Method for measuring carbonation depth of artificial coarse aggregate-based concrete

Abstract

The application discloses a method for measuring carbonation depth of artificial coarse aggregate-based concrete, which comprises the following steps: splitting a test block along a carbonation direction, spraying a phenolphthalein alcohol solution on a section, and marking a plurality of parallel straight lines after color development is completed; when the carbonation rate of the artificial coarse aggregate is greater than an interface transition zone, the method for measuring carbonation depth of cement matrix and artificial coarse aggregate comprises the following steps: if there is aggregate existing at a carbonation boundary line on the straight line, measuring carbonation depth of the matrix on both sides of the aggregate and taking an average value, and measuring carbonation depth of the aggregate on the straight line; if there is aggregate existing below the carbonation boundary line on the straight line, measuring carbonation depth of the matrix above the aggregate on the straight line, and measuring carbonation depth of the aggregate on the straight line; and if there is no aggregate existing at the carbonation boundary line on the straight line, measuring carbonation depth of the matrix on the straight line, and measuring carbonation depth of the aggregate on both sides of the matrix and taking an average value. The method can correct the shortcomings of a traditional method and reduce deviation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of concrete carbonation depth testing, and particularly relates to a measurement method of carbonation depth of artificial coarse aggregate-based concrete. BACKGROUND

[0002] CO2 has a high content in the atmosphere and has good heat preservation and heat absorption effects, and therefore CO2 has become one of the most important greenhouse gases. Traditional carbon capture and storage (CCS) is an effective method for reducing carbon emissions, but has a high economic cost, resulting in a small use scale, and therefore it is of great significance to seek a new method for reducing carbon emissions. Carbon capture, utilization and storage (CCUS) can solve the problems existing in traditional CCS, and at present, CCUS is used in the construction industry to reduce CO2 emissions, and the captured CO2 is used to produce value-added products in a raw material mixture. Research has proved that the use of solid waste for carbon sequestration can not only enhance the performance of materials, but also achieve CO2 sequestration.

[0003] Compared with high carbon emissions caused by traditional high-temperature calcination, artificial coarse aggregate-based concrete has better environmental friendliness, has more and larger pores than natural coarse aggregate-based concrete, and has alkaline earth metals inside, which can ensure the entry and reaction of CO2, that is, artificial coarse aggregate can also be carbonated. In engineering practice, acidic gases (CO2) in the air will erode concrete samples, causing the alkalinity of the concrete samples to decrease, causing steel corrosion and damaging the bonding between steels, and the carbonation depth of concrete is an important indicator for measuring carbon sequestration performance, and measuring the carbonation depth is beneficial to preventing concrete deterioration. However, the current standard measurement method for carbonation depth (GB / T50082-2009 “Standard Test Methods for Long-Term Properties and Durability of Concrete”) is only applicable to concrete using natural coarse aggregate, and in the measurement method of the specification, the coarse aggregate is regarded as a part that cannot be carbonated, and therefore the measurement method is not applicable to artificial coarse aggregate-based concrete. If the existing specification measurement method is used to test the carbonation depth of artificial coarse aggregate-based concrete, there will be a large deviation. Therefore, it is necessary to establish a measurement method for the carbonation depth of artificial coarse aggregate-based concrete.

[0004] Therefore, the prior art still needs to be improved and developed. SUMMARY

[0005] In view of the deficiencies of the prior art, the purpose of the present application is to provide a measurement method of carbonation depth of artificial coarse aggregate-based concrete, which aims to solve the problem that the existing measurement method of carbonation depth of natural coarse aggregate-based concrete will have a large deviation when used to measure artificial coarse aggregate-based concrete because artificial coarse aggregate can be carbonated.

[0006] The technical scheme of the present application is as follows:

[0007] The present application provides a method for measuring carbonation depth of artificial coarse aggregate based concrete, wherein the artificial coarse aggregate based concrete comprises a cement matrix and artificial coarse aggregates dispersed in the cement matrix, an interface transition zone wrapping the artificial coarse aggregates exists at the interface between the cement matrix and the artificial coarse aggregates, the carbonation depth of the artificial coarse aggregate based concrete comprises the carbonation depth of the cement matrix and the carbonation depth of the artificial coarse aggregates, and the method for measuring the carbonation depth of the cement matrix and the carbonation depth of the artificial coarse aggregates comprises the following steps:

[0008] A test block of artificial coarse aggregate based concrete is provided, the test block is split along the carbonation direction, phenolphthalein alcohol solution is sprayed on the fracture surface, after color development, several parallel straight lines with a preset distance are marked on the fracture surface, the carbonation depth of the cement matrix and the carbonation depth of the artificial coarse aggregates at each straight line position are measured respectively, the average values of the carbonation depth of the cement matrix and the carbonation depth of the artificial coarse aggregates at each straight line position are calculated respectively, and the carbonation depth of the cement matrix and the carbonation depth of the artificial coarse aggregates in the artificial coarse aggregate based concrete are obtained respectively.

[0009] When the carbonation rate of the artificial coarse aggregates is greater than the carbonation rate of the interface transition zone, the method for measuring the carbonation depth of the cement matrix and the carbonation depth of the artificial coarse aggregates at each straight line position comprises the following steps:

[0010] If there are artificial coarse aggregate particles at the carbonation boundary line on a straight line, the carbonation depths of the cement matrix on both sides of the artificial coarse aggregate particles are measured and the arithmetic mean value is taken to obtain the carbonation depth of the cement matrix at the straight line position, and the carbonation depth of the artificial coarse aggregates on the straight line is measured to obtain the carbonation depth of the artificial coarse aggregates at the straight line position.

[0011] If there are artificial coarse aggregate particles below the carbonation boundary line on a straight line, the carbonation depth of the cement matrix above the artificial coarse aggregate particles on the straight line is measured to obtain the carbonation depth of the cement matrix at the straight line position, and the carbonation depth of the artificial coarse aggregates on the straight line is measured to obtain the carbonation depth of the artificial coarse aggregates at the straight line position.

[0012] If there are no artificial coarse aggregate particles at the carbonation boundary line on a straight line, the carbonation depth of the cement matrix on the straight line is directly measured to obtain the carbonation depth of the cement matrix at the straight line position, and the carbonation depths of the artificial coarse aggregates on both sides of the cement matrix are measured and the arithmetic mean value is taken to obtain the carbonation depth of the artificial coarse aggregates at the straight line position.

[0013] Optionally, when the carbonation rate of the artificial coarse aggregate is less than the carbonation rate of the interface transition zone, the method for measuring the carbonation depth of the artificial coarse aggregate at each straight line position specifically comprises the following steps:

[0014] If there is an artificial coarse aggregate particle at the carbonation boundary line of a straight line, the carbonation depth of the interface transition zone on the straight line is measured to obtain the carbonation depth of the artificial coarse aggregate at the straight line position;

[0015] If there is an artificial coarse aggregate particle below the carbonation boundary line of a straight line and the interface transition zone is not completely carbonated, the carbonation depths of the interface transition zones on both sides of the artificial coarse aggregate particle are measured and the arithmetic mean value is taken to obtain the carbonation depth of the artificial coarse aggregate at the straight line position;

[0016] If there is no artificial coarse aggregate particle at the carbonation boundary line of a straight line, the carbonation depths of the interface transition zones on both sides of the cement matrix are measured and the arithmetic mean value is taken to obtain the carbonation depth of the artificial coarse aggregate at the straight line position.

