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

Abstract

The invention 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 percentage by mass: 40-50% of cement, 3-5% of an early strength agent, 0.5-1.5% of a water reducing agent, 3-20% of a mineral admixture, 0.2-1% of a defoaming agent and 35-50% of aggregate, the early strength agent is a composition of a ground nano seed crystal early strength agent based on hydrated calcium silicate and lithium sulfate, and the water reducing agent is an asparaginic acid ester modified polycarboxylic acid water reducing agent. According to the invention, high fluidity and high stability of the cement-based grouting material are realized, the problem of insufficient early strength of the traditional grouting material is solved, and sufficient grouting in a complex and narrow construction environment can be met.

Description

Technical Field

[0001] The invention relates to the technical field of grouting materials, and more specifically to an early-strength high-fluidity cement-based grouting material and a preparation method thereof. Background Art

[0002] With the continuous development of the construction industry, the requirements for construction speed and building quality are getting higher and higher, especially in key engineering fields such as bridges, tunnels, underground projects and high-rise buildings, which have higher requirements 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 are in urgent need of rapid opening to traffic or commissioning, these problems will lead to serious delays in construction and increased costs. Summary of the invention

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

[0004] In order to achieve the above object, the present invention adopts the following technical solution:

[0005] The invention discloses an early-strength high-fluidity cement-based grouting material. The grouting material is made of the following raw materials in percentage by weight, based on 100% of the total weight of the grouting material: 40-50% of cement, 3-5% of an early-strength agent, 0.5-1.5% of a water-reducing agent, 3-20% of a mineral admixture, 0.2-1% of a defoaming agent, and 35-50% of an aggregate. The early-strength agent is a composition of a powdered nano-crystal seed early-strength agent based on hydrated calcium silicate and lithium sulfate, and the water-reducing agent is an aspartic acid ester-modified polycarboxylic acid water-reducing agent.

[0006] The present invention is further configured such that the early strength agent is a composition of a powdered nano-crystal early strength agent based on hydrated calcium silicate and lithium sulfate mixed in a mass ratio of 1:1-3.

[0007] The present invention is further configured such that the powdered nano-crystal seed early strength agent based on hydrated calcium silicate is a crystal seed early strength agent S7044.

[0008] The present invention is further configured such that the defoamer is a modified polyether defoamer.

[0009] The present invention is further configured that the defoaming agent is DYFOMA 108 powder defoaming agent.

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

[0011] The present invention is further configured such that the aggregate is at least one of natural sand and regenerated sand.

[0012] The present invention is further configured that, based on 100% of the total mass of the grouting material, the grouting material is made of the following raw materials in percentage by mass: 42.6% of cement, 41.2% of seed early strength agent S704, 2.4% of lithium sulfate, 1.5% of aspartic acid ester modified polycarboxylic acid water reducer, 8% of fly ash, 0.9% of DYFOMA 108 powder defoaming agent, and 43.4% of natural sand.

[0013] A method for preparing an early-strength high-fluidity cement-based grouting material comprises the following steps:

[0014] a. Drying and grinding the mineral admixtures;

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

[0016] In summary, the present invention has the following beneficial effects:

[0017] 1. The use of early strength agents with rapid hydration reaction enables the grouting materials to reach high compressive strength in a short time, solving the problem of insufficient early strength of traditional grouting materials.

[0018] 2. Through the use of new water-reducing agents, high fluidity of the material can be achieved, and sufficient grouting can be achieved even in complex and narrow construction environments to avoid the occurrence of voids or unevenness.

[0019] 3. Add the powdered nano-crystal seed early strength agent S7044 based on hydrated calcium silicate, compound it with aspartic acid ester modified polycarboxylic acid water reducer and modified polyether type DYFOMA 108 powder defoamer, and use the synergistic effect among the three to further improve the early strength and stability of the grouting material. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present invention are described clearly and completely below. 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 creative work are within the scope of protection of the present invention.

[0021] The early strength high fluidity cement-based grouting material of the present invention 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 mineral admixture is dried and ground; then the cement, early strength agent, water reducer, mineral admixture, defoamer, and aggregate are uniformly mixed according to a certain proportion to obtain the early strength high fluidity cement-based grouting material.

