Preparation method of high-temperature-resistant ceramsite concrete

Abstract

The invention discloses a preparation method of high-temperature-resistant ceramsite concrete, and belongs to the field of concrete materials. The ceramsite is soaked in the alkaline solution in advance, then the alkaline-leached ceramsite, the cement, the machine-made sand, the vitrified microbeads, the water reducing agent and the water are mixed, curing is conducted under the proper condition, and the high-temperature-resistant ceramsite concrete can be obtained. By adopting the preparation method of the high-temperature-resistant ceramsite concrete, the prepared ceramsite concrete has very good high-temperature-resistant performance, the problems of great strength loss, internal cracking, poor binding performance and the like of common lightweight aggregate concrete after high-temperature treatment are solved, and in addition, the high-temperature-resistant ceramsite concrete prepared by adopting the preparation method of the high-temperature-resistant ceramsite concrete has the advantages that the high-temperature-resistant performance is good. The prepared ceramsite concrete not only has small loss of compressive strength and breaking strength, but also has a wider application range.

Description

Technical Field

[0001] The invention relates to the technical field of concrete materials, and in particular to a method for preparing high-temperature resistant ceramsite concrete. Background Art

[0002] When a building fire occurs, high temperatures will directly act on the concrete, causing changes in its mechanical properties. As the temperature rises, the concrete's pores begin to lose moisture and the structure becomes loose. At this point, the concrete's internal structure is damaged, cracks appear, and the mechanical properties decrease. These changes not only affect the stability of the building, but also pose a threat to the safety of people's lives.

[0003] Existing technologies include a Chinese invention patent, a high-temperature resistant concrete and a preparation method thereof, with announcement number CN115124291A. The high-temperature resistant concrete proposed in this invention patent uses two types of fibers, graphene fiber and glass fiber. Carbon fiber can improve the high-temperature resistance of concrete and limit the generation and development of tiny cracks. Glass fiber can maintain a certain bearing capacity after high temperature, but softening will occur at around 500°C, resulting in an accelerated decrease in concrete strength. At the same time, nanomaterials are expensive and difficult to be widely used in actual engineering.

[0004] Ceramic aggregate has a spherical shape, a smooth and hard surface, a honeycomb-like interior, and the characteristics of low density, low thermal conductivity, and high strength. It can be used as a lightweight aggregate or coarse aggregate in concrete. It can reduce the weight of concrete while enhancing the strength and high temperature resistance of concrete. Therefore, it is increasingly favored by engineers. However, traditional ceramsite concrete is only used in a single concrete. After high temperature, the strength of ceramsite concrete loses greatly, and it is difficult to meet the requirements for the use of concrete today.

[0005] In view of the above problems, a preparation method of high temperature resistant ceramsite concrete is proposed. Summary of the invention

[0006] The purpose of the present invention is to provide a method for preparing high-temperature resistant ceramsite concrete. The method is used to prepare high-temperature resistant ceramsite concrete, thereby solving the problem that traditional ceramsite concrete in the above background is only used in concrete, and the strength loss of ceramsite concrete is large after high temperature, making it difficult to meet the current requirements for concrete use.

[0007] To achieve the above object, the present invention provides the following technical solution: a method for preparing high temperature resistant ceramsite concrete, comprising the following steps:

[0008] S1: pre-soaking and modifying ceramsite with alkaline aqueous solution;

[0009] S2: treating the alkali-leached ceramsite to a saturated surface dry state;

[0010] S3: adding the modified ceramsite treated to a saturated surface dry state after alkali leaching to cement to obtain a ceramsite cement mixture;

[0011] S4: adding other raw materials to the mixture obtained in S3 to obtain a mixed slurry;

[0012] S5: Pour the mixed slurry in S4 into the mold for hardening.

[0013] Furthermore, the specific steps of pre-impregnating and modifying ceramsite with an alkaline aqueous solution in S1 are as follows:

[0014] S101: The ceramsite completely immersed in the alkaline aqueous solution is stirred by using an ultrasonic device or a stirring device to remove bubbles in the ceramsite, and then the ceramsite is continuously immersed until the ceramsite is saturated with water.

[0015] Furthermore, in S101, the ceramsite completely immersed in the alkaline aqueous solution is stirred by an ultrasonic device or a stirring device to remove bubbles in the ceramsite, and then the ceramsite is continuously immersed until the ceramsite is saturated with water. The specific steps are as follows:

[0016] S1011: Using an ultrasonic device or a stirring device, stir the ceramsite completely immersed in the alkaline aqueous solution for 2-5 minutes, and then continue to soak for 0.5-4 hours to perform modification treatment.

[0017] Further, in S3, the modified ceramsite treated to a saturated surface dry state after alkali leaching is added to cement to obtain a ceramsite cement mixture, and the specific steps are as follows:

[0018] S301: Evenly mix the modified ceramsite and cement to obtain a ceramsite-cement mixture.

