenes or polyacetals
- C08F283/065—Macromolecular compounds obtained by polymerising monomers on to polymers provided for in subclass C08G on to polyethers, polyoxymethylenes or polyacetals on to unsaturated polyethers, polyoxymethylenes or polyacetals
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
- Y02W30/91—Use of waste materials as fillers for mortars or concrete
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Curing Cements, Concrete, And Artificial Stone (AREA)
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
Abstract
The blending agent for resisting the shrinkage cracks of the bridge guardrail concrete comprises DGMA, a shrinkage-reducing water reducing agent, an internal curing agent and a ternary composite system, wherein the DGMA comprises the following raw materials in percentage by weight: 170, 680 parts of maleic anhydride and 80-320 parts of dibutylene glycol monobutyl ether, wherein the raw material ratio of the reduction type water reducer is as follows: 3400 part of water, 5-20 parts of sodium methallyl sulfonate, 20-80 parts of ammonium persulfate, 500-2000 parts of allyl polyethylene glycol, 45-180 parts of methacrylic acid and 130-520 parts of DGMA; the raw material proportion for preparing the internal curing agent is as follows: 560 parts of sodium hydroxide 140-; the raw material proportion of the ternary composite system is as follows: 1-6 parts of a shrinkage-reducing water reducing agent, 1-6 parts of a defoaming agent and 1-3 parts of an air entraining agent; the invention has the beneficial effects that: the problems of single technical mode, poor effect, high cost and low energy efficiency of the traditional additive are solved, and the technical targets of low cost, high efficiency and high adaptability are achieved.
Description
Technical Field
The invention relates to a building concrete functional additive material, in particular to a blending agent for resisting concrete shrinkage cracks of a bridge guardrail and a preparation method thereof.
Background
At present, the early shrinkage of the concrete material of the bridge guardrail is obvious, so that the shrinkage and cracking of the concrete of the bridge guardrail can be easily caused in the construction process, the engineering quality is seriously influenced, the crack generation is a problem which is particularly worthy of attention in the construction process or the use stage, the concrete structure and the crack control are quite strict, and a plurality of technologies are adopted to prevent or reduce the crack.
The prior art mostly adopts single technical route to realize that the concrete reduces shrinkage and reduces the fracture, if: (1) the expansion agent is doped, and the shrinkage is inhibited by using an expansion compensation method, so that the cracking risk is reduced; (2) the watering maintenance and the covering of the reinforced concrete are enhanced, the water loss is reduced, and the cracking risk is reduced; (3) the shrinkage value of the concrete is reduced and early cracking is reduced by using a mode of singly mixing the small molecular shrinkage reducing agent. However, the above method has poor effect when used singly, and negative effects in different aspects may also occur.
Disclosure of Invention
In view of the above, the invention aims to provide a blending agent for resisting concrete shrinkage cracks of a bridge guardrail, which overcomes the problems of single technical mode, poor effect, high cost and low energy efficiency of the traditional additive, and achieves the technical aims of low cost, high efficiency and high adaptability.
Another purpose of the invention is to provide a preparation method of blending agent, its method is simple, the cost is lower, the effect is slightly inferior when various raw materials are used alone, but adopt the blending method of this technology and compound with other components can overcome the general problem of reducing efficiency, reach better reducing crack-resistant effect, in order to achieve the above-mentioned purpose, the invention provides the following technical scheme:
the blending agent for resisting the shrinkage cracks of the bridge guardrail concrete comprises DGMA, a shrinkage-reducing water reducing agent prepared by the DGMA, an internal curing agent, a ternary composite system prepared by the shrinkage-reducing water reducing agent and a blending agent prepared by the internal curing agent and the ternary composite system, and is calculated by weight:
the DGMA comprises the following raw materials in percentage by weight: 170-680 parts of maleic anhydride and 80-320 parts of dibutylene glycol monobutyl ether;
the reducing water reducer comprises the following raw materials in proportion: 3400 part of water, 5-20 parts of sodium methallyl sulfonate, 20-80 parts of ammonium persulfate, 500-2000 parts of allyl polyethylene glycol, 45-180 parts of methacrylic acid and 130-520 parts of DGMA;
the raw material proportion of the prepared internal curing agent is as follows: 560 parts of sodium hydroxide 140-;
the ternary composite system comprises the following raw materials in proportion: 5000 plus 20000 parts of shrinkage-reducing water reducing agent, 1-6 parts of defoaming agent and 1-3 parts of air entraining agent;
the blending agent comprises the following raw materials in percentage by weight: 850-3400 parts of water, 55-230 parts of internal curing agent and 25-110 parts of ternary complex.
Further, the air entraining agent is a sodium abietate air entraining agent, and the defoaming agent is polyether.
The air entraining agent is selected from sodium abietate and the defoaming agent is selected from polyether, so that the air entraining agent and the defoaming agent have good compatibility with the prepared shrinkage-reducing water reducing agent and can play respective roles.
