A fast-hardening road repair mortar

Abstract

The application discloses a kind of fast hard type road surface repair mortar, belongs to mortar technical field.The mortar is made of the following weight parts of component: ordinary Portland cement 10-23 parts, sulphoaluminate cement 25-35 parts, natural river sand 30-50 parts, ethylene-vinyl acetate copolymer 1-3 parts, polypropylene fiber 1-2.4 parts, hydroxypropyl methylcellulose puzzle 0.1-0.2 parts, defoaming agent 1-1.5 parts, water reducing agent 1-2 parts, lithium carbonate 0.1-0.2 parts, expanding agent 0.1-0.5 parts.The application can realize the "fast hard" effect of mortar, effectively improve the crack resistance and toughness of mortar, and improve its bonding performance, successfully solve the industry problem that traditional fast hard mortar material is easy to crack.

Description

Technical Field

[0001] This invention relates to the field of mortar technology, and more specifically, to a fast-setting road repair mortar. Background Technology

[0002] With the continuous expansion of transportation infrastructure networks, maintenance work has fully entered a new stage of "preventive maintenance + precision repair," and maintenance operations increasingly emphasize the needs for "speed" and "efficiency." Currently, traditional road repair materials suffer from shortcomings such as low early strength, long maintenance cycles, and poor interfacial adhesion, leading to traffic congestion and secondary problems like cracking and detachment after repair. This results in short repair lifespans, high maintenance costs, and significant economic losses. Therefore, there is an urgent need to develop a mortar material capable of rapid road repair to address these issues. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a fast-hardening road repair mortar.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A fast-setting road repair mortar, comprising the following components in parts by weight: 10-23 parts ordinary silicate cement, 25-35 parts sulfoaluminate cement, 30-50 parts natural river sand, 1-3 parts ethylene-vinyl acetate copolymer, 1-2.4 parts polypropylene fiber, 0.1-0.2 parts hydroxypropyl methylcellulose, 1-1.5 parts defoamer, 1-2 parts water-reducing agent, 0.1-0.2 parts lithium carbonate, and 0.1-0.5 parts expanding agent.

[0006] The present invention is further configured with 15 parts of ordinary silicate cement, 31 parts of sulfoaluminate cement, 46 parts of natural river sand, 2.2 parts of ethylene-vinyl acetate copolymer, 1.7 parts of polypropylene fiber, 0.15 parts of hydroxypropyl methylcellulose ether, 1 part of defoamer, 2 parts of water-reducing agent, 0.1 parts of lithium carbonate, and 0.3 parts of calcium sulfoaluminate expansion agent.

[0007] The present invention is further configured such that the defoamer is at least one of silicone defoamer and polyether defoamer.

[0008] The present invention is further configured such that the expanding agent is at least one of calcium sulfoaluminate expanding agents, calcium oxide expanding agents, magnesium oxide expanding agents, and aluminum powder expanding agents.

[0009] The present invention is further configured such that the water-reducing agent is at least one of polycarboxylate water-reducing agents, naphthalene-based water-reducing agents, and lignin-based water-reducing agents.

[0010] The present invention is further configured such that the water-reducing agent is a modified water-reducing agent, and its preparation method is as follows:

[0011] (a) 1-Vinyl-3-butylimidazolium chloride, allylamine, and hydroxyethyl methacrylate react under the action of an initiator to prepare [BVIm]-g-AA-HEMA copolymer;

[0012] (b) A modified water-reducing agent is prepared by reacting SiO2 modified with silane coupling agent with [BVIm]-g-AA-HEMA copolymer under the action of an initiator.

[0013] The present invention is further configured such that step (a) specifically comprises: adding 1-vinyl-3-butylimidazolium chloride, allylamine, hydroxyethyl methacrylate and ammonium persulfate to deionized water, purging with nitrogen to remove oxygen, stirring at 75°C, and then raising the temperature to 80°C to continue the reaction; after the reaction, cooling to room temperature, adding cold ethanol to precipitate, filtering, and vacuum drying to obtain [BVIm]-g-AA-HEMA copolymer.

[0014] The present invention is further configured such that, in step (a), the mass ratio of 1-vinyl-3-butylimidazolium chloride, allylamine, hydroxyethyl methacrylate, and ammonium persulfate is 30:8:6:0.3.

[0015] The present invention is further configured such that step (c) specifically comprises: ultrasonically dispersing silane coupling agent modified SiO2 in an ethanol aqueous solution, adding [BVIm]-g-AA-HEMA copolymer and ammonium persulfate, stirring and reacting at 80°C under nitrogen protection; cooling to room temperature after reaction, centrifuging separation, washing the product with ethanol aqueous solution, and vacuum drying to obtain modified water-reducing agent.

