Water-resistant lightweight gypsum mortar and preparation method thereof

Abstract

The application provides a kind of water-resistant lightweight gypsum mortar and preparation method thereof, belong to building material technical field, including the following steps: sodium silicate and sodium aluminate are treated with glucosyl rutin respectively, aging, freeze-drying, high-temperature calcination, then 4-benzyloxy phenyl ethyl decanoate is added, to obtain inorganic water-resistant lightweight aggregate;Polyoxyethyl polyoxpropyl glycerol ether, poly (styrene-divinyl benzene) and water are homogenized, sodium bicarbonate, C16-18-fatty acid and polyethylene oxide sulfosuccinic acid lauryl sodium are added, stirring, aging, heat treatment, drying, to obtain organic water-resistant lightweight aggregate;Modified heavy calcium powder is obtained by modifying heavy calcium powder with bis (2-ethylhexyl) cyclohexane-1,2-dicarboxylic acid ester;Gypsum, water, inorganic and organic water-resistant lightweight aggregate, modified heavy calcium powder and other additives are mixed to obtain water-resistant lightweight gypsum mortar. The technical scheme provided by the application not only has excellent water resistance, lightweight performance, but also has good environmental protection and cost effectiveness.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of building materials, and particularly relates to a water-resistant light gypsum mortar and a preparation method thereof. BACKGROUND

[0002] Most of the gypsum mortars used in actual projects at present are traditional material proportioning gypsum mortars with large bulk density, poor energy consumption, and low environmental protection rate, which cannot well meet people's requirements for indoor decoration of buildings in terms of living comfort and environmental health.

[0003] The water-resistant light gypsum mortar generally comprises gypsum as a main component, light aggregate and heavy calcium powder as secondary components, and various air entraining agents, retarders, water retaining agents and other additives and water.

[0004] In addition, although the existing water-resistant light aggregate can provide certain water resistance, its water resistance will gradually decrease in long-term contact with water, and the compressive strength of the water-resistant light gypsum mortar is generally lower and the durability is poorer than that of the traditional gypsum mortar.

[0005] Therefore, it is necessary to provide a water-resistant light gypsum mortar and a preparation method thereof to solve the problems of water resistance, lightness and durability of the water-resistant light gypsum mortar and have good cost-effectiveness. SUMMARY

[0006] Therefore, the application provides a water-resistant light gypsum mortar and a preparation method thereof, which improves the water resistance, lightness, bending resistance and compressive strength of the gypsum mortar by using inorganic and organic water-resistant light aggregates, modified heavy calcium powder and other components, and has good environmental protection and cost-effectiveness.

[0007] To achieve the above-mentioned purpose, the application provides a preparation method of a water-resistant light gypsum mortar, comprising the following steps:

[0008] S1, sodium silicate and sodium aluminate are respectively treated with glucosyl rutin, aged, frozen, dried, high-temperature calcined to obtain porous silicon dioxide and porous aluminum oxide, and then the porous silicon dioxide and the porous aluminum oxide are added into a suspension of 4-benzyloxyphenyl ethyl decanoate, stirred, washed and dried to obtain inorganic water-resistant light aggregate;

[0009] S2, polyoxyethyl polyoxypropyl glycerol ether and poly (styrene-divinyl benzene) are added into deionized water, homogeneous dispersion is carried out, then sodium bicarbonate, C16-18-fatty acid and polyethylene oxide sodium lauryl sulfosuccinate are added, stirring, aging, heat treatment, ultrasonic, freeze drying are carried out, and organic water-resistant lightweight aggregate is obtained;

[0010] S3, after drying and ball milling of heavy calcium powder, the heavy calcium powder is added into bis (2-ethylhexyl) cyclohexane-1,2-dicarboxylic acid ester and ethanol, and homogeneous washing and drying are carried out, and modified heavy calcium powder is obtained;

[0011] S4, gypsum, water, inorganic and organic water-resistant lightweight aggregate, modified heavy calcium powder and other additives are mixed, and water-resistant lightweight gypsum mortar is obtained.

[0012] The organic water-resistant lightweight aggregate is prepared by compounding poly (styrene-divinyl benzene) and polyoxyethyl polyoxypropyl glycerol ether, wherein the polyoxyethyl chain segment in the polyoxyethyl polyoxypropyl glycerol ether has good hydrophilicity, and the polyoxypropyl chain segment and glycerol group can form hydrogen bond and van der waals force with the hydrophobic long chain of poly (styrene-divinyl benzene), which is helpful for the combination between the internal components of the composite material and forms a stable suspension under the action of homogenization. The introduction of sodium bicarbonate can generate CO2 after thermal decomposition, form bubbles in the high-density base material and constitute a porous structure, so as to reduce the material density and meet the lightweight requirement.

[0013] In the preparation of the inorganic water-resistant lightweight aggregate, the glucosyl rutin introduced can form pores after high-temperature carbonization, which is helpful for forming a porous structure, reducing the material density, meeting the lightweight requirement, providing additional adsorption sites for 4-benzyloxyphenyl ethyl caprate and helping 4-benzyloxyphenyl ethyl caprate to form a hydrophobic adsorption layer on the surface of the porous material, so as to reduce the penetration of water and improve the water resistance. Meanwhile, the sulfonate ions contained in the polyethylene oxide sodium lauryl sulfosuccinate and the hydroxyl groups on the polyoxyethyl polyoxypropyl glycerol ether can form hydrogen bond and electrostatic interaction with the ester groups of 4-benzyloxyphenyl ethyl caprate in the inorganic water-resistant lightweight aggregate, so as to improve the compatibility and interfacial adhesion between the organic and inorganic components.

[0014] The present application also introduces bis (2-ethylhexyl) cyclohexane-1,2-dicarboxylic acid ester to adsorb on the surface of the heavy calcium powder, so as to form a hydrophobic coating layer and improve the water resistance of the heavy calcium powder. In addition, the bis (2-ethylhexyl) cyclohexane-1,2-dicarboxylic acid ester can also be compatible with the inorganic water-resistant lightweight aggregate and the organic components in the organic water-resistant lightweight aggregate, increase the dispersion compatibility between the modified heavy calcium powder and the organic phase and the inorganic phase, help to improve the interfacial adhesion of each component of the water-resistant lightweight gypsum mortar, and further increase the stability of the water-resistant lightweight gypsum mortar system.