The other purpose of the invention is realized by the technical scheme, and the preparation method of the blending agent for resisting the shrinkage cracks of the bridge guardrail concrete comprises the following steps: preparing DGMA, a shrinkage-reducing water reducing agent, an internal curing agent, a ternary composite system and a blending agent, wherein
S1, configuring DGMA:
adding 170-680 parts of maleic anhydride into the container, and heating to 45-65 ℃ to melt the maleic anhydride; adding 80-320 parts of dibutylene glycol monobutyl ether, continuously heating to 110-150 ℃, keeping the temperature to obtain DGMA, cooling and discharging, and purifying for later use;
s2, preparing a reduction type water reducing agent:
adding 3400 parts of 850-90 parts of water and 5-20 parts of sodium methallyl sulfonate into a container, heating to 70-90 ℃, dropwise adding an initiator formed by 20-80 parts of ammonium persulfate, 500-2000 parts of allyl polyethylene glycol, 45-180 parts of methacrylic acid and 130-520 parts of DGMA prepared in the step S1 under the protection of protective gas, continuing to react for 1.5-2.5 hours after the dropwise adding is finished, cooling after the reaction, and adjusting the pH value to be neutral by using sodium hydroxide;
s3, preparing an internal curing agent:
adding 560 parts of sodium hydroxide 140 and 3400 parts of water 850 into a container, adding 1440 parts of acrylic acid 360 and 3400 parts of deionized water under the condition of water bath, and weighing 65-260 parts of acrylamide to mix in the solution to complete the preparation of the comonomer solution;
pouring the comonomer solution, 70-280 parts of ammonium persulfate solution and 17-70 parts of N, N' -methylene-bisacrylamide into another beaker, mixing, stirring at 30-50 ℃, and removing oxygen;
putting the mixed solution into a water bath kettle, carrying out water bath reaction at 55-65 ℃ for 1-2 hours, heating to 66-75 ℃, continuing to heat in the water bath for 1-2 hours, then heating to 76-85 ℃, continuing to heat in the water bath for 0.5-1.5 hours, finally cleaning the polymer gel by using 750 plus 3000 parts of absolute ethyl alcohol, drying to constant weight after cleaning, and crushing the polymer gel to obtain an internal curing agent;
s4, configuring a ternary composite system, comprising:
adding 5000-;
s5, preparing a blending agent, which comprises:
and weighing the internal curing agent prepared in the step S3, adding water in an amount which is 10-20 times the weight of the internal curing agent into the internal curing agent, and weighing the ternary composite system in the step S4 and adding the ternary composite system into the internal curing agent to obtain the blending agent.
Further, a heating container for preparing maleic anhydride in the DGMA is a three-neck flask, and a thermometer, a stirrer and a reflux condenser tube are arranged in the three-neck flask; a container in the reduction type water reducing agent is configured into a four-mouth flask; preparing an internal curing agent, and taking a container in the ternary composite system as a beaker.
Further, the water bath condition of sodium hydroxide in the internal curing agent is ice water bath, the mixed solution is placed in a constant-temperature water bath kettle, and protective gas is introduced below the liquid level of the mixed solution to remove oxygen.
Furthermore, the mass of the internal curing agent in the prepared blending agent is 2-4% of the total weight of the gel material, the weight of water is 12-18 times of that of the internal curing agent, and the mass of the ternary composite system is 2-4% of the total weight of the premixed concrete.
Furthermore, when the polymer gel is washed by the absolute ethyl alcohol, the polymer gel is firstly sheared.
The polymer gel is sheared to be more convenient to clean, and the effect that the anhydrous ethanol fully covers the surface of the polymer gel is achieved.
The invention has the beneficial effects that:
1. in the base material used by the invention, the shrinkage-reducing water reducing agent is a preparation of polycarboxylic acid water reducing agent grafted and copolymerized with shrinkage-reducing groups, and has the characteristics of low cost and poor effect when used alone, but the shrinkage-reducing water reducing agent is compounded with other components to overcome the problems of common shrinkage-reducing effect and poor effect when used alone.
2. In the internal curing agent prepared by the invention, the internal curing agent is a porous super absorbent resin powder material (SAP), and the most outstanding characteristic is that the SAP can absorb water which is several times or even hundreds of times of the self-mass, so that a reservoir can be formed in the concrete to achieve the internal curing effect, but the problem of common reduction and crack resistance when the SAP is used alone is also existed, and the problem can be overcome by combining the SAP with other components.
3. The air-entraining defoaming composite additive is a concrete rheological property and air content regulating additive, and can assist a shrinkage-reducing water reducing agent and an internal curing agent to achieve a good shrinkage-reducing and crack-resisting effect.
The innovation points of the invention are as follows:
the shrinkage-reducing and anti-cracking admixture with low cost and poor single use effect is compounded to achieve the technical goals of low cost and high efficiency, and the use effect in practical engineering shows that the admixture has better capability of controlling the shrinkage crack of the concrete of the bridge guardrail and has wider applicability compared with other anti-cracking technologies.
Detailed Description
The present invention will be further described with reference to the following examples.
Example 1
A preparation method of a blending agent for resisting concrete shrinkage cracks of a bridge guardrail comprises DGMA, a shrinkage-reducing water reducing agent prepared by the DGMA, an internal curing agent, a ternary composite system prepared by the shrinkage-reducing water reducing agent and a blending agent prepared by the internal curing agent and the ternary composite system, wherein the blending agent is prepared from the following components in parts by weight:
s1, configuring DGMA:
adding 340 parts of maleic anhydride into a three-neck flask provided with a thermometer, a stirrer and a reflux condenser, heating to 55 ℃ to completely melt the maleic anhydride, adding 160 parts of dibutylene glycol monobutyl ether, continuously heating to 130 ℃, keeping the temperature for 30 minutes to obtain DGMA, cooling, discharging and purifying for later use;
the three-neck flask can be simultaneously provided with a thermometer, a stirrer and a reflux condenser pipe during the reaction so as to meet the preparation requirement.
