阅读说明：本技术 一种硅酸盐水泥灌浆修复混凝土裂缝的方法 (Method for repairing concrete crack by silicate cement grouting ) 是由 加尼·阿卜杜勒·瑞泽普 赵婷 于 2020-04-13 设计创作，主要内容包括：本发明公开了一种硅酸盐水泥灌浆修复混凝土裂缝的方法,该方法利用硅酸盐水泥与水的混合液,灌浆注入混凝土裂缝中,当多余的水从裂缝中渗出时,停止操作；裂缝水面下降后,重复上述操作,直到裂缝修复完全,固化后的水泥修复混凝土裂缝。所述硅酸盐水泥与水质量比为1:2。本发明修复裂缝使用的普通硅酸盐水泥廉价易得,经济实用。水泥灌浆修复过程简单易操作,而且不会产生有害物质,环境友好,而且与混凝土的膨胀系数相近,一般不会产生二次裂缝。(The invention discloses a method for repairing concrete cracks by portland cement grouting, which utilizes mixed liquid of portland cement and water to fill the grout into the concrete cracks, and stops the operation when excessive water seeps out of the cracks; and after the water surface of the crack descends, repeating the operation until the crack is completely repaired, and repairing the concrete crack by the cured cement. The mass ratio of the portland cement to water is 1: 2. The ordinary portland cement used for repairing cracks is cheap and easy to obtain, and is economical and practical. The cement grouting repairing process is simple and easy to operate, does not generate harmful substances, is environment-friendly, has a similar expansion coefficient with concrete, and generally does not generate secondary cracks.)

1. A method for repairing concrete cracks by portland cement grouting is characterized by comprising the following steps: the method comprises the steps of injecting grout into concrete cracks by using a mixed solution of portland cement and water, and stopping operation when excessive water seeps out of the cracks; and after the water surface of the crack descends, repeating the operation until the crack is completely repaired, and repairing the concrete crack by the cured cement.

2. The method for repairing concrete cracks by portland cement grouting according to claim 1, wherein: the mass ratio of the portland cement to water is 1: 2.

Technical Field

The invention belongs to the technical field of concrete crack repair, and particularly relates to a method for repairing a concrete crack by using a portland cement grouting method.

Background

Concrete is one of the most important building materials in the world, and the second most material is used. However, concrete has a heavy self-weight, a long curing period, a low tensile strength, and is prone to crack formation. After concrete cracks appear, many harmful substances such as acid, alkali, gas and water invade the interior of the concrete portion through a single mechanism or a combined mechanism such as diffusion, capillary action, permeation, etc., resulting in corrosion of steel bars and deterioration of concrete structures. If other harmful substances reach the inside of the concrete, they may react with the components of the concrete or directly damage the structure of the concrete, thereby seriously affecting the durability of the concrete. Therefore, how to effectively repair the concrete cracks is very important.

Although the existing traditional concrete crack repairing methods such as epoxy resin injection, gravity filling, polymer impregnation and the like have good engineering effects, the used materials such as epoxy resin, carbamate and the like are easy to age, have low heat resistance and different thermal expansion coefficients with concrete, and the repaired concrete crack may be secondarily cracked, which is not acceptable for economic and safety reasons.

The cement is used as a raw material for preparing concrete, is added with water and stirred to form slurry, can be hardened in air or water, and can firmly bond materials such as sand, stone and the like together. When the cement is used, carbon dioxide can be generated, but polluting substances can not be generated, and the expansion coefficient of the cement is similar to that of the concrete, so that the defects of other traditional concrete repairing technologies can be well overcome. And through patent retrieval, no research is available for repairing concrete cracks by utilizing cement grouting.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides an economical, simple and feasible concrete crack repairing method. The method utilizes the mixed liquid of cement and water to fill the concrete cracks with grouting, and the cured cement repairs the concrete cracks.

In order to achieve the above purpose, the technical scheme of the invention is as follows:

a method for repairing concrete crack by silicate cement grouting, the method utilizes the mixed solution of silicate cement and water, the grouting is poured into the concrete crack, when the surplus water oozes out from the crack, stop the operation; and after the water surface of the crack descends, repeating the operation until the crack is completely repaired, and repairing the concrete crack by the cured cement.

The mass ratio of the portland cement to water is 1: 2.

The production process flow adopted by the invention is shown in the figure, and the adopted technical scheme is as follows:

(1) purchasing ordinary portland cement;

(2) determining the optimal mixing ratio of cement and water;

(3) manufacturing a concrete sample and making cracks, wherein the schematic diagrams are shown in figures 2 and 3;

(4) cleaning concrete cracks; firstly, placing a concrete sample under a faucet for washing so as to remove some fragments in cracks, then scraping some other fragments by using a feeler gauge, placing the concrete sample under the faucet for washing again, and finally drying at room temperature;

(5) sticking a waterproof adhesive tape at the bottom of the crack; the waterproof adhesive tape has the functions of allowing excessive water to pass through, and the repairing material is kept in the crack;

(6) grouting according to the optimal proportion of cement and water;

(7) stopping the operation when excess water seeps out of the crack; and after the water surface of the crack descends, repeating the operation until the crack is completely repaired, and obtaining a concrete sample after the cement grouting repair as shown in figure 4.