[0015] Optionally, in the S1, the sodium silicate and the glucorutin are added into the deionized water and stirred to obtain a treated sodium silicate solution, the sodium aluminate and the glucorutin are added into the deionized water and stirred to obtain a treated sodium aluminate solution, the treated sodium silicate solution and the treated sodium aluminate solution are respectively subjected to aging, quick freezing, freeze drying and high-temperature calcination to obtain porous silica and porous alumina with stable pore structure, and then the porous silica and the porous alumina are added into the suspension of 4-benzyloxyphenyl ethyl decanoate, stirred, washed, and dried to obtain the inorganic water-resistant lightweight aggregate.

[0016] The aging treatment of the present application helps to enhance the interaction of sodium silicate, sodium aluminate and glucorutin; the quick freezing helps to fix the structure; the vacuum freeze drying can remove water at low temperature and low pressure, avoiding the structure damage caused by high temperature; the high-temperature calcination can carbonize and remove the organic matter, forming the pore structure, and improving the mechanical strength and chemical stability of the inorganic water-resistant lightweight aggregate.

[0017] Optionally, in the S1, the stirring speed is 400-500 r / min, and the stirring time is 1-2 h; the mass ratio of the glucorutin, the sodium silicate and the sodium aluminate is 5:4:4; in the process of aging, quick freezing, freeze drying and high-temperature calcination of the treated sodium silicate solution, the aging time is 20-24 h, the quick freezing time is 1-2 h, the freeze drying time is 10-12 h, and the high-temperature calcination temperature is 500-600℃, and the high-temperature calcination time is 3-4 h; in the process of aging, quick freezing, freeze drying and high-temperature calcination of the treated sodium aluminate solution, the aging time is 20-24 h, the quick freezing time is 1-2 h, the freeze drying time is 10-12 h, the high-temperature calcination temperature is 1000-1100℃, and the high-temperature calcination time is 4-5 h; in the process of stirring, washing and drying of the porous silica and the porous alumina added into the suspension of 4-benzyloxyphenyl ethyl decanoate, the drying temperature is 80-90℃, and the drying time is 5-6 h; in the suspension of 4-benzyloxyphenyl ethyl decanoate, the mass ratio of 4-benzyloxyphenyl ethyl decanoate to ethanol is 1:10.

[0018] Optionally, in the S2, the polyoxyethyl polyoxypropyl glycerol ether and the poly(styrene-divinylbenzene) are added into the deionized water, homogeneously dispersed at 400-500 r / min for 30-40 min, then the sodium bicarbonate, the C16-18-fatty acid and the polyethylene oxide sulfosuccinic acid lauryl sodium are added, stirred at 400-500 r / min for 1.5-3 h, and aged at room temperature for 20-24 h to obtain the preliminary product of the organic water-resistant lightweight aggregate.

[0019] Optionally, in S2, the preliminary product of the organic water-resistant lightweight aggregate is first subjected to heat treatment in a 40℃ hot air circulation oven for 3-4h, then the temperature is raised to 60℃ for 3-4h, and then to 80℃ for 3-4h, washed with deionized water for 3 times, ultrasonic in deionized water at 400-500r / min for 20-30min, and then washed with deionized water for 3 times, to remove the sodium salt generated in the reaction, and vacuum freeze-dried for 10-12h to obtain the organic water-resistant lightweight aggregate.

[0020] The present application first homogeneously disperses polyoxyethyl polyoxypropyl glycerol ether and poly(styrene-divinylbenzene) to increase the dispersibility of the two polymers in deionized water. Then sodium bicarbonate, C16-18-fatty acid and polyethylene oxide sodium lauryl sulfosuccinate are added to form a crosslinked network. Through stirring and air aging, the reaction between the components is promoted to form a stable gel network. Next, heat treatment is used to remove moisture to avoid structural damage. Finally, ultrasonic and deionized water washing are combined to ensure complete removal of impurities, followed by freeze-drying to maintain the porous structure, to obtain dry organic water-resistant lightweight aggregate.

[0021] Optionally, in S3, the heavy calcium powder is dried and ball milled to obtain pretreated heavy calcium powder, and then bis(2-ethylhexyl) cyclohexane-1,2-dicarboxylate is added to ethanol, stirred, and then the pretreated heavy calcium powder is added and subjected to homogenization, washing and drying to obtain modified heavy calcium powder.

[0022] The present application pretreats the heavy calcium powder by drying and ball milling, which helps to make the surface of the pretreated heavy calcium powder drier and have a higher specific surface area, avoids the adhesion phenomenon between the heavy calcium powders due to moisture, and is easier to disperse, which helps to improve the subsequent surface modification effect.

[0023] Optionally, in S3, the drying temperature in the drying and ball milling of the heavy calcium powder is 80-90℃, and the time is 1-2h; the stirring speed is 300-400r / min, and the time is 0.5-1h; the drying temperature in the drying and ball milling of the heavy calcium powder is 80-90℃, and the time is 1-2h; after adding the pretreated heavy calcium powder, the homogenization speed is 300-400r / min, the homogenization time is 20-30min, the drying temperature is 80-90℃, and the drying time is 5-6h.

[0024] Optionally, in S4, the gypsum, inorganic water-resistant lightweight aggregate, organic water-resistant lightweight aggregate, modified heavy calcium powder and other additives are stirred, and tap water is added twice during stirring to obtain water-resistant lightweight gypsum mortar.

[0025] The application adopts a method of mixing all components except water first and then gradually adding water in the preparation process of the water-resistant lightweight gypsum mortar, mainly to enhance the dispersion of all components in the mortar, avoid local high or low concentration, and control the hydration reaction speed by adding water twice, which helps to improve the fluidity and construction performance of the mortar.

[0026] Optionally, in the S4, the stirring speed is 600-700 r / min, and the stirring time is 5-6 h; the mass ratio of the organic water-resistant lightweight aggregate, the inorganic water-resistant lightweight aggregate and the modified heavy calcium powder is (8-20):(5-10):(5-10); and the other additives are methyl cellulose, citric acid and sodium polyacrylate.