S2, preparing a reduction type water reducing agent:
adding 1700 parts of water and 10 parts of sodium methallyl sulfonate into a four-neck flask, heating to 80 ℃, dropwise adding an initiator formed by 40 parts of ammonium persulfate, 1000 parts of allyl polyethylene glycol, 90 parts of methacrylic acid and 260 parts of DGMA prepared in the step S1 under the protection of protective gas, ensuring that ammonium persulfate, allyl polyethylene glycol, methacrylic acid and DGMA are dropwise added simultaneously and do not influence each other in the four-neck flask, wherein all the components are dropwise added within 5 minutes, the protective gas selected in the embodiment is nitrogen, continuously reacting for 2 hours after the dropwise addition is finished, cooling after the reaction, and adjusting the pH value to 7 by using sodium hydroxide to obtain a finished product of the shrinkage-reducing water reducer;
s3, preparing an internal curing agent:
adding 280 parts of sodium hydroxide and 1700 parts of water into a beaker, slowly adding 720 parts of acrylic acid under the condition of ice water bath, adding 1700 parts of deionized water, weighing 130 parts of acrylic acid, and mixing in the solution to complete the preparation of the comonomer solution;
pouring the comonomer solution, 140 parts of ammonium persulfate solution and 35 parts of N, N' -methylene bisacrylamide into another beaker, mixing, mechanically stirring at 40 ℃, and continuously introducing nitrogen below the liquid level during stirring to remove oxygen;
placing the deoxidized mixed solution into a water bath kettle, carrying out water bath reaction at 60 ℃ for 1.5 hours, then heating to 70 ℃ to continue heating in the water bath for 1.5 hours, then heating to 80 ℃, continuing heating in the water bath for 1 hour, and taking out a beaker to obtain polymer gel;
cleaning the polymer gel with 1500 parts of absolute ethyl alcohol, drying to constant weight after cleaning, and crushing the polymer gel to obtain an internal curing agent;
s4, configuring a ternary composite system, including:
adding 10000 parts of the shrinkage-reducing water reducing agent prepared in the step S2 into a beaker, adding 3 parts of a defoaming agent, mixing the two, standing for 20 minutes, and adding 2 parts of an air entraining agent to form a ternary composite system;
s5, preparing a blending agent, which comprises:
when the concrete is mixed, 113 parts of the internal curing agent prepared in the step S3 is weighed, the mass of the internal curing agent is 1.1% of the total weight of the gel material, then 15 times of the weight of the internal curing agent is weighed, water is added into the internal curing agent, finally 55 parts of the ternary composite system prepared in the step S4 is weighed and mixed into the internal curing agent to obtain a prepared blending agent, and the mass of the ternary composite system is 3% of the total weight of the ready-mixed concrete.
Example 2
A preparation method of a blending agent for resisting the shrinkage cracks of bridge guardrail concrete comprises the steps of preparing DGMA, a shrinkage-reducing water reducing agent, an internal curing agent, a ternary composite system and a blending agent, wherein the blending agent comprises
S1, configuring DGMA:
adding 680 parts of maleic anhydride into a three-neck flask provided with a thermometer, a stirrer and a reflux condenser, heating to 55 ℃ to completely melt the maleic anhydride, adding 320 parts of dibutylene glycol monobutyl ether, continuously heating to 130 ℃, keeping the temperature for 30 minutes to obtain DGMA, cooling, discharging and purifying for later use;
the three-neck flask can be simultaneously provided with a thermometer, a stirrer and a reflux condenser pipe during the reaction so as to meet the preparation requirement.
S2, preparing a reduction type water reducing agent:
adding 3400 part of water and 20 parts of sodium methallyl sulfonate into a four-neck flask, heating to 80 ℃, dropwise adding an initiator formed by 80 parts of ammonium persulfate, 2000 parts of allyl polyethylene glycol, 180 parts of methacrylic acid and 520 parts of DGMA prepared in the step S1 under the protection of protective gas, wherein the four-neck flask can ensure that the ammonium persulfate, the allyl polyethylene glycol, the methacrylic acid and the DGMA are dropwise added simultaneously and do not influence each other, all the components are dropwise added within 5 minutes, the protective gas selected in the embodiment is nitrogen, continuously reacting for 2 hours after the dropwise adding is finished, cooling after the reaction is finished, and adjusting the pH value to 7 by using sodium hydroxide to obtain a finished product of the shrinkage-reducing water reducer;
s3, preparing an internal curing agent:
560 parts of sodium hydroxide and 3400 parts of water are added into a beaker, 1440 parts of acrylic acid is slowly added under the condition of ice-water bath, 3400 parts of deionized water is added, 260 parts of acrylic acid is weighed and mixed in the solution, and the preparation of the comonomer solution is completed;
pouring the comonomer solution, 280 parts of ammonium persulfate solution and 70 parts of N, N' -methylene-bisacrylamide into another beaker, mixing, mechanically stirring at 40 ℃, and continuously introducing nitrogen below the liquid level during stirring to remove oxygen;
placing the deoxidized mixed solution into a water bath kettle, carrying out water bath reaction at 60 ℃ for 1.5 hours, then heating to 70 ℃ to continue heating in the water bath for 1.5 hours, then heating to 80 ℃, continuing heating in the water bath for 1 hour, and taking out a beaker to obtain polymer gel;
washing the polymer gel with 3000 parts of absolute ethyl alcohol, drying to constant weight after washing, and crushing the polymer gel to obtain an internal curing agent;
s4, configuring a ternary composite system, comprising:
20000 parts of the shrinkage-reducing water reducer prepared in the step S2 are added into a beaker, and 3 parts of a defoaming agent are added, wherein the defoaming agent is a polyether defoaming agent in the embodiment;
the two are mixed evenly and placed for 20 minutes, and then 2 parts of air entraining agent is added to form a ternary composite system, wherein the air entraining agent is a sodium abietate air entraining agent in the embodiment;
s5, preparing a blending agent, which comprises:
when the concrete is mixed, 230 parts of the internal curing agent prepared in the step S3 is weighed, the mass of the internal curing agent is 1.1% of the total weight of the gel material, 15 times of the weight of the internal curing agent is weighed, water is added into the internal curing agent, 110 parts of the ternary composite system prepared in the step S4 is weighed and mixed into the internal curing agent to obtain a prepared blending agent, and the mass of the ternary composite system is 3% of the total weight of the ready-mixed concrete.