[0022] The early strength agent is a composition of a powdered nano-crystal seed early strength agent based on hydrated calcium silicate and lithium sulfate, preferably 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, wherein the powdered nano-crystal seed early strength agent based on hydrated calcium silicate is preferably a seed early strength agent S7044 produced by Nanjing Xinyi Synthetic Technology Co., Ltd. The water reducer is preferably an aspartic acid ester modified polycarboxylic acid water reducer [prepared according to the method described in the paper (Synthesis and Performance Study of Aspartic Acid Ester Modified Polycarboxylic Acid Water Reducer. Li Meili, Mi Jinling, Yuan Ruizeng, Duan Yanhong, Li Yuanfeng. Henan Building Materials, 2016 (06)]. The defoamer is a modified polyether defoamer, preferably DYFOMA 108 powder defoamer 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 regenerated sand.

[0023] The preferred embodiment is:

[0024] Example 1

[0025] (1) Prepare the raw materials according to the following mass percentages: cement 42.6%, seed early strength agent S70441.2%, lithium sulfate 2.4%, aspartic acid ester modified polycarboxylic acid water reducer 1.5%, fly ash 8%, DYFOMA 108 powder defoamer 0.9%, and natural sand 43.4%.

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

[0027] Comparative Example 1

[0028] The cement-based grouting material was prepared according to the method of Example 1, but without adding the seed early strength agent S7044.

[0029] Comparative Example 2

[0030] The cement-based grouting material was prepared according to the method of Example 1, but without adding the aspartic acid ester modified polycarboxylate water reducer.

[0031] Comparative Example 3

[0032] The cement-based grouting material was prepared according to the method of Example 1, but without adding DYFOMA 108 powder defoamer.

[0033] Comparative Example 4

[0034] The cement-based grouting material was prepared according to the method of Example 1, except that the mass of the seed early strength agent S7044 was replaced by lithium sulfate.

[0035] Comparative Example 5

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

[0037] The grouting materials prepared in Example 1 and Comparative Examples 1 to 5 were subjected to performance tests (each grouting material was added to water and stirred for 10 minutes to obtain a uniform slurry, and the fluidity was tested at -5°C, and the grouting material was poured into a channel with a pore diameter of 2 cm and a length of 30 cm, and cured for 28 days), and the results are shown in Table 1. As can be seen from Table 1, the grouting material prepared by the present invention has significant advantages in fluidity, early strength, and volume stability, and the seed early strength agent S7044, aspartic acid ester modified polycarboxylic acid water reducer, and DYFOMA 108 powder defoamer have a synergistic effect, which can further improve the performance of the grouting material.

[0038] Table 1

[0039]

[0040] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. An early-strength 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 composition 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.

2. The early-strength high-fluidity cement-based grouting material according to claim 1, characterized in that: The early strength agent is a composition in which a powdered nano-crystal early strength agent based on hydrated calcium silicate and lithium sulfate are mixed in a mass ratio of 1:1-3.

3. The early-strength high-fluidity cement-based grouting material according to claim 1, characterized in that: The powdered nano-crystal seed early strength agent based on hydrated calcium silicate is the crystal seed early strength agent S7044.

4. The early-strength high-fluidity cement-based grouting material according to claim 1, characterized in that: The defoamer is a modified polyether defoamer.

5. The early-strength high-fluidity cement-based grouting material according to claim 4, characterized in that: The defoamer is DYFOMA 108 powder defoamer.

6. The early-strength 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.

7. The early-strength 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.

8. The early-strength 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: 42.6% cement, 1.2% seed early strength agent S704, 2.4% lithium sulfate, 1.5% aspartic acid ester modified polycarboxylic acid water reducer, 8% fly ash, 0.9% DYFOMA 108 powder defoaming agent, and 43.4% natural sand.

9. A method for preparing the early strength and high fluidity cement-based grouting material according to any one of claims 1 to 8, characterized in that: The following steps are involved: a. Drying and grinding the mineral admixtures; b. Mix cement, early strength agent, water reducing agent, mineral admixture, defoaming agent and aggregate evenly in proportion to obtain early strength and high fluidity cement-based grouting material.

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