The invention has the advantages and beneficial effects that:

(1) the ordinary portland cement used for repairing cracks is cheap and easy to obtain, and is economical and practical.

(2) The cement grouting repairing process is simple and easy to operate, does not generate harmful substances, is environment-friendly, has a similar expansion coefficient with concrete, and generally does not generate secondary cracks.

(3) And (3) carrying out constant water head permeability test on the concrete sample with the cracks repaired by cement grouting, and observing for 24 hours to find that no leakage occurs in the cracks of the repaired sample. In contrast, the unrepaired cracked concrete specimens showed uninterrupted leakage. Thus, in current tests, the grout was able to seal the widest (1.5mm) of the three fracture sizes.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1: the invention has the overall technical route schematic diagram;

FIG. 2: a concrete sample model diagram;

FIG. 3: concrete sample entity diagram;

FIG. 4: the invention relates to a concrete sample repaired by cement grouting;

FIG. 5: the transmission time schematic diagram of the concrete sample before and after the crack is repaired by the ultrasonic wave in the cement grouting process;

FIG. 6: the values of the elastic modulus of 5 times of repetition of the crack unrepaired group W and the cement grouting restoration group C are shown schematically;

FIG. 7: the load-mid-span deflection curves of a concrete sample CA after cement grouting restoration and an unrepaired concrete sample W;

wherein, CB refers to a concrete test piece before cement grouting repair; CA refers to the concrete specimen after cementing.

Detailed Description

For a better understanding of the nature of the invention, reference will now be made to the following examples taken in conjunction with the accompanying drawings.

Example 1

The invention discloses a method for repairing concrete cracks by portland cement grouting, which utilizes a mixed solution of portland cement and water to fill grout into concrete cracks as shown in figure 1, and stops operation when excessive water seeps out of the cracks; and after the water surface of the crack descends, repeating the operation until the crack is completely repaired, and repairing the concrete crack by the cured cement. The mass ratio of the portland cement to water is 1: 2.

The specific operation is implemented as follows:

(1) purchasing ordinary portland cement;

(2) determining the optimal mixing ratio of cement and water according to the size of the crack so that the cement and water-organism mixed liquid can enter the crack;

(3) manufacturing a concrete sample and making cracks, wherein the schematic diagrams are shown in figures 2 and 3;

(4) cleaning concrete cracks; firstly, placing a concrete sample under a faucet for washing so as to remove some fragments in cracks, then scraping some other fragments by using a feeler gauge, placing the concrete sample under the faucet for washing again, and finally drying at room temperature;

(5) sticking a waterproof adhesive tape at the bottom of the crack; the waterproof adhesive tape has the functions of allowing excessive water to pass through, and the repairing material is kept in the crack;

(6) grouting according to the optimal ratio of cement to water, namely the mass ratio of 1: 2: the mixed liquid is sucked by a liquid-transferring gun and is quickly injected into concrete cracks;

(7) stopping the operation when excess water seeps out of the crack; after the fracture surface is lowered, the above operation is repeated until the fracture is completely repaired, as shown in fig. 4.

And (3) carrying out constant water head permeability test on the concrete sample with the cracks repaired by cement grouting, and observing for 24 hours to find that no leakage occurs in the cracks of the repaired sample. In contrast, the unrepaired cracked concrete specimens showed uninterrupted leakage. Thus, in current tests, the grout was able to seal the widest (1.5mm) of the three fracture sizes.

Ultrasonic pulse speed detection analysis is carried out on the concrete test piece after the cement grouting repairing, and the propagation time of the repaired concrete test piece is obviously reduced, which shows that the cracks are sealed after the cement is cured, so that ultrasonic waves are allowed to pass through the sealed cracks along a more direct path, and the experimental result is shown in fig. 5.

The elastic modulus detection analysis is carried out on the concrete test piece after the cement grouting repairing, and the elastic modulus of 80% of the test pieces in the group C is larger than that of the test pieces in the group W for the unrepaired concrete test piece (W) and the concrete test piece after the cement grouting repairing, so that the elastic modulus of most of the concrete test pieces after the cement grouting repairing is improved, and the experimental result is shown in fig. 6.

And (3) performing deflection analysis on the concrete sample after the cement grouting repairing, and finding that the strength of the concrete sample is sequenced to be that the concrete sample after the cement grouting repairing is larger than the concrete sample which is not repaired, which shows that the strength of the concrete sample after the cement grouting repairing is recovered, and the experimental result is shown in fig. 7.