Example 3
A method for preparing a blending agent for resisting the shrinkage cracks of bridge guardrail concrete comprises the steps of preparing DGMA, a reduction type water reducing agent, an internal curing agent, a ternary composite system and a blending agent, wherein the blending agent comprises
S1, configuring DGMA:
adding 170 parts of maleic anhydride into a three-neck flask provided with a thermometer, a stirrer and a reflux condenser, heating to 55 ℃ to completely melt the maleic anhydride, adding 80 parts of dibutylene glycol monobutyl ether, continuously heating to 130 ℃, keeping the temperature for 30 minutes to obtain DGMA, cooling, discharging and purifying for later use;
the three-neck flask can be simultaneously provided with a thermometer, a stirrer and a reflux condenser pipe during the reaction so as to meet the preparation requirement.
S2, preparing a reduction type water reducing agent:
adding 850 parts of water and 5 parts of sodium methallyl sulfonate into a four-neck flask, heating to 80 ℃, dropwise adding an initiator formed by 20 parts of ammonium persulfate, 500 parts of allyl polyethylene glycol, 45 parts of methacrylic acid and 130 parts of DGMA prepared in the step S1 under the protection of protective gas, ensuring that ammonium persulfate, allyl polyethylene glycol, methacrylic acid and DGMA are dropwise added simultaneously and do not influence each other in the four-neck flask, finishing dropwise adding all the components within 5 minutes, wherein the protective gas selected in the embodiment is nitrogen, continuing to react for 2 hours after dropwise adding is finished, cooling after complete reaction, and adjusting the pH value to 7 by using sodium hydroxide to obtain a finished product of the shrinkage-reducing water reducer;
s3, preparing an internal curing agent:
adding 140 parts of sodium hydroxide and 850 parts of water into a beaker, slowly adding 360 parts of acrylic acid under the condition of ice water bath, then adding 850 parts of deionized water, weighing 65 parts of acrylic acid, and mixing in the solution to complete the preparation of the comonomer solution;
pouring the comonomer solution, 70 parts of ammonium persulfate solution and 17 parts of N, N' -methylene bisacrylamide into another beaker, mixing, mechanically stirring at 40 ℃, and continuously introducing nitrogen below the liquid level during stirring to remove oxygen;
placing the deoxidized mixed solution into a water bath kettle, carrying out water bath reaction at 60 ℃ for 1.5 hours, then heating to 70 ℃ to continue heating in the water bath for 1.5 hours, then heating to 80 ℃, continuing heating in the water bath for 1 hour, and taking out a beaker to obtain polymer gel;
cleaning the polymer gel with 750 parts of absolute ethyl alcohol, drying to constant weight after cleaning, and crushing the polymer gel to obtain an internal curing agent;
s4, configuring a ternary composite system, comprising:
5000 parts of the shrinkage-reducing water reducer prepared in the step S2 is added into a beaker, and 3 parts of a defoaming agent is added, wherein the defoaming agent is a polyether defoaming agent in the embodiment;
the two are mixed evenly and placed for 20 minutes, and then 2 parts of air entraining agent is added to form a ternary composite system, wherein the air entraining agent is a sodium abietate air entraining agent in the embodiment;
s5, preparing a blending agent, which comprises:
when the concrete is mixed, firstly, 55 parts of the internal curing agent prepared in the step S3 is weighed, the mass of the internal curing agent is 1.1% of the total weight of the gel material, then, 15 times of the weight of water of the internal curing agent is weighed and added into the internal curing agent, finally, 25 parts of the ternary composite system prepared in the step S4 is weighed and mixed into the internal curing agent to obtain a prepared blending agent, and the mass of the ternary composite system is 3% of the total weight of the ready-mixed concrete.
Example 4
A method for preparing a blending agent for resisting the shrinkage cracks of bridge guardrail concrete comprises the steps of preparing DGMA, a reduction type water reducing agent, an internal curing agent, a ternary composite system and a blending agent, wherein the blending agent comprises
S1, configuring DGMA:
adding 340 parts of maleic anhydride into a three-neck flask provided with a thermometer, a stirrer and a reflux condenser, heating to 55 ℃ to completely melt the maleic anhydride, adding 160 parts of dibutylene glycol monobutyl ether, continuously heating to 130 ℃, keeping the temperature for 30 minutes to obtain DGMA, cooling, discharging and purifying for later use;
the three-neck flask can be simultaneously provided with a thermometer, a stirrer and a reflux condenser pipe during the reaction so as to meet the preparation requirement.
