阅读说明：本技术 水泥基灌浆料及其制备方法 (Cement-based grouting material and preparation method thereof ) 是由 周希圣 方从启 黄小平 张伟 吴东鹏 段俊 卞国强 纪腾飞 薛文涛 于 2021-07-29 设计创作，主要内容包括：本发明提供了一种水泥基灌浆料及其制备方法,按重量份数计,所述水泥基灌浆料包括：52.5级硅酸盐水泥400-500份,石英砂465-640份,膨胀剂16-30份,减水剂1.4-2.6份,消泡剂0.6-1.2份,稳定剂0.4-0.75份以及塑性膨胀剂0.2-0.5份。本发明降低工程加固改造用的水泥基灌浆料的成本,同时显著提高灌浆料与旧混凝土间的粘结性能,进而提供一种流动性能、强度、稳定性等优良的用于梁、柱截面加宽的高粘结性能水泥基灌浆料。(The invention provides a cement-based grouting material and a preparation method thereof, wherein the cement-based grouting material comprises the following components in parts by weight: 400 portions of 52.5-grade portland cement, 640 portions of quartz sand, 16 to 30 portions of expanding agent, 1.4 to 2.6 portions of water reducing agent, 0.6 to 1.2 portions of defoaming agent, 0.4 to 0.75 portion of stabilizing agent and 0.2 to 0.5 portion of plastic expanding agent. The invention reduces the cost of the cement-based grouting material for engineering reinforcement and reconstruction, and simultaneously obviously improves the bonding property between the grouting material and the old concrete, thereby providing the cement-based grouting material with high bonding property for widening the cross sections of beams and columns, which has excellent flowing property, strength, stability and the like.)

1. The cement-based grouting material is characterized by comprising the following components in parts by weight: 400 portions of 52.5-grade portland cement, 640 portions of quartz sand, 16 to 30 portions of expanding agent, 1.4 to 2.6 portions of water reducing agent, 0.6 to 1.2 portions of defoaming agent, 0.4 to 0.75 portion of stabilizing agent and 0.2 to 0.5 portion of plastic expanding agent.

2. The cement-based grouting material as claimed in claim 1, wherein the quartz sand is a mixture of 20-50 mesh quartz sand and 40-80 mesh quartz sand at a ratio of 1: 1.15.

3. The cement-based grouting material of claim 1, wherein the expanding agent is a sulfoaluminate expanding agent, an aluminate expanding agent, or a mixture thereof.

4. The cement-based grouting material of claim 1, wherein the plastic swelling agent is a nitroso compound, an azo compound, a sulfonyl hydrazide compound, or a mixture thereof.

5. The cement-based grouting material of claim 1, wherein the water reducing agent is a polycarboxylic acid water reducing agent, a lignosulfonate water reducing agent or a mixture thereof.

6. The preparation method of the cement-based grouting material is characterized by comprising the following steps:

placing the expanding agent, the water reducing agent, the defoaming agent, the stabilizing agent and the plastic expanding agent into a forced concrete mixer and stirring for 2 minutes;

adding quartz sand and portland cement at a constant speed and stirring for 3 minutes;

stirring at constant speed for 5 minutes.

Technical Field

The invention relates to a high-bonding-performance grouting material for widening cross sections of beams and columns and a preparation method thereof, in particular to a high-bonding-performance grouting material suitable for widening cross sections of beams and columns in a concrete structure.

Background

The structural reinforcement or transformation engineering adopting the beam and column section expansion method usually requires good reinforcement effect, quick construction period and easy construction, the reinforcement material has good stability and low long-term shrinkage rate, and meanwhile, the reliable bonding between the reinforcement material and the old concrete is ensured. The requirements on the grouting material are the indexes of the grouting material such as fluidity, expansion rate, strength, bleeding rate and the like. If the flowing performance is not necessary, the filling cannot be carried out in a narrow space, and the full filling effect cannot be achieved. In order to obtain a full filling effect after the grouting material is hardened, the grouting material must have the characteristics of micro-expansion and no shrinkage, and the slurry itself should be very stable. In structural reinforcement or reconstruction projects, generally, high early strength is required so as to be put into use as early as possible, namely, the final setting time is expected to be as short as possible, but the initial setting time is not too short, and the construction operation and the pouring quality are easily influenced in case of too short time.