[0027] To achieve the above object, the application further provides a water-resistant lightweight gypsum mortar, which comprises the following raw materials in mass fractions: gypsum 60-80 parts, water 60 parts, other additives 1 part, glucosyl rutin 2.5-5 parts, sodium silicate 2-4 parts, sodium aluminate 2-4 parts, 4-benzyloxyphenyl ethyl decanoate 1-2 parts, polyoxyethyl polyoxypropyl glycerol ether 5-10 parts, poly(styrene-divinylbenzene) 5-10 parts, sodium bicarbonate 3-6 parts, C16-18-fatty acid 2-4 parts, polyethylene oxide sulfosuccinic acid lauryl sodium 0.3-0.5 parts, heavy calcium powder 5-10 parts and bis(2-ethylhexyl) cyclohexane-1,2-dicarboxylate 1-2 parts.

[0028] The water-resistant lightweight gypsum mortar obtained by the application has good environmental protection and cost effectiveness while improving the water resistance, lightweight, folding resistance and compressive resistance.

[0029] The above technical solution of the application at least has the following beneficial effects:

[0030] 1. The application improves the water resistance and lightweight of the water-resistant lightweight organic aggregate by compounding the amphiphilic poly(styrene-divinylbenzene) and polyoxyethyl polyoxypropyl glycerol ether, introducing sodium bicarbonate to form a porous structure, and then adding the hydrophobic C16-18-fatty acid and the amphiphilic polyethylene oxide sulfosuccinic acid lauryl sodium, polyoxyethyl polyoxypropyl glycerol ether and poly(styrene-divinylbenzene) to form a main interaction of hydrogen bond and van der Waals force, which further improves the water resistance of the water-resistant lightweight organic aggregate while helping to maintain good dispersing capacity and interfacial action.

[0031] 2. The application also uses sodium silicate and sodium aluminate as inorganic material precursors, respectively mixes them with glucosyl rutin in deionized water, and then removes the organic matter by freeze-drying and high-temperature calcination and carbonization to form a porous structure, thereby reducing the material density, improving the lightweight of the inorganic water-resistant lightweight aggregate, and using the hydrophobic property of 4-benzyloxyphenyl ethyl decanoate for water resistance modification, which helps to improve the water resistance and durability of the inorganic water-resistant lightweight aggregate.

[0032] 3. The heavy calcium carbonate powder used in this invention is first dried and ball-milled, and then surface-treated with bis(2-ethylhexyl)cyclohexane-1,2-dicarboxylic acid ester, which improves the water resistance of the heavy calcium carbonate powder. The hydrophobic layer formed by bis(2-ethylhexyl)cyclohexane-1,2-dicarboxylic acid ester is similar and compatible with the components in organic and inorganic water-resistant lightweight aggregates, thereby enhancing the compatibility and interfacial adhesion between the components in the water-resistant lightweight gypsum mortar.

[0033] 4. All materials used in this invention are non-toxic and harmless, and the preparation process is simple and the cost is relatively low, which has good environmental protection and cost-effectiveness. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention are within the scope of protection of the present invention.

[0035] Example 1

[0036] Four parts sodium silicate and five parts glucosylrutin were added to 20 parts deionized water and stirred at 400 rpm for 2 hours to obtain a treated sodium silicate solution. Four parts sodium aluminate and five parts glucosylrutin were added to 20 parts deionized water and stirred at 400 rpm for 2 hours to obtain a treated sodium aluminate solution. The treated sodium silicate solution was aged at room temperature for 24 hours, then rapidly frozen in liquid nitrogen for 2 hours, and then freeze-dried under vacuum for 12 hours to obtain a sodium silicate-containing solid. The sodium silicate-containing solid was calcined at 500℃ for 3 hours to obtain porous silica with a stable pore structure. The treated sodium aluminate solution was aged at room temperature for 24 hours, then rapidly frozen in liquid nitrogen for 2 hours, and then freeze-dried under vacuum for 12 hours to obtain a sodium aluminate-containing solid. The sodium aluminate-containing solid was calcined at 1100℃ for 4 hours to obtain porous alumina with a stable pore structure. The porous silica and porous alumina prepared above were added to a suspension of 22 parts of 4-benzyloxyphenylethyl decanoate (the mass ratio of 4-benzyloxyphenylethyl decanoate to ethanol in the suspension of 4-benzyloxyphenylethyl decanoate was 1:10), stirred at 400 r / min for 2 h, washed 3 times with deionized water, and then vacuum dried at 80 °C for 6 h to obtain inorganic water-resistant lightweight aggregate.

[0037] Ten parts of polyoxyethyl polyoxypropyl glycerol ether and ten parts of poly(styrene-divinylbenzene) were added to 100 parts of deionized water and homogenized at 400 rpm for 40 min. Then, six parts of sodium bicarbonate, four parts of C16-18 fatty acid, and 0.5 parts of polyoxyethylene sulfosuccinate lauryl sodium were added and stirred at 400 rpm for 2 h. The mixture was then aged at room temperature under ventilation for 24 h to obtain a preliminary product of organic water-resistant lightweight aggregate. The preliminary product of organic water-resistant lightweight aggregate was first heat-treated in a 40℃ hot air circulating oven for 3-4 h, then the temperature was increased to 60℃ for 3-4 h, and then increased to 80℃ for 3-4 h. The aggregate was washed three times with deionized water, then sonicated in deionized water at 500 rpm for 30 min, and then washed three times with deionized water to remove the sodium salt generated in the reaction. Finally, the aggregate was freeze-dried under vacuum for 12 h to obtain organic water-resistant lightweight aggregate.

[0038] Ten parts of heavy calcium carbonate powder were dried at 80℃ for 2 hours and then refined into powder in a ball mill to obtain pretreated heavy calcium carbonate powder. Two parts of bis(2-ethylhexyl)cyclohexane-1,2-dicarboxylic acid ester were added to 20 parts of ethanol and stirred at 300 r / min for 1 hour. Ten parts of pretreated heavy calcium carbonate powder were added and homogenized at 300 r / min for 20 minutes. The mixture was washed three times with deionized water and vacuum dried at 80℃ for 6 hours to obtain modified heavy calcium carbonate powder.