[0017] Optionally, when the interface transition zone on the section is stripped, the method for measuring the carbonation depth of the cement matrix at each straight line position specifically comprises the following steps:

[0018] If there is an artificial coarse aggregate particle at the carbonation boundary line of a straight line, the carbonation depths of the cement matrix on both sides of the artificial coarse aggregate particle are measured and the arithmetic mean value is taken to obtain the carbonation depth of the cement matrix at the straight line position;

[0019] If there is an artificial coarse aggregate particle below the carbonation boundary line of a straight line, the carbonation depth of the cement matrix above the artificial coarse aggregate particle on the straight line is measured to obtain the carbonation depth of the cement matrix at the straight line position;

[0020] If there is no artificial coarse aggregate particle at the carbonation boundary line of a straight line, the carbonation depth of the cement matrix on the straight line is directly measured to obtain the carbonation depth of the cement matrix at the straight line position.

[0021] Optionally, when the artificial coarse aggregate is broken in the middle on the section, the method for measuring the carbonation depth of the cement matrix at each straight line position specifically comprises the following steps:

[0022] If there is an artificial coarse aggregate particle at the carbonation boundary line of a straight line, the carbonation depths of the cement matrix on both sides of the artificial coarse aggregate particle are measured and the arithmetic mean value is taken to obtain the carbonation depth of the cement matrix at the straight line position;

[0023] If there is no artificial coarse aggregate particle at the carbonation boundary line of a straight line, the carbonation depth of the cement matrix is directly measured to obtain the carbonation depth of the cement matrix on the straight line.

[0024] Optionally, the phenolphthalein alcohol solution has a mass concentration of 1%, and the preset distance is 10 mm.

[0025] Optionally, the preparation method of the artificial coarse aggregate comprises the following steps:

[0026] Providing garbage incineration bottom ash particles;

[0027] Mixing the garbage incineration bottom ash particles, cement and mineral admixtures according to a mass ratio of 70:(20-30):(0-10) to obtain a mixture;

[0028] Granulating the mixture in a disc granulator to obtain an artificial coarse aggregate embryo;

[0029] Obtaining the artificial coarse aggregate after water bath curing of the artificial coarse aggregate embryo.

[0030] Optionally, the mineral admixtures comprise mineral powder and / or fly ash.

[0031] Optionally, the disc granulator has a diameter of 100 cm, an edge height of 15 cm, an inclination angle of 45° and a rotating disc speed of 35 rap / min.

[0032] Optionally, the step of granulating the mixture in the disc granulator specifically comprises:

[0033] Batching the mixture into the disc granulator and spraying water during the batching of the mixture, with a total water consumption to mass ratio of the mixture being 20%-22%.

[0034] Optionally, the water bath curing has a temperature of 20±2°C and a time of at least 28 days.

[0035] Beneficial effects: The measurement method of the artificial coarse aggregate-based concrete provided by the present application can correct the deficiencies of the current traditional measurement method, reduce measurement deviation, provide a method with higher precision for accurately measuring the carbonation depth of the artificial coarse aggregate-based concrete, and can use the measurement method provided by the present application to study the influence of different artificial coarse aggregate replacement rates and the same artificial coarse aggregate replacement rate on the carbonation depth of the artificial coarse aggregate-based concrete, thereby providing a sustainable development method for studying the internal structure and carbon sequestration amount of the artificial coarse aggregate-based concrete and the carbon sequestration performance of alkali-containing solid waste. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 FIG. 1 is a schematic diagram of the measurement of the carbonation depth of natural coarse aggregate-based concrete in the embodiments of the present application.

[0037] Figure 2Figures (a), (b), (c), (d), (e) and (f) are carbonation depth measurement diagrams of the artificial coarse aggregate based concrete according to the embodiments of the present application.

[0038] Figure 3 Figure is a flow diagram of the carbonation depth measurement method of the artificial coarse aggregate based concrete according to the embodiments of the present application.

[0039] Figure 4 Figure is a carbonation depth measurement diagram of the artificial coarse aggregate based concrete according to the embodiments of the present application.

[0040] Figure 5 Figure is a carbonation depth measurement diagram of the artificial coarse aggregate based concrete according to the embodiments of the present application.

[0041] Figure 6 Figure is a preparation diagram of the artificial coarse aggregate according to the embodiments of the present application.

[0042] Figure 7 Figure is a cross-sectional view of the natural coarse aggregate based concrete C-NA according to Embodiment 3 of the present application.

[0043] Figure 8 Figure is a cross-sectional view of the artificial coarse aggregate based concrete C-FC30 according to Embodiment 4 of the present application.

[0044] Figure 9 Figure is a cross-sectional view of the artificial coarse aggregate based concrete C-FC100 according to Embodiment 5 of the present application.

[0045] Figure 10 Figure is a cross-sectional view of the artificial coarse aggregate based concrete C-KC100 according to Embodiment 6 of the present application.

[0046] Figure 11 Figure is a cross-sectional view of the artificial coarse aggregate based concrete C-FK100 according to Embodiment 7 of the present application.

[0047] Figure 12 Figures are carbonation depths of the natural coarse aggregate based concrete, cement matrix of the artificial coarse aggregate based concrete and the artificial coarse aggregate according to Embodiments 3-7 of the present application. DETAILED DESCRIPTION

