Early-strength high-fluidity cement-based grouting material and preparation method thereof

Abstract

The application discloses an early-strength high-fluidity cement-based grouting material and a preparation method thereof, and belongs to the technical field of grouting materials. The grouting material is prepared from the following raw materials in mass percentage: cement 40-50%, early-strength agent 3-5%, water reducing agent 0.5-1.5%, mineral admixture 3-20%, defoaming agent 0.2-1%, and aggregate 35-50%. The early-strength agent is a combination of a ground-like nanocrystalline seed early-strength agent based on calcium silicate hydrate and lithium sulfate, and the water reducing agent is an aspartate modified polycarboxylic acid water reducing agent. The application realizes high fluidity and high stability of the cement-based grouting material, solves the problem of insufficient early strength of traditional grouting materials, and can meet sufficient grouting in complex and narrow construction environments.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of grouting materials, and more particularly to an early-strength high-fluidity cement-based grouting material and a preparation method thereof. BACKGROUND

[0002] With the continuous development of the construction industry, there are higher requirements for construction speed and building quality, especially in key engineering fields such as bridges, tunnels, underground engineering and high-rise buildings, and there are higher demands for the early strength and fluidity of materials. Traditional grouting materials often have problems such as insufficient early strength, poor fluidity and poor stability, which affect the efficiency and safety of construction, especially in some projects that urgently need to be opened to traffic or put into use, these problems will cause serious delay in construction period and increase in cost. SUMMARY

[0003] The present application aims to overcome the shortcomings of the prior art and provide an early-strength high-fluidity cement-based grouting material and a preparation method thereof.

[0004] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0005] An early-strength high-fluidity cement-based grouting material, made of the following raw materials in a total mass of 100%: cement 40-50%, early-strength agent 3-5%, water reducing agent 0.5-1.5%, mineral admixture 3-20%, defoaming agent 0.2-1%, and aggregate 35-50%.

[0006] The present application further provides that the early-strength agent is a combination of a pulverized nano-crystal seed early-strength agent based on hydrated calcium silicate and lithium sulfate in a mass ratio of 1:1-3.

[0007] The present application further provides that the pulverized nano-crystal seed early-strength agent based on hydrated calcium silicate is seed early-strength agent S7044.

[0008] The present application further provides that the defoaming agent is a modified polyether defoaming agent.

[0009] The present application further provides that the defoaming agent is DYFOMA 108 powder defoaming agent.

[0010] The present application further provides that the mineral admixture is at least one of fly ash and slag powder.

[0011] The present application further provides that the aggregate is at least one of natural sand and recycled sand.

[0012] The early-strength high-fluidity cement-based grouting material is prepared from the following raw materials in percentage of total mass of the grouting material: cement 42.6%, early-strength agent S7044 41.2%, lithium sulfate 2.4%, aspartate-modified polycarboxylic acid water reducing agent 1.5%, fly ash 8%, DYFOMA 108 powder defoaming agent 0.9%, and natural sand 43.4%.

[0013] A preparation method of an early-strength high-fluidity cement-based grouting material, comprising the following steps:

[0014] a. drying and grinding the mineral admixture;

[0015] b. mixing the cement, early-strength agent, water reducing agent, mineral admixture, defoaming agent and aggregate in proportion to obtain the early-strength high-fluidity cement-based grouting material.

[0016] In summary, the present application has the following advantages:

[0017] 1. The early-strength agent with fast hydration reaction is used to make the grouting material reach high compressive strength in a short time, solving the problem of insufficient early strength of traditional grouting materials.

[0018] 2. The use of the new water reducing agent realizes high fluidity of the material, so that sufficient grouting can be achieved even in complex and narrow construction environment, avoiding the generation of voids or unevenness.

[0019] 3. The powder-like nanocrystalline early-strength agent S7044 based on hydrated calcium silicate is compounded with the aspartate-modified polycarboxylic acid water reducing agent and the modified polyether DYFOMA 108 powder defoaming agent, and the early strength and stability of the grouting material are further improved by the synergistic effect of the three. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0021] The early-strength high-fluidity cement-based grouting material of the present application is prepared from the following raw materials in percentage of total mass of the grouting material: cement 40-50%, early-strength agent 3-5%, water reducing agent 0.5-1.5%, mineral admixture 3-20%, defoaming agent 0.2-1%, and aggregate 35-50%. The mineral admixture is dried and ground, and then the cement, early-strength agent, water reducing agent, mineral admixture, defoaming agent and aggregate are mixed in proportion to obtain the early-strength high-fluidity cement-based grouting material.

[0022] wherein the early strength agent is a composition of a ground-like nanocrystalline early strength agent based on hydrated calcium silicate and lithium sulfate, preferably a composition of a ground-like nanocrystalline early strength agent based on hydrated calcium silicate and lithium sulfate mixed at a mass ratio of 1:1-3, wherein the ground-like nanocrystalline early strength agent based on hydrated calcium silicate is preferably the seed early strength agent S7044 produced by Nanjing Xinyiheng Synthesis Technology Co., Ltd. The water reducing agent is preferably a poly-carboxylic acid water reducing agent modified by aspartic acid [prepared according to the method described in the paper (Synthesis and Performance Research of Poly-carboxylic Acid Water Reducing Agent Modified by Aspartic Acid. Li Meili, Mi Jinglei, Yuan Ruizeng, Duan Yanhong, Li Yuangfeng. Henan Building Materials, 2016(06))]. The defoaming agent is a modified polyether defoaming agent, preferably the DYFOMA 108 powder defoaming agent purchased from Shandong Zhongwei High-tech Materials Co., Ltd. The mineral admixture is at least one of fly ash and slag powder. The aggregate is at least one of natural sand and recycled sand.