[0039] 60 parts of gypsum, 20 parts of organic water-resistant lightweight aggregate, 10 parts of inorganic water-resistant lightweight aggregate, 10 parts of modified heavy calcium carbonate powder, 0.4 parts of methylcellulose, 0.3 parts of citric acid, and 0.3 parts of sodium polyacrylate were placed in a reactor and stirred at 600 r / min for 6 hours. During the stirring, 60 parts of tap water were added twice to obtain water-resistant lightweight gypsum mortar.

[0040] Example 2

[0041] Four parts sodium silicate and five parts glucosylrutin were added to 20 parts deionized water and stirred at 500 rpm for 1.5 h to obtain a treated sodium silicate solution. Four parts sodium aluminate and five parts glucosylrutin were added to 20 parts deionized water and stirred at 500 rpm for 1.5 h to obtain a treated sodium aluminate solution. The treated sodium silicate solution was aged at room temperature for 24 h, then rapidly frozen in liquid nitrogen for 2 h, and then freeze-dried under vacuum for 12 h to obtain a sodium silicate-containing solid. The sodium silicate-containing solid was calcined at 600 °C for 3 h to obtain porous silica with a stable pore structure. The treated sodium aluminate solution was aged at room temperature for 24 h, then rapidly frozen in liquid nitrogen for 2 h, and then freeze-dried under vacuum for 12 h to obtain a sodium aluminate-containing solid. The sodium aluminate-containing solid was calcined at 1000 °C for 4 h to obtain porous alumina with a stable pore structure. The porous silica and porous alumina prepared above were added to a suspension of 22 parts of 4-benzyloxyphenylethyl decanoate (the mass ratio of 4-benzyloxyphenylethyl decanoate to ethanol in the suspension of 4-benzyloxyphenylethyl decanoate was 1:10), stirred at 500 r / min for 2 h, washed 3 times with deionized water, and then vacuum dried at 90 °C for 5 h to obtain inorganic water-resistant lightweight aggregate.

[0042] Ten parts of polyoxyethyl polyoxypropyl glycerol ether and ten parts of poly(styrene-divinylbenzene) were added to 100 parts of deionized water and homogenized at 500 rpm for 30 min. Then, four parts of sodium bicarbonate, four parts of C16-18 fatty acid, and 0.5 parts of polyoxyethylene sulfosuccinate lauryl sodium were added and stirred at 500 rpm for 1.5 h. The mixture was then aged at room temperature under ventilation for 22 h to obtain a preliminary product of organic water-resistant lightweight aggregate. The preliminary product of organic water-resistant lightweight aggregate was first heat-treated in a 40℃ hot air circulating oven for 3-4 h, then the temperature was increased to 60℃ for 3-4 h, and then increased to 80℃ for 3-4 h. The aggregate was washed three times with deionized water, then sonicated in deionized water at 500 rpm for 20 min, and then washed three times with deionized water to remove the sodium salt generated in the reaction. Finally, the aggregate was freeze-dried under vacuum for 12 h to obtain organic water-resistant lightweight aggregate.

[0043] Ten parts of heavy calcium carbonate powder were dried at 80℃ for 2 hours and then refined into powder in a ball mill to obtain pretreated heavy calcium carbonate powder. Two parts of bis(2-ethylhexyl)cyclohexane-1,2-dicarboxylic acid ester were added to 20 parts of ethanol and stirred at 300 r / min for 1 hour. During the stirring, 10 parts of pretreated heavy calcium carbonate powder were added, and the mixture was homogenized at 300 r / min for 30 minutes. The mixture was washed three times with deionized water and then vacuum dried at 80℃ for 6 hours to obtain modified heavy calcium carbonate powder.

[0044] 65 parts gypsum, 15 parts organic water-resistant lightweight aggregate, 10 parts inorganic water-resistant lightweight aggregate, 10 parts modified heavy calcium carbonate powder, 0.4 parts methylcellulose, 0.3 parts citric acid, and 0.3 parts sodium polyacrylate were placed in a reactor and stirred at 700 r / min for 5 hours. During the stirring process, 60 parts tap water were added in two batches to obtain water-resistant lightweight gypsum mortar.

[0045] Example 3

[0046] Four parts sodium silicate and five parts glucosylrutin were added to 20 parts deionized water and stirred at 500 rpm for 1.5 h to obtain a treated sodium silicate solution. Four parts sodium aluminate and five parts glucosylrutin were added to 20 parts deionized water and stirred at 500 rpm for 1.5 h to obtain a treated sodium aluminate solution. The treated sodium silicate solution was aged at room temperature for 22 h, then rapidly frozen in liquid nitrogen for 2 h, and then freeze-dried under vacuum for 12 h to obtain a sodium silicate-containing solid. The sodium silicate-containing solid was calcined at 550 °C for 3.5 h to obtain porous silica with a stable pore structure. The treated sodium aluminate solution was aged at room temperature for 22 h, then rapidly frozen in liquid nitrogen for 2 h, and then freeze-dried under vacuum for 12 h to obtain a sodium aluminate-containing solid. The sodium aluminate-containing solid was calcined at 1050 °C for 4.5 h to obtain porous alumina with a stable pore structure. The porous silica and porous alumina prepared above were added to a suspension of 22 parts of 4-benzyloxyphenylethyl decanoate (the mass ratio of 4-benzyloxyphenylethyl decanoate to ethanol in the suspension of 4-benzyloxyphenylethyl decanoate was 1:10), stirred at 400 r / min for 2 h, stirred at 500 r / min for 1.5 h, washed three times with deionized water, and then vacuum dried at 90 °C for 6 h to obtain inorganic water-resistant lightweight aggregate.

[0047] Five parts of polyoxyethyl polyoxypropyl glycerol ether and five parts of poly(styrene-divinylbenzene) were added to 50 parts of deionized water and homogenized at 400 rpm for 40 min. Then, three parts of sodium bicarbonate, two parts of C16-18 fatty acid, and 0.3 parts of polyoxyethylene sulfosuccinate lauryl sodium were added and stirred at 400 rpm for 1.5 h. The mixture was then aged at room temperature under ventilation for 20 h to obtain a preliminary product of organic water-resistant lightweight aggregate. The preliminary product of organic water-resistant lightweight aggregate was first heat-treated in a 40℃ hot air circulating oven for 3-4 h, then the temperature was increased to 60℃ for 3-4 h, and then increased to 80℃ for 3-4 h. The aggregate was washed three times with deionized water, then sonicated in deionized water at 400 rpm for 20 min, and then washed three times with deionized water to remove the sodium salt generated in the reaction. Finally, the aggregate was freeze-dried under vacuum for 10 h to obtain organic water-resistant lightweight aggregate.