[0048] The application provides a measurement method of carbonation depth of artificial coarse aggregate-based concrete. The application is further described in detail below. It should be understood that the specific examples described herein are only used to explain the application and not to limit the application.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0050] The measurement method of carbonation depth of conventional concrete is shown in GB / T50082-2009. Specifically, a pressure testing machine is used to split the concrete after carbonation for 28 days from the middle, the residual powder on the split section is brushed off, a phenolphthalein alcohol solution with a mass concentration of 1% is sprayed, the section is colored after about 30 seconds, and the carbonation depth of each point is measured with a steel ruler according to the 10mm measurement point marked. Figure 1As shown, if the measuring point is just embedded with coarse aggregate particles (such as the particles at the middle position in the figure), the arithmetic mean of the carbonation depths at both sides of the particles is taken as the carbonation depth value (i.e. the length of the double-headed line at the middle). The principle of the traditional concrete carbonation depth measurement method is that the interior of the concrete is weakly alkaline, and after the addition of phenolphthalein, it will turn purple. The places that are carbonated have undergone neutralization reaction with CO2 and do not show color, so the carbonation depth can be measured by the boundary between the colored and uncolored places. During the carbonation process of the concrete, CO2 invades from one end, and the places where natural coarse aggregates are encountered will be preferentially carbonated from the interfacial transition zone, and the properties of natural coarse aggregates are relatively stable and will not react with CO2. However, artificial coarse aggregates have alkaline earth metals inside and have good porosity, which can ensure the entry and reaction of CO2. Therefore, it can be observed that in artificial coarse aggregate-based concrete, the carbonation rate of artificial coarse aggregates is faster than that of the cement matrix; artificial coarse aggregates exist in contact with the cement matrix in space, so in the case of a large amount of artificial coarse aggregate, artificial coarse aggregates can overcome the cement matrix and carbonize to a deeper distance. Therefore, if the existing measurement method of the carbonation depth of natural coarse aggregate-based concrete is used to measure artificial coarse aggregate-based concrete, there will be a large deviation. Based on this, the embodiment of the present application provides a measurement method of the carbonation depth of artificial coarse aggregate-based concrete, and the artificial coarse aggregate-based concrete comprises a cement matrix and artificial coarse aggregates dispersed in the cement matrix, and there is an interfacial transition zone (ITZ, which is a shell surrounding the coarse aggregate) wrapping the artificial coarse aggregate at the interface between the cement matrix and the artificial coarse aggregate. In natural coarse aggregate-based concrete, there is also an interfacial transition zone wrapping natural coarse aggregates at the interface between the cement matrix and the natural coarse aggregates. However, the density of natural coarse aggregates and cement paste is more compact, and due to the large difference in solid phase between natural coarse aggregate particles and cement particles, a water-rich zone with low cement content is formed on the surface of the aggregate, and this "wall effect" leads to a weak interface between natural coarse aggregates and the cement matrix. However, the situation is not similar for artificial coarse aggregate-based concrete. For artificial coarse aggregate-based concrete, the structure is more loose, and there are many pores in the artificial coarse aggregate, so the cement paste can penetrate into the surface pores of the artificial coarse aggregate, forming a mechanical interlock between the artificial coarse aggregate and the cement matrix, thereby producing a high-quality ITZ. Therefore, the ITZ needs to be considered when measuring the carbonation depth of artificial coarse aggregate-based concrete. Therefore, in the embodiment of the present application, according to the different carbonation rates of the three phases (ITZ, cement matrix, and artificial coarse aggregate) of artificial coarse aggregate-based concrete, and according to the characteristics that the cement matrix is relatively dense, the artificial coarse aggregate can be carbonized, and the carbonation rate of the artificial coarse aggregate is faster than that of the cement matrix, the following measurement method is proposed. Specifically, the carbonation depth of the artificial coarse aggregate-based concrete includes the carbonation depth of the cement matrix and the carbonation depth of the artificial coarse aggregate, and the measurement method of the carbonation depth of the cement matrix and the carbonation depth of the artificial coarse aggregate includes the following steps:

[0051] S1. Provide test blocks of artificial coarse aggregate based concrete;

[0052] S2. Split the artificial coarse aggregate-based concrete test block along the carbonation direction, spray phenolphthalein alcohol solution on the cross-section (if there is powder on the cross-section, brush off the powder first and then spray phenolphthalein alcohol solution), after the color development is completed (the color development is completed in about 30 seconds), mark several parallel straight lines with a preset distance on the cross-section.

[0053] S3. Measure the carbonation depth of the cement matrix and the carbonation depth of the artificial coarse aggregate at each straight position, and calculate the average value of the carbonation depth of the cement matrix and the carbonation depth of the artificial coarse aggregate at each straight position to obtain the carbonation depth of the cement matrix and the carbonation depth of the artificial coarse aggregate in the artificial coarse aggregate-based concrete.

[0054] Among them, such as Figure 2 As shown, when the carbonization rate of the artificial coarse aggregate is greater than the carbonization rate of the ITZ, that is, when the carbonization rate of the artificial coarse aggregate is greater than the carbonization rate of the ITZ and greater than the carbonization rate of the cement matrix, since the ITZ is thinner, it will be carbonized together with the artificial coarse aggregate during the carbonization process. Therefore, it can be considered together with the artificial coarse aggregate. CO2 will preferentially enter from the artificial coarse aggregate and diffuse to the next adjacent artificial coarse aggregate. When there is no adjacent artificial coarse aggregate, CO2 needs to pass through the cement matrix and then be transferred to the next layer.

[0055] In step S3, such as Figure 3 As shown, the specific steps for measuring the carbonation depth of the cement matrix and the artificial coarse aggregate at each straight-line position include:

[0056] S311. If there are artificial coarse aggregate particles at the carbonation boundary line on a certain straight line, measure the carbonation depth of the cement matrix on both sides of the artificial coarse aggregate particles and take the arithmetic mean to obtain the carbonation depth of the cement matrix at the position of the straight line. Measure the carbonation depth of the artificial coarse aggregate particles on the straight line to obtain the carbonation depth of the artificial coarse aggregate at the position of the straight line.

[0057] S312. If there are artificial coarse aggregate particles that have carbonized beyond the cement matrix below the carbonization boundary line on a certain straight line, then measure the carbonization depth of the cement matrix above the artificial coarse aggregate particles on the straight line to obtain the carbonization depth of the cement matrix at the position of the straight line, and measure the carbonization depth of the artificial coarse aggregate particles on the straight line to obtain the carbonization depth of the artificial coarse aggregate at the position of the straight line.

[0058] S313. If there are no artificial coarse aggregate particles at the carbonation boundary line on a certain straight line, the carbonation depth of the cement matrix on the straight line is directly measured to obtain the carbonation depth of the cement matrix at the position of the straight line. The carbonation depth of the artificial coarse aggregate particles on both sides of the cement matrix is ​​measured and the arithmetic mean is taken to obtain the carbonation depth of the artificial coarse aggregate at the position of the straight line.

[0059] When the carbonation rate of the artificial coarse aggregate is greater than the carbonation rate of the ITZ (Intense Pulsed Zone) and greater than the carbonation rate of the cement matrix, the method for measuring the carbonation depth of the cement matrix and the artificial coarse aggregate is as follows: Figure 4 Taking this example, three parallel straight lines a, b, and c are marked on the cross-section, with a distance of 1 cm between any two adjacent lines. Line a represents the carbonation boundary where artificial coarse aggregate particles are present. At this point, the carbonation depth of the cement matrix on both sides of the artificial coarse aggregate particle is measured and its arithmetic mean is taken. This is the average of the distance h1 from point A to the top surface of the concrete specimen and the distance h2 from point B to the top surface of the concrete specimen. This gives the carbonation depth of the cement matrix at this straight line position (the length of the black dashed line at line a in the diagram, i.e., the length of the short dashed line). The carbonation depth of the artificial coarse aggregate particle at the straight line position is then directly measured, i.e., the distance from point D to the top surface of the concrete specimen. This gives the carbonation depth of the artificial coarse aggregate at this straight line position (the length of the green dashed line at line a in the diagram, i.e., the length of the long dashed line). At position b on line 1, there are artificial coarse aggregate particles that have carbonized beyond the cement matrix below the carbonation boundary line. Therefore, measure the carbonation depth of the cement matrix above these artificial coarse aggregate particles on line 1, i.e., the distance from point E to the top surface of the concrete specimen. This gives the carbonation depth of the cement matrix at this position (the length of the black dashed line at position b in the diagram, i.e., the length of the short dashed line). Alternatively, directly measure the carbonation depth of the artificial coarse aggregate particles on line 1, i.e., the distance from point F to the top surface of the concrete specimen. This gives the carbonation depth of the artificial coarse aggregate at this position (the length of the green dashed line at position b in the diagram, i.e., the length of the long dashed line). At position c on line 'C', where there are no artificial coarse aggregate particles at the carbonation boundary, the carbonation depth of the cement matrix on this line is directly measured, i.e., the distance from point G to the upper surface of the concrete specimen. This gives the carbonation depth of the cement matrix at this line position (the length of the black dashed line at position c in the figure, i.e., the length of the short dashed line). The carbonation depths at the deepest points of the adjacent artificial coarse aggregate particles R1 and R2 on both sides of the cement matrix are measured and their arithmetic average is taken (for artificial coarse aggregate particle R1, the carbonation depth at its deepest point can be considered as the distance from point F to the upper surface of the concrete specimen; for artificial coarse aggregate particle R2, the carbonation depth at its deepest point is the distance from point H to the upper surface of the concrete specimen). This gives the carbonation depth of the artificial coarse aggregate at this line position (the length of the green dashed line at position c in the figure, i.e., the length of the long dashed line).