At present, a common Portland cement-sulphoaluminate cement binary cementing system is generally adopted as a grouting material for engineering reconstruction and reinforcement at home and abroad to achieve the purpose of high early strength, but the use of sulphoaluminate cement can cause the problems of reduced fluidity of the grouting material, too fast initial setting time and final setting time and the like. Therefore, the existing grouting material product also contains mineral admixtures such as mineral powder and the like, and various high-performance additives such as retarder and the like, which undoubtedly causes great increase of the cost. The use of such special grouting materials is certainly uneconomical for conventional reinforcement engineering with widening of the beam and column sections. Meanwhile, the bonding property between the current main grouting material products and the old concrete is mostly low, so that the mechanical property of the beam and the column after the section is enlarged by using the grouting material cannot be accurately mastered.

Disclosure of Invention

The invention overcomes the defects in the prior art, and aims to reduce the cost of the cement-based grouting material for engineering reinforcement and reconstruction, and simultaneously remarkably improve the bonding property between the grouting material and the old concrete, thereby providing the cement-based grouting material with high bonding property for widening the cross sections of beams and columns, which has excellent flowing property, strength, stability and the like.

According to one aspect of the present invention, there is provided a cement-based grouting material, comprising, in parts by weight: 400 portions of 52.5-grade portland cement, 640 portions of quartz sand, 16 to 30 portions of expanding agent, 1.4 to 2.6 portions of water reducing agent, 0.6 to 1.2 portions of defoaming agent, 0.4 to 0.75 portion of stabilizing agent and 0.2 to 0.5 portion of plastic expanding agent.

In some embodiments of the invention, the quartz sand is 20-50 mesh quartz sand mixed with 40-80 mesh quartz sand at a ratio of 1: 1.15.

In some embodiments of the invention, the swelling agent is a sulfoaluminate swelling agent, an aluminate swelling agent, or a mixture thereof.

In some embodiments of the invention, the plastic swelling agent is a nitroso compound, an azo compound, a sulfonyl hydrazide compound, or a mixture thereof.

In some embodiments of the invention, the water reducer is a polycarboxylic acid water reducer, a lignosulfonate water reducer, or a mixture thereof.

According to another aspect of the present invention, there is also provided a method for preparing a cement-based grouting material, comprising:

placing the expanding agent, the water reducing agent, the defoaming agent, the stabilizing agent and the plastic expanding agent into a forced concrete mixer and stirring for 2 minutes;

adding quartz sand and portland cement at a constant speed and stirring for 3 minutes;

stirring at constant speed for 5 minutes.

Compared with the prior art, the invention has the beneficial effects that:

(1) the bonding strength is high: the cement-based grouting material for widening the cross sections of the beams and the columns, provided by the invention, has the tensile bonding strength of more than 1.75MPa, can ensure the reliable bonding between the grouting material and the old concrete, and can ensure the mechanical properties of the reinforced beams and columns;

(2) slow setting and good fluidity: the initial fluidity of the cement-based grouting material provided by the invention can reach more than 290mm, part of the mixture ratio can reach 330mm, and the fluidity decrement is 10-20mm in half an hour, so that the construction quality of the grouting material can be effectively ensured;

(3) high strength and low cost: the cement-based grouting material provided by the invention has the advantages that the 1d strength can reach 23.5MPa, the 28d strength can reach more than 73.4MPa, the components are simple, and the cost is low.

Detailed Description

Example embodiments will now be described more fully. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments of the disclosure. One skilled in the relevant art will recognize, however, that the subject matter of the present disclosure can be practiced without one or more of the specific details, or with other methods, materials, devices, etc. In other instances, well-known technical solutions have not been shown or described in detail to avoid obscuring aspects of the present disclosure.

The terms "a," "an," "the," "said," and "at least one" are used to indicate the presence of one or more elements/components/parts/etc.; the terms "comprising," "having," and "providing" are intended to be inclusive and mean that there may be additional elements/components/etc. other than the listed elements/components/etc.

