Water-resistant lightweight gypsum mortar and preparation method thereof

Abstract

The invention provides water-resistant lightweight gypsum mortar and a preparation method thereof, and belongs to the technical field of building materials, and the preparation method comprises the following steps: respectively treating sodium silicate and sodium aluminate with glucosylrutin, aging, freeze-drying, calcining at high temperature, and adding 4-benzyloxy phenyl ethyl caprate to obtain inorganic water-resistant lightweight aggregate; the preparation method comprises the following steps: homogenizing polyoxyethylene polyoxypropyl glyceryl ether, poly (styrene-divinylbenzene) and water, adding sodium bicarbonate, C16-18-fatty acid and polyethylene oxide sulfosuccinic acid lauryl sodium salt, stirring, aging, carrying out heat treatment, and drying to obtain the organic water-resistant lightweight aggregate. The preparation method comprises the following steps: modifying heavy calcium carbonate powder by using bis (2-ethylhexyl) cyclohexane-1, 2-dicarboxylate to obtain modified heavy calcium carbonate powder; mixing gypsum, water, the inorganic and organic water-resistant lightweight aggregate, the modified heavy calcium powder and other auxiliaries to obtain the water-resistant lightweight gypsum mortar. The technical scheme provided by the invention not only has excellent water resistance and light weight performance, but also has good environmental protection property and cost effectiveness.

Description

Technical Field

[0001] The invention belongs to the technical field of building materials, and particularly relates to a water-resistant lightweight gypsum mortar and a preparation method thereof. Background Art

[0002] At present, most of the gypsum mortars used in actual projects are made of traditional material ratios, which have high volume density, poor energy consumption and low environmental protection rate. They cannot meet people's requirements for living comfort and environmental health in building interior decoration.

[0003] Water-resistant lightweight gypsum mortar typically consists of gypsum as the primary component, with lightweight aggregate and heavy calcium powder as secondary components, along with various additives such as air-entraining agents, retarders, and water-retaining agents, as well as water. Current organic water-resistant lightweight aggregates generally offer excellent lightweight properties but suffer from low compressive strength, making them difficult to use in load-bearing structures or applications requiring high loads. Inorganic water-resistant lightweight aggregates offer higher compressive strength and excellent stability, but they suffer from high density and relatively high cost, making them difficult to use for large-scale paving or applications requiring high economic efficiency.

[0004] In addition, although existing water-resistant lightweight aggregates can provide certain water resistance, their water resistance will gradually decrease under long-term contact with water. Compared with traditional gypsum mortar, water-resistant lightweight gypsum mortar usually has lower compressive strength and poorer durability.

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

[0006] In view of this, the present invention provides a water-resistant lightweight gypsum mortar and a preparation method thereof. The present invention improves the water resistance, lightness, flexural resistance and compressive resistance of the gypsum mortar through the composite use of inorganic and organic water-resistant lightweight aggregates, modified heavy calcium powder, gypsum and other components, and also has good environmental protection and cost-effectiveness.

[0007] To achieve the above object, the present invention provides a method for preparing water-resistant lightweight gypsum mortar, comprising the following steps: S1. Sodium silicate and sodium aluminate are treated with glucosylrutin, aged, quickly frozen, dried, and calcined at high temperature to obtain porous silica and porous alumina, respectively. The porous silica and porous alumina are then added to a suspension of 4-benzyloxyphenylethyldecanoate, stirred, washed, and dried to obtain an inorganic water-resistant lightweight aggregate. S2, adding polyoxyethyl polyoxypropyl glyceryl ether and poly(styrene-divinylbenzene) into deionized water, homogenizing and dispersing them, adding sodium bicarbonate, C16-18 fatty acid and sodium lauryl polyethylene oxide sulfosuccinate, stirring, aging, heat treating, ultrasonicating and freeze drying to obtain an organic water-resistant lightweight aggregate; S3, drying and ball-milling the heavy calcium powder, adding bis(2-ethylhexyl)cyclohexane-1,2-dicarboxylate and ethanol, homogenizing, washing and drying to obtain modified heavy calcium powder; S4. Mix gypsum, water, inorganic and organic water-resistant lightweight aggregates, modified heavy calcium powder and other additives to obtain water-resistant lightweight gypsum mortar.

[0008] The present invention prepares an organic water-resistant lightweight aggregate by compounding poly(styrene-divinylbenzene) and polyoxyethyl polyoxypropyl glyceryl ether. The polyoxyethyl segment in the polyoxyethyl polyoxypropyl glyceryl ether has good hydrophilicity, and the polyoxypropyl segment and the glycerol group can form hydrogen bonds and van der Waals forces with the hydrophobic long chain of poly(styrene-divinylbenzene), thereby facilitating the bonding between components within the composite material and forming a stable suspension under the action of homogenization. Sodium bicarbonate is introduced, and the property of generating CO2 after the thermal decomposition of sodium bicarbonate is used to form bubbles in the high-density base material, forming a porous structure, thereby reducing the material density and meeting the lightweight requirements.