[0060] The ITZ (Intense Zone of Gravity) in concrete is a weak point. Natural coarse aggregate, due to its higher strength, will not fracture under stress but will instead spall along the ITZ. However, artificial coarse aggregate, due to its lower strength, will exhibit different behaviors; different failure modes will result in different interfaces, all of which will cause some deviation in the test results. Therefore,

[0061] like Figure 2 As shown, when the carbonation rate of the artificial coarse aggregate is less than that of the ITZ (i.e., the ITZ carbonation rate is greater than that of the artificial coarse aggregate and greater than that of the cement matrix), CO2 will first enter from the ITZ and spread to the interface zone of the next adjacent artificial coarse aggregate. When there is no adjacent artificial coarse aggregate, CO2 needs to pass through the cement matrix and then be transferred to the next layer. In step S3, as... Figure 3 As shown, the method for measuring the carbonation depth of artificial coarse aggregate at each straight position includes the following steps:

[0062] S3211. If there are artificial coarse aggregate particles at the carbonization boundary line on a certain straight line, measure the carbonization depth of ITZ on that straight line to obtain the carbonization depth of artificial coarse aggregate at that position.

[0063] S3212. If there are artificial coarse aggregate particles that have carbonized beyond the cement matrix below the carbonation boundary line on a certain straight line and the ITZ is not completely carbonized, then measure the carbonation depth of the ITZ on both sides of the artificial coarse aggregate particles and take the arithmetic mean to obtain the carbonation depth of the artificial coarse aggregate at the position of the straight line.

[0064] S3213. If there are no artificial coarse aggregate particles at the carbonation boundary line on a certain straight line, measure the carbonation depth of the ITZs on both sides of the cement matrix and take the arithmetic mean to obtain the carbonation depth of the artificial coarse aggregate at the position of the straight line.

[0065] When the ITZ peels off at the cross-section, that is, when the strength of the ITZ is much lower than that of the artificial coarse aggregate (the carbonation depth of the cement matrix is ​​the same as when the carbonation rate of the ITZ is greater than that of the artificial coarse aggregate and greater than that of the cement matrix), the method for measuring the carbonation depth of the cement matrix at each straight position in step S3 specifically includes the following steps:

[0066] S3221. If there are artificial coarse aggregate particles at the carbonation boundary line on a certain straight line, measure the carbonation depth of the cement matrix on both sides of the artificial coarse aggregate particles and take the arithmetic mean to obtain the carbonation depth of the cement matrix at the position of the straight line.

[0067] S3222. If there are artificial coarse aggregate particles that have carbonized beyond the cement matrix below the carbonation boundary line on a certain straight line, then measure the carbonation depth of the cement matrix above the artificial coarse aggregate particles on the straight line to obtain the carbonation depth of the cement matrix at the position of the straight line.

[0068] S3223, if there is no artificial coarse aggregate particle at the carbonation boundary line on a straight line, the carbonation depth of the cement matrix on the straight line is directly measured to obtain the carbonation depth of the cement matrix at the straight line position.

[0069] When the intermediate cracking zone (ITZ) is broken in the artificial coarse aggregate section, that is, the ITZ strength is weaker than the artificial coarse aggregate, but not significantly weaker than the artificial coarse aggregate, the measurement method of the carbonation depth of the cement matrix at each straight line position in step S3 (the same as the natural coarse aggregate-based concrete) specifically includes the following steps:

[0070] S3231, if there is an artificial coarse aggregate particle at the carbonation boundary line on a straight line, the carbonation depths of the cement matrix on both sides of the artificial coarse aggregate particle are measured and the arithmetic mean value is obtained to obtain the carbonation depth of the cement matrix at the straight line position;

[0071] S3232, if there is no artificial coarse aggregate particle at the carbonation boundary line on a straight line, the carbonation depth of the cement matrix is directly measured to obtain the carbonation depth of the cement matrix on the straight line.

[0072] When the carbonation rate of the ITZ is greater than the carbonation rate of the artificial coarse aggregate, which is greater than the carbonation rate of the cement matrix, the measurement method of the carbonation depth of the cement matrix and the artificial coarse aggregate is described by taking Figure 5 as an example. At the position of straight line d, there is an artificial coarse aggregate particle at the carbonation boundary line, so the carbonation depths of the cement matrix on both sides of the artificial coarse aggregate particle are measured and the arithmetic mean value is obtained (for details, refer to the measurement method of the carbonation depth of the cement matrix at the position of straight line a in Figure 4 ), to obtain the carbonation depth of the cement matrix at the straight line position (the length of the black dashed line at the position of straight line d in the figure, that is, the length of the short dashed line); the carbonation depth of the ITZ on the straight line is directly measured, that is, the distance from point J to the upper surface of the concrete test block, to obtain the carbonation depth of the artificial coarse aggregate at the straight line position (the length of the green dashed line at the position of straight line d in the figure, that is, the length of the long dashed line); at the position of straight line e, there is an artificial coarse aggregate particle that has carbonated beyond the cement matrix below the carbonation boundary line and the ITZ has not carbonated completely, so the carbonation depth of the cement matrix above the artificial coarse aggregate particle on the straight line is measured, that is, the distance from point K to the upper surface of the concrete test block, to obtain the carbonation depth of the cement matrix at the straight line position (the length of the black dashed line at the position of straight line e in the figure, that is, the length of the short dashed line); the carbonation depths of the ITZ on both sides of the artificial coarse aggregate particle are measured and the average value is obtained, that is, the average value of the distances from points L and M to the upper surface of the concrete test block, to obtain the carbonation depth of the artificial coarse aggregate at the straight line position (the length of the green dashed line at the position of straight line e in the figure, that is, the length of the long dashed line); at the position of straight line f, there is no artificial coarse aggregate particle at the carbonation boundary line, so the carbonation depth of the cement matrix on the straight line is directly measured (for details, refer to Figure 4The carbonation depth of the cement matrix at the position of the straight line c is measured, and the carbonation depth of the cement matrix at the position of the straight line is obtained (the length of the black dotted line in the figure, that is, the length of the short dotted line); the carbonation depths at the deepest positions of the interface transition zones Q1 and Q2 on both sides of the cement matrix are measured and the arithmetic mean value is obtained (for the interface transition zone Q1, the carbonation depth at the deepest position can be considered as the distance from the point M to the surface of the concrete test block, and for the interface transition zone Q2, the carbonation depth at the deepest position is the distance from the point N to the upper surface of the concrete test block), and the carbonation depth of the artificial coarse aggregate at the position of the straight line is obtained (the length of the green dotted line at the position of the straight line f in the figure, that is, the length of the long dotted line).