[0016] The present invention is further configured such that, in step (c), the mass ratio of silane coupling agent modified SiO2, [BVIm]-g-AA-HEMA copolymer, and ammonium persulfate is 5:22:0.6.

[0017] In summary, the present invention has the following beneficial effects:

[0018] By combining early-strength sulfoaluminate cement with ordinary silicate cement, and combining it with ethylene-vinyl acetate copolymer, polypropylene fiber, hydroxypropyl methylcellulose ether and other materials, a "fast-hardening" effect is achieved in the mortar, which effectively improves the crack resistance and toughness of the mortar and enhances its bonding performance, thus successfully solving the industry problem of easy cracking of traditional fast-hardening mortar materials. Detailed Implementation

[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Example 1

[0021] By weight, the quick-setting road repair mortar is composed of the following components: 15 parts ordinary silicate cement, 31 parts sulfoaluminate cement, 46 parts natural river sand (using ISO standard sand), 2.2 parts ethylene-vinyl acetate copolymer, 1.7 parts polypropylene fiber, 0.15 parts hydroxypropyl methylcellulose ether (HPMC), 1 part defoamer, 2 parts polycarboxylate superplasticizer, 0.1 parts lithium carbonate, and 0.3 parts calcium sulfoaluminate expanding agent. The above raw materials are added to a high-speed mixer in the specified proportions and mixed thoroughly to obtain the quick-setting road repair mortar.

[0022] Ordinary Portland cement, P.O42.5 grade, was purchased from Wuxi Tianshan Cement Co., Ltd. Sulfoaluminate cement, A00305, was purchased from Wuhan Jiyesheng Chemical Co., Ltd.

[0023] The natural river sand has a particle size range of 0.5~1.75mm. The ethylene-vinyl acetate copolymer is EVA2315 (Hanwha, South Korea). Polypropylene fiber was purchased from Langfang Maisen Building Materials Co., Ltd., item number: MS. Defoamer was purchased from Yantai Hengxin Chemical Technology Co., Ltd., model THIX-568. Polycarboxylate superplasticizer was purchased from Liaoning Kelong Fine Chemical Co., Ltd., model SP-409. Hydroxypropyl methylcellulose ether was purchased from Nanjing Yaojie Energy Saving Technology Co., Ltd., model LH40M. Calcium sulfoaluminate expanding agent was purchased from Nanjing Yaojie Energy Saving Technology Co., Ltd., model HP-CSA.

[0024] Example 2

[0025] According to the formula of Example 1, but replacing the polycarboxylate superplasticizer by mass with a modified superplasticizer, a fast-setting road repair mortar was prepared. The preparation method of the modified superplasticizer is as follows:

[0026] (a) 30 g of 1-vinyl-3-butylimidazolium chloride ([BVIm]Cl), 8 g of allylamine (AA), 6 g of hydroxyethyl methacrylate (HEMA) and 0.3 g of ammonium persulfate (APS) were added to 300 mL of deionized water, and nitrogen gas was purged for 30 min to remove oxygen. The mixture was stirred at 75 °C for 2 h, and then heated to 80 °C to continue the reaction for 4 h. After the reaction, the mixture was cooled to room temperature, and precipitated with cold ethanol at -20 °C. The precipitate was filtered and dried under vacuum at 60 °C to obtain the [BVIm]-g-AA-HEMA copolymer.

[0027] (b) 3g of nano-SiO2 was ultrasonically dispersed in 100mL of 50% ethanol aqueous solution, 0.2g of silane coupling agent KH-560 was added, the pH was adjusted to 4 with hydrochloric acid, and the temperature was raised to 70℃ and stirred for 2h. After the reaction, the mixture was centrifuged, washed 3 times with ethanol, and dried under vacuum at 60℃ to obtain silane coupling agent modified SiO2 (KH-560-SiO2).

[0028] (c) 5g of silane coupling agent modified SiO2 was ultrasonically dispersed in 200mL of 50% ethanol aqueous solution, 22g of [BVIm]-g-AA-HEMA copolymer and 0.6g of ammonium persulfate were added, and the mixture was stirred at 80℃ for 6h under nitrogen protection. After the reaction, the mixture was cooled to room temperature, centrifuged, and the product was washed three times with 50% ethanol aqueous solution and dried under vacuum at 60℃ to obtain the modified water-reducing agent.

[0029] By weight, the quick-setting road repair mortar is composed of the following components: 15 parts ordinary silicate cement, 31 parts sulfoaluminate cement, 46 parts natural river sand, 2.2 parts ethylene-vinyl acetate copolymer, 1.7 parts polypropylene fiber, 0.15 parts hydroxypropyl methylcellulose ether (HPMC), 1 part defoamer, 2 parts polycarboxylate superplasticizer, 0.1 parts lithium carbonate, and 0.3 parts calcium sulfoaluminate expanding agent. The above raw materials are added to a high-speed mixer in the specified proportions and stirred until homogeneous to obtain the quick-setting road repair mortar.