[0019] Further, in S4, other raw materials are added to the mixed material obtained in S3 for compounding to obtain a mixed slurry, and the specific steps are as follows:

[0020] S401: Other raw materials include tap water, machine-made sand, vitrified microspheres and water reducing agent, and are added in the order of tap water, machine-made sand, vitrified microspheres and water reducing agent, and then stirred evenly to obtain a mixed slurry.

[0021] Further, in S5, the mixed slurry obtained in S4 is poured into a mold for hardening, and the specific steps are as follows:

[0022] S501: After the mixed slurry is poured into a mold for hardening, standard steam is introduced for curing until a specified age, and high temperature resistant ceramsite concrete can be obtained.

[0023] Furthermore, the alkaline aqueous solution is selected from one or more of NaOH solution, Ca(OH)2 solution, Na2CO3 solution, and CaCO3 solution, and the pH of the alkaline aqueous solution is in the range of 8-11.

[0024] Furthermore, the high temperature resistant ceramsite concrete is composed of the following raw materials in parts by mass:

[0025] 400-500 parts of cement, 400-800 parts of expanded clay, 200-300 parts of machine-made sand, 200-300 parts of vitrified microspheres, 15-20 parts of water reducer, and 150-200 parts of tap water.

[0026] Furthermore, the cement is ordinary Portland cement with a strength ≥ P·42.5R.

[0027] Furthermore, the water reducing agent is a polycarboxylic acid-based water reducing agent.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. The high temperature resistance of alkali-modified expanded clay concrete is effectively improved compared with ordinary expanded clay concrete.

[0030] 2. The ceramsite processing method is simple and convenient. The preparation process does not use a large amount of organic reagents such as epoxy resin, which is more environmentally friendly and easy to industrialize. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is the overall flow chart of the present invention;

[0032] Figure 2 A flow chart of the specific steps of pre-impregnation modification of ceramsite of the present invention;

[0033] Figure 3 It is a schematic diagram of the stirring time and the soaking time of the present invention;

[0034] Figure 4 The present invention is a flow chart of the specific steps of forming a ceramsite cement mixture from modified ceramsite and cement;

[0035] Figure 5 It is a raw material configuration diagram of the present invention;

[0036] Figure 6 A flow chart showing the specific steps of hardening the mixed slurry of the present invention;

[0037] Figure 7 It is a cross-sectional view of a ceramsite concrete cement test block before high temperature treatment of the present invention;

[0038] Figure 8 It is a cross-sectional view of a ceramsite concrete cement test block after high temperature treatment of the present invention;

[0039] Fig. 9 It is a cross-sectional comparison diagram of a concrete test block after alkali treatment of the present invention and a concrete test block without alkali treatment. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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.

[0041] Embodiment 1:

[0042] like Figure 1-Figure 6 As shown, the following preferred technical solution is provided: a method for preparing high temperature resistant ceramsite concrete, comprising the following steps:

[0043] Step 1: Wet the ceramsite in ordinary water, and then completely immerse it in a NaOH solution with a pH of 8, remove the bubbles in the ceramsite by ultrasonic or mixing for 5 minutes, and then continue to immerse for 3 hours for modification, while allowing the ceramsite to absorb water to saturation;

[0044] Step 2: Treat the alkali-leached ceramsite to a saturated surface dry state, and weigh 400 parts by weight;

[0045] Step 3: Pour the ceramsite obtained in step 2 into 400 parts by weight of cement, and stir evenly to obtain a ceramsite cement mixture;

[0046] Step 4: Add 180 parts by weight of tap water to the mixture obtained in step 3, stir evenly, then add 200 parts by weight of machine-made sand, 200 parts by weight of vitrified microspheres and 15 parts by weight of water reducing agent, and continue to stir evenly to obtain a mixed slurry;

[0047] Step 5: Pour the mixed slurry obtained in step 4 into a mold, and perform standard steam curing after hardening to a specified age to obtain high temperature resistant ceramsite concrete.

[0048] Embodiment 2:

[0049] The preparation method of the high temperature resistant ceramsite concrete in this embodiment is similar to that in Embodiment 1, except that: in this embodiment, the ceramsite is pre-soaked in a NaOH solution with a pH value of 9 for 3 hours for modification.

[0050] Embodiment 3:

[0051] The preparation method of the high temperature resistant ceramsite concrete in this embodiment is similar to that in Embodiment 1, except that: in this embodiment, the ceramsite is pre-soaked in a NaOH solution with a pH value of 10 for 3 hours for modification.

[0052] Embodiment 4:

[0053] The preparation method of the high temperature resistant ceramsite concrete in this embodiment is similar to that in Embodiment 1, except that: in this embodiment, the ceramsite is pre-soaked in a NaOH solution with a pH of 11 for 3 hours for modification.

[0054] Comparative Example 1:

[0055] The comparative example provides a method for preparing ceramsite concrete by using alkali-modified ceramsite, which is a method for improving its high temperature resistance.

[0056] The operation method and steps in this comparative example are the same as those in Example 1, except that: in this example, the ceramsite is not modified in any way.