[0073] The measurement method of the artificial coarse aggregate-based concrete provided by the present application can correct the shortcomings of the current traditional measurement method, reduce the large deviation of the current method, and provide a more accurate method for accurately measuring the carbonation depth of the artificial coarse aggregate-based concrete. On the other hand, the measurement method provided by the present application can be used to study the influence of different artificial coarse aggregate replacement rates and the same artificial coarse aggregate replacement rate on the carbonation depth of the artificial coarse aggregate-based concrete, thereby providing a sustainable method for studying the internal structure and carbon fixation amount of the artificial coarse aggregate-based concrete and the carbon fixation performance of the solid waste containing alkaline earth metals.

[0074] In some embodiments, the mass concentration of the phenolphthalein alcohol solution is 1%, and the preset distance is 10 mm. That is, the carbonation depth of the artificial coarse aggregate-based concrete is measured every 10 mm.

[0075] In some embodiments, as shown in Figure 6 The preparation method of the artificial coarse aggregate includes the following steps:

[0076] S11, providing garbage incineration bottom ash particles;

[0077] S12, mixing the garbage incineration bottom ash particles, cement and mineral admixtures according to a mass ratio of 70:(20-30):(0-10) to obtain a mixture;

[0078] S13, feeding the mixture into a disc granulator for granulation to obtain an artificial coarse aggregate embryo;

[0079] S14, obtaining the artificial coarse aggregate after water bath curing of the artificial coarse aggregate embryo.

[0080] The measurement method of the carbonation depth provided in the present application is very suitable for the carbonation depth of the artificial coarse aggregate-based concrete prepared by using garbage incineration bottom ash. The relationship between the artificial aggregate replacement rate and the carbonation depth is discussed by using the measurement method, thereby providing a sustainable method for studying the internal structure and carbon fixation amount of the artificial coarse aggregate-based concrete and the carbon fixation performance of the solid waste containing alkaline earth metals.

[0081] In step S12, in some embodiments, the mineral admixture includes mineral powder and / or fly ash, but is not limited thereto.

[0082] In step S13, in some embodiments, the diameter of the disc granulator is 100 cm, the edge height is 15 cm, the inclination angle is 45°, and the rotating disc speed is 35 rap / min.

[0083] In some embodiments, the step of feeding the mixture into the disc granulator for granulation specifically includes:

[0084] The mixture is fed into the disc granulator in batches, and water is sprayed during the feeding of the mixture, with a total water quantity to mass ratio of the mixture of 20%-22%.

[0085] To avoid performance differences in the artificial coarse aggregate, a portion of the mixture is first fed into the disc granulator, and the remaining portion of the mixture is added in subsequent water spraying. In this embodiment, a low water content can result in the inability to form agglomerates, while a high water content can result in the formation of mud balls. When the portion of the mixture that is first fed into the disc granulator begins to agglomerate and gradually form particles, and the surface of the particles is wet, the remaining portion of the mixture is added. The reason for this operation is that: (1) the artificial coarse aggregate is formed by layer-by-layer bonding, and the pores between the internal particles are filled with water, which is beneficial to improving the performance; (2) it can avoid the situation that the surface of the artificial coarse aggregate is too wet, resulting in the mutual bonding of the artificial aggregate particles.

[0086] In some embodiments, the mixture is fed into the disc granulator for granulation, and after sieving, artificial coarse aggregate embryos with a particle size greater than 2.36 mm are obtained, and the particle size less than 2.36 mm is regranulated.

[0087] In step S14, in some embodiments, the temperature of the water bath curing is 20±2°C, and the time of the water bath curing is at least 28 days. In this embodiment, water bath curing is used, and the hydration process is faster than humidity curing, and water bath curing can isolate air to avoid severe carbonation of the artificial coarse aggregate before application.

[0088] The present application also provides a preparation method of artificial coarse aggregate-based concrete, including the following steps:

[0089] The artificial coarse aggregate after water bath curing is taken out of the water and allowed to drain (the artificial coarse aggregate has the characteristic of high water absorption, which can increase the amount of water required for mixing, so the artificial aggregate needs to be in a saturated state before the concrete is made);

[0090] The cement, sand and artificial coarse aggregate are dry mixed, and then water is added for stirring to obtain a mixture slurry;

[0091] The mixture slurry is poured into a mold, air bubbles are discharged by a vibrating table, the surface is scraped flat by a scraper, and after molding, the standard curing chamber is entered to obtain the artificial coarse aggregate-based concrete.

[0092] The following is described in detail through specific examples.

[0093] Example 1

[0094] The abbreviations of the raw material components and sources are as follows:

[0095] MSWIBA (MSWIBA, Ma Yong Environmental Protection Thermal Power Plant in Dongguan, China), GGBFS (GGBFS, Shenzhen Antuoshan Concrete Co., Ltd. in China), fly ash (FA, Shenzhen Antuoshan Concrete Co., Ltd. in China, belonging to F class II fly ash), ordinary Portland cement (OPC, Haibo brand P·O 42.5 ordinary Portland cement, in line with GB 175-2007), natural coarse aggregate (NA, broken stone, particle size of 4.75-9.50 mm, bulk density of 1306 kg / m 3 , apparent density of 2543 kg / m 3 , water absorption of 0.9%).

[0096] Table 1, artificial coarse aggregate mixing ratio

[0097]

[0098] Note: UA represents uncarbonated artificial coarse aggregate after water bath curing, CA represents carbonated artificial coarse aggregate after water bath curing, and the suffix C represents OPC, F represents FA, and K represents GGBFS.

[0099] As shown in Figure 6 , the preparation method of the artificial coarse aggregate is as follows:

[0100] According to the weight proportions in Table 1 above, the raw materials are uniformly mixed to obtain a mixture;

[0101] 50% of the mixture by mass is loaded into a disc granulator for granulation, the diameter of the disc granulator is 100 cm, the edge height is 15 cm, the inclination angle is 45°, and the rotating disc speed is 35 rap / min. At the same time, water is sprayed into the disc during the operation of the disc granulator, and the water content is controlled at 20% of the mass of the mixture. The remaining 50% of the mixture is added during the water spraying process. After granulation, sieving is performed to obtain artificial coarse aggregate embryos with a particle size greater than 2.36 mm;

[0102] The artificial coarse aggregate embryo is placed in a water bath at a temperature of 20±2℃ for curing for 28 days to obtain artificial coarse aggregate (not carbonized), which is denoted as UA-FC, UA-KC and UA-FK, respectively. The apparent densities of UA-FC, UA-KC and UA-FK are 2036 kg / m 3 , 2127 kg / m 3 , and 1987 kg / m 3 , respectively.

[0103] The artificial coarse aggregate not subjected to carbonization is placed in a carbonization box (CO2 concentration of 20% and humidity of 75%) for carbonization for 2 days to obtain carbonized artificial coarse aggregate, which is denoted as CA-FC, CA-KC and CA-FK, respectively.