[0009] During the preparation of the inorganic water-resistant lightweight aggregate, the glucosylrutin introduced into the present invention can form pores after high-temperature carbonization, helping to form a porous structure, reduce material density, and meet lightweighting requirements. It also provides additional adsorption sites for 4-benzyloxyphenylethyldecanoate, helping 4-benzyloxyphenylethyldecanoate to form a hydrophobic adsorption layer on the surface of the porous material, thereby reducing water penetration and improving water resistance. Furthermore, the sulfonate ions contained in the sodium lauryl polyethylene oxide sulfosuccinate and the hydroxyl groups on the polyoxyethyl polyoxypropyl glyceryl ether can form hydrogen bonds and electrostatic interactions with the ester groups of 4-benzyloxyphenylethyldecanoate in the inorganic water-resistant lightweight aggregate, thereby improving the compatibility and interfacial adhesion between the organic and inorganic components.

[0010] The present invention also improves the water resistance of the heavy calcium powder by introducing bis(2-ethylhexyl)cyclohexane-1,2-dicarboxylate, which is adsorbed on the surface of the heavy calcium powder to form a hydrophobic coating. Furthermore, bis(2-ethylhexyl)cyclohexane-1,2-dicarboxylate is structurally compatible with the organic components in inorganic and organic water-resistant lightweight aggregates, increasing the dispersion compatibility between the modified heavy calcium powder and the organic and inorganic phases. This helps improve the interfacial adhesion between the components of the water-resistant lightweight gypsum mortar, thereby increasing the stability of the water-resistant lightweight gypsum mortar system.

[0011] Optionally, in 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, and then the porous silica and porous alumina are added to a suspension of 4-benzyloxyphenylethyldecanoate, stirred, washed, and dried to obtain an inorganic water-resistant lightweight aggregate.

[0012] The aging treatment of the present invention helps to enhance the interaction between sodium silicate, sodium aluminate and glucosylrutin; rapid freezing helps to fix the structure; vacuum freeze drying can remove moisture at low temperature and low pressure, avoiding structural damage caused by high temperature; high-temperature calcination can carbonize and remove organic matter, form a porous structure, and improve the mechanical strength and chemical stability of the inorganic water-resistant lightweight aggregate.

[0013] Optionally, in the S1, the stirring speed is 400~500r / min, and the time is 1~2h; the mass ratio of the glucosylrutin, sodium silicate and sodium aluminate is 5:4:4; the treated sodium silicate solution is aged, quick-frozen, freeze-dried and calcined at high temperature, the aging time is 20~24h, the quick-freezing time is 1~2h, the freeze-drying time is 10~12h, the high-temperature calcination temperature is 500~600℃, and the high-temperature calcination time is 3~4h; the treated sodium aluminate solution is aged, quick-frozen, freeze-dried and calcined at high temperature, The aging time during the high-temperature calcination process is 20 to 24 hours, the quick-freezing time is 1 to 2 hours, the freeze-drying time is 10 to 12 hours, the high-temperature calcination temperature is 1000 to 1100° C., and the high-temperature calcination time is 4 to 5 hours. The porous silica and porous alumina are added to a suspension of 4-benzyloxyphenyl ethyl decanoate, and the drying temperature during the stirring, washing, and drying process is 80 to 90° C. and the drying time is 5 to 6 hours. The mass ratio of 4-benzyloxyphenyl ethyl decanoate to ethanol in the suspension of 4-benzyloxyphenyl ethyl decanoate is 1:10.

[0014] Optionally, in S2, polyoxyethylene polyoxypropyl glyceryl ether and poly(styrene-divinylbenzene) are added to deionized water, homogenized and dispersed at 400-500 r / min for 30-40 min, and then sodium bicarbonate, C16-18-fatty acid and polyethylene oxide sulfosuccinate lauryl sodium are added, stirred at 400-500 r / min for 1.5-3 h, and aged under ventilation at room temperature for 20-24 h to obtain a preliminary product of organic water-resistant lightweight aggregate.

[0015] Optionally, in S2, the preliminary product of the organic water-resistant lightweight aggregate is first heat-treated in a hot air circulation oven at 40°C for 3-4 hours, then the temperature is raised to 60°C for heat treatment for 3-4 hours, and then raised to 80°C for heat treatment for 3-4 hours, washed with deionized water three times, ultrasonicated in deionized water at 400-500 r / min for 20-30 minutes, and then washed with deionized water three times to remove the sodium salt generated by the reaction, and vacuum freeze-dried for 10-12 hours to obtain the organic water-resistant lightweight aggregate.

[0016] The present invention first homogeneously disperses polyoxyethyl polyoxypropyl glyceryl ether and poly(styrene-divinylbenzene) to increase the dispersibility of the two polymers in deionized water. Subsequently, sodium bicarbonate, C16-18 fatty acids, and sodium lauryl polyethylene oxide sulfosuccinate are added to form a cross-linked network. Stirring and ventilation aging are performed to promote the reaction between the components and 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 that impurities are completely removed, and then freeze-drying is performed to maintain the porous structure to obtain a dry organic water-resistant lightweight aggregate.

[0017] Optionally, in S3, the heavy calcium powder is dried and ball-milled to obtain pretreated heavy calcium powder, di(2-ethylhexyl)cyclohexane-1,2-dicarboxylate is added to ethanol and stirred, and after adding the pretreated heavy calcium powder, homogenization, washing, and drying are performed to obtain modified heavy calcium powder.

[0018] The present invention pre-treats the heavy calcium powder by drying and ball milling, which helps to make the surface of the pre-treated heavy calcium powder drier and have a higher specific surface area, avoids the adhesion phenomenon between the heavy calcium powders due to moisture, makes it easier to disperse, and helps to improve the subsequent surface modification effect.

