Slab ballastless track concrete based on efflorescence inhibition and mechanical properties and preparation method thereof

Abstract

The present invention discloses a slab track concrete that improves efflorescence inhibition and mechanical properties. The concrete comprises the following raw materials by weight: 40-45 parts of Portland cement, 15-20 parts of aggregate, 5-20 parts of fly ash, 10-15 parts of a nano-silica coordinated whisker modifier, 3-6 parts of a sodium silicate pre-adjusted chitosan solution modified bentonite, 2-6 parts of a water reducer, 0.5-1 part of a retarder, and 50-60 parts of deionized water. The slab track concrete uses Portland cement, aggregate, and fly ash as a base material. By adding the nano-silica coordinated whisker modifier and the sodium silicate pre-adjusted chitosan solution modified bentonite, the two materials work synergistically to enhance the product's efflorescence inhibition and mechanical properties.

Description

Technical Field

[0001] The present invention relates to the technical field of concrete, and in particular to a slab-type ballastless track concrete based on efflorescence inhibition and mechanical properties and a preparation method thereof. Background Art

[0002] Ballastless track boasts high track stability, uniform rigidity, strong structural durability, minimal maintenance, and relatively mature technology, making it widely used on my country's high-speed railways. Given the long lengths and vast north-south spans of my country's high-speed railways, track slab damage is inevitable due to numerous factors, including geology, the environment, climate, and construction. When track slabs are severely damaged, replacement becomes essential. In road and railway projects, ballastless track slabs constructed with concrete are often exposed to wind, rain, and direct sunlight. In the saline-alkali areas of western China, erosion of ballastless track systems by various chemical substances is commonplace. Due to the unpredictable humidity and temperature in the service environment, white flocculent substances often precipitate at the interface between the track slab and the base plate of the ballastless track. When the base plate and the track slab above are separated, a large area of ​​"white frost" is found. Compared with concrete components, mortar has a larger porosity and lower density, so it is more prone to the precipitation of alkali and salt substances. Long-term seepage of alkali substances will cause the decomposition of silicate gel C-S-H, eventually leading to strength failure and affecting the driving quality and safety of the ballastless track system.

[0003] In order to inhibit the efflorescence effect, existing ballastless track concrete adds nano-silica to inhibit efflorescence. However, the addition of nano-silica is easy to agglomerate, which affects the efficiency of inhibiting efflorescence and the mechanical strength properties of the product, limiting the efficiency of the product. Summary of the Invention

[0004] In view of the defects of the prior art, the purpose of the present invention is to provide a slab track concrete based on efflorescence inhibition and mechanical properties and a preparation method thereof, so as to solve the problems raised in the above background technology.

[0005] The present invention solves the technical problem by adopting the following technical solutions:

[0006] The present invention provides a slab ballastless track concrete based on efflorescence inhibition and mechanical properties, comprising the following raw materials in parts by weight:

[0007] 40-45 parts of Portland cement, 15-20 parts of aggregate, 5-20 parts of fly ash, 10-15 parts of nano-silica coordinated whisker regulating modifier, 3-6 parts of sodium silicate pre-adjusted chitosan solution modified bentonite, 2-6 parts of water reducer, 0.5-1 part of retarder, and 50-60 parts of deionized water.

[0008] Preferably, the slab track concrete based on efflorescence inhibition and mechanical properties comprises the following raw materials in parts by weight:

[0009] 42.5 parts of Portland cement, 17.5 parts of aggregate, 12.5 parts of fly ash, 12.5 parts of nano-silica coordinated whisker regulating modifier, 4.5 parts of sodium silicate pre-adjusted chitosan solution modified bentonite, 4 parts of water reducing agent, 0.75 parts of sodium gluconate, and 55 parts of deionized water.

[0010] Preferably, the aggregate is natural coarse aggregate, which is 10-20 mm continuously graded natural crushed stone with a mud content of less than 0.05%; the water reducer is sodium lignin sulfonate; and the retarder is sodium gluconate.

[0011] Preferably, the preparation method of the nano-silica coordinated whisker regulating modifier is:

[0012] S01: adding aluminum borate whiskers to a 2% potassium permanganate solution at a weight ratio of 1:5, stirring evenly, then washing with water and drying to obtain a first aluminum borate whisker agent;

[0013] S02: adding the first aluminum borate whisker agent to a sodium alginate aqueous solution having a mass fraction of 3 to 5 times the total amount of the first aluminum borate whisker agent, and then adding a 2% hydrochloric acid solution having a mass fraction of 10 to 15% of the total amount of the first aluminum borate whisker agent, stirring evenly, washing with water, and drying to obtain a second aluminum borate whisker agent;

[0014] S03: adding 5 to 10 parts of the second aluminum borate whisker agent to 35 to 45 parts of ethanol solvent, and then adding 1 to 3 parts of silane coupling agent KH560, 0.35 to 0.45 parts of isoeugenol and 0.15 to 0.25 parts of tocopherol acetate, and stirring thoroughly to obtain an aluminum borate whisker adjustment compound solution;

[0015] S04: Add the nano-silica treatment agent to the aluminum borate whisker adjustment compound liquid at a weight ratio of 1:5, stir and react, and after stirring, wash with water and dry to obtain the nano-silica coordinated whisker adjustment modifier.