[0104] Example 2

[0105] Table 2, mix proportion of concrete

[0106]

[0107] Note: NC in the suffix represents concrete prepared by using natural coarse aggregate, and the numbers 30, 60 and 100 in the number represent the volume replacement rate of artificial coarse aggregate, that is, the volume of artificial coarse aggregate and the sum of the volumes of artificial coarse aggregate and natural coarse aggregate. Taking the amount of sand in C-FC30 as an example, the amount in the table is explained. In C-FC30, the amount of sand is 617.7 kg / m 3 , which means that the amount of sand in 1 m 3 of concrete is 617.7 kg, and the meanings of other amounts are similar.

[0108] The preparation method of the artificial coarse aggregate-based concrete comprises the following steps:

[0109] According to the proportions in Table 2, the artificial coarse aggregate (removed from water and allowed to drain on the surface) in Example 1, cement and sand are poured into a mixer for dry mixing for 2 minutes, then water is poured into the mixer for stirring, the uniformly mixed mixture is loaded into a mold, air bubbles are removed by a vibration table, the surface is scraped flat with a spatula, and plastic wrap is covered to prevent water loss. After 1 day of molding, it is placed in a standard curing room.

[0110] The 28-day standard curing and 28-day rapid carbonization experiment has been completed according to the standard GB / T 50082 “Standard for Testing Methods for Long-term Performance and Durability of Concrete”, and is used to test the carbonation depth.

[0111] Example 3

[0112] The measurement method of the carbonation depth of the natural coarse aggregate-based concrete C-NA is carried out according to GB / T50082-2009, comprising the following steps:

[0113] The three cubic concrete test blocks with a side length of 100 mm are split from the middle using a pressure testing machine, after removing the residual powder on the fracture surface, spraying a phenolphthalein alcohol solution with a mass concentration of 1% on the fracture surface, completing color development, and the fracture surface images of the three concrete test blocks after color development are as shown in Figure 7 Figure 7 The fracture surface images of test block 1, test block 2 and test block 3 from left to right are shown in the figure.

[0114] Test points are selected on the straight lines on the fracture surface every 10 mm, a total of 9 test points are set, and each of the 9 carbonation depths is Figure 7 Each of the figures from left to right is h1, h2, h3, h4, h5, h6, h7, h8, h9, and the average value is obtained after measurement, as shown in Table 3. Finally, the average carbonation depth is 7.49 mm.

[0115] Table 3, carbonation depth of natural coarse aggregate-based concrete C-NA

[0116]

[0117] Example 4

[0118] (1) According to the method (i.e. the traditional method) in GB / T50082-2009, the carbonation depth of artificial coarse aggregate-based concrete C-FC30 is measured, including the steps of:

[0119] The three cubic concrete test blocks with a side length of 100 mm are split from the middle using a pressure testing machine, after removing the residual powder on the fracture surface, spraying a phenolphthalein alcohol solution with a mass concentration of 1% on the fracture surface, completing color development, and the fracture surface images of the three concrete test blocks after color development are as shown in Figure 8 Figure 8 The fracture surface images of test block 1, test block 2 and test block 3 from left to right are shown in the figure.

[0120] The measured carbonation depth is shown in Table 4. Finally, the average carbonation depth is 11.15 mm.

[0121] Table 4, carbonation depth of artificial coarse aggregate-based concrete C-FC30 measured by the traditional measurement method

[0122]

[0123] (2) The carbonation depth of artificial coarse aggregate-based concrete C-FC30 is measured by the measurement method in the present application, including the above steps S1 to S3, S311 to S313, S3211 to S3213, S3221 to S3223, S3231 to S3232, including the steps of:

[0124] ​​The three cubic concrete test blocks with a side length of 100 mm are split from the middle by using a pressure testing machine, after removing the residual powder on the fracture surface, a phenolphthalein alcohol solution with a mass concentration of 1% is sprayed on the fracture surface, color development is completed, and the fracture surface image is obtained, as shown in Figure 8 , Figure 8 The fracture surface images of test block 1, test block 2 and test block 3 from left to right are shown in the middle, and the carbonation depth of the cement matrix and the carbonation depth of the artificial coarse aggregate are measured respectively.

[0125] The measured carbonation depth of the cement matrix is shown in Table 5 below, and the average value is 5.38 mm, that is, the carbonation depth of the cement matrix is 5.38 mm; the measured carbonation depth of the artificial coarse aggregate is 11.05 mm.

[0126] Table 5, the carbonation depth of the cement matrix of the artificial coarse aggregate based concrete C-FC30 measured by the measurement method of the present application

[0127]

[0128] Example 5

[0129] (1) The carbonation depth of the artificial coarse aggregate based concrete C-FC100 is measured according to the method in GB / T50082-2009, including the steps of:

[0130] The three cubic concrete test blocks with a side length of 100 mm are split from the middle by using a pressure testing machine, after removing the residual powder on the fracture surface, a phenolphthalein alcohol solution with a mass concentration of 1% is sprayed on the fracture surface, color development is completed, and the fracture surface image is obtained, as shown in Figure 9 , Figure 9 The fracture surface images of test block 1, test block 2 and test block 3 from left to right are shown in the middle, and the carbonation depth is tested. The measured carbonation depth is shown in Table 6 below. Finally, the average carbonation depth is calculated to be 17.3 mm.

[0131] Table 6, the carbonation depth of the artificial coarse aggregate based concrete C-FC100 measured by the traditional measurement method

[0132]

[0133] (2) The carbonation depth of the artificial coarse aggregate based concrete C-FC100 is measured by the measurement method in the present application including the above steps S1 to S3, S311 to S313, S3211 to S3213, S3221 to S3223, S3231 to S3232, including the steps of:

[0134] The three cubic concrete test blocks with a side length of 100 mm are split from the middle using a pressure testing machine, after removing the residual powder on the fracture surface, spraying a phenolphthalein alcohol solution with a mass concentration of 1% on the fracture surface, completing color development, and obtaining a fracture image, as shown in Figure 9 , Figure 9 From left to right in the middle are the fracture images of test block 1, test block 2, and test block 3, respectively, and the carbonation depths of the cement matrix and the carbonation depths of the artificial coarse aggregate are measured. Figure 2 and 9 The carbonation depths of the cement matrix obtained by the test are shown in Table 7 below, and the average value is 6.50 mm, i.e., the carbonation depth of the cement matrix is 6.50 mm. The carbonation depth of the artificial coarse aggregate obtained by the test is 17.24 mm.

[0135] Table 7 Carbonation depths of cement matrix of artificial coarse aggregate-based concrete C-FC100 measured by the measurement method of the present application

[0136]

[0137] Example 6

[0138] (1) According to the method in GB / T50082-2009, the carbonation depth of the artificial coarse aggregate-based concrete C-KC100 is tested, including the steps of:

[0139] The three cubic test blocks with a side length of 100 mm are split from the middle using a pressure testing machine, after removing the residual powder on the fracture surface, spraying a phenolphthalein alcohol solution with a mass concentration of 1% on the fracture surface, completing color development, and obtaining a fracture image, as shown in Figure 10 , Figure 10 From left to right in the middle are the fracture images of test block 1, test block 2, and test block 3, respectively, and the carbonation depths of the cement matrix and the carbonation depths of the artificial coarse aggregate are measured.