[0019] Optionally, in S3, the heavy calcium powder is dried, the drying temperature during ball milling is 80~90℃, and the time is 1~2h; the stirring speed is 300~400r / min, and the time is 0.5~1h; the heavy calcium powder is dried, the drying temperature during ball milling is 80~90℃, and the time is 1~2h; after adding the pretreated heavy calcium powder, the homogenization, washing and drying process is carried out at a homogenization speed of 300~400r / min, the homogenization time is 20~30min, the drying temperature is 80~90℃, and the drying time is 5~6h.

[0020] Optionally, in S4, 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 the stirring to obtain water-resistant lightweight gypsum mortar.

[0021] The present invention adopts a method of first mixing the components except water and then gradually adding water in the preparation process of the water-resistant lightweight gypsum mortar, mainly to enhance the dispersion of the components in the mortar and avoid excessively high or low local concentrations. At the same time, adding water twice can also control the speed of the hydration reaction, which helps to improve the fluidity and construction performance of the mortar.

[0022] Optionally, in S4, the stirring speed is 600~700r / min, and the time is 5~6h; the mass ratio of the organic water-resistant lightweight aggregate, inorganic water-resistant lightweight aggregate, and modified heavy calcium powder added is (8~20): (5~10): (5~10); the other additives are methyl cellulose, citric acid, and sodium polyacrylate.

[0023] In order to achieve the above-mentioned object, the present invention also provides a water-resistant lightweight gypsum mortar, comprising the following raw materials in parts by mass: 60-80 parts of gypsum, 60 parts of water, 1 part of other additives, 2.5-5 parts of glucosylrutin, 2-4 parts of sodium silicate, 2-4 parts of sodium aluminate, 1-2 parts of 4-benzyloxyphenyl ethyl decanoate, 5-10 parts of polyoxyethyl polyoxypropyl glyceryl ether, 5-10 parts of poly(styrene-divinylbenzene), 3-6 parts of sodium bicarbonate, 2-4 parts of C16-18-fatty acid, 0.3-0.5 parts of sodium lauryl polyethylene oxide sulfosuccinate, 5-10 parts of heavy calcium powder, and 1-2 parts of bis(2-ethylhexyl)cyclohexane-1,2-dicarboxylate.

[0024] The water-resistant lightweight gypsum mortar obtained by the invention has good environmental protection and cost-effectiveness while improving water resistance, lightness, flexural resistance and compression resistance.

[0025] The above technical solution of the present invention includes at least the following beneficial effects: 1. The present invention improves the water resistance and lightness of the water-resistant lightweight organic aggregate by compounding amphiphilic poly(styrene-divinylbenzene) and polyoxyethyl polyoxypropyl glyceryl ether and introducing sodium bicarbonate to form a porous structure. Then, a hydrophobic C16-18-fatty acid and amphiphilic sodium lauryl polyethylene oxide sulfosuccinate are added to form an interaction mainly based on hydrogen bonds and van der Waals forces with polyoxyethyl polyoxypropyl glyceryl ether and poly(styrene-divinylbenzene), thereby further improving the water resistance of the water-resistant lightweight organic aggregate and helping to maintain good dispersibility and interfacial effects.

[0026] 2. The present invention also forms a porous structure by using sodium silicate and sodium aluminate as inorganic material precursors, mixing them with glucosylrutin in deionized water, and then removing organic matter through freeze-drying and high-temperature calcination and carbonization, thereby reducing the material density and improving the lightweight of the inorganic water-resistant lightweight aggregate. At the same time, the hydrophobic properties of 4-benzyloxyphenylethyldecanoate are used to perform water-resistant modification, which helps to improve the water resistance and durability of the inorganic water-resistant lightweight aggregate.

[0027] 3. The heavy calcium powder used in the present invention is first dried and ball-milled, and then surface-treated with bis(2-ethylhexyl)cyclohexane-1,2-dicarboxylate, thereby improving the water resistance of the heavy calcium powder. The hydrophobic layer formed by bis(2-ethylhexyl)cyclohexane-1,2-dicarboxylate is similarly compatible with the components in the organic water-resistant lightweight aggregate and the inorganic water-resistant lightweight aggregate, thereby enhancing the compatibility and interfacial adhesion between the components in the water-resistant lightweight gypsum mortar.

[0028] 4. The materials used in the present invention are all non-toxic and harmless, and the preparation process is simple, the cost is relatively low, and it has good environmental protection and cost-effectiveness. DETAILED DESCRIPTION

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, 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 part of the embodiments of the present invention, not all of the embodiments. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of the present invention.

[0030] Example 1 4 parts sodium silicate and 5 parts glucosylrutin were added to 20 parts deionized water and stirred at 400 rpm for 2 hours to obtain a treated sodium silicate solution. 4 parts sodium aluminate and 5 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 in a vacuum for 12 hours to obtain a sodium silicate-containing solid. The sodium silicate-containing solid was calcined at 500°C 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 in a vacuum for 12 hours to obtain a sodium aluminate-containing solid. The sodium aluminate-containing solid was calcined at 1100°C 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-benzyloxyphenylethyldecanoate (the mass ratio of 4-benzyloxyphenylethyldecanoate to ethanol in the suspension of 4-benzyloxyphenylethyldecanoate was 1:10), stirred at 400 r / min for 2 h, washed with deionized water three times, and then vacuum dried at 80°C for 6 h to obtain an inorganic water-resistant lightweight aggregate.

[0031] 10 parts of polyoxyethylene polyoxypropyl glycerol ether and 10 parts of poly(styrene-divinylbenzene) were added to 100 parts of deionized water and homogenized at 400 r / min for 40 minutes. Then, 6 parts of sodium bicarbonate, 4 parts of C16-18 fatty acid, and 0.5 parts of sodium lauryl polyethylene oxide sulfosuccinate were added and stirred at 400 r / min for 2 hours. The mixture was aged at room temperature for 24 hours under ventilation to obtain a preliminary product of an organic water-resistant lightweight aggregate. The preliminary product of the organic water-resistant lightweight aggregate was first heat-treated in a hot air circulation oven at 40°C for 3-4 hours, then heated to 60°C for 3-4 hours, and then heated to 80°C for 3-4 hours. The product was washed with deionized water three times, ultrasonicated in deionized water at 500 r / min for 30 minutes, and then washed with deionized water three times to remove the sodium salt generated by the reaction. The product was then freeze-dried in vacuum for 12 hours to obtain the organic water-resistant lightweight aggregate.

[0032] 10 parts of heavy calcium powder were dried at 80°C for 2 hours and then refined in a ball mill to obtain pretreated heavy calcium powder. 2 parts of bis(2-ethylhexyl)cyclohexane-1,2-dicarboxylate were added to 20 parts of ethanol and stirred at 300 r / min for 1 hour. 10 parts of pretreated heavy calcium powder were added and homogenized at 300 r / min for 20 minutes. The mixture was washed with deionized water three times and vacuum dried at 80°C for 6 hours to obtain modified heavy calcium powder.

[0033] 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 powder, 0.4 parts of methyl cellulose, 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 this period, 60 parts of tap water were added twice to obtain water-resistant lightweight gypsum mortar.

[0034] Example 2 4 parts sodium silicate and 5 parts glucosylrutin were added to 20 parts deionized water and stirred at 500 rpm for 1.5 hours to obtain a treated sodium silicate solution. 4 parts sodium aluminate and 5 parts glucosylrutin were added to 20 parts deionized water and stirred at 500 rpm for 1.5 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 in a vacuum for 12 hours to obtain a sodium silicate-containing solid. The sodium silicate-containing solid was calcined at 600°C 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 in a vacuum for 12 hours to obtain a sodium aluminate-containing solid. The sodium aluminate-containing solid was calcined at 1000°C 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-benzyloxyphenylethyldecanoate (the mass ratio of 4-benzyloxyphenylethyldecanoate to ethanol in the suspension of 4-benzyloxyphenylethyldecanoate was 1:10), stirred at 500 r / min for 2 hours, washed with deionized water three times, and then vacuum dried at 90°C for 5 hours to obtain an inorganic water-resistant lightweight aggregate.

[0035] 10 parts of polyoxyethylene polyoxypropyl glycerol ether and 10 parts of poly(styrene-divinylbenzene) were added to 100 parts of deionized water and homogenized at 500 r / min for 30 minutes. Then, 4 parts of sodium bicarbonate, 4 parts of C16-18 fatty acid, and 0.5 parts of sodium lauryl polyoxyethylene sulfosuccinate were added. The mixture was stirred at 500 r / min for 1.5 hours and aged at room temperature for 22 hours to obtain a preliminary product of an organic water-resistant lightweight aggregate. The preliminary product of the organic water-resistant lightweight aggregate was first heat-treated in a hot air circulation oven at 40°C for 3-4 hours, then heated to 60°C for 3-4 hours, and then heated to 80°C for 3-4 hours. The product was washed with deionized water three times, ultrasonicated in deionized water at 500 r / min for 20 minutes, and then washed with deionized water three times to remove the sodium salt generated by the reaction. The product was then freeze-dried in vacuum for 12 hours to obtain the organic water-resistant lightweight aggregate.

[0036] 10 parts of heavy calcium powder were dried at 80°C for 2 hours and then refined in a ball mill to obtain pretreated heavy calcium powder. 2 parts of bis(2-ethylhexyl)cyclohexane-1,2-dicarboxylate were added to 20 parts of ethanol and stirred at 300 r / min for 1 hour. During this time, 10 parts of pretreated heavy calcium powder were added and homogenized at 300 r / min for 30 minutes. The mixture was washed with deionized water three times and vacuum dried at 80°C for 6 hours to obtain modified heavy calcium powder.

[0037] 65 parts of gypsum, 15 parts of organic water-resistant lightweight aggregate, 10 parts of inorganic water-resistant lightweight aggregate, 10 parts of modified heavy calcium powder, 0.4 parts of methyl cellulose, 0.3 parts of citric acid, and 0.3 parts of sodium polyacrylate were placed in a reactor and stirred at 700 r / min for 5 hours. During this period, 60 parts of tap water were added twice to obtain water-resistant lightweight gypsum mortar.

[0038] Example 3 4 parts sodium silicate and 5 parts glucosylrutin were added to 20 parts deionized water and stirred at 500 rpm for 1.5 hours to obtain a treated sodium silicate solution. 4 parts sodium aluminate and 5 parts glucosylrutin were added to 20 parts deionized water and stirred at 500 rpm for 1.5 hours to obtain a treated sodium aluminate solution. The treated sodium silicate solution was aged at room temperature for 22 hours, then rapidly frozen in liquid nitrogen for 2 hours, and then freeze-dried in a vacuum for 12 hours to obtain a sodium silicate-containing solid. The sodium silicate-containing solid was calcined at 550°C for 3.5 hours to obtain porous silica with a stable pore structure. The treated sodium aluminate solution was aged at room temperature for 22 hours, then rapidly frozen in liquid nitrogen for 2 hours, and then freeze-dried in a vacuum for 12 hours to obtain a sodium aluminate-containing solid. The sodium aluminate-containing solid was calcined at 1050°C for 4.5 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 is 1:10), stirred at 400 r / min for 2 hours and at 500 r / min for 1.5 hours, washed with deionized water three times, and then vacuum dried at 90°C for 6 hours to obtain an inorganic water-resistant lightweight aggregate.

[0039] 5 parts of polyoxyethylene polyoxypropyl glycerol ether and 5 parts of poly(styrene-divinylbenzene) were added to 50 parts of deionized water and homogenized at 400 r / min for 40 minutes. Then, 3 parts of sodium bicarbonate, 2 parts of C16-18 fatty acid, and 0.3 parts of sodium lauryl polyoxyethylene sulfosuccinate were added. The mixture was stirred at 400 r / min for 1.5 hours and aged at room temperature for 20 hours to obtain a preliminary product of an organic water-resistant lightweight aggregate. The preliminary product of the organic water-resistant lightweight aggregate was first heat-treated in a hot air circulation oven at 40°C for 3-4 hours, then heated to 60°C for 3-4 hours, and then heated to 80°C for 3-4 hours. The product was washed with deionized water three times, ultrasonicated in deionized water at 400 r / min for 20 minutes, and then washed with deionized water three times to remove the sodium salt generated by the reaction. The product was then freeze-dried in vacuum for 10 hours to obtain the organic water-resistant lightweight aggregate.

[0040] 10 parts of heavy calcium powder were dried at 90°C for 2 hours and then refined in a ball mill to obtain pretreated heavy calcium powder. 2 parts of bis(2-ethylhexyl)cyclohexane-1,2-dicarboxylate were added to 20 parts of ethanol and stirred at 300 r / min for 1 hour. During this period, 10 parts of pretreated heavy calcium powder were added and homogenized at 400 r / min for 20 minutes. The mixture was washed with deionized water three times and vacuum dried at 90°C for 6 hours to obtain modified heavy calcium powder.

[0041] 70 parts of gypsum, 10 parts of organic water-resistant lightweight aggregate, 10 parts of inorganic water-resistant lightweight aggregate, 10 parts of modified heavy calcium powder, 0.4 parts of methyl cellulose, 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 hours. During this period, 60 parts of tap water were added twice to obtain water-resistant lightweight gypsum mortar.

[0042] Example 4 2 parts sodium silicate and 2.5 parts glucosylrutin were added to 10 parts deionized water and stirred at 400 rpm for 2 hours to obtain a treated sodium silicate solution. 2 parts sodium aluminate and 2.5 parts glucosylrutin were added to 10 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 20 hours, then rapidly frozen in liquid nitrogen for 1 hour, and then freeze-dried in a vacuum for 10 hours to obtain a sodium silicate-containing solid. The sodium silicate-containing solid was calcined at 500°C 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 in a vacuum for 10 hours to obtain a sodium aluminate-containing solid. The sodium aluminate-containing solid was calcined at 1000°C for 4.5 hours to obtain porous alumina with a stable pore structure. The porous silica and porous alumina prepared above were added to a suspension of 11 parts of 4-benzyloxyphenylethyldecanoate (the mass ratio of 4-benzyloxyphenylethyldecanoate to ethanol in the suspension of 4-benzyloxyphenylethyldecanoate was 1:10), stirred at 400 r / min for 1 hour, washed with deionized water three times, and then vacuum dried at 80°C for 6 hours to obtain an inorganic water-resistant lightweight aggregate.

[0043] 5 parts of polyoxyethylene polyoxypropyl glycerol ether and 5 parts of poly(styrene-divinylbenzene) were added to 50 parts of deionized water and homogenized at 500 r / min for 40 minutes. Then, 3 parts of sodium bicarbonate, 2 parts of C16-18 fatty acid, and 0.3 parts of sodium lauryl polyoxyethylene sulfosuccinate were added and stirred at 500 r / min for 1.5 hours. The product was aged at room temperature under ventilation for 22 hours to obtain a preliminary product of an organic water-resistant lightweight aggregate. The preliminary product of the organic water-resistant lightweight aggregate was first heat-treated in a hot air circulation oven at 40°C for 3-4 hours, then heated to 60°C for 3-4 hours, and then heated to 80°C for 3-4 hours. The product was washed with deionized water three times, ultrasonicated in deionized water at 500 r / min for 20 minutes, and then washed with deionized water three times to remove the sodium salt generated by the reaction. The product was then freeze-dried in vacuum for 10 hours to obtain the organic water-resistant lightweight aggregate.

[0044] 5 parts of heavy calcium powder were dried at 90°C for 1.5 hours and then refined in a ball mill to obtain pretreated heavy calcium powder. 1 part of bis(2-ethylhexyl)cyclohexane-1,2-dicarboxylate was added to 10 parts of ethanol solution and stirred at 400 r / min for 0.5 hours. During this period, 10 parts of pretreated heavy calcium powder were added and homogenized at 400 r / min for 30 minutes. The mixture was washed with deionized water three times and vacuum dried at 90°C for 5 hours to obtain modified heavy calcium powder.

[0045] 75 parts of gypsum, 15 parts of organic water-resistant lightweight aggregate, 5 parts of inorganic water-resistant lightweight aggregate, 5 parts of modified heavy calcium powder, 0.4 parts of methyl cellulose, 0.3 parts of citric acid, and 0.3 parts of sodium polyacrylate were placed in a reactor and stirred at 700 r / min for 5.5 hours. During this period, 60 parts of tap water were added twice to obtain water-resistant lightweight gypsum mortar.

[0046] Example 5 2 parts sodium silicate and 2.5 parts glucosylrutin were added to 20 parts deionized water and stirred at 500 rpm for 1 hour to obtain a treated sodium silicate solution. 2 parts sodium aluminate and 2.5 parts glucosylrutin were added to 20 parts 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 sodium silicate-containing solid. The sodium silicate-containing solid was calcined at 500°C 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 sodium aluminate-containing solid. The sodium aluminate-containing solid was calcined at 1100°C 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 11 parts of 4-benzyloxyphenylethyldecanoate (the mass ratio of 4-benzyloxyphenylethyldecanoate to ethanol in the suspension of 4-benzyloxyphenylethyldecanoate was 1:10), stirred at 500 r / min for 1 hour, washed with deionized water three times, and then vacuum dried at 90°C for 5 hours to obtain an inorganic water-resistant lightweight aggregate.

[0047] 5 parts of polyoxyethylene polyoxypropyl glycerol ether and 5 parts of poly(styrene-divinylbenzene) were added to 50 parts of deionized water and homogenized at 400 r / min for 30 minutes. Then, 3 parts of sodium bicarbonate, 2 parts of C16-18 fatty acid, and 0.3 parts of sodium lauryl polyethylene oxide sulfosuccinate were added. The mixture was stirred at 400 r / min for 2 hours and aged at room temperature for 22 hours to obtain a preliminary product of an organic water-resistant lightweight aggregate. The preliminary product of the organic water-resistant lightweight aggregate was first heat-treated in a hot air circulation oven at 40°C for 3-4 hours, then heated to 60°C for 3-4 hours, and then heated to 80°C for 3-4 hours. The product was washed with deionized water three times, ultrasonicated in deionized water at 400 r / min for 30 minutes, and then washed with deionized water three times to remove the sodium salt generated by the reaction. The product was then freeze-dried in vacuum for 11 hours to obtain the organic water-resistant lightweight aggregate.

[0048] 5 parts of heavy calcium powder were dried at 80°C for 2 hours and then refined in a ball mill to obtain pretreated heavy calcium powder. 1 part of bis(2-ethylhexyl)cyclohexane-1,2-dicarboxylate was added to 10 parts of ethanol and stirred at 300 r / min for 1 hour. During this period, 10 parts of pretreated heavy calcium powder were added and homogenized at 300 r / min for 20 minutes. The mixture was washed with deionized water three times and vacuum dried at 80°C for 6 hours to obtain modified heavy calcium powder.

[0049] 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 powder, 0.4 parts of methyl cellulose, 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 hours. During this period, 60 parts of tap water were added twice to obtain water-resistant lightweight gypsum mortar.

[0050] Example 6 4 parts sodium silicate and 5 parts glucosylrutin were added to 20 parts deionized water and stirred at 400 rpm for 2 hours to obtain a treated sodium silicate solution. 4 parts sodium aluminate and 5 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 in a vacuum for 12 hours to obtain a sodium silicate-containing solid. The sodium silicate-containing solid was calcined at 500°C 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 in a vacuum for 12 hours to obtain a sodium aluminate-containing solid. The sodium aluminate-containing solid was calcined at 1100°C 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-benzyloxyphenylethyldecanoate (the mass ratio of 4-benzyloxyphenylethyldecanoate to ethanol in the suspension of 4-benzyloxyphenylethyldecanoate was 1:10), stirred at 500 r / min for 1.5 h, washed with deionized water three times, and then vacuum dried at 90°C for 6 h to obtain an inorganic water-resistant lightweight aggregate.

[0051] 5 parts of polyoxyethylene polyoxypropyl glycerol ether and 5 parts of poly(styrene-divinylbenzene) were added to 50 parts of deionized water and homogenized at 500 r / min for 30 minutes. Then, 3 parts of sodium bicarbonate, 2 parts of C16-18 fatty acid, and 0.3 parts of sodium lauryl polyoxyethylene sulfosuccinate were added. The mixture was stirred at 500 r / min for 1.5 hours and aged at room temperature for 24 hours to obtain a preliminary product of an organic water-resistant lightweight aggregate. The preliminary product of the organic water-resistant lightweight aggregate was first heat-treated in a hot air circulation oven at 40°C for 3-4 hours, then heated to 60°C for 3-4 hours, and then heated to 80°C for 3-4 hours. The product was washed with deionized water three times, ultrasonicated in deionized water at 500 r / min for 20 minutes, and then washed with deionized water three times to remove the sodium salt generated by the reaction. The product was then freeze-dried in vacuum for 11 hours to obtain the organic water-resistant lightweight aggregate.

[0052] 5 parts of heavy calcium powder were dried at 90°C for 1 hour and then refined in a ball mill to obtain pretreated heavy calcium powder. 1 part of bis(2-ethylhexyl)cyclohexane-1,2-dicarboxylate was added to 10 parts of ethanol and stirred at 400 r / min for 0.5 hour. During this period, 10 parts of pretreated heavy calcium powder were added and homogenized at 400 r / min for 20 minutes. The mixture was washed with deionized water three times and vacuum dried at 90°C for 5 hours to obtain modified heavy calcium powder.

[0053] 80 parts of gypsum, 8 parts of organic water-resistant lightweight aggregate, 7 parts of inorganic water-resistant lightweight aggregate, 5 parts of modified heavy calcium powder, 0.4 parts of methyl cellulose, 0.3 parts of citric acid, and 0.3 parts of sodium polyacrylate were placed in a reactor and stirred at 700 r / min for 5 hours. During this period, 60 parts of tap water were added twice to obtain water-resistant lightweight gypsum mortar.

[0054] The present invention also provides comparative examples and related experiments.

[0055] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that, in the preparation process of the inorganic water-resistant lightweight aggregate, the sodium silicate solution and the sodium aluminate solution are not treated with glucosylrutin, and are directly subjected to subsequent treatments such as aging and quick freezing. The other compositions and preparation methods are the same as those in Example 1, and a water-resistant lightweight gypsum mortar is finally prepared.

[0056] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that organic water-resistant lightweight aggregate is not prepared, and 20 parts of commercially available polystyrene foam are directly used instead of 20 parts of organic water-resistant lightweight aggregate. The other compositions and preparation methods are the same as those in Example 1, and finally a water-resistant lightweight gypsum mortar is prepared.

[0057] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that modified heavy calcium powder is not prepared, and 10 parts of commercially available ordinary heavy calcium powder are directly used instead of 10 parts of modified heavy calcium powder. The other compositions and preparation methods are the same as those in Example 1, and finally water-resistant lightweight gypsum mortar is prepared.

[0058] Performance testing The water-resistant lightweight gypsum mortars of Examples 1 to 6 and Comparative Examples 1 to 3 were subjected to relevant performance tests according to the testing standards and performance indicators in Table 1. The test results are summarized in Tables 2 and 3.

[0059] Table 1

[0060] Table 2

[0061] It can be seen from Table 1 and Table 2 that the test results of the bulk density, flexural strength, compressive strength and tensile bond strength of the water-resistant lightweight gypsum mortar prepared in Examples 1 to 6 are significantly better than those of the water-resistant lightweight gypsum mortar prepared in Comparative Examples 1 to 3, and Example 1 has the best performance and is the optimal solution of the present invention.

[0062] According to the bulk density test results of Comparative Examples 1 to 3 and Example 1, and combined with the performance indicators in Table 1, it can be seen that without the addition of glucosyl rutin and modified heavy calcium powder, the bulk density values of Comparative Examples 1 and 3 are large and do not meet the performance indicators in Table 1, while the bulk density of the polystyrene foam in Comparative Example 2 is relatively light, which meets the bulk density performance indicators in Table 1. It can be seen that the addition of glucosyl rutin, organic water-resistant lightweight aggregate and modified heavy calcium powder has a greater effect on the lightweight properties of the water-resistant lightweight gypsum mortar, among which glucosyl rutin and modified heavy calcium powder have the greatest effect.

[0063] From the test data of flexural strength, compressive strength, and tensile bond strength of Example 1 and Comparative Examples 1 to 3, and in combination with the performance indicators in Table 1, it can be seen that the compressive strength of Comparative Examples 1 to 3 all meet the performance indicators in Table 1, the flexural strength of Comparative Examples 1 and 2 and the tensile bond strength of Comparative Examples 1 and 3 do not meet the performance indicators in Table 1, and the flexural strength of Comparative Example 2 is the worst, only 0.5 MPa, and the tensile bond strength of Comparative Example 1 is the smallest, 0.14 MPa. It can be seen that the addition of glucosylrutin and organic water-resistant lightweight aggregate has a greater effect on the flexural strength performance of water-resistant lightweight gypsum mortar, and the addition of glucosylrutin and modified heavy calcium powder has a greater effect on the tensile bond strength performance of water-resistant lightweight gypsum mortar.

[0064] Table 3

[0065] It can be seen from Table 1 and Table 3 that the water resistance, durability and construction performance of the water-resistant lightweight gypsum mortars prepared in Examples 1 to 6 are significantly higher than those prepared in Comparative Examples 1 to 3, and Example 1 has the best performance and is the optimal solution of the present invention.

[0066] Combining the performance indicators in Table 1 with the water retention test data in Table 3, a comparison of the test data of Example 1 with Comparative Examples 1-3 shows that the water retention rates of Comparative Examples 1-3 were 52%, 89%, and 78%, respectively, all less than 96% in Example 1. With the exception of Comparative Example 2, all other examples did not meet the performance indicator of 88% or greater in Table 1. As can be seen, the lack of the glucosylrutin treatment step significantly reduced the water retention rate in Comparative Example 1, and the water retention rate was also affected in Comparative Example 3, which used ordinary heavy calcium powder. However, the water retention rate of Comparative Example 2, which used commercially available polystyrene foam instead of organic water-resistant lightweight aggregate, essentially met the requirements in Table 1.

[0067] According to the performance indicators and test results of 28d anti-seepage pressure, 28d compressive strength, 14d tensile bonding strength, 28d shrinkage rate and plastic preservation time of Comparative Examples 1 to 3 and Example 1, it can be seen that the test result of 28d compressive strength of Comparative Example 1 can meet the requirements of Table 1, but does not meet the requirements of other performances; while the performance of 28d anti-seepage pressure, tensile bonding strength and plastic preservation time of Comparative Example 2 is good, but the 28d compressive strength and 28d shrinkage rate are poor, which do not meet the requirements of Table 1; Comparative Example 3 has only good 28d compressive strength performance, and the other performance tests do not meet the requirements of Table 1.

[0068] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing water-resistant lightweight gypsum mortar, characterized in that: The following steps are involved: S1. Sodium silicate and sodium aluminate are treated with glucosylrutin, aged, quickly frozen, freeze-dried, and calcined at high temperature to obtain porous silica and porous alumina, respectively. The porous silica and porous alumina are then added to a suspension of 4-benzyloxyphenylethyldecanoate, stirred, washed, and dried to obtain an inorganic water-resistant lightweight aggregate. S2, adding polyoxyethyl polyoxypropyl glyceryl ether and poly(styrene-divinylbenzene) into deionized water, homogenizing and dispersing them, adding sodium bicarbonate, C16-18 fatty acid and sodium lauryl polyethylene oxide sulfosuccinate, stirring, aging, heat treating, ultrasonicating and freeze drying to obtain an organic water-resistant lightweight aggregate; S3, drying and ball-milling the heavy calcium powder, adding bis(2-ethylhexyl)cyclohexane-1,2-dicarboxylate and ethanol, homogenizing, washing and drying to obtain modified heavy calcium powder; S4. Mix gypsum, water, inorganic and organic water-resistant lightweight aggregates, modified heavy calcium powder and other additives to obtain water-resistant lightweight gypsum mortar.

2. The method for preparing a water-resistant lightweight gypsum mortar according to claim 1, characterized in that: In the 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, and then the porous silica and porous alumina are added to a suspension of 4-benzyloxyphenylethyldecanoate, stirred, washed, and dried to obtain an inorganic water-resistant lightweight aggregate.

3. The method for preparing a water-resistant lightweight gypsum mortar according to claim 2, characterized in that: In S1, the stirring speed is 400-500 r / min, and the stirring time is 1-2 h; the mass ratio of glucosylrutin, sodium silicate and sodium aluminate is 5:4:4; The treated sodium silicate solution is subjected to aging, quick freezing, freeze drying, and high-temperature calcination, wherein the aging time is 20-24 hours, the quick freezing time is 1-2 hours, the freeze drying time is 10-12 hours, the high-temperature calcination temperature is 500-600°C, and the high-temperature calcination time is 3-4 hours. The treated sodium aluminate solution is subjected to aging, quick freezing, freeze drying, and high-temperature calcination, wherein the aging time is 20-24 hours, the quick freezing time is 1-2 hours, the freeze drying time is 10-12 hours, the high-temperature calcination temperature is 1000-1100°C, and the high-temperature calcination time is 4-5 hours. The porous silica and porous alumina are added to the suspension of 4-benzyloxyphenylethyldecanoate, and the drying temperature is 80-90°C and the drying time is 5-6 hours during the stirring, washing, and drying processes. The mass ratio of 4-benzyloxyphenylethyldecanoate to ethanol in the suspension of 4-benzyloxyphenylethyldecanoate is 1:

10.

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

5. The method for preparing a water-resistant lightweight gypsum mortar according to claim 1, characterized in that: In S2, the preliminary product of the organic water-resistant lightweight aggregate is first heat-treated in a hot air circulation oven at 40° C. for 3 to 4 hours, then the temperature is raised to 60° C. for heat treatment for 3 to 4 hours, and then raised to 80° C. for heat treatment for 3 to 4 hours, washed three times with deionized water, ultrasonicated in deionized water at 400 to 500 r / min for 20 to 30 minutes, and then washed three times with deionized water to remove sodium salt generated by the reaction, and vacuum freeze-dried for 10 to 12 hours to obtain the organic water-resistant lightweight aggregate.

6. The method for preparing a water-resistant lightweight gypsum mortar according to claim 1, characterized in that: In S3, the heavy calcium powder is dried and ball-milled to obtain pretreated heavy calcium powder, bis(2-ethylhexyl)cyclohexane-1,2-dicarboxylate is added to ethanol, stirred, and the pretreated heavy calcium powder is added, homogenized, washed, and dried to obtain modified heavy calcium powder.

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

8. The method for preparing a water-resistant lightweight gypsum mortar according to claim 1, characterized in that: In the S4, 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 the stirring to obtain water-resistant lightweight gypsum mortar.

9. The method for preparing a water-resistant lightweight gypsum mortar according to claim 8, characterized in that: In the S4, the stirring speed is 600-700 r / min and the time is 5-6 hours; the mass ratio of the organic water-resistant lightweight aggregate, the inorganic water-resistant lightweight aggregate, and the modified heavy calcium powder added is (8-20): (5-10): (5-10); the other additives are methyl cellulose, citric acid, and sodium polyacrylate.

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

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