[0016] Preferably, the stirring reaction treatment has a rotation speed of 550-750 r / min, a stirring time of 20-30 min, and a stirring temperature of 40-45°C.

[0017] Preferably, the preparation method of the nano-silica treatment agent is:

[0018] The nano-silica is preheated at 55-65° C. for 1-2 hours and kept warm. Then, a lanthanum sulfate solution containing 10-20% of the total amount of the nano-silica, a silica sol containing 1-5% of the total amount of the nano-silica and sodium carboxymethyl cellulose containing 2-6% of the total amount of the nano-silica are added thereto, the mixture is stirred evenly, and then the mixture is sent to a ball mill for ball milling. After the ball milling is completed, the mixture is washed with water and dried to obtain a nano-silica treating agent.

[0019] Preferably, the mass fraction of the lanthanum sulfate solution is 5-10%; the rotation speed of the ball milling treatment is 1000-1500 r / min, and the ball milling time is 1-2 h.

[0020] Preferably, the preparation method of the sodium silicate pre-adjusted chitosan solution modified bentonite body is:

[0021] S111: adding 10 to 20 parts by mass of a 5% chitosan aqueous solution to 35 to 45 parts by mass of a 10% sodium silicate aqueous solution and stirring uniformly, then adding 1 to 3 parts of a phosphate buffer solution and continuing to stir thoroughly to obtain a chitosan-modified sodium silicate solution;

[0022] S112: The bentonite is heated at 110-120° C. for 10-20 minutes, then heated to 220-240° C. at a rate of 1-3° C. / min, kept at this temperature for 5-10 minutes, and then air-cooled to room temperature to obtain a heat-modified bentonite body;

[0023] S113: Adding the heat-modified bentonite body into the chitosan-modified sodium silicate solution at a weight ratio of 1:6 and stirring evenly to obtain a sodium silicate-pre-modified chitosan solution-modified bentonite body.

[0024] Preferably, the pH value of the phosphate buffer solution is 5.5-6.5.

[0025] The present invention also provides a method for preparing slab ballastless track concrete based on efflorescence inhibition and mechanical properties, comprising the following steps:

[0026] Step 1: Add Portland cement, aggregate, fly ash and deionized water into a mixer in sequence, mix well and set aside;

[0027] Step 2: Mix the nano-silica coordinated whisker regulating modifier and the sodium silicate pre-adjusted chitosan solution modified bentonite thoroughly, then add it to the product of step 1, stir at a speed of 650-750 r / min for 20-30 minutes, and then set aside after stirring;

[0028] Step 3: adding a water reducer and a setting retarder to the product of step 2, stirring at a rotation speed of 1050 to 1150 r / min for 45 to 55 minutes, and completing the stirring to obtain the slab ballastless track concrete of the present invention.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The slab ballastless track concrete adopts silicate cement, aggregate and fly ash as matrix materials, adds nano-silica coordinated whisker regulating modifier and sodium silicate pre-adjusted chitosan solution to modify bentonite, the two are coordinated and synergistic, and the product's efflorescence inhibition effect and mechanical performance effect are enhanced, and a water reducer and a setting retarder are used as additives to further optimize the performance effect of the product; the nano-silica coordinated whisker regulating modifier adopts aluminum borate whiskers treated with potassium permanganate solution to improve the activity, and then combined with sodium alginate aqueous solution and hydrochloric acid solution to optimize the dispersion and activity of the whiskers; the optimized second aluminum borate whisker agent is combined with a silane coupling agent KH560, isoeugenol and tocopherol acetate to form an aluminum borate whisker regulating compound liquid; the raw materials are coordinated and combined with each other, and the nano-silica coordinated whisker regulating modifier is prepared. The silicon treatment agent adopts nano-silica which is heat-activated and heat-insulated, and is stirred and ball-milled by lanthanum sulfate solution, silica sol and sodium carboxymethyl cellulose to further optimize the coordination and synergistic effect of the nano-silica treatment agent and the aluminum borate whisker adjustment compound liquid. The prepared nano-silica coordinated whisker adjustment modifier is distributed in the matrix with optimized nano-silica coordinated whisker body, which can coordinate the mechanical properties of the product and the alkali-inhibiting effect of the product, and play a role in improving the efficiency of performance coordination. The bentonite is heat-modified to expand the interlamellar spacing, and is coordinated with chitosan aqueous solution, sodium silicate aqueous solution and phosphate buffer solution. The lamellae of bentonite are distributed in the chitosan compound sodium silicate solution, thereby synergizing with the nano-silica coordinated whisker adjustment modifier to achieve a reinforcing and synergistic effect, thereby further improving the performance of the product. DETAILED DESCRIPTION

[0031] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0032] The slab track concrete based on efflorescence inhibition and mechanical properties of this embodiment includes the following raw materials in parts by weight:

[0033] 40-45 parts of Portland cement, 15-20 parts of aggregate, 5-20 parts of fly ash, 10-15 parts of nano-silica coordinated whisker regulating modifier, 3-6 parts of sodium silicate pre-adjusted chitosan solution modified bentonite, 2-6 parts of water reducer, 0.5-1 part of retarder, and 50-60 parts of deionized water.