[0140] The carbonation depths of the cement matrix obtained by the test are shown in Table 8 below, and the average value is 14.53 mm, i.e., the carbonation depth of the cement matrix is 14.53 mm.

[0141] Table 8 Carbonation depths of artificial coarse aggregate-based concrete C-KC100 measured by the traditional measurement method

[0142]

[0143] (2) The carbonation depth of the artificial coarse aggregate-based concrete C-KC100 is measured by the measurement method of the present application including the above steps S1 to S3, S311 to S313, S3211 to S3213, S3221 to S3223, S3231 to S3232, including the steps of:

[0144] The three cubic concrete test blocks with a side length of 100 mm are split from the middle using a pressure testing machine, and after removing the residual powder on the fracture surface, a phenolphthalein alcohol solution with a mass concentration of 1% is sprayed on the fracture surface, color development is completed, and the fracture surface image is obtained, as shown in Figure 10 Figure 10 The fracture surface images of test block 1, test block 2 and test block 3 from left to right are shown in Figure 2 and 10 The carbonation depth of the cement matrix and the carbonation depth of the artificial coarse aggregate are measured respectively.

[0145] The measured carbonation depth of the cement matrix is shown in Table 9, and the average value is 4.55 mm, that is, the carbonation depth of the cement matrix is 4.55 mm; the measured carbonation depth of the artificial coarse aggregate is 14.53 mm.

[0146] Table 9, the carbonation depth of the cement matrix of the artificial coarse aggregate-based concrete C-KC100 measured by the measurement method of the present application

[0147]

[0148] Example 7

[0149] (1) According to the method in GB / T50082-2009, the carbonation depth of the artificial coarse aggregate-based concrete C-FK100 is tested, including the steps of:

[0150] The three cubic concrete test blocks with a side length of 100 mm are split from the middle using a pressure testing machine, and after removing the residual powder on the fracture surface, a phenolphthalein alcohol solution with a mass concentration of 1% is sprayed on the fracture surface, color development is completed, and the fracture surface image is obtained, as shown in Figure 11 Figure 11 The fracture surface images of test block 1, test block 2 and test block 3 from left to right are shown in Figure 2 and 10 The carbonation depth test is carried out, and the measured carbonation depth is shown in Table 10. Finally, the average carbonation depth is calculated to be 16.78 mm.

[0151] Table 10, the carbonation depth of the artificial coarse aggregate-based concrete C-FK100 measured by the traditional measurement method

[0152]

[0153] ​​(2) The carbonation depth of the artificial coarse aggregate-based concrete C-FK100 is measured by the measurement method comprising the steps S1 to S3, S311 to S313, S3211 to S3213, S3221 to S3223, S3231 to S3232, and the steps of the measurement method are as follows:

[0154] The three cubic concrete test blocks with a side length of 100 mm are split from the middle using a pressure testing machine, after removing the residual powder on the fracture surface, spraying a phenolphthalein alcohol solution with a mass concentration of 1% on the fracture surface, completing the color development, and obtaining the fracture surface image, as shown in Figure 11 Figure 11 The fracture surface images of the test block 1, the test block 2 and the test block 3 from left to right are shown in the middle.

[0155] The measured carbonation depth of the cement matrix is shown in Table 11 below, and the average value is 3.85 mm, that is, the carbonation depth of the cement matrix is 3.85 mm; the measured carbonation depth of the artificial coarse aggregate-based concrete C-FK100 is 16.78 mm.

[0156] Table 11, the measured carbonation depth of the cement matrix of the artificial coarse aggregate-based concrete C-FK100 by the measurement method of the present application

[0157]

[0158] By comparing the data of Examples 3-7, it can be concluded that the carbonation depth of the artificial coarse aggregate-based concrete measured according to the measurement method specified in the standard GB-T 50082-2009 has certain limitations and produces a large error. The carbonation depth of the cement matrix and the carbonation depth of the artificial coarse aggregate of the artificial coarse aggregate-based concrete C-FC60, C-KC30, C-KC60, C-FK30 and C-FK60 are measured by the measurement method provided by the present application, and all the results and the data of Examples 3-7 are summarized as shown in Figure 12 The height of the solid column is the carbonation depth of the cement matrix, and the total height of the solid column and the dashed column is the carbonation depth of the artificial coarse aggregate.

[0159] For the natural coarse aggregate-based concrete C-NA, the carbonation depth is 7.49 mm. After adding the artificial coarse aggregate, the carbonation depth of the cement matrix decreases, and the reason may be that the artificial coarse aggregate competes for CO2, thereby reducing the carbonation rate of the cement matrix and protecting the concrete from being eroded and damaged by CO2.

[0160] ​For the artificial coarse aggregate based concrete C-FC30, C-FC60 and C-FC100 with UA-FC, the carbonation depth of cement matrix in C-FC30 reduced to 5.38 mm when 30% UA-FC was added. With the continuous increase of UA-FC, the carbonation depth of cement matrix in C-FC100 reached 6.50 mm. The reason for this phenomenon can be that the artificial coarse aggregate is internally connected, and CO2 also increases the contact area with the cement matrix through the internal of the artificial coarse aggregate, thereby accelerating the carbonation process, but overall the carbonation depth is still less than C-NA.

[0161] For the artificial coarse aggregate based concrete C-KC30, C-KC60 and C-CK100 with UA-KC, the carbonation depth of cement matrix decreases with the increase of the content of artificial coarse aggregate, and the carbonation depth of cement matrix in C-KC100 reduces to 4.55 mm.

[0162] The carbonation depth of cement matrix in artificial coarse aggregate based concrete C-FK (with UA-FK) shows a similar pattern to that of artificial coarse aggregate based concrete C-FC (with UA-FC). When 30% artificial coarse aggregate is added, C-FK30 shows the smallest carbonation depth of cement matrix, which is 3.38 mm. With the increase of the content of UA-FK, the carbonation depth of cement matrix in C-FK100 also only reaches 3.85 mm.

[0163] Overall, artificial coarse aggregate can alleviate the possibility of CO2 erosion of cement matrix, among which UA-FK is the best protection for cement matrix, maintaining the carbonation depth of cement matrix below 50% of that of natural coarse aggregate concrete (C-NA carbonation depth 7.49 mm).

[0164] For the carbonation depth of artificial coarse aggregate, artificial coarse aggregate based concrete C-FC, C-KC and C-FK all increase with the increase of the content of artificial coarse aggregate. The carbonation depth of artificial coarse aggregate in artificial coarse aggregate based concrete C-FC100, C-KC100 and C-FK100 respectively reached 17.24 mm, 14.53 mm and 16.78 mm. Among them, the carbonation depth of artificial coarse aggregate in C-KC100 is the smallest, because the porosity and carbonation rate of artificial coarse aggregate UA-KC are smaller than those of UA-FC and UA-FK.

