Method for detecting mixing uniformity of steel slag improved soil

Abstract

The invention discloses a method for detecting the mixing uniformity of steel slag improved soil, and belongs to the technical field of highway construction. The method comprises the following steps: carrying out infrared irradiation on the steel slag improved high liquid limit soil by adopting an infrared heating device; an infrared imager is adopted to observe and photograph the steel slag improved high-liquid-limit soil which is heated by infrared irradiation or cooled after irradiation is stopped; and performing real-time judgment on the mixing uniformity of the steel slag in the steel slag improved high liquid limit soil area irradiated by the infrared rays according to the color difference. Compared with the prior art, the method disclosed by the invention has the following beneficial effects that (1) the mixing uniformity of the improved soil and the steel slag is judged by utilizing the obvious difference between the heat conductivity coefficient and the specific heat of the steel slag and the high liquid limit soil, so that direct visual misjudgment is avoided; and (2) the method provided by the invention is simple and easy to implement, the detection time is short, consumables are not needed, and the method has remarkable popularization and application values.

Description

Technical Field

[0001] The invention belongs to the technical field of highway construction, and in particular relates to a method for detecting uniformity of steel slag improved soil mixing. Background Art

[0002] In highway engineering, soil with a liquid limit of more than 50% is called high liquid limit soil. High liquid limit soil is a kind of unsuitable soil for direct embankment filling. Generally, it can only be used for highway roadbed filling after being improved. The conventional methods are: chemical improvement method with lime, cement and other substances; physical improvement method with crushed stone, gravel and other substances.

[0003] Using steel slag to improve high liquid limit soil is a relatively new improvement method. The particle size distribution range of steel slag is 0.001-20mm; the particle density generally exceeds 3.1-3.7g / cm 3 (The density of soil particles is generally 2.6g / cm 3 The main cation in the particles is Ca 2+ , Fe 2+ Mg 2+ , Mn 2+ 、Zn 2+ , Cu 2+ Cr 2+ Therefore, the principle of steel slag improving high liquid limit soil is: the continuous precipitation of high-valent cations in the particles and the low-valent Na + Ion exchange reduces the liquid limit of high liquid limit soil; large-particle steel slag is added to the soil to improve the soil gradation and increase the soil strength. Therefore, steel slag improves high liquid limit soil with both chemical and physical improvement effects. Experiments and practice have shown that the high liquid limit soil improved by 10% to 15% steel slag by mass has a good effect, significantly reducing the liquid limit of high liquid limit soil and improving the strength of improved soil, which has significant engineering promotion and application value.

[0004] In engineering, the improvement effect of improved soil depends largely on the uniformity of the improved materials mixed in the soil. Therefore, it is necessary to evaluate the mixing uniformity during the mixing construction process to decide whether to continue mixing. On the other hand, the mixing time length during the improved soil construction process has a greater impact on the project cost. Shortening the mixing time can save project costs.

[0005] At present, there is no good way to improve the uniformity of soil mixing. There are two methods in engineering. One is to take multiple samples of the improved soil at any time and test the steel slag content. If the content is very different, it means that the mixing is not uniform. This method requires a large amount of testing of the steel slag content, and the test workload is huge, so it is difficult to be widely used in engineering. The other is to use the visual method, that is, based on the difference in the surface color of the steel slag and the soil, the color uniformity of the mixture is observed to judge whether the mixture is mixed uniformly. The visual method is a common method used in lime and cement improved soil, because lime is white, cement is gray, the particles are very small and significantly different from the rock of the soil. At the beginning of mixing, the white lime (or gray cement) lumps are clearly distinguished from the soil, indicating that further mixing is required; through continuous mixing, the lumps are broken, and the color of the lime (cement) improved soil gradually becomes uniform. However, this visual method is not suitable for steel slag to improve high liquid limit soil, because steel slag is granular, and high liquid limit soil containing a certain amount of water has strong viscosity and is more likely to adhere to the surface of steel slag particles, thus becoming the same color as the soil.

[0006] Therefore, it is necessary to provide a method for detecting the uniformity of mixing steel slag with high liquid limit soil to solve the above problems. Summary of the invention

[0007] The object of the present invention is to provide a method for detecting the mixing uniformity of steel slag improved soil, which adopts an infrared imager to observe and photograph the steel slag improved soil during heating or cooling, and judges whether the steel slag improved high liquid limit soil steel slag is mixed uniformly by visually interpreting the photos, thereby solving at least one technical problem involved in the background technology.

[0008] In order to solve the above-mentioned technical problems, the present invention is achieved as follows:

[0009] The present invention provides a method for detecting uniformity of mixing of steel slag-improved soil, comprising the following steps:

[0010] Step 1: using an infrared heating device to heat the steel slag improved high liquid limit soil by infrared irradiation;

[0011] Step 2: using an infrared imager to continuously observe the steel slag-improved high liquid limit soil during heating, and taking photos of the obvious color difference between the steel slag particles and the high liquid limit soil, to obtain photo A;

[0012] Step 3: After the steel slag improved high liquid limit soil is heated to a certain temperature, the infrared irradiation is stopped, and the steel slag improved high liquid limit soil is allowed to cool down naturally;

[0013] Step 4: Use an infrared imager to continuously observe the steel slag-improved high liquid limit soil during cooling, and take photos of the obvious color difference between the steel slag particles and the high liquid limit soil to obtain Photo B;

[0014] Step 5: Determine the uniformity of the slag-improved soil mixing based on the uniformity of the slag particle distribution in Photos A and B.

[0015] Optionally, in step one, an infrared heating device with a certain power is selected to irradiate the steel slag improved high liquid limit soil, so that the surface temperature of the steel slag improved high liquid limit soil rises from ambient temperature to 90° C. within 1 minute.