[0034] The slab track concrete based on efflorescence inhibition and mechanical properties of this embodiment includes the following raw materials in parts by weight:

[0035] 42.5 parts of Portland cement, 17.5 parts of aggregate, 12.5 parts of fly ash, 12.5 parts of nano-silica coordinated whisker regulating modifier, 4.5 parts of sodium silicate pre-adjusted chitosan solution modified bentonite, 4 parts of water reducing agent, 0.75 parts of sodium gluconate, and 55 parts of deionized water.

[0036] The aggregate of this embodiment is natural coarse aggregate, which is natural crushed stone with a continuous grade of 10 to 20 mm and a mud content of less than 0.05%; the water reducer is sodium lignin sulfonate; and the retarder is sodium gluconate.

[0037] The preparation method of the nano-silicon dioxide coordinated whisker regulating modifier of this embodiment is:

[0038] S01: adding aluminum borate whiskers to a 2% potassium permanganate solution at a weight ratio of 1:5, stirring evenly, then washing with water and drying to obtain a first aluminum borate whisker agent;

[0039] S02: adding the first aluminum borate whisker agent to a sodium alginate aqueous solution having a mass fraction of 3 to 5 times the total amount of the first aluminum borate whisker agent, and then adding a 2% hydrochloric acid solution having a mass fraction of 10 to 15% of the total amount of the first aluminum borate whisker agent, stirring evenly, washing with water, and drying to obtain a second aluminum borate whisker agent;

[0040] S03: adding 5 to 10 parts of the second aluminum borate whisker agent to 35 to 45 parts of ethanol solvent, and then adding 1 to 3 parts of silane coupling agent KH560, 0.35 to 0.45 parts of isoeugenol and 0.15 to 0.25 parts of tocopherol acetate, and stirring thoroughly to obtain an aluminum borate whisker adjustment compound solution;

[0041] S04: Add the nano-silica treatment agent to the aluminum borate whisker adjustment compound liquid at a weight ratio of 1:5, stir and react, and after stirring, wash with water and dry to obtain the nano-silica coordinated whisker adjustment modifier.

[0042] The stirring reaction process in this embodiment has a rotation speed of 550-750 r / min, a stirring time of 20-30 min, and a stirring temperature of 40-45°C.

[0043] The preparation method of the nano-silicon dioxide treatment agent of this embodiment is:

[0044] The nano-silica is preheated at 55-65° C. for 1-2 hours and kept warm. Then, a lanthanum sulfate solution containing 10-20% of the total amount of the nano-silica, a silica sol containing 1-5% of the total amount of the nano-silica and sodium carboxymethyl cellulose containing 2-6% of the total amount of the nano-silica are added thereto, the mixture is stirred evenly, and then the mixture is sent to a ball mill for ball milling. After the ball milling is completed, the mixture is washed with water and dried to obtain a nano-silica treating agent.

[0045] The mass fraction of the lanthanum sulfate solution in this embodiment is 5-10%; the rotation speed of the ball milling treatment is 1000-1500 r / min, and the ball milling time is 1-2 h.

[0046] The preparation method of the sodium silicate pre-adjusted chitosan solution modified bentonite body of this embodiment is:

[0047] S111: adding 10 to 20 parts by mass of a 5% chitosan aqueous solution to 35 to 45 parts by mass of a 10% sodium silicate aqueous solution and stirring uniformly, then adding 1 to 3 parts of a phosphate buffer solution and continuing to stir thoroughly to obtain a chitosan-modified sodium silicate solution;

[0048] S112: The bentonite is heated at 110-120° C. for 10-20 minutes, then heated to 220-240° C. at a rate of 1-3° C. / min, kept at this temperature for 5-10 minutes, and then air-cooled to room temperature to obtain a heat-modified bentonite body;

[0049] S113: Adding the heat-modified bentonite body into the chitosan-modified sodium silicate solution at a weight ratio of 1:6 and stirring evenly to obtain a sodium silicate-pre-modified chitosan solution-modified bentonite body.

[0050] The pH value of the phosphate buffer solution of this embodiment is 5.5-6.5.