[0165] In summary, the measuring method of the artificial coarse aggregate-based concrete provided by the application can correct the shortcomings of the current traditional measuring method, reduce the large deviation of the current method, provide a method with higher precision for accurately measuring the carbonation depth of the artificial coarse aggregate-based concrete, on the other hand, the measuring method provided by the application can be used to study the influence of different artificial coarse aggregate replacement rates and the same artificial coarse aggregate replacement rate on the carbonation depth of the artificial coarse aggregate-based concrete, and provide a sustainable method for studying the internal structure and carbon sequestration capacity of the artificial coarse aggregate-based concrete and the carbon sequestration performance of the alkali-containing solid waste.

[0166] It should be understood that the application of the application is not limited to the above examples, and those skilled in the art can improve or change according to the above description, and all these improvements and changes shall belong to the protection scope of the claims of the application.

Claims

1. A method of measuring the carbonation depth of artificial coarse aggregate-based concrete, characterized by, The artificial coarse aggregate-based concrete comprises a cement matrix and artificial coarse aggregates dispersed in the cement matrix, and an interface transition zone wrapping the artificial coarse aggregates exists at the interface between the cement matrix and the artificial coarse aggregates. The carbonation depth of the artificial coarse aggregate-based concrete comprises a carbonation depth of the cement matrix and a carbonation depth of the artificial coarse aggregates. The measurement method of the carbonation depth of the cement matrix and the carbonation depth of the artificial coarse aggregates comprises the following steps: providing an artificial coarse aggregate-based concrete test block, splitting the artificial coarse aggregate-based concrete test block along the carbonation direction, spraying a phenolphthalein alcohol solution on the fracture surface, marking a plurality of parallel straight lines with a preset distance on the fracture surface after color development, respectively measuring the carbonation depth of the cement matrix and the carbonation depth of the artificial coarse aggregates at each straight line position, respectively calculating the average value of the carbonation depth of the cement matrix and the carbonation depth of the artificial coarse aggregates at each straight line position, and respectively obtaining the carbonation depth of the cement matrix and the carbonation depth of the artificial coarse aggregates in the artificial coarse aggregate-based concrete; wherein, when the carbonation rate of the artificial coarse aggregates is greater than the carbonation rate of the interface transition zone, the measurement method of the carbonation depth of the cement matrix and the carbonation depth of the artificial coarse aggregates at each straight line position specifically comprises the following steps: if there is an artificial coarse aggregate particle at the carbonation boundary line on a straight line, the carbonation depth of the cement matrix on both sides of the artificial coarse aggregate particle is measured and the arithmetic mean value is taken to obtain the carbonation depth of the cement matrix at the straight line position, and the carbonation depth of the artificial coarse aggregate on the straight line is measured to obtain the carbonation depth of the artificial coarse aggregate at the straight line position; if there is an artificial coarse aggregate particle below the carbonation boundary line on a straight line, the carbonation depth of the cement matrix above the artificial coarse aggregate particle on the straight line is measured to obtain the carbonation depth of the cement matrix at the straight line position, and the carbonation depth of the artificial coarse aggregate on the straight line is measured to obtain the carbonation depth of the artificial coarse aggregate at the straight line position; if there is no artificial coarse aggregate particle at the carbonation boundary line on a straight line, the carbonation depth of the cement matrix on the straight line is directly measured to obtain the carbonation depth of the cement matrix at the straight line position, and the carbonation depth of the artificial coarse aggregates on both sides of the cement matrix is measured and the arithmetic mean value is taken to obtain the carbonation depth of the artificial coarse aggregates at the straight line position; when the carbonation rate of the artificial coarse aggregates is less than the carbonation rate of the interface transition zone, the measurement method of the carbonation depth of the artificial coarse aggregates at each straight line position specifically comprises the following steps: if there is an artificial coarse aggregate particle at the carbonation boundary line on a straight line, the carbonation depth of the interface transition zone on the straight line is measured to obtain the carbonation depth of the artificial coarse aggregates at the straight line position; if there is an artificial coarse aggregate particle below the carbonation boundary line on a straight line and the interface transition zone is not carbonated completely, the carbonation depth of the interface transition zone on both sides of the artificial coarse aggregate particle is measured and the arithmetic mean value is taken to obtain the carbonation depth of the artificial coarse aggregates at the straight line position; If there is no artificial coarse aggregate particle at the carbonation boundary line on a straight line, the carbonation depths of the cement matrix on both sides of the interface transition zone near the straight line are measured and the arithmetic mean value is obtained as the carbonation depth of the artificial coarse aggregate at the straight line position.

2. The measurement method according to claim 1, characterized in that, The method for measuring the carbonation depth of the cement matrix at each straight line position when the interface transition zone on the section peels off specifically includes the following steps: If there is no artificial coarse aggregate particle at the carbonation boundary line on a straight line, the carbonation depth of the cement matrix on the straight line is directly measured to obtain the carbonation depth of the cement matrix at the straight line position. If there is no artificial coarse aggregate particle at the carbonation boundary line on a straight line, the carbonation depth of the cement matrix on the straight line is directly measured to obtain the carbonation depth of the cement matrix at the straight line position. If there is no artificial coarse aggregate particle at the carbonation boundary line on a straight line, the carbonation depth of the cement matrix on the straight line is directly measured to obtain the carbonation depth of the cement matrix at the straight line position.

3. The measurement method according to claim 1, characterized in that, The method for measuring the carbonation depth of the cement matrix at each straight line position when the artificial coarse aggregate is broken in the middle on the section specifically includes the following steps: If there is no artificial coarse aggregate particle at the carbonation boundary line on a straight line, the carbonation depth of the cement matrix on the straight line is directly measured to obtain the carbonation depth of the cement matrix at the straight line position. If there is no artificial coarse aggregate particle at the carbonation boundary line on a straight line, the carbonation depth of the cement matrix on the straight line is directly measured to obtain the carbonation depth of the cement matrix at the straight line position.

4. The measurement method according to claim 1, characterized by, The mass concentration of the phenolphthalein alcohol solution is 1%, and the preset distance is 10 mm.

5. The measuring method according to any one of claims 1 to 4, characterized in that, The preparation method of the artificial coarse aggregate includes the following steps: Providing garbage incineration bottom ash particles; Mixing the garbage incineration bottom ash particles, cement and mineral admixtures according to a mass ratio of 70: (20-30): (0-10) to obtain a mixture; Putting the mixture into a disc granulator to granulate to obtain an artificial coarse aggregate embryo; After water bath curing the artificial coarse aggregate embryo, the artificial coarse aggregate is obtained.

6. The measurement method according to claim 5, characterized in that, The mineral admixtures include mineral powder and / or fly ash.

7. The measurement method according to claim 5, characterized by, The diameter of the disc granulator is 100 cm, the edge height is 15 cm, the inclination angle is 45°, and the rotating disc speed is 35 rap / min.

8. The measurement method according to claim 5, characterized by, The step of putting the mixture into the disc granulator to granulate specifically includes the following steps: The mixture is put into the disc granulator in batches, and water is sprayed in the process of putting in the mixture, and the total water consumption is 20%-22% of the mass of the mixture.

9. The measurement method according to claim 5, characterized by, The temperature of the water bath curing is 20±2°C, and the time of the water bath curing is at least 28 days.

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