[0030] The mortars of each embodiment were mixed with water at a water-cement ratio of 0.25. The compressive strength of mortar specimens at 2h, 24h, and 28d, and the flexural strength of mortar specimens at 8d (specimen size 40mm×40mm×160mm) were tested according to GB / T 17671-2021, "Test Method for Strength of Cement Mortar (ISO Method)". Referring to "Repair Mortar" (JC / T 2381-2016), the interfacial flexural strength was used as the evaluation index, and the specimen age was 28d. The bond strength of the mortars in each embodiment was tested (the substrate specimens used in the experiment were ordinary mortar (purchased from Shenzhen Hongda Building Materials Technology Development Co., Ltd.)). The results are shown in the table below:

[0031]

[0032] The mortar in the above embodiments is a preferred mix ratio. The fast-hardening road repair mortar of the present invention is not limited to the ratio described in the embodiments and can be adjusted to: 10-23 parts by weight of ordinary silicate cement, 25-35 parts by weight of sulfoaluminate cement, 30-50 parts by weight of natural river sand, 1-3 parts by weight of ethylene-vinyl acetate copolymer, 1-2.4 parts by weight of polypropylene fiber, 0.1-0.2 parts by weight of hydroxypropyl methylcellulose, 1-1.5 parts by weight of defoamer, 1-2 parts by weight of water-reducing agent, 0.1-0.2 parts by weight of lithium carbonate, and 0.1-0.5 parts by weight of expanding agent. The sources of each component are not limited to those described in the examples. For example, the defoamer may be at least one of silicone defoamer or polyether defoamer; the expanding agent may be at least one of calcium sulfoaluminate expanding agent, calcium oxide expanding agent, magnesium oxide expanding agent, or aluminum powder expanding agent; the water reducing agent may be at least one of polycarboxylic acid water reducing agent, naphthalene-based water reducing agent, or lignin-based water reducing agent; other raw materials such as ethylene-vinyl acetate copolymer and hydroxypropyl methylcellulose ether produced by other manufacturers may also be used.

[0033] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A rapid hardening pavement repair mortar, characterized by, This road repair mortar is made from the following components in parts by weight: 10-23 parts ordinary silicate cement, 25-35 parts sulfoaluminate cement, 30-50 parts natural river sand, 1-3 parts ethylene-vinyl acetate copolymer, 1-2.4 parts polypropylene fiber, 0.1-0.2 parts hydroxypropyl methylcellulose ether, 1-1.5 parts defoamer, 1-2 parts water-reducing agent, 0.1-0.2 parts lithium carbonate, and 0.1-0.5 parts expanding agent; The water-reducing agent is a modified water-reducing agent, and its preparation method is as follows: (a) 1-Vinyl-3-butylimidazolium chloride, allylamine, hydroxyethyl methacrylate and ammonium persulfate were added to deionized water, and the mixture was stirred at 75°C after purging with nitrogen to remove oxygen. The temperature was then raised to 80°C to continue the reaction. After the reaction, the mixture was cooled to room temperature, precipitated with cold ethanol, filtered, and dried under vacuum to obtain [BVIm]-g-AA-HEMA copolymer. The mass ratio of 1-vinyl-3-butylimidazolium chloride, allylamine, hydroxyethyl methacrylate and ammonium persulfate was 30:8:6:0.

3. (b) The silane coupling agent modified SiO2 was ultrasonically dispersed in an ethanol aqueous solution, and [BVIm]-g-AA-HEMA copolymer and ammonium persulfate were added. The mixture was stirred at 80°C under nitrogen protection. After the reaction, the mixture was cooled to room temperature, centrifuged, and the product was washed with an ethanol aqueous solution and vacuum dried to obtain the modified water-reducing agent. The mass ratio of silane coupling agent modified SiO2, [BVIm]-g-AA-HEMA copolymer and ammonium persulfate was 5:22:0.

6.

2. The rapid hardening pavement repair mortar according to claim 1, wherein 15 parts ordinary silicate cement, 31 parts sulfoaluminate cement, 46 parts natural river sand, 2.2 parts ethylene-vinyl acetate copolymer, 1.7 parts polypropylene fiber, 0.15 parts hydroxypropyl methylcellulose ether, 1 part defoamer, 2 parts water-reducing agent, 0.1 parts lithium carbonate, and 0.3 parts calcium sulfoaluminate expanding agent.

3. The fast-setting road repair mortar according to claim 1, characterized in that, The defoamer is at least one of silicone defoamers and polyether defoamers.

4. The fast-setting road repair mortar according to claim 1, characterized in that, The expanding agent is at least one of the following: calcium sulfoaluminate expanding agent, calcium oxide expanding agent, magnesium oxide expanding agent, and aluminum powder expanding agent.

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