The cement-based grouting material provided by the invention is used for high-bonding-performance grouting material for widening the cross sections of beams and columns, and comprises the following components in parts by weight: 400 portions of 52.5-grade ordinary portland cement, 640 portions of quartz sand, 16 to 30 portions of expanding agent, 1.4 to 2.6 portions of water reducing agent, 0.6 to 12 portions of defoaming agent, 0.4 to 0.75 portion of stabilizing agent and 0.2 to 0.5 portion of plastic expanding agent.

Specifically, the grouting material is prepared by mixing 20-50 meshes of quartz sand and 40-80 meshes of quartz sand according to a ratio of 1: 1.15. The expanding agent used in the grouting material is sulphoaluminate expanding agent, aluminate expanding agent or the mixture thereof. The plastic expanding agent used by the grouting material is a nitroso compound, an azo compound, a sulfonyl hydrazide compound or a mixture thereof.

Specifically, the water reducing agent used by the grouting material is a polycarboxylic acid water reducing agent, a lignosulfonate water reducing agent or a mixture thereof.

Specifically, the preparation method of the cement-based grouting material comprises the following steps: placing the expanding agent, the water reducing agent, the defoaming agent, the stabilizing agent and the plastic expanding agent into a forced concrete mixer and stirring for 2 minutes; adding quartz sand and portland cement at a constant speed and stirring for 3 minutes; stirring at constant speed for 5 minutes. Finally, the mixture can be taken out and bagged.

The cement-based grouting material with high bonding performance for reinforcing the sections of the beams and the columns, provided by the invention, has the main performance indexes through various performance tests as follows:

(1) fluidity: the initial fluidity is 290mm, and the fluidity is more than or equal to 270mm in 30 min;

(2) strength: 23.5MPa for 1d strength, 47.8MPa for 3d strength and 73.4MPa for 28d strength;

(3) expansion ratio: 1d expansion rate is 0.10%;

(4) bonding strength: tensile bond strength 1.75MPa.

The following provides examples of the invention:

the first embodiment is as follows: high-adhesion grouting material for widening cross sections of beams and columns

400 parts of 52.5-grade ordinary portland cement, 500 parts of quartz sand, 20 parts of an expanding agent, 1.6 parts of a water reducing agent, 0.8 part of a defoaming agent, 0.4 part of a stabilizer, 0.2 part of a plastic expanding agent and 130 parts of tap water.

The main properties of the obtained grouting material are as follows:

example two: high-adhesion grouting material for widening cross sections of beams and columns

450 parts of 52.5-grade ordinary portland cement, 600 parts of quartz sand, 18 parts of an expanding agent, 2.0 parts of a water reducing agent, 1.0 part of a defoaming agent, 0.6 part of a stabilizer, 0.3 part of a plastic expanding agent and 142 parts of tap water.

The main properties of the obtained grouting material are as follows:

the foregoing is merely an exemplary description of various embodiments of the invention and is not intended to be limiting thereof.

Compared with the prior art, the invention has the beneficial effects that:

(1) the bonding strength is high: the cement-based grouting material for widening the cross sections of the beams and the columns, provided by the invention, has the tensile bonding strength of more than 1.75MPa, can ensure the reliable bonding between the grouting material and the old concrete, and can ensure the mechanical properties of the reinforced beams and columns;

(2) slow setting and good fluidity: the initial fluidity of the cement-based grouting material provided by the invention can reach more than 290mm, part of the mixture ratio can reach 330mm, and the fluidity decrement is 10-20mm in half an hour, so that the construction quality of the grouting material can be effectively ensured;

(3) high strength and low cost: the cement-based grouting material provided by the invention has the advantages that the 1d strength can reach 23.5MPa, the 28d strength can reach more than 73.4MPa, the components are simple, and the cost is low.

In the description herein, references to the description of "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," etc., indicate that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The foregoing is a more detailed description of the invention in connection with specific preferred embodiments and it is not intended that the invention be limited to these specific details. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.