S2, preparing a reduction type water reducing agent:
adding 1700 parts of water and 10 parts of sodium methallyl sulfonate into a four-neck flask, heating to 80 ℃, dropwise adding an initiator formed by 40 parts of ammonium persulfate, 1000 parts of allyl polyethylene glycol, 90 parts of methacrylic acid and 260 parts of DGMA prepared in the step S1 under the protection of protective gas, ensuring that ammonium persulfate, allyl polyethylene glycol, methacrylic acid and DGMA are dropwise added simultaneously and do not influence each other in the four-neck flask, wherein all the components are dropwise added within 5 minutes, the protective gas selected in the embodiment is nitrogen, continuously reacting for 2 hours after the dropwise addition is finished, cooling after the reaction, and adjusting the pH value to 7 by using sodium hydroxide to obtain a finished product of the shrinkage-reducing water reducer;
s3, preparing an internal curing agent:
adding 280 parts of sodium hydroxide and 1700 parts of water into a beaker, slowly adding 720 parts of acrylic acid under the condition of ice-water bath, then adding 1700 parts of deionized water, weighing 130 parts of acrylic acid, and mixing in the solution to complete the preparation of a comonomer solution;
pouring the comonomer solution, 140 parts of ammonium persulfate solution and 35 parts of N, N' -methylene bisacrylamide into another beaker, mixing, mechanically stirring at 40 ℃, and continuously introducing nitrogen below the liquid level during stirring to remove oxygen;
placing the deoxidized mixed solution into a water bath kettle, carrying out water bath reaction at 60 ℃ for 1.5 hours, then heating to 70 ℃ to continue heating in the water bath for 1.5 hours, then heating to 80 ℃, continuing heating in the water bath for 1 hour, and taking out a beaker to obtain polymer gel;
cleaning the polymer gel with 1500 parts of absolute ethyl alcohol, drying to constant weight after cleaning, and crushing the polymer gel to obtain an internal curing agent;
s4, configuring a ternary composite system, comprising:
adding 10000 parts of the shrinkage-reducing water reducing agent prepared in the step S2 into a beaker, adding 6 parts of a defoaming agent, mixing the two, standing for 20 minutes, and adding 2 parts of an air entraining agent to form a ternary composite system;
s5, preparing a blending agent, which comprises:
when the concrete is mixed, 113 parts of the internal curing agent prepared in the step S3 is weighed, the mass of the internal curing agent is 1.1% of the total weight of the gel material, then 15 times of the weight of the internal curing agent is weighed, water is added into the internal curing agent, finally 55 parts of the ternary composite system prepared in the step S4 is weighed and mixed into the internal curing agent to obtain a prepared blending agent, and the mass of the ternary composite system is 3% of the total weight of the ready-mixed concrete.
Example 5
A preparation method of a blending agent for resisting the shrinkage cracks of bridge guardrail concrete comprises the steps of preparing DGMA, a shrinkage-reducing water reducing agent, an internal curing agent, a ternary composite system and a blending agent, wherein the blending agent comprises
S1, configuring DGMA:
adding 340 parts of maleic anhydride into a three-neck flask provided with a thermometer, a stirrer and a reflux condenser, heating to 55 ℃ to completely melt the maleic anhydride, adding 160 parts of dibutylene glycol monobutyl ether, continuously heating to 130 ℃, keeping the temperature for 30 minutes to obtain DGMA, cooling, discharging and purifying for later use;
the three-neck flask can be simultaneously provided with a thermometer, a stirrer and a reflux condenser during reaction so as to meet the preparation requirement.
S2, preparing a reduction type water reducing agent:
adding 1700 parts of water and 10 parts of sodium methallyl sulfonate into a four-neck flask, heating to 80 ℃, dropwise adding an initiator formed by 40 parts of ammonium persulfate, 1000 parts of allyl polyethylene glycol, 90 parts of methacrylic acid and 260 parts of DGMA prepared in the step S1 under the protection of protective gas, wherein the four-neck flask can ensure that the ammonium persulfate, the allyl polyethylene glycol, the methacrylic acid and the DGMA are dropwise added simultaneously and do not influence each other, all the components are dropwise added within 5 minutes, the protective gas selected in the embodiment is nitrogen, continuously reacting for 2 hours after the dropwise adding is finished, cooling after the reaction, and adjusting the pH value to 7 by using sodium hydroxide to obtain a finished product of the shrinkage-reducing water reducer;
s3, preparing an internal curing agent:
adding 280 parts of sodium hydroxide and 1700 parts of water into a beaker, slowly adding 720 parts of acrylic acid under the condition of ice water bath, adding 1700 parts of deionized water, weighing 130 parts of acrylic acid, and mixing in the solution to complete the preparation of the comonomer solution;
pouring a comonomer solution, 140 parts of an ammonium persulfate solution and 35 parts of N, N' -methylene-bisacrylamide into another beaker, mixing, mechanically stirring at 40 ℃, and continuously introducing nitrogen below the liquid level during stirring to remove oxygen;
placing the deoxidized mixed solution into a water bath kettle, carrying out water bath reaction at 60 ℃ for 1.5 hours, then heating to 70 ℃ to continue heating in the water bath for 1.5 hours, then heating to 80 ℃, continuing heating in the water bath for 1 hour, and taking out a beaker to obtain polymer gel;
cleaning the polymer gel with 1500 parts of absolute ethyl alcohol, drying to constant weight after cleaning, and crushing the polymer gel to obtain an internal curing agent;
s4, configuring a ternary composite system, comprising:
adding 10000 parts of the shrinkage-reducing water reducing agent prepared in the step S2 into a beaker, adding 3 parts of a defoaming agent, mixing the two, standing for 20 minutes, and adding 1 part of an air entraining agent to form a ternary composite system;
s5, the preparing and mixing agent includes:
when the concrete is mixed, 113 parts of the internal curing agent prepared in the step S3 is weighed, the mass of the internal curing agent is 1.1% of the total weight of the gel material, then 15 times of the weight of water of the internal curing agent is weighed and added into the internal curing agent, finally 55 parts of the ternary composite system prepared in the step S4 is weighed and doped into the internal curing agent to obtain a prepared blending agent, and the mass of the ternary composite system is 3% of the total weight of the premixed concrete.
Comparative example 1
Comparative example 1 differs from example 1 in that a commercially available polycarboxylic acid water reducing agent was added to the concrete in place of the formulation, and the weight of the two was the same before and after replacement.
Comparative example 2:
comparative example 2 is different from example 1 in that, in the preparation of the ternary complex system in step S4, a commercially available polycarboxylic acid water reducing agent is used in place of the prepared reduction type water reducing agent, and the weight of the two is the same before and after the replacement, and the rest of the preparation method is kept unchanged.