[0051] A method for preparing slab ballastless track concrete based on efflorescence inhibition and mechanical properties in this embodiment includes the following steps:

[0052] Step 1: Add Portland cement, aggregate, fly ash and deionized water into a mixer in sequence, mix well and set aside;

[0053] Step 2: Mix the nano-silica coordinated whisker regulating modifier and the sodium silicate pre-adjusted chitosan solution modified bentonite thoroughly, then add it to the product of step 1, stir at a speed of 650-750 r / min for 20-30 minutes, and then set aside after stirring;

[0054] Step 3: adding a water reducer and a retarder to the product of step 2, stirring at a rotation speed of 1050 to 1150 r / min for 45 to 55 minutes, and completing the stirring to obtain the slab ballastless track concrete of the present invention.

[0055] Example 1.

[0056] The slab track concrete based on efflorescence inhibition and mechanical properties of this embodiment includes the following raw materials in parts by weight:

[0057] 40 parts of Portland cement, 15 parts of aggregate, 5 parts of fly ash, 10 parts of nano-silica coordinated whisker regulating modifier, 3 parts of sodium silicate pre-adjusted chitosan solution modified bentonite, 2 parts of water reducer, 0.5 parts of retarder, and 5 parts of deionized water.

[0058] The aggregate of this embodiment is natural coarse aggregate, which is 10mm continuously graded natural crushed stone with a mud content of less than 0.05%; the water reducer is sodium lignin sulfonate; and the retarder is sodium gluconate.

[0059] The preparation method of the nano-silicon dioxide coordinated whisker regulating modifier of this embodiment is:

[0060] S01: adding aluminum borate whiskers to a 2% potassium permanganate solution at a weight ratio of 1:5, stirring evenly, then washing with water and drying to obtain a first aluminum borate whisker agent;

[0061] S02: adding the first aluminum borate whisker agent to a sodium alginate aqueous solution having a mass fraction of 3 times the total mass of the first aluminum borate whisker agent, and then adding a 2% hydrochloric acid solution having a mass fraction of 10% of the total mass of the first aluminum borate whisker agent, stirring evenly, washing with water, and drying to obtain a second aluminum borate whisker agent;

[0062] S03: adding 5 parts of the second aluminum borate whisker agent to 35 parts of ethanol solvent, and then adding 1 part of silane coupling agent KH560, 0.35 parts of isoeugenol and 0.15 parts of tocopherol acetate, and stirring thoroughly to obtain an aluminum borate whisker adjustment compound solution;

[0063] S04: Add the nano-silica treatment agent to the aluminum borate whisker adjustment compound liquid at a weight ratio of 1:5, stir and react, and after stirring, wash with water and dry to obtain the nano-silica coordinated whisker adjustment modifier.

[0064] The stirring reaction process in this embodiment has a rotation speed of 550 r / min, a stirring time of 20 min, and a stirring temperature of 40°C.

[0065] The preparation method of the nano-silicon dioxide treatment agent of this embodiment is:

[0066] The nano-silica was preheated at 55°C for 1 hour and kept warm. Then, lanthanum sulfate solution containing 10% of the total amount of nano-silica, silica sol containing 1% of the total amount of nano-silica and sodium carboxymethyl cellulose containing 2% of the total amount of nano-silica were added thereto, stirred evenly, and then sent to a ball mill for ball milling. After the ball milling was completed, the nano-silica treatment agent was washed with water and dried.

[0067] The mass fraction of the lanthanum sulfate solution in this embodiment is 5%; the rotation speed of the ball milling treatment is 1000 r / min, and the ball milling time is 1 hour.

[0068] The preparation method of the sodium silicate pre-adjusted chitosan solution modified bentonite body of this embodiment is:

[0069] S111: adding 10 parts by mass of a 5% chitosan aqueous solution to 35 parts by mass of a 10% sodium silicate aqueous solution and stirring uniformly, then adding 1 part of a phosphate buffer solution and continuing to stir thoroughly to obtain a chitosan-modified sodium silicate solution;

[0070] S112: The bentonite is heated at 110°C for 10 minutes, then heated to 220°C at a rate of 1°C / min, kept at this temperature for 5 minutes, and then air-cooled to room temperature to obtain a thermally modified bentonite body;

[0071] S113: Adding the heat-modified bentonite body into the chitosan-modified sodium silicate solution at a weight ratio of 1:6 and stirring evenly to obtain a sodium silicate-pre-modified chitosan solution-modified bentonite body.

[0072] The pH value of the phosphate buffer solution in this example is 5.5.

[0073] A method for preparing slab ballastless track concrete based on efflorescence inhibition and mechanical properties in this embodiment includes the following steps:

[0074] Step 1: Add Portland cement, aggregate, fly ash and deionized water into a mixer in sequence, mix well and set aside;

[0075] Step 2: Mix the nano-silica coordinated whisker regulating modifier and the sodium silicate pre-adjusted chitosan solution modified bentonite thoroughly, then add it to the product of step 1, stir at a speed of 650r / min for 20min, and then set aside after stirring;

[0076] Step 3: adding a water reducer and a retarder to the product of step 2, stirring at a speed of 1050 r / min for 45 minutes, and completing the stirring to obtain the slab ballastless track concrete of the present invention.