[0016] Optionally, step five specifically includes:

[0017] Select the photo with the best color contrast between the slag particles and the high liquid limit soil from photo A and photo B, then visually identify the selected photos to judge the uniformity of the slag mixing.

[0018] Optionally, when the mixing uniformity of the steel slag cannot be judged, the steel slag-improved high liquid limit soil is continued to be mixed and then tested again; if the two test results show that the mixing uniformity is close, it can be considered that the mixing has been uniform.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] (1) The present invention utilizes the significant difference in thermal conductivity between steel slag and high liquid limit soil to judge the uniformity of the improved soil steel slag mixing, thus avoiding visual misjudgment;

[0021] (2) The method provided by the present invention is simple and easy to use, has a short detection time, and does not require consumables, and has significant promotion and application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work, among which:

[0023] Figure 1 This is a photo of the steel slag improved high liquid limit soil provided by the present invention being heated from 20°C to 45°C;

[0024] Figure 2 This is a photo of the steel slag improved high liquid limit soil provided by the present invention being heated from 20°C to 60°C;

[0025] Figure 3 This is a photo of the steel slag improved high liquid limit soil provided by the present invention being heated from 20°C to 75°C. DETAILED DESCRIPTION

[0026] The technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. 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.

[0027] The present invention provides a method for detecting uniformity of mixing of steel slag-improved soil, comprising the following steps:

[0028] Step 1: using an infrared heating device to heat the steel slag improved high liquid limit soil by infrared irradiation;

[0029] Step 2: using an infrared imager to continuously observe the steel slag-improved high liquid limit soil during heating, and taking photos of the obvious color difference between the steel slag particles and the high liquid limit soil, to obtain photo A;

[0030] Step 3: After the steel slag improved high liquid limit soil is heated to a certain temperature, the infrared irradiation is stopped, and the steel slag improved high liquid limit soil is allowed to cool down naturally;

[0031] Step 4: Use an infrared imager to continuously observe the steel slag-improved high liquid limit soil during cooling, and take photos of the obvious color difference between the steel slag particles and the high liquid limit soil to obtain Photo B;

[0032] Step 5: Determine the uniformity of the slag-improved soil mixing based on the uniformity of the slag particle distribution in Photos A and B.

[0033] In step 1, an infrared heating device with a certain power is selected to irradiate the steel slag improved high liquid limit soil, so that the surface temperature of the steel slag improved high liquid limit soil rises from the ambient temperature to 90° C. within 1 minute.

[0034] Specifically, the ambient temperature is between 5 and 40°C.

[0035] Step 5 specifically includes:

[0036] Select the photo with the best color contrast between the slag particles and the high liquid limit soil from photo A and photo B, then visually identify the selected photos to judge the uniformity of the slag mixing.

[0037] Optionally, when the mixing uniformity of the steel slag cannot be judged, the steel slag-improved high liquid limit soil is continued to be mixed and then tested again; if the two test results show that the mixing uniformity is close, it can be considered that the mixing has been uniform.

[0038] See also Figure 1-Figure 3 As shown by Figure 1 It can be seen that the slag particles are not clearly displayed and it is impossible to judge whether the slag is mixed evenly. Figure 2 It can be seen that the slag particles are clearly displayed and the slag is evenly distributed in the soil. Figure 3 It can be seen that the slag particles are not clearly displayed and it is impossible to judge whether the slag is mixed evenly.

[0039] It should be noted that, in this article, the terms "include", "comprises" or any other variations 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. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0040] In addition, it should be noted that the scope of the methods and systems in the embodiments of the present invention is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved. For example, the described methods may be performed in an order different from that described, and various steps may be added, omitted, or combined. In addition, features described with reference to certain examples may be combined in other examples.

[0041] The embodiments of the present invention are described above, but the present invention is not limited to the above-mentioned specific implementation modes. The above-mentioned specific implementation modes are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, all of which are protected by the present invention.

Claims

1. A method for detecting uniformity of mixing of steel slag-improved soil, characterized in that: The steps include: Step 1: using an infrared heating device to heat the steel slag improved high liquid limit soil by infrared irradiation; Step 2: using an infrared imager to continuously observe the steel slag-improved high liquid limit soil during heating, and taking photos of the obvious color difference between the steel slag particles and the high liquid limit soil to obtain photo A; Step 3: After the steel slag improved high liquid limit soil is heated to a certain temperature, the infrared irradiation is stopped, and the steel slag improved high liquid limit soil is allowed to cool down naturally; Step 4: Use an infrared imager to continuously observe the steel slag-improved high liquid limit soil during cooling, and take photos of the obvious color difference between the steel slag particles and the high liquid limit soil to obtain Photo B; Step 5: Determine the uniformity of the slag-improved soil mixing based on the uniformity of the slag particle distribution in Photos A and B.

2. The method for detecting uniformity of mixing of steel slag-improved soil according to claim 1, characterized in that: In step 1, an infrared heating device with a certain power is selected to irradiate the steel slag improved high liquid limit soil, so that the surface temperature of the steel slag improved high liquid limit soil rises from the ambient temperature to 90° C. within 1 minute.

3. The method for detecting uniformity of mixing of steel slag-improved soil according to claim 1 or 2, characterized in that: Step 5 specifically includes: Select the photo with the best color contrast between the slag particles and the high liquid limit soil from photo A and photo B, then visually identify the selected photos to judge the uniformity of the slag mixing.

4. The method for detecting uniformity of mixing of steel slag-improved soil according to claim 3, characterized in that: When the mixing uniformity of steel slag cannot be judged, the steel slag improved high liquid limit soil shall continue to be mixed and tested again; if the two test results show that the mixing uniformity is close, it can be considered that the mixing has been uniform.

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