For the blending agents prepared in the above examples 1-5, C30 concrete was used, the blending ratio was not changed, only the blending amount of each component of the blending agent was adjusted, and the influence of the blending amount of different components on the performance of the concrete was studied. The concrete mix ratios used in the tests are given in table 1 below:
the mixing proportion of C30 concrete is kg/m3
The effect of the different component formulations on the working properties of fresh concrete is shown in table 2 below:
the comparative example 1 is to change the blending agent into a common polycarboxylic acid water reducing agent with equal mass on the market, and the comparative example 2 is to change the self-prepared reduction type water reducing agent in the blending agent into a common polycarboxylic acid water reducing agent on the market.
As can be seen from the above Table 2, the C30 concrete prepared in example 1 is most suitable for engineering, and the surface of the guardrail has no large bubbles and no cracks; in the embodiment 2, more shrinkage-reducing water reducing agents are added, and concrete is isolated and bleeds; in the embodiment 3, the added shrinkage-reducing water reducing agent is less, and the blended concrete has no flowability; example 4, the consumption of the defoaming agent is increased, so that the concrete has a pseudo-coagulation phenomenon, is insufficient in fluidity and is not suitable for construction; example 5, the amount of the air entraining agent is increased, so that the air content of concrete is too high, and bubbles are distributed on the surface of the poured concrete guardrail; the comparative example 1 is a polycarboxylic acid water reducing agent commonly used in engineering, the mixed concrete has good workability, but the gas content is high, the air bubbles on the surface of the guardrail are more, and the concrete cracks; comparative example 2 the self-formulated water reducing agent was replaced with a commercially available polycarboxylic acid water reducing agent, which had a fluidity similar to that of example 1, but a relatively high gas content, indicating that the compatibility of the three in combination was not as good as that of the self-formulated water reducing agent, and that the guardrail concrete cracked.
Finally, it is noted that the above-mentioned preferred embodiments illustrate rather than limit the invention, and that, although the invention has been described in detail with reference to the above-mentioned preferred embodiments, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the scope of the invention as defined by the appended claims.
Claims (10)
1. The blending agent for resisting the concrete shrinkage cracks of the bridge guardrail is characterized by comprising DGMA, a shrinkage-reducing water reducing agent prepared by the DGMA, an internal curing agent, a ternary composite system prepared by the shrinkage-reducing water reducing agent and a blending agent prepared by the internal curing agent and the ternary composite system, wherein the blending agent is prepared by the following components in parts by weight:
the DGMA comprises the following raw materials in percentage by weight: 170-680 parts of maleic anhydride and 80-320 parts of dibutylene glycol monobutyl ether;
the reducing water reducer comprises the following raw materials in proportion: 3400 part of water, 5-20 parts of sodium methallyl sulfonate, 20-80 parts of ammonium persulfate, 500-2000 parts of allyl polyethylene glycol, 45-180 parts of methacrylic acid and 130-520 parts of DGMA;
the raw material proportion of the prepared internal curing agent is as follows: 560 parts of sodium hydroxide 140-;
the ternary composite system comprises the following raw materials in proportion: 5000 plus 20000 parts of shrinkage-reducing water reducing agent, 1-6 parts of defoaming agent and 1-3 parts of air entraining agent;
the blending agent comprises the following raw materials in percentage by weight: 850-3400 parts of water, 55-230 parts of internal curing agent and 25-110 parts of ternary composite system.
2. The formulation for resisting the shrinkage crack of the concrete of the bridge guardrail according to claim 1,
the DGMA raw material ratio for preparing the reduction type water reducing agent is as follows: 340 parts of maleic anhydride, 160 parts of dibutylene glycol monobutyl ether;
the raw material proportion for preparing the reduction type water reducing agent is as follows: 1700 parts of water, 10 parts of sodium methallyl sulfonate, 40 parts of ammonium persulfate, 1000 parts of allyl polyethylene glycol, 90 parts of methacrylic acid and 260 parts of DGMA;
the raw material proportion of the prepared internal curing agent is as follows: 280 parts of sodium hydroxide, 1700 parts of water, 720 parts of acrylic acid, 1700 parts of deionized water, 130 parts of acrylamide, 140 parts of ammonium persulfate, 35 parts of N, N' -methylene-bisacrylamide and 1500 parts of absolute ethyl alcohol;
the ternary composite system comprises the following raw materials in proportion: 10000 parts of a shrinkage-reducing water reducing agent, 3 parts of a defoaming agent and 2 parts of an air entraining agent;
the blending agent comprises the following raw materials in percentage by weight: 1700 parts of water, 113 parts of internal curing agent and 55 parts of ternary composite system.
3. The formulation for resisting the shrinkage crack of the concrete of the bridge guardrail according to claim 1,
the DGMA raw material ratio for preparing the reduction type water reducing agent is as follows: 170 parts of maleic anhydride, 80 parts of dibutylene glycol monobutyl ether;
the raw material proportion for preparing the reduction type water reducing agent is as follows: 850 parts of water, 5 parts of sodium methallyl sulfonate, 20 parts of ammonium persulfate, 500 parts of allyl polyethylene glycol, 45 parts of methacrylic acid and 130 parts of DGMA;
the raw material proportion of the prepared internal curing agent is as follows: 140 parts of sodium hydroxide, 850 parts of water, 360 parts of acrylic acid, 850 parts of deionized water, 65 parts of acrylamide, 70 parts of ammonium persulfate, 17 parts of N, N' -methylene-bisacrylamide and 750 parts of absolute ethyl alcohol;
the ternary composite system comprises the following raw materials in proportion: 5000 parts of a shrinkage-reducing water reducing agent, 3 parts of a defoaming agent and 2 parts of an air entraining agent;
the blending agent comprises the following raw materials in percentage by weight: 850 parts of water, 55 parts of internal curing agent and 25 parts of ternary composite system.