[0023] The preferred embodiment is:

[0024] Example 1

[0025] (1) Prepare raw materials cement 42.6%, seed early strength agent S7044 1.2%, lithium sulfate 2.4%, poly-carboxylic acid water reducing agent modified by aspartic acid 1.5%, fly ash 8%, DYFOMA 108 powder defoaming agent 0.9%, natural sand 43.4% at the following mass percentage.

[0026] (2) Dry the fly ash and grind it to a particle size of 6-50 μm; then mix the cement, early strength agent, water reducing agent, mineral admixture, defoaming agent, and aggregate in proportion to obtain the early strength high fluidity cement-based grouting material.

[0027] Comparative Example 1

[0028] Prepare the cement-based grouting material according to the method of Example 1, but do not add the seed early strength agent S7044.

[0029] Comparative Example 2

[0030] Prepare the cement-based grouting material according to the method of Example 1, but do not add the poly-carboxylic acid water reducing agent modified by aspartic acid.

[0031] Comparative Example 3

[0032] Prepare the cement-based grouting material according to the method of Example 1, but do not add the DYFOMA 108 powder defoaming agent.

[0033] Comparative Example 4

[0034] Prepare the cement-based grouting material according to the method of Example 1, but replace the seed early strength agent S7044 with an equal amount of lithium sulfate.

[0035] Comparative Example 5

[0036] The cement-based grouting material was prepared according to the method of Example 1, but the aspartate-modified polycarboxylic acid water reducer was replaced by an unmodified conventional polycarboxylic acid water reducer.

[0037] The grouting materials prepared in Example 1 and Comparative Examples 1-5 were tested for performance (after each grouting material was added to water and stirred for 10 min to obtain a uniform slurry, the flowability was tested at -5℃, and the grouting material was cast into a hole with a diameter of 2 cm and a length of 30 cm and cured for 28 d). The results are shown in Table 1. As shown in Table 1, the grouting material prepared according to the present application has significant advantages in terms of flowability, early strength, and volume stability, and the seed early strength agent S7044, the aspartate-modified polycarboxylic acid water reducer, and the DYFOMA 108 powder defoaming agent have a synergistic effect, which can further improve the performance of the grouting material.

[0038] Table 1

[0039]

[0040] The above description is only preferred embodiments of the present application, and the protection scope of the present application is not limited to the above-described embodiments. Any technical solutions falling within the concept of the present application shall be considered as falling within the protection scope of the present application. It should be noted that, for ordinary skilled persons in the art, some improvements and refinements without departing from the principles of the present application shall also be considered as falling within the protection scope of the present application.

Claims

1. An early-strength and high-fluidity cement-based grouting material, characterized in that: The grouting material is made of the following raw materials in percentage by weight, based on the total weight of the grouting material: 40-50% cement, 3-5% early strength agent, 0.5-1.5% water reducer, 3-20% mineral admixture, 0.2-1% defoamer, and 35-50% aggregate; the early strength agent is a combination of a powdered nano-crystal early strength agent based on hydrated calcium silicate and lithium sulfate; and the water reducer is an aspartic acid ester-modified polycarboxylic acid water reducer. The early strength agent is a composition of a powdered nano-crystal seed early strength agent based on hydrated calcium silicate and lithium sulfate mixed in a mass ratio of 1:1-3; the powdered nano-crystal seed early strength agent based on hydrated calcium silicate is seed early strength agent S7044; The defoaming agent is DYFOMA 108 powder defoaming agent.

2. The early-strength and high-fluidity cement-based grouting material according to claim 1, characterized in that: The mineral admixture is at least one of fly ash and slag powder.

3. The early-strength and high-fluidity cement-based grouting material according to claim 1, characterized in that: The aggregate is at least one of natural sand and regenerated sand.

4. The early-strength and high-fluidity cement-based grouting material according to claim 1, characterized in that: Based on the total mass of the grouting material as 100%, the grouting material is made of the following raw materials in percentage by mass: cement 42.6%, seed crystal accelerator S70441.2%, lithium sulfate 2.4%, aspartic acid ester modified polycarboxylic acid water reducer 1.5%, fly ash 8%, DYFOMA 108 powder defoaming agent 0.9%, and natural sand 43.4%.

5. A method for preparing the early strength and high fluidity cement-based grouting material according to any one of claims 1 to 4, characterized in that: The following steps are involved: a. Drying and grinding the mineral admixtures; b. Mix cement, early strength agent, water reducer, mineral admixture, defoamer and aggregate evenly in proportion to obtain early strength and high fluidity cement-based grouting material.

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