[0057] The performance of the ceramsite concrete test blocks prepared in the above embodiments and comparative examples was tested, and the test results are shown in the following table:

[0058] Table 1 Comparison of mechanical properties of ceramsite concrete test blocks at different temperatures

[0059]

[0060]

[0061] From the comparison of the data in the table, it can be seen that the ceramsite concrete prepared by immersing the modified ceramsite in alkaline solution has less strength loss than the ordinary ceramsite concrete after high temperature treatment. Figure 7 and Figure 8 This is a comparison of the cross-section of ceramsite concrete cement test blocks before and after high temperature treatment. Figure 7 This is the cross-section of the cement concrete block before high temperature treatment. Figure 8 This is the cross-sectional view of the ceramsite concrete cement test block after high temperature treatment. Figure 7 and Figure 8 The following conclusions can be drawn: even after high temperature treatment, the interface between ceramsite and cement is still relatively tight; Fig. 9 It can be seen that the cross section of the concrete specimen after alkali treatment is relatively dense, while the cross section of the concrete specimen without alkali treatment is deteriorated and accompanied by cracks ( Fig. 9 The left part of the picture is a cross-section of a concrete specimen without alkali treatment. Fig. 9 The picture on the right side is a cross-section of an alkali-treated concrete specimen).

[0062] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0063] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing high temperature resistant ceramsite concrete, characterized in that: The following steps are involved: S1: pre-soaking and modifying the ceramsite with an alkaline aqueous solution; S2: treating the alkali-leached ceramsite to a saturated surface dry state; S3: adding the modified ceramsite treated to a saturated surface dry state after alkali leaching to cement to obtain a ceramsite cement mixture; S4: adding other raw materials to the mixture obtained in S3 to obtain a mixed slurry; S5: Pour the mixed slurry in S4 into the mold for hardening.

2. The method for preparing a high temperature resistant ceramsite concrete according to claim 1, characterized in that: The specific steps of pre-impregnating and modifying ceramsite with alkaline aqueous solution in S1 are as follows: S101: The ceramsite completely immersed in the alkaline aqueous solution is stirred by using an ultrasonic device or a stirring device to remove bubbles in the ceramsite, and then the ceramsite is continuously immersed until the ceramsite is saturated with water.

3. The method for preparing a high temperature resistant ceramsite concrete according to claim 2, characterized in that: In S101, the ceramsite completely immersed in the alkaline aqueous solution is stirred by an ultrasonic device or a stirring device to remove bubbles in the ceramsite, and then the ceramsite is continuously immersed until the ceramsite is saturated with water. The specific steps are as follows: S1011: Using an ultrasonic device or a stirring device, stir the ceramsite completely immersed in the alkaline aqueous solution for 2-5 minutes, and then continue to soak for 0.5-4 hours to perform modification treatment.

4. The method for preparing a high temperature resistant ceramsite concrete according to claim 3, characterized in that: In S3, the modified ceramsite treated to a saturated surface dry state after alkali leaching is added to cement to obtain a ceramsite cement mixture, and the specific steps are as follows: S301: Evenly mix the modified ceramsite and cement to obtain a ceramsite-cement mixture.

5. The method for preparing a high temperature resistant ceramsite concrete according to claim 4, characterized in that: In S4, other raw materials are added to the mixed material obtained in S3 for compounding to obtain a mixed slurry. The specific steps are as follows: S401: Other raw materials include tap water, machine-made sand, vitrified microspheres and water reducing agent, and are added in the order of tap water, machine-made sand, vitrified microspheres and water reducing agent, and then stirred evenly to obtain a mixed slurry.

6. The method for preparing a high temperature resistant ceramsite concrete according to claim 5, characterized in that: In S5, the mixed slurry obtained in S4 is poured into a mold for hardening. The specific steps are as follows: S501: After the mixed slurry is poured into a mold for hardening, standard steam is introduced for curing until a specified age, and high temperature resistant ceramsite concrete can be obtained.

7. The method for preparing a high temperature resistant ceramsite concrete according to claim 6, characterized in that: The alkaline aqueous solution is selected from one or more of NaOH solution, Ca(OH)2 solution, Na2CO3 solution, and CaCO3 solution, and the pH of the alkaline aqueous solution is in the range of 8-11.

8. The method for preparing a high temperature resistant ceramsite concrete according to claim 7, characterized in that: The high temperature resistant ceramsite concrete is composed of the following raw materials in parts by mass: 400-500 parts of cement, 400-800 parts of expanded clay, 200-300 parts of machine-made sand, 200-300 parts of vitrified microspheres, 15-20 parts of water reducer, and 150-200 parts of tap water.

9. The method for preparing high temperature resistant ceramsite concrete according to claim 8, characterized in that: The cement is ordinary Portland cement with strength ≥P·42.5R.

10. The method for preparing high temperature resistant ceramsite concrete according to claim 9, characterized in that: The water reducing agent is a polycarboxylic acid water reducing agent.

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