4. The formulation for resisting the shrinkage crack of the concrete of the bridge guardrail according to claim 1,
the DGMA raw material proportion for preparing the reduction type water reducing agent is as follows: 680 parts of maleic anhydride and 320 parts of dibutylene glycol monobutyl ether;
the raw material proportion for preparing the reduction type water reducing agent is as follows: 3400 part of water, 20 parts of sodium methallyl sulfonate, 80 parts of ammonium persulfate, 2000 parts of allyl polyethylene glycol, 180 parts of methacrylic acid and 520 parts of DGMA;
the raw material proportion of the prepared internal curing agent is as follows: 560 parts of sodium hydroxide, 3400 parts of water, 1440 parts of acrylic acid, 3400 parts of deionized water, 260 parts of acrylamide, 280 parts of ammonium persulfate, 70 parts of N, N' -methylene-bisacrylamide and 3000 parts of absolute ethyl alcohol;
the ternary composite system comprises the following raw materials in proportion: 20000 parts of shrinkage-reducing water reducing agent, 3 parts of defoaming agent and 2 parts of air entraining agent;
the blending agent comprises the following raw materials in percentage by weight: 3400 part of water, 230 parts of internal curing agent and 110 parts of ternary composite system.
5. The blending agent for resisting the shrinkage cracks of the bridge guardrail concrete according to claim 1, wherein the air entraining agent is sodium abietate and the defoaming agent is polyether.
6. The preparation method of the blending agent for resisting the shrinkage crack of the concrete of the bridge guardrail according to any one of claims 1 to 5, comprising the following steps: preparing DGMA, a shrinkage-reducing water reducing agent, an internal curing agent, a ternary composite system and a blending agent, wherein
S1, configuring DGMA:
adding 170-680 parts of maleic anhydride into the container, and heating to 45-65 ℃ to melt the maleic anhydride; adding 80-320 parts of dibutylene glycol monobutyl ether, continuously heating to 110-150 ℃, keeping the temperature to obtain DGMA, cooling and discharging, and purifying for later use;
s2, preparing a reduction type water reducing agent:
adding 3400 parts of 850-90 parts of water and 5-20 parts of sodium methallyl sulfonate into a container, heating to 70-90 ℃, dropwise adding an initiator formed by 20-80 parts of ammonium persulfate, 500-2000 parts of allyl polyethylene glycol, 45-180 parts of methacrylic acid and 130-520 parts of DGMA prepared in the step S1 under the protection of protective gas, continuing to react for 1.5-2.5 hours after the dropwise adding is finished, cooling after the reaction, and adjusting the pH value to be neutral by using sodium hydroxide;
s3, preparing an internal curing agent:
adding 560 parts of sodium hydroxide 140 and 3400 parts of water 850 into a container, adding 1440 parts of acrylic acid 360 and 3400 parts of deionized water under the condition of water bath, and weighing 65-260 parts of acrylamide to mix in the solution to complete the preparation of the comonomer solution;
pouring the comonomer solution, 70-280 parts of ammonium persulfate solution and 17-70 parts of N, N' -methylene-bisacrylamide into another beaker, mixing, stirring at 30-50 ℃, and removing oxygen;
putting the mixed solution into a water bath kettle, carrying out water bath reaction at 55-65 ℃ for 1-2 hours, heating to 66-75 ℃, continuing to heat in the water bath for 1-2 hours, then heating to 76-85 ℃, continuing to heat in the water bath for 0.5-1.5 hours, finally cleaning the polymer gel by using 750 plus 3000 parts of absolute ethyl alcohol, drying to constant weight after cleaning, and crushing the polymer gel to obtain an internal curing agent;
s4, configuring a ternary composite system, comprising:
adding 5000-;
s5, preparing a blending agent, which comprises:
and weighing the internal curing agent prepared in the step S3, adding water in an amount which is 10-20 times the weight of the internal curing agent into the internal curing agent, and weighing the ternary composite system in the step S4 and adding the ternary composite system into the internal curing agent to obtain the blending agent.
7. The preparation method of the blending agent for resisting the shrinkage cracks of the concrete of the bridge guardrail, according to claim 6, is characterized in that: preparing a heating container of maleic anhydride in DGMA into a three-neck flask, wherein a thermometer, a stirrer and a reflux condenser tube are arranged in the three-neck flask; a container in the reduction type water reducing agent is configured into a four-mouth flask; preparing an internal curing agent, and taking a container in the ternary composite system as a beaker.
8. The preparation method of the blending agent for resisting the shrinkage cracks of the concrete of the bridge guardrail, according to claim 6, is characterized in that: and preparing the sodium hydroxide in the internal curing agent under the ice water bath condition, putting the mixed solution into a constant-temperature water bath kettle, and introducing protective gas below the liquid level of the mixed solution to remove oxygen.
9. The preparation method of the blending agent for resisting the shrinkage cracks of the concrete of the bridge guardrail, according to claim 6, is characterized in that: the mass of the internal curing agent in the prepared blending agent is 2-4% of the total weight of the gel material, the weight of water is 12-18 times of that of the internal curing agent, and the mass of the ternary composite system is 2-4% of the total weight of the premixed concrete.