[0048] Ten parts of heavy calcium carbonate powder were dried at 90℃ for 2 hours and then refined into powder in a ball mill to obtain pretreated heavy calcium carbonate powder. Two parts of bis(2-ethylhexyl)cyclohexane-1,2-dicarboxylic acid ester were added to 20 parts of ethanol and stirred at 300 r / min for 1 hour. During the stirring, 10 parts of pretreated heavy calcium carbonate powder were added, and the mixture was homogenized at 400 r / min for 20 minutes. The mixture was washed three times with deionized water and then vacuum dried at 90℃ for 6 hours to obtain modified heavy calcium carbonate powder.

[0049] 70 parts gypsum, 10 parts organic water-resistant lightweight aggregate, 10 parts inorganic water-resistant lightweight aggregate, 10 parts modified heavy calcium carbonate powder, 0.4 parts methylcellulose, 0.3 parts citric acid, and 0.3 parts sodium polyacrylate were placed in a reactor and stirred at 600 r / min for 5.5 h. During the stirring process, 60 parts tap water were added in two batches to obtain water-resistant lightweight gypsum mortar.

[0050] Example 4

[0051] Two parts of sodium silicate and 2.5 parts of glucosylrutin were added to 10 parts of deionized water and stirred at 400 rpm for 2 hours to obtain a treated sodium silicate solution. Two parts of sodium aluminate and 2.5 parts of glucosylrutin were added to 10 parts of deionized water and stirred at 400 rpm for 2 hours to obtain a treated sodium aluminate solution. The treated sodium silicate solution was aged at room temperature for 20 hours, then rapidly frozen in liquid nitrogen for 1 hour, and then freeze-dried under vacuum for 10 hours to obtain a sodium silicate-containing solid. The sodium silicate-containing solid was calcined at 500℃ for 3.5 hours to obtain porous silica with a stable pore structure. The treated sodium aluminate solution was aged at room temperature for 20 hours, then rapidly frozen in liquid nitrogen for 1 hour, and then freeze-dried under vacuum for 10 hours to obtain a sodium aluminate-containing solid. The sodium aluminate-containing solid was calcined at 1000℃ for 4.5 hours to obtain porous alumina with a stable pore structure. The porous silica and porous alumina prepared above were added to 11 parts of a suspension of 4-benzyloxyphenylethyl decanoate (the mass ratio of 4-benzyloxyphenylethyl decanoate to ethanol in the suspension of 4-benzyloxyphenylethyl decanoate was 1:10), stirred at 400 r / min for 1 h, washed 3 times with deionized water, and then vacuum dried at 80 °C for 6 h to obtain inorganic water-resistant lightweight aggregate.

[0052] Five parts of polyoxyethyl polyoxypropyl glycerol ether and five parts of poly(styrene-divinylbenzene) were added to 50 parts of deionized water and homogenized at 500 rpm for 40 min. Then, three parts of sodium bicarbonate, two parts of C16-18 fatty acid, and 0.3 parts of polyoxyethylene sulfosuccinate lauryl sodium were added and stirred at 500 rpm for 1.5 h. The mixture was then aged at room temperature under ventilation for 22 h to obtain a preliminary product of organic water-resistant lightweight aggregate. The preliminary product of organic water-resistant lightweight aggregate was first heat-treated in a 40℃ hot air circulating oven for 3-4 h, then the temperature was increased to 60℃ for 3-4 h, and then increased to 80℃ for 3-4 h. The mixture was washed three times with deionized water, ultrasonicated in deionized water at 500 rpm for 20 min, and then washed three times with deionized water to remove the sodium salt generated in the reaction. The mixture was then freeze-dried under vacuum for 10 h to obtain organic water-resistant lightweight aggregate.

[0053] Five parts of heavy calcium carbonate powder were dried at 90℃ for 1.5 h and then refined into powder in a ball mill to obtain pretreated heavy calcium carbonate powder. One part of bis(2-ethylhexyl)cyclohexane-1,2-dicarboxylic acid ester was added to 10 parts of ethanol solution and stirred at 400 r / min for 0.5 h. During the stirring, 10 parts of pretreated heavy calcium carbonate powder were added, and the mixture was homogenized at 400 r / min for 30 min. The mixture was washed three times with deionized water and then vacuum dried at 90℃ for 5 h to obtain modified heavy calcium carbonate powder.

[0054] 75 parts gypsum, 15 parts organic water-resistant lightweight aggregate, 5 parts inorganic water-resistant lightweight aggregate, 5 parts modified heavy calcium carbonate powder, 0.4 parts methylcellulose, 0.3 parts citric acid, and 0.3 parts sodium polyacrylate were placed in a reactor and stirred at 700 r / min for 5.5 h. During the stirring process, 60 parts tap water were added in two batches to obtain water-resistant lightweight gypsum mortar.

[0055] Example 5

[0056] Two parts of sodium silicate and 2.5 parts of glucosylrutin were added to 20 parts of deionized water and stirred at 500 rpm for 1 hour to obtain a treated sodium silicate solution. Two parts of sodium aluminate and 2.5 parts of glucosylrutin were added to 20 parts of deionized water and stirred at 500 rpm for 1 hour to obtain a treated sodium aluminate solution. The treated sodium silicate solution was aged at room temperature for 20 hours, then rapidly frozen in liquid nitrogen for 1 hour, and then freeze-dried under vacuum for 10 hours to obtain a solid containing sodium silicate. The solid containing sodium silicate was calcined at 500℃ for 4 hours to obtain porous silica with a stable pore structure. The treated sodium aluminate solution was aged at room temperature for 20 hours, then rapidly frozen in liquid nitrogen for 1 hour, and then freeze-dried under vacuum for 10 hours to obtain a solid containing sodium aluminate. The solid containing sodium aluminate was calcined at 1100℃ for 5 hours to obtain porous alumina with a stable pore structure. The porous silica and porous alumina prepared above were added to 11 parts of a suspension of 4-benzyloxyphenylethyl decanoate (the mass ratio of 4-benzyloxyphenylethyl decanoate to ethanol in the suspension of 4-benzyloxyphenylethyl decanoate was 1:10), stirred at 500 r / min for 1 h, washed 3 times with deionized water, and then vacuum dried at 90 °C for 5 h to obtain inorganic water-resistant lightweight aggregate.

[0057] Five parts of polyoxyethyl polyoxypropyl glycerol ether and five parts of poly(styrene-divinylbenzene) were added to 50 parts of deionized water and homogenized at 400 rpm for 30 min. Then, three parts of sodium bicarbonate, two parts of C16-18 fatty acid, and 0.3 parts of polyoxyethylene sulfosuccinate lauryl sodium were added and stirred at 400 rpm for 2 h. The mixture was then aged at room temperature under ventilation for 22 h to obtain a preliminary product of organic water-resistant lightweight aggregate. The preliminary product of organic water-resistant lightweight aggregate was first heat-treated in a 40℃ hot air circulating oven for 3-4 h, then the temperature was increased to 60℃ for 3-4 h, and then increased to 80℃ for 3-4 h. The aggregate was washed three times with deionized water, then sonicated in deionized water at 400 rpm for 30 min, and then washed three times with deionized water to remove the sodium salt generated in the reaction. Finally, the aggregate was freeze-dried under vacuum for 11 h to obtain organic water-resistant lightweight aggregate.

[0058] Five parts of heavy calcium carbonate powder were dried at 80℃ for 2 hours and then refined into powder in a ball mill to obtain pretreated heavy calcium carbonate powder. One part of bis(2-ethylhexyl)cyclohexane-1,2-dicarboxylic acid ester was added to 10 parts of ethanol and stirred at 300 r / min for 1 hour. During the stirring, 10 parts of pretreated heavy calcium carbonate powder were added and homogenized at 300 r / min for 20 minutes. The mixture was washed three times with deionized water and vacuum dried at 80℃ for 6 hours to obtain modified heavy calcium carbonate powder.

[0059] 80 parts of gypsum, 10 parts of organic water-resistant lightweight aggregate, 5 parts of inorganic water-resistant lightweight aggregate, 5 parts of modified heavy calcium carbonate powder, 0.4 parts of methylcellulose, 0.3 parts of citric acid, and 0.3 parts of sodium polyacrylate were placed in a reactor and stirred at 600 r / min for 5.5 h. During the stirring process, 60 parts of tap water were added in two batches to obtain water-resistant lightweight gypsum mortar.

[0060] Example 6

[0061] Four parts sodium silicate and five parts glucosylrutin were added to 20 parts deionized water and stirred at 400 rpm for 2 hours to obtain a treated sodium silicate solution. Four parts sodium aluminate and five parts glucosylrutin were added to 20 parts deionized water and stirred at 400 rpm for 2 hours to obtain a treated sodium aluminate solution. The treated sodium silicate solution was aged at room temperature for 24 hours, then rapidly frozen in liquid nitrogen for 2 hours, and then freeze-dried under vacuum for 12 hours to obtain a sodium silicate-containing solid. The sodium silicate-containing solid was calcined at 500℃ for 4 hours to obtain porous silica with a stable pore structure. The treated sodium aluminate solution was aged at room temperature for 24 hours, then rapidly frozen in liquid nitrogen for 2 hours, and then freeze-dried under vacuum for 12 hours to obtain a sodium aluminate-containing solid. The sodium aluminate-containing solid was calcined at 1100℃ for 5 hours to obtain porous alumina with a stable pore structure. The porous silica and porous alumina prepared above were added to a suspension of 22 parts of 4-benzyloxyphenylethyl decanoate (the mass ratio of 4-benzyloxyphenylethyl decanoate to ethanol in the suspension of 4-benzyloxyphenylethyl decanoate was 1:10), stirred at 500 r / min for 1.5 h, washed three times with deionized water, and then vacuum dried at 90 °C for 6 h to obtain inorganic water-resistant lightweight aggregate.

[0062] Five parts of polyoxyethyl polyoxypropyl glycerol ether and five parts of poly(styrene-divinylbenzene) were added to 50 parts of deionized water and homogenized at 500 rpm for 30 min. Then, three parts of sodium bicarbonate, two parts of C16-18 fatty acid, and 0.3 parts of polyoxyethylene sulfosuccinate lauryl sodium were added and stirred at 500 rpm for 1.5 h. The mixture was then aged at room temperature under ventilation for 24 h to obtain a preliminary product of organic water-resistant lightweight aggregate. The preliminary product of organic water-resistant lightweight aggregate was first heat-treated in a 40℃ hot air circulating oven for 3-4 h, then the temperature was increased to 60℃ for 3-4 h, and then increased to 80℃ for 3-4 h. The aggregate was washed three times with deionized water, then sonicated in deionized water at 500 rpm for 20 min, and then washed three times with deionized water to remove the sodium salt generated in the reaction. Finally, the aggregate was freeze-dried under vacuum for 11 h to obtain organic water-resistant lightweight aggregate.

[0063] Five parts of heavy calcium carbonate powder were dried at 90℃ for 1 hour and then refined into powder in a ball mill to obtain pretreated heavy calcium carbonate powder. One part of bis(2-ethylhexyl)cyclohexane-1,2-dicarboxylic acid ester was added to 10 parts of ethanol and stirred at 400 r / min for 0.5 hours. During the stirring, 10 parts of pretreated heavy calcium carbonate powder were added, and the mixture was homogenized at 400 r / min for 20 minutes. The mixture was washed three times with deionized water and then vacuum dried at 90℃ for 5 hours to obtain modified heavy calcium carbonate powder.

[0064] 80 parts gypsum, 8 parts organic water-resistant lightweight aggregate, 7 parts inorganic water-resistant lightweight aggregate, 5 parts modified heavy calcium carbonate powder, 0.4 parts methylcellulose, 0.3 parts citric acid, and 0.3 parts sodium polyacrylate were placed in a reactor and stirred at 700 r / min for 5 hours. During the stirring process, 60 parts tap water were added in two batches to obtain water-resistant lightweight gypsum mortar.

[0065] The present invention also includes comparative examples and related experiments.

[0066] Comparative Example 1

[0067] The difference between Comparative Example 1 and Example 1 is that in the preparation process of inorganic water-resistant lightweight aggregate, the sodium silicate solution and sodium aluminate solution were not treated with glucosylrutin, but were directly subjected to subsequent treatments such as aging and quick-freezing. The other components and preparation methods were the same as in Example 1, and water-resistant lightweight gypsum mortar was finally prepared.

[0068] Comparative Example 2

[0069] The difference between Comparative Example 2 and Example 1 is that the organic water-resistant lightweight aggregate was not prepared, but 20 parts of commercially available polystyrene foam were used instead of 20 parts of organic water-resistant lightweight aggregate. The other components and preparation methods were the same as in Example 1, and water-resistant lightweight gypsum mortar was finally prepared.

[0070] Comparative Example 3

[0071] The difference between Comparative Example 3 and Example 1 is that no modified heavy calcium carbonate powder was prepared. Instead, 10 parts of commercially available ordinary heavy calcium carbonate powder were used instead of 10 parts of modified heavy calcium carbonate powder. The other components and preparation methods were the same as in Example 1, and water-resistant lightweight gypsum mortar was finally prepared.

[0072] Performance testing

[0073] The water-resistant lightweight gypsum mortars of Examples 1-6 and Comparative Examples 1-3 were subjected to relevant performance tests according to the test standards and performance indicators in Table 1. The test results are summarized in Tables 2 and 3.

[0074] Table 1

[0075]

[0076] Table 2

[0077]

[0078] As can be seen from Tables 1 and 2, the test results of the bulk density, flexural strength, compressive strength and tensile bond strength of the water-resistant lightweight gypsum mortars prepared in Examples 1 to 6 are significantly better than those of the water-resistant lightweight gypsum mortars prepared in Comparative Examples 1 to 3. Furthermore, Example 1 has the best performance and is the optimal solution of this invention.

[0079] Based on the bulk density test results of Comparative Examples 1-3 and Example 1, and in conjunction with the performance indicators in Table 1, it can be seen that without the addition of glucosylrutin and modified heavy calcium carbonate powder, the bulk density values ​​of Comparative Examples 1 and 3 are relatively large and do not meet the performance indicators in Table 1. In contrast, the bulk density of polystyrene foam in Comparative Example 2 is relatively low and meets the bulk density performance indicators in Table 1. Therefore, it can be concluded that the addition of glucosylrutin, organic water-resistant lightweight aggregate, and modified heavy calcium carbonate powder has a significant impact on the lightweight properties of water-resistant lightweight gypsum mortar, with glucosylrutin and modified heavy calcium carbonate powder having the greatest impact.

[0080] Based on the test data of flexural strength, compressive strength, and tensile bond strength of Examples 1 and Comparative Examples 1-3, and in conjunction with the performance indicators in Table 1, it can be seen that the compressive strength of Comparative Examples 1-3 all meet the performance indicators in Table 1. However, the flexural strength and tensile bond strength of Comparative Examples 1 and 2 do not meet the performance indicators in Table 1. Furthermore, Comparative Example 2 has the worst flexural strength, at only 0.5 MPa, while Comparative Example 1 has the lowest tensile bond strength, at 0.14 MPa. Therefore, it can be concluded that the addition of glucosyl rutin and organic water-resistant lightweight aggregate has a significant impact on the flexural strength of water-resistant lightweight gypsum mortar, while the addition of glucosyl rutin and modified heavy calcium carbonate powder has a significant impact on the tensile bond strength of water-resistant lightweight gypsum mortar.

[0081] Table 3

[0082]

[0083] As shown in Tables 1 and 3, the water-resistant lightweight gypsum mortars prepared in Examples 1-6 have significantly higher water resistance, durability, and workability than the water-resistant lightweight gypsum mortars prepared in Comparative Examples 1-3. Furthermore, Example 1 exhibits the best performance and is the optimal solution of this invention.

[0084] Combining the performance indicators in Table 1 and the water retention rate test data in Table 3, a comparison of the test data of Example 1 and Comparative Examples 1-3 shows that the water retention rates of Comparative Examples 1-3 are 52%, 89%, and 78%, respectively, all lower than the 96% in Example 1. Furthermore, except for Comparative Example 2, none of them meet the performance indicator of greater than or equal to 88% in Table 1. It is evident that the lack of the glucosylrutin treatment step significantly reduces the water retention rate in Comparative Example 1. The water retention rate of Comparative Example 3, which uses ordinary heavy calcium carbonate powder, is also affected. However, the water retention rate of Comparative Example 2, which uses commercially available polystyrene foam instead of organic water-resistant lightweight aggregate, basically meets the requirements of Table 1.

[0085] Based on the performance indicators and test results of Comparative Examples 1-3 and Example 1 regarding 28-day impermeability pressure, 28-day compressive strength, 14-day tensile bond strength, 28-day shrinkage rate, and plastic retention time, it can be seen that the 28-day compressive strength test result of Comparative Example 1 meets the requirements of Table 1, but does not meet the requirements of the other performances; while Comparative Example 2 has good performance in 28-day impermeability pressure, tensile bond strength, and plastic retention time, but poor performance in 28-day compressive strength and 28-day shrinkage rate, which does not meet the requirements of Table 1; Comparative Example 3 only has good performance in 28-day compressive strength, and the other performance tests do not meet the requirements of Table 1.

[0086] The above are preferred embodiments of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing water-resistant lightweight gypsum mortar, characterized in that, Includes the following steps: S1. Sodium silicate and glucosylrutin are added to deionized water and stirred to obtain a treated sodium silicate solution. Sodium aluminate and glucosylrutin are added to deionized water and stirred to obtain a treated sodium aluminate solution. The treated sodium silicate solution and the treated sodium aluminate solution are aged, quick-frozen, freeze-dried, and calcined at high temperature to obtain porous silica and porous alumina with stable pore structures, respectively. Then, the porous silica and porous alumina are added to a suspension of 4-benzyloxyphenyl ethyl decanoate, stirred, washed, and dried to obtain inorganic water-resistant lightweight aggregate. S2. Polyoxyethyl polyoxypropyl glycerol ether and poly(styrene-divinylbenzene) are added to deionized water and homogenized and dispersed. Then, sodium bicarbonate, C16-18 fatty acid and polyoxyethylene sulfosuccinate lauryl sodium are added, stirred and aged to obtain a preliminary product of organic water-resistant lightweight aggregate. The product is first heat-treated in a 40℃ hot air circulating oven for 3-4 hours, then the temperature is increased to 60℃ for 3-4 hours, and then the temperature is increased to 80℃ for 3-4 hours. After washing with deionized water, ultrasonic and freeze-drying are performed to obtain organic water-resistant lightweight aggregate. S3. After drying and ball milling the heavy calcium carbonate powder, add it to bis(2-ethylhexyl)cyclohexane-1,2-dicarboxylic acid ester and ethanol, homogenize, wash and dry to obtain modified heavy calcium carbonate powder. S4. Mix gypsum, water, inorganic water-resistant lightweight aggregate, organic water-resistant lightweight aggregate, modified heavy calcium carbonate powder and other additives to obtain water-resistant lightweight gypsum mortar. The mass ratio of glucosylrutin, sodium silicate and sodium aluminate is 5:4:4; The treated sodium silicate solution and sodium aluminate solution were calcined at high temperatures of 500~600℃ and 1000~1100℃, respectively, for 3~4h and 4~5h, respectively; the mass ratio of the organic water-resistant lightweight aggregate, inorganic water-resistant lightweight aggregate, and modified heavy calcium carbonate powder was (8~20):(5~10):(5~10).

2. The method for preparing a water-resistant lightweight gypsum mortar according to claim 1, characterized in that, In step S1, the stirring speed is 400-500 r / min and the stirring time is 1-2 h. The aging time for the treated sodium silicate solution during aging, quick-freezing, freeze-drying, and high-temperature calcination is 20-24 h, the quick-freezing time is 1-2 h, and the freeze-drying time is 10-12 h. Similarly, the aging time for the treated sodium aluminate solution during aging, quick-freezing, freeze-drying, and high-temperature calcination is 20-24 h, the quick-freezing time is 1-2 h, and the freeze-drying time is 10-12 h. The porous silica and porous alumina are added to a suspension of 4-benzyloxyphenylethyl decanoate, and the drying temperature during stirring, washing, and drying is 80-90°C for 5-6 h. The mass ratio of 4-benzyloxyphenylethyl decanoate to ethanol in the 4-benzyloxyphenylethyl decanoate suspension is 1:

10.

3. The method for preparing a water-resistant lightweight gypsum mortar according to claim 1, characterized in that, In step S2, polyoxyethyl polyoxypropyl glycerol ether and poly(styrene-divinylbenzene) are added to deionized water and homogenized at 400-500 r / min for 30-40 min. Then, sodium bicarbonate, C16-18 fatty acid and polyoxyethylene sulfosuccinate lauryl sodium are added and stirred at 400-500 r / min for 1.5-3 h. The mixture is then aged at room temperature under ventilation for 20-24 h to obtain a preliminary product of organic water-resistant lightweight aggregate.

4. The method for preparing a water-resistant lightweight gypsum mortar according to claim 3, characterized in that, In step S2, the preliminary product of the organic water-resistant lightweight aggregate is heat-treated, washed three times with deionized water, ultrasonicated in deionized water at 400-500 r / min for 20-30 min, washed three times with deionized water to remove the sodium salt generated in the reaction, and then freeze-dried under vacuum for 10-12 h to obtain the organic water-resistant lightweight aggregate.

5. The method for preparing a water-resistant lightweight gypsum mortar according to claim 1, characterized in that, In step S3, the heavy calcium carbonate powder is dried and ball-milled to obtain pretreated heavy calcium carbonate powder. Bis(2-ethylhexyl)cyclohexane-1,2-dicarboxylic acid ester is added to ethanol, stirred, and then the pretreated heavy calcium carbonate powder is added. The mixture is homogenized, washed, and dried to obtain modified heavy calcium carbonate powder.

6. The method for preparing a water-resistant lightweight gypsum mortar according to claim 5, characterized in that, In step S3, the stirring speed is 300-400 r / min and the time is 0.5-1 h; the drying temperature during ball milling of the heavy calcium carbonate powder is 80-90℃ and the time is 1-2 h; after adding the pretreated heavy calcium carbonate powder, the homogenization process is carried out at a speed of 300-400 r / min, the homogenization time is 20-30 min, the drying temperature is 80-90℃, and the drying time is 5-6 h.

7. The method for preparing a water-resistant lightweight gypsum mortar according to claim 1, characterized in that, In step S4, gypsum, inorganic water-resistant lightweight aggregate, organic water-resistant lightweight aggregate, modified heavy calcium carbonate powder, and other additives are stirred together, with tap water added twice during the process to obtain water-resistant lightweight gypsum mortar.

8. The method for preparing a water-resistant lightweight gypsum mortar according to claim 7, characterized in that, In step S4, the stirring speed is 600~700 r / min and the stirring time is 5~6 h; the other additives are methylcellulose, citric acid, and sodium polyacrylate.

9. A water-resistant lightweight gypsum mortar, characterized in that, The water-resistant lightweight gypsum mortar is prepared by the method described in any one of claims 1 to 8, comprising the following raw materials in parts by weight: 60-80 parts gypsum, 60 parts water, 1 part other additives, 2.5-5 parts glucosyl rutin, 2-4 parts sodium silicate, 2-4 parts sodium aluminate, 1-2 parts 4-benzyloxyphenyl ethyl decanoate, 5-10 parts polyoxyethyl polyoxypropyl glycerol ether, 5-10 parts poly(styrene-divinylbenzene), 3-6 parts sodium bicarbonate, 2-4 parts C16-18-fatty acid, 0.3-0.5 parts sodium lauryl sulfosuccinate, 5-10 parts heavy calcium carbonate powder, and 1-2 parts bis(2-ethylhexyl)cyclohexane-1,2-dicarboxylic acid ester.

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