[0077] Example 2.

[0078] The slab track concrete based on efflorescence inhibition and mechanical properties of this embodiment includes the following raw materials in parts by weight:

[0079] 45 parts of Portland cement, 20 parts of aggregate, 20 parts of fly ash, 15 parts of nano-silica coordinated whisker regulating modifier, 6 parts of sodium silicate pre-adjusted chitosan solution modified bentonite, 6 parts of water reducing agent, 1 part of retarder, and 60 parts of deionized water.

[0080] The aggregate of this embodiment is natural coarse aggregate, which is natural crushed stone with a continuous grade of 10 to 20 mm and a mud content of less than 0.05%; the water reducer is sodium lignin sulfonate; and the retarder is sodium gluconate.

[0081] The preparation method of the nano-silicon dioxide coordinated whisker regulating modifier of this embodiment is:

[0082] S01: adding aluminum borate whiskers to a 2% potassium permanganate solution at a weight ratio of 1:5, stirring evenly, then washing with water and drying to obtain a first aluminum borate whisker agent;

[0083] S02: adding the first aluminum borate whisker agent to a sodium alginate aqueous solution having a mass fraction of 5 times that of the first aluminum borate whisker agent, and then adding a 2% hydrochloric acid solution having a mass fraction of 15% of the total mass of the first aluminum borate whisker agent, stirring evenly, washing with water, and drying to obtain a second aluminum borate whisker agent;

[0084] S03: adding 10 parts of the second aluminum borate whisker agent to 45 parts of ethanol solvent, and then adding 3 parts of silane coupling agent KH560, 0.45 parts of isoeugenol and 0.25 parts of tocopherol acetate, and stirring thoroughly to obtain an aluminum borate whisker adjustment compound solution;

[0085] S04: Add the nano-silica treatment agent to the aluminum borate whisker adjustment compound liquid at a weight ratio of 1:5, stir and react, and after stirring, wash with water and dry to obtain the nano-silica coordinated whisker adjustment modifier.

[0086] The stirring reaction process in this embodiment has a rotation speed of 750 r / min, a stirring time of 30 min, and a stirring temperature of 45°C.

[0087] The preparation method of the nano-silicon dioxide treatment agent of this embodiment is:

[0088] The nano-silica was preheated at 65°C for 2 hours and kept warm. Then, lanthanum sulfate solution containing 20% ​​of the total amount of nano-silica, silica sol containing 5% of the total amount of nano-silica and sodium carboxymethyl cellulose containing 6% of the total amount of nano-silica were added thereto, stirred evenly, and then sent to a ball mill for ball milling. After the ball milling was completed, the nano-silica treatment agent was obtained by washing with water and drying.

[0089] The mass fraction of the lanthanum sulfate solution in this embodiment is 10%; the rotation speed of the ball milling treatment is 1500 r / min, and the ball milling time is 2 h.

[0090] The preparation method of the sodium silicate pre-adjusted chitosan solution modified bentonite body of this embodiment is:

[0091] S111: adding 20 parts by mass of a 5% chitosan aqueous solution to 45 parts by mass of a 10% sodium silicate aqueous solution and stirring uniformly, then adding 3 parts of a phosphate buffer solution and continuing to stir thoroughly to obtain a chitosan-modified sodium silicate solution;

[0092] S112: The bentonite is heated at 120°C for 20 minutes, then heated to 240°C at a rate of 3°C / min, kept at this temperature for 10 minutes, and then air-cooled to room temperature to obtain a heat-modified bentonite body;

[0093] S113: Adding the heat-modified bentonite body into the chitosan-modified sodium silicate solution at a weight ratio of 1:6 and stirring evenly to obtain a sodium silicate-pre-modified chitosan solution-modified bentonite body.

[0094] The pH value of the phosphate buffer solution in this example is 6.5.

[0095] A method for preparing slab ballastless track concrete based on efflorescence inhibition and mechanical properties in this embodiment includes the following steps:

[0096] Step 1: Add Portland cement, aggregate, fly ash and deionized water into a mixer in sequence, mix well and set aside;

[0097] Step 2: Mix the nano-silica coordinated whisker modifier and the sodium silicate pre-adjusted chitosan solution modified bentonite thoroughly, then add it to the product of step 1, stir at a speed of 750r / min for 30min, and then set aside after stirring;

[0098] Step 3: adding a water reducer and a retarder to the product of step 2, stirring at a speed of 1150 r / min for 55 minutes, and completing the stirring to obtain the slab ballastless track concrete of the present invention.

[0099] Example 3.

[0100] The slab track concrete based on efflorescence inhibition and mechanical properties of this embodiment includes the following raw materials in parts by weight:

[0101] 42.5 parts of Portland cement, 17.5 parts of aggregate, 12.5 parts of fly ash, 12.5 parts of nano-silica coordinated whisker regulating modifier, 4.5 parts of sodium silicate pre-adjusted chitosan solution modified bentonite, 4 parts of water reducing agent, 0.75 parts of sodium gluconate, and 55 parts of deionized water.

[0102] The aggregate in this embodiment is natural coarse aggregate, which is 15mm continuously graded natural crushed stone with a mud content of less than 0.05%; the water reducer is sodium lignin sulfonate; and the retarder is sodium gluconate.

[0103] The preparation method of the nano-silicon dioxide coordinated whisker regulating modifier of this embodiment is:

[0104] S01: adding aluminum borate whiskers to a 2% potassium permanganate solution at a weight ratio of 1:5, stirring evenly, then washing with water and drying to obtain a first aluminum borate whisker agent;

[0105] S02: adding the first aluminum borate whisker agent to a sodium alginate aqueous solution having a mass fraction of 4 times that of the first aluminum borate whisker agent, and then adding a 2% hydrochloric acid solution having a mass fraction of 12.5% ​​of the total mass of the first aluminum borate whisker agent, stirring evenly, washing with water, and drying to obtain a second aluminum borate whisker agent;

[0106] S03: adding 7.5 parts of the second aluminum borate whisker agent to 40 parts of ethanol solvent, and then adding 2 parts of silane coupling agent KH560, 0.40 parts of isoeugenol and 0.20 parts of tocopherol acetate, and stirring thoroughly to obtain an aluminum borate whisker adjustment compound solution;

[0107] S04: Add the nano-silica treatment agent to the aluminum borate whisker adjustment compound liquid at a weight ratio of 1:5, stir and react, and after stirring, wash with water and dry to obtain the nano-silica coordinated whisker adjustment modifier.

[0108] The stirring reaction process in this embodiment has a rotation speed of 600 r / min, a stirring time of 25 min, and a stirring temperature of 42.5°C.

[0109] The preparation method of the nano-silicon dioxide treatment agent of this embodiment is:

[0110] The nano-silica was preheated at 60°C for 1.5 hours and kept warm. Then, lanthanum sulfate solution containing 15% of the total amount of nano-silica, silica sol containing 3% of the total amount of nano-silica and sodium carboxymethyl cellulose containing 4% of the total amount of nano-silica were added thereto, stirred evenly, and then sent to a ball mill for ball milling. After the ball milling was completed, the nano-silica treatment agent was obtained by washing with water and drying.

[0111] The mass fraction of the lanthanum sulfate solution in this embodiment is 7.5%; the rotation speed of the ball milling treatment is 1250 r / min, and the ball milling time is 1.5 h.

[0112] The preparation method of the sodium silicate pre-adjusted chitosan solution modified bentonite body of this embodiment is:

[0113] S111: adding 15 parts by mass of a 5% chitosan aqueous solution to 40 parts by mass of a 10% sodium silicate aqueous solution and stirring uniformly, then adding 2 parts by mass of a phosphate buffer solution and continuing to stir thoroughly to obtain a chitosan-modified sodium silicate solution;

[0114] S112: The bentonite is heated at 115°C for 15 minutes, then heated to 230°C at a rate of 2°C / min, kept at this temperature for 7.5 minutes, and then air-cooled to room temperature to obtain a thermally modified bentonite body;

[0115] S113: Adding the heat-modified bentonite body into the chitosan-modified sodium silicate solution at a weight ratio of 1:6 and stirring evenly to obtain a sodium silicate-pre-modified chitosan solution-modified bentonite body.

[0116] The pH value of the phosphate buffer solution in this example is 6.0.

[0117] A method for preparing slab ballastless track concrete based on efflorescence inhibition and mechanical properties in this embodiment includes the following steps:

[0118] Step 1: Add Portland cement, aggregate, fly ash and deionized water into a mixer in sequence, mix well and set aside;

[0119] Step 2: Mix the nano-silica coordinated whisker modifier and the sodium silicate pre-adjusted chitosan solution modified bentonite thoroughly, then add it to the product of step 1, stir at a speed of 700 r / min for 25 minutes, and then set aside after stirring;

[0120] Step 3: adding a water reducer and a retarder to the product of step 2, stirring at a speed of 1100 r / min for 50 minutes, and completing the stirring to obtain the slab ballastless track concrete of the present invention.

[0121] Comparative Example 1.

[0122] The difference from Example 3 is that the nano-silica coordinated whisker regulating modifier is replaced by nano-silica.

[0123] Comparative Example 2.

[0124] The difference from Example 3 is that the preparation method of the aluminum borate whisker regulating compound liquid in the preparation of the nano-silica coordinated whisker regulating modifier is different: 5 to 10 parts of aluminum borate whiskers are added to 35 to 45 parts of ethanol solvent, and then 1 to 3 parts of silane coupling agent KH560, 0.35 to 0.45 parts of isoeugenol and 0.15 to 0.25 parts of tocopherol acetate are added, and stirred thoroughly to obtain the aluminum borate whisker regulating compound liquid.

[0125] Comparative Example 3.

[0126] The difference from Example 3 is that the preparation method of the aluminum borate whisker adjustment compound liquid is different: 5 to 10 parts of the second aluminum borate whisker agent are added to 35 to 45 parts of ethanol solvent, and then 0.35 to 0.45 parts of isoeugenol are added and stirred thoroughly to obtain the aluminum borate whisker adjustment compound liquid.

[0127] Comparative Example 4.

[0128] The difference from Example 3 is that the preparation method of the nano-silica coordinated whisker regulating modifier is different: the nano-silica treating agent is replaced by nano-silica.

[0129] Comparative Example 5.

[0130] The difference from Example 3 is that the preparation method of the nano-silicon dioxide treating agent is:

[0131] Add lanthanum sulfate solution containing 10-20% of the total amount of nano-silicon dioxide and silica sol containing 1-5% of the total amount of nano-silicon dioxide into nano-silicon dioxide, stir evenly, and then send into a ball mill for ball milling. After the ball milling is completed, wash with water and dry to obtain a nano-silicon dioxide treating agent.

[0132] Comparative Example 6.

[0133] The difference from Example 3 is that sodium silicate pre-adjusted chitosan solution is not added to modify the bentonite body.

[0134] Comparative Example 7.

[0135] The difference from Example 3 is that the preparation method of the sodium silicate pre-adjusted chitosan solution modified bentonite body is different;

[0136] S111: adding 10 to 20 parts by mass of a 5% chitosan aqueous solution to 35 to 45 parts by mass of a 10% sodium silicate aqueous solution and stirring evenly, and continuing to stir thoroughly to obtain a chitosan-modified sodium silicate solution;

[0137] S112: Adding bentonite into the chitosan-modified sodium silicate solution at a weight ratio of 1:6 and stirring evenly to obtain a sodium silicate-pre-modified chitosan solution-modified bentonite body.

[0138] Comparative Example 8.

[0139] The difference from Example 3 is that in the preparation of the sodium silicate pre-adjusted chitosan solution modified bentonite, graphene is used instead of bentonite.

[0140] The product performance tests of Examples 1 to 3 and Comparative Examples 1 to 8 are as follows:

[0141] The test method refers to the national standard GB / T50081-2019 "Standard for Test Methods of Physical and Mechanical Properties of Concrete". The product's 28d compressive strength is tested, and the product is placed at 2% acid corrosion for 2 hours and 65°C for 2 hours to test its acid corrosion resistance and heat resistance. At the same time, the sample is placed in a test environment with a temperature of 0-4°C and a humidity of 60%. After 5 days, the alkali efflorescence area on the sample surface is calculated.

[0142]

[0143] It can be seen from Comparative Examples 1 to 8 and Examples 1 to 3 that;

[0144] The product of Example 3 of the present invention has an excellent efflorescence inhibition effect. At the same time, the 28d compressive strength is significantly improved under room temperature, 2% acid rot and 65°C for 2h, and the strength stability of the product is significant.

[0145] When nano-silica coordinated whisker modifier was used instead of nano-silica and sodium silicate pre-adjusted chitosan solution was not added to modify the bentonite, the performance of the product deteriorated significantly, including the efflorescence inhibition effect, 28d compressive strength, and stability. However, when the two raw materials were blended, the performance of the product was significantly improved.

[0146] At the same time, the performance of the products tends to deteriorate when the preparation methods of the aluminum borate whisker regulating compound liquid in the preparation of the nano-silica coordinated whisker regulating modifier are different, the nano-silica treating agent is replaced by nano-silica, and the preparation methods of the nano-silica treating agent are different. The preparation methods of the sodium silicate pre-adjusted chitosan solution modified bentonite body are different, and the bentonite raw material is replaced by graphene. Only the products prepared by the method of the present invention, the sodium silicate pre-adjusted chitosan solution modified bentonite body, and the nano-silica coordinated whisker regulating modifier have significant performance coordination and synergistic effects, and the performance of the products is the most obvious.

[0147] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

[0148] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A slab track concrete based on efflorescence inhibition and mechanical properties, characterized in that: It includes the following raw materials in parts by weight: 40-45 parts of Portland cement, 15-20 parts of aggregate, 5-20 parts of fly ash, 10-15 parts of nano-silica coordinated whisker modifier, 3-6 parts of sodium silicate pre-adjusted chitosan solution modified bentonite, 2-6 parts of water reducer, 0.5-1 part of retarder, and 50-60 parts of deionized water; The preparation method of the nano-silicon dioxide coordinated whisker regulating modifier is as follows: S01: adding aluminum borate whiskers to a 2% potassium permanganate solution at a weight ratio of 1:5, stirring evenly, then washing with water and drying to obtain a first aluminum borate whisker agent; S02: adding the first aluminum borate whisker agent to a sodium alginate aqueous solution having a mass fraction of 3 to 5 times the total amount of the first aluminum borate whisker agent, and then adding a 2% hydrochloric acid solution having a mass fraction of 10 to 15% of the total amount of the first aluminum borate whisker agent, stirring evenly, washing with water, and drying to obtain a second aluminum borate whisker agent; S03: adding 5-10 parts of the second aluminum borate whisker agent to 35-45 parts of ethanol solvent, and then adding 1-3 parts of silane coupling agent KH560, 0.35-0.45 parts of isoeugenol and 0.15-0.25 parts of tocopherol acetate, and stirring thoroughly to obtain an aluminum borate whisker adjustment compound solution; S04: adding the nano-silica treatment agent to the aluminum borate whisker adjustment compound solution at a weight ratio of 1:5, stirring and reacting, and washing and drying after stirring to obtain the nano-silica coordinated whisker adjustment modifier; The preparation method of the nano-silicon dioxide treating agent is: The nano-silica is preheated at 55-65°C for 1-2 hours, kept warm, and then lanthanum sulfate solution containing 10-20% of the total amount of nano-silica, silica sol containing 1-5% of the total amount of nano-silica, and sodium carboxymethyl cellulose containing 2-6% of the total amount of nano-silica are added thereto, stirred evenly, and then sent to a ball mill for ball milling. After the ball milling is completed, the nano-silica treatment agent is washed with water and dried to obtain the nano-silica treatment agent; The preparation method of the sodium silicate pre-adjusted chitosan solution modified bentonite body is: S111: adding 10-20 parts by mass of a 5% chitosan aqueous solution to 35-45 parts by mass of a 10% sodium silicate aqueous solution and stirring uniformly, then adding 1-3 parts of a phosphate buffer solution and continuing to stir thoroughly to obtain a chitosan-modified sodium silicate solution; S112: The bentonite is heated at 110-120°C for 10-20 minutes, then heated to 220-240°C at a rate of 1-3°C / min, kept at this temperature for 5-10 minutes, and then air-cooled to room temperature to obtain a thermally modified bentonite body; S113: Adding the heat-modified bentonite body into the chitosan-modified sodium silicate solution at a weight ratio of 1:6 and stirring evenly to obtain a sodium silicate-pre-modified chitosan solution-modified bentonite body.

2. The slab track concrete based on efflorescence inhibition and mechanical properties according to claim 1, characterized in that: The slab track concrete based on efflorescence inhibition and mechanical properties comprises the following raw materials in parts by weight: 42.5 parts of Portland cement, 17.5 parts of aggregate, 12.5 parts of fly ash, 12.5 parts of nano-silica coordinated whisker regulating modifier, 4.5 parts of sodium silicate pre-adjusted chitosan solution modified bentonite, 4 parts of water reducer, 0.75 parts of sodium gluconate as retarder, and 55 parts of deionized water.

3. The slab track concrete based on efflorescence inhibition and mechanical properties according to claim 1, characterized in that: The aggregate is natural coarse aggregate, which is natural crushed stone with a continuous gradation of 10 to 20 mm and a mud content of less than 0.05%; the water reducer is sodium lignin sulfonate; and the retarder is sodium gluconate.

4. The slab track concrete based on efflorescence inhibition and mechanical properties according to claim 1, characterized in that: The stirring reaction process has a rotation speed of 550-750 r / min, a stirring time of 20-30 min, and a stirring temperature of 40-45° C.

5. The slab track concrete based on efflorescence inhibition and mechanical properties according to claim 1, characterized in that: The mass fraction of the lanthanum sulfate solution is 5-10%; the rotation speed of the ball milling treatment is 1000-1500 r / min, and the ball milling time is 1-2 h.

6. The slab track concrete based on efflorescence inhibition and mechanical properties according to claim 1, characterized in that: The pH value of the phosphate buffer solution is 5.5-6.

5.

7. A method for preparing slab ballastless track concrete based on efflorescence inhibition and mechanical properties according to any one of claims 1 to 6, characterized in that: The following steps are involved: Step 1: Add Portland cement, aggregate, fly ash and deionized water into a mixer in sequence, mix well and set aside; Step 2: Mix the nano-silica coordinated whisker regulating modifier and the sodium silicate pre-adjusted chitosan solution modified bentonite thoroughly, then add it to the product of step 1, stir at a speed of 650-750 r / min for 20-30 minutes, and then set aside after stirring; Step 3: Add a water reducer and a retarder to the product of step 2, and stir at a speed of 1050-1150 r / min for 45-55 minutes. After stirring, slab ballastless track concrete is obtained.

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