10. The preparation method of the blending agent for resisting the shrinkage cracks of the concrete of the bridge guardrail, according to claim 6, is characterized in that: when the polymer gel is washed by the absolute ethyl alcohol, the polymer gel is firstly sheared.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210407252.0A CN114671639B (en) | 2022-04-19 | 2022-04-19 | Blending agent for resisting concrete shrinkage cracks of bridge guardrail and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210407252.0A CN114671639B (en) | 2022-04-19 | 2022-04-19 | Blending agent for resisting concrete shrinkage cracks of bridge guardrail and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114671639A true CN114671639A (en) | 2022-06-28 |
| CN114671639B CN114671639B (en) | 2023-03-21 |
Family
ID=82078087
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210407252.0A Active CN114671639B (en) | 2022-04-19 | 2022-04-19 | Blending agent for resisting concrete shrinkage cracks of bridge guardrail and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114671639B (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102010160A (en) * | 2010-10-29 | 2011-04-13 | 广西壮族自治区水利科学研究院 | Crack-resistant abrasion-resistant hydraulic concrete and preparation method thereof |
| CN103193410A (en) * | 2013-03-27 | 2013-07-10 | 华南理工大学 | Shrinkage-reducing poly carboxylic acid water reducing agent and preparation method |
| CN103864980A (en) * | 2014-02-24 | 2014-06-18 | 杭州电子科技大学 | Method for preparing agricultural super absorbent resin for ternary copolymerization |
| CN105542072A (en) * | 2016-01-28 | 2016-05-04 | 北京金隅水泥节能科技有限公司 | Internal curing agent suitable for concrete in strong alkaline environment and preparation method thereof |
| CN105884959A (en) * | 2016-05-10 | 2016-08-24 | 中山大学 | Preparation method of polyacrylic acid super absorbent resin through room-temperature solution polymerization |
| CN110092862A (en) * | 2019-05-27 | 2019-08-06 | 廊坊师范学院 | A kind of preparation method of acrylic type water-absorbing resin |
| WO2021103473A1 (en) * | 2019-11-25 | 2021-06-03 | 科之杰新材料集团有限公司 | Shrinkage-reducing polycarboxylic acid water reducing agent and preparation method thereof |
-
2022
- 2022-04-19 CN CN202210407252.0A patent/CN114671639B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102010160A (en) * | 2010-10-29 | 2011-04-13 | 广西壮族自治区水利科学研究院 | Crack-resistant abrasion-resistant hydraulic concrete and preparation method thereof |
| CN103193410A (en) * | 2013-03-27 | 2013-07-10 | 华南理工大学 | Shrinkage-reducing poly carboxylic acid water reducing agent and preparation method |
| CN103864980A (en) * | 2014-02-24 | 2014-06-18 | 杭州电子科技大学 | Method for preparing agricultural super absorbent resin for ternary copolymerization |
| CN105542072A (en) * | 2016-01-28 | 2016-05-04 | 北京金隅水泥节能科技有限公司 | Internal curing agent suitable for concrete in strong alkaline environment and preparation method thereof |
| CN105884959A (en) * | 2016-05-10 | 2016-08-24 | 中山大学 | Preparation method of polyacrylic acid super absorbent resin through room-temperature solution polymerization |
| CN110092862A (en) * | 2019-05-27 | 2019-08-06 | 廊坊师范学院 | A kind of preparation method of acrylic type water-absorbing resin |
| WO2021103473A1 (en) * | 2019-11-25 | 2021-06-03 | 科之杰新材料集团有限公司 | Shrinkage-reducing polycarboxylic acid water reducing agent and preparation method thereof |
Non-Patent Citations (1)
| Title |
|---|
| 张雄等: "聚羧酸减水剂引气效应复配优化研究", 《建筑材料学报》 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114671639B (en) | 2023-03-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9365669B2 (en) | Slump retaining polycarboxylic acid superplasticizer | |
| CN114195421A (en) | Preparation method of polycarboxylic acid admixture for machine-made sand concrete | |
| CN109369859B (en) | Concrete tackifying type viscosity regulator and preparation method thereof | |
| CN108059381A (en) | A kind of clear-water concrete chemical admixture and preparation method thereof | |
| CN108047393A (en) | A kind of preparation method for enhancing viscosity reduction type polycarboxylic acids plasticiser | |
| CN101585900B (en) | Method for synthesizing polycarboxylic acid concrete high-performance water reducing agent | |
| CN113816690A (en) | Concrete repairing material and preparation method thereof | |
| CN110590223A (en) | Concrete segregation resisting agent and concrete | |
| CN112126022A (en) | Formula and preparation method of polycarboxylate superplasticizer | |
| CN114671639B (en) | Blending agent for resisting concrete shrinkage cracks of bridge guardrail and preparation method thereof | |
| CN108117626A (en) | A kind of high performance water reducing agent of polyocarboxy acid | |
| CN110436811A (en) | A kind of chlorine-free alkali-free liquid accelerating agent and preparation method thereof | |
| CN112708073A (en) | Defoaming type polycarboxylate superplasticizer and preparation method thereof | |
| CN115215581B (en) | Concrete foam stabilizer, preparation method thereof, concrete water reducing agent and concrete | |
| CN111087552A (en) | Synthetic method of polycarboxylic acid water reducer with high water reducing rate and mud resistance | |
| CN108276534A (en) | A kind of preparation method of the polycarboxylate water-reducer of high-molecular-weight poly ether monomer synthesis | |
| CN105503141A (en) | Waste-residue and magnesium-phosphate cement self-leveling mortar | |
| CN109306038A (en) | A kind of extra retarded set type poly carboxylic acid series water reducer and its preparation method and application | |
| CN109133697A (en) | A kind of Compositional type polycarboxylate water-reducer and the preparation method for preparing polycarboxylate water-reducer in the Compositional type polycarboxylate water-reducer | |
| CN111978468B (en) | Reaction air-entraining thickening agent and preparation method thereof | |
| CN108285286A (en) | A kind of preparation method of polycarboxylate water-reducer suitable for mortar | |
| CN111689724A (en) | Machine-made sand concrete and preparation method thereof | |
| CN110527077A (en) | A kind of sustained release collapse-preventing type water-reducing agent and preparation method thereof | |
| CN113060969A (en) | Special additive for self-compacting concrete and preparation method and application thereof | |
| CN112300341A (en) | Formula and preparation method of water reducing agent for phosphogypsum |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |