Method and device for evaluating the mass loss rate of concrete under liquid-solid abrasion

Abstract

The application discloses a kind of liquid-solid abrasion under concrete quality loss rate evaluation method and device, belong to civil engineering field.Concrete quality loss rate prediction model is defined, the saturated surface dry mass loss of concrete test piece before and after liquid-solid abrasion effect of different scouring rate, scouring angle, silt content is obtained by abrasion accelerated test, and the concrete quality loss rate is calculated;The calculated value of concrete quality loss rate is substituted into prediction model, and the to-be-solved parameter is fitted to obtain;The to-be-solved parameter fitted to obtain is substituted into prediction model, and the concrete quality loss rate under the liquid-solid abrasion effect of different scouring rate, scouring angle, scouring time, silt content is predicted using model.The abrasion accelerated test described above is realized using concrete quality loss rate test device.The abrasion of concrete member under the condition of different scouring rate, scouring angle, silt content in sea area can be realized by the present application to predict the quality loss rate.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of civil engineering, and particularly relates to a method and device for evaluating the mass loss rate of concrete under liquid-solid erosion. BACKGROUND

[0002] The construction of marine nearshore and offshore concrete infrastructure represented by cross-sea bridges, port terminals, offshore wind turbines and artificial islands is long-term exposed to harsh environments such as turbulent flow, strong tidal surge and frequent sediment transport. Under the severe scouring action of sediment-laden flow, the concrete surface will be damaged and eroded, and a large number of micro-cracks will be generated and accumulated in the hardened paste, coarse aggregate and interfacial transition zone of the concrete surface, forming local weak areas on the concrete surface, and further causing phenomena such as hardened paste wear and coarse aggregate exposure and spalling, which affect the normal service and service life of the structure.

[0003] Generally speaking, the erosion rate will affect the energy and frequency of the action of water flow particles on the concrete. When the water flow produces a normal impact on the concrete surface, the mass loss of the concrete surface increases with the increase of the erosion rate, and shows a quadratic function relationship. The higher the sediment concentration of the water flow, the more serious the mass loss of the concrete surface. For the mechanism of the effect of the scouring angle on the material, domestic and foreign scholars have studied the influence of the action angle of fluid particles on plastic materials and brittle materials through experimental research, and found that there is a most unfavorable scouring angle that makes the mass loss of the material reach the maximum value. Among them: the mass loss of plastic materials reaches the maximum value at a scouring angle of 20°-30°, which is mainly affected by the tangential cutting action; the mass loss of brittle materials is most serious at a scouring angle of 90°, which is mainly affected by the normal impact. Zarrabi found through a 3h short-term erosion test that the erosion depth of the concrete surface increases linearly with the increase of the angle. In fact, unlike plastic or brittle materials, concrete is a multiphase quasi-brittle material, and the influence of erosion on the concrete surface aggregate and mortar is different. After erosion, the surface morphology of the concrete will no longer remain homogeneous and planar, and when the aggregate is exposed, the angle between the concrete surface and the water flow will further change. Therefore, the most unfavorable scouring angle of the water flow will also change.

[0004] On the other hand, in the past decade, many scholars have devoted to the research on the mass loss rate of concrete erosion in different working conditions, and the test methods used include: ring method, underwater steel ball method and sand blasting method. The subsequent test method for the erosion resistance of concrete generally refers to the analysis method of the anti-erosion strength and the erosion rate in SL / T 352-2020 “Hydraulic Concrete Test Procedures” to determine the mass loss rate of concrete erosion. However, the ring method and the underwater steel ball method cannot change the water flow erosion angle, and the sand blasting method cannot provide a water flow environment, so it is difficult to predict the mass loss rate of concrete when the sand-carrying water flow changes in the erosion rate and the erosion angle, thereby causing considerable safety hazards in the design and operation of concrete structures and deviating from the engineering practice. Therefore, the evaluation method and test device for the mass loss rate of concrete under the action of liquid-solid erosion in the marine environment should be paid attention to. SUMMARY

[0005] In order to solve the above problems, the application provides a liquid-solid erosion concrete mass loss rate evaluation method and device for predicting the erosion mass loss rate of concrete members under different erosion rates, erosion angles and sediment concentrations in sea areas.

[0006] In order to achieve the above purpose, the technical scheme adopted by the application is as follows:

[0007] A liquid-solid erosion concrete mass loss rate evaluation method, comprising the following steps:

[0008] Step 1, defining the tangential cutting mass loss rate and the normal impact mass loss rate of concrete under the action of liquid-solid erosion with different erosion rates, erosion angles, erosion times and sediment concentrations, and obtaining a concrete mass loss rate prediction model based on the sum of the two:

[0009]

[0010] In the formula, w represents the mass loss rate of concrete, M s represents the cumulative sand mass in the water flow erosion process, κ represents the energy required for unit mass loss caused by tangential cutting, ε represents the energy required for unit mass loss caused by normal impact, A represents the erosion area of concrete, t represents the erosion time of concrete, v τ represents the tangential residual rate of sand-carrying water flow after eroding the surface of concrete, v n represents the normal residual rate of sand-carrying water flow after eroding the surface of concrete, v represents the erosion rate, v τ,lim represents the tangential critical rate, v n,lim represents the normal critical rate, α represents the water flow erosion angle, and n and m are the tangential and normal coefficients of the water flow erosion angle.

[0011] Step 2, obtaining the saturated surface dry mass loss of the concrete test piece before and after liquid-solid abrasion at different scouring rates, scouring angles and sediment concentrations through the abrasion-accelerated test, and calculating the concrete mass loss rate;

[0012] Step 3, substituting the calculated value of the concrete mass loss rate into the concrete mass loss rate prediction model in Step 1 to fit the to-be-solved parameters, including the tangential critical rate v τ,lim , the normal critical rate v n,lim , the tangential coefficient n of the scouring angle, the tangential coefficient m of the scouring angle, the energy κ required for unit mass loss caused by tangential cutting, and the energy ε required for unit mass loss caused by normal impact;

[0013] Step 4, substituting the to-be-solved parameters fitted in Step 3 into the concrete mass loss rate prediction model in Step 1 to predict the concrete mass loss rate under the action of liquid-solid abrasion at different scouring rates, scouring angles, scouring times and sediment concentrations by using the model in Step 1.

[0014] Further, in Step 2, the calculation formula of the concrete mass loss rate is as follows:

[0015]

[0016] Wherein, M t represents the saturated surface dry mass of the concrete test piece after scouring for t hours, and M0 represents the initial saturated surface dry mass of the concrete test piece after being treated by water saturation and sealing before scouring.

[0017] Further, the water saturation and sealing treatment specifically refers to: using a vacuum water saturation machine to perform water saturation treatment on the concrete test piece, and using epoxy resin to seal the remaining surfaces of the concrete test piece after water saturation treatment.

[0018] Further, the calculation formula of the cumulative sand mass in the water scouring abrasion process is as follows:

[0019] M s = vSQ s t

[0020] Wherein, S represents the flow section area in the water scouring process, and Q s represents the sediment concentration of the water flow.

[0021] Further, the range of the water scouring angle is 0°-90°, and the range of the scouring rate is 0 m / s-20 m / s.

[0022] A device for implementing the above-mentioned abrasion acceleration test, comprising an erosion reaction box, a wear-resistant sand slurry pump, a water-sand stirring pump, an impeller, a water flow power control system, and a test piece clamp;

[0023] The water-sand stirring pump is connected with the impeller installed in the erosion reaction box, and is used to drive the impeller to stir the water-sand mixture in the erosion reaction box; the wear-resistant sand slurry pump forms a circulating passage with the erosion reaction box through a water-sand transportation pipeline and a circulating water pipeline, and is used to draw the water flow in the erosion reaction box from one side through the circulating water pipeline and flow into the top through the water-sand transportation pipeline; the test piece clamp is installed in the erosion reaction box and below the outlet of the water-sand transportation pipeline, and the angle of the test piece clamp can be adjusted; and the water flow power control system is used to control the power and operation time of the pump motors of the wear-resistant sand slurry pump and the water-sand stirring pump.

[0024] Further, the number of the water-sand stirring pump and the impeller is 2-4, and the impellers are uniformly distributed at the bottom of the erosion reaction box, and the bottom of the erosion reaction box is provided with a drain hole.

[0025] Further, the number of the test piece clamp is several, and the angle of each test piece clamp can be adjusted individually.

[0026] Further, the number of the water-sand transportation pipeline outlet is consistent with the number of the test piece clamp.

[0027] Further, the flushing nozzle is installed at the outlet of the water-sand transportation pipeline, and the flowmeter is installed at the flow surface of the water-sand transportation pipeline.

[0028] Compared with the prior art, the present application has the following advantages:

[0029] The liquid-solid abrasion concrete quality loss rate evaluation method provided by the present application can predict the actual scour quality loss of the actual member under any scouring rate, scouring angle and scouring time in the marine environment, the device provided by the present application can restore the deterioration conditions of the concrete member under different scouring rates, scouring angles and sand contents in the marine environment, and the v τ,lim , v n,lim , v τ , v n , κ and ε fitted based on the parameters measured by the test device can be substituted into the evaluation method prediction model to predict the actual scour quality loss of the actual member under any scouring rate, scouring angle and scouring time in the marine environment. The present application provides test conditions and theoretical research methods for the research on the concrete deterioration mechanism under the action of marine environment scouring and abrasion, provides deeper test data and theoretical support for the safe work of the concrete structure in the marine environment for a service life, and thus improves the service health level of the concrete structure. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 A structural schematic diagram of a liquid-solid abrasion concrete mass loss rate test device according to an embodiment of the present application is shown in the figure;

[0031] Figure 2 A structural schematic diagram of an inside of an erosion reaction box according to an embodiment of the present application is shown in the figure;

[0032] Figure 3 A mass loss rate test result according to an embodiment of the present application is shown in the figure;

[0033] In the figure, 1 is an erosion reaction box, 2 is a box cover plate, 3 is a box reinforcing steel belt, 4 is a wear-resistant mortar pump, 5 is a water-sand mixing pump, 6 is a water flow power control system, 7 is a water-sand transportation pipeline, 8 is a flow meter, 9 is a scouring nozzle, 10 is a test piece clamp, 11 is a drain hole, 12 is a circulating water pipeline, and 13 is an impeller. DETAILED DESCRIPTION

[0034] The present application will be further described in detail through specific embodiments below, which are only descriptive and not limiting, and cannot limit the protection scope of the present application.

[0035] The present application proposes a liquid-solid abrasion concrete mass loss rate evaluation method, including the following steps:

[0036] S1, defining the tangential cutting mass loss rate and the normal impact mass loss rate of concrete under liquid-solid abrasion at different scouring rates, scouring angles, scouring times, and sand contents, as follows:

[0037]

[0038]

[0039] wherein w cut represents the tangential cutting mass loss rate, w imp represents the normal impact mass loss rate;

[0040] The present application considers the mass loss rate under impact in different directions, and establishes a concrete mass loss rate prediction model based on the sum of the two:

[0041]

[0042] wherein w represents the concrete mass loss rate, unit g / s·m 2 ; M s =vSQ s t represents the cumulative sand mass in the water flow scouring and abrasion process, unit kg; S represents the flow section area in the water flow scouring process, unit m 2 ; Q sS represents the sediment concentration of the water flow, with the unit of kg / m 3 ; κ represents the energy required for tangential cutting to cause unit mass loss, with the unit of (kg·m 2 ) / (g·s 2 ); ε represents the energy required for normal impact to cause unit mass loss, with the unit of (kg·m 2 ) / (g·s 2 ); A represents the erosion area of the concrete, t represents the erosion time of the concrete, v τ,lim represents the tangential critical velocity, with the unit of m / s; v n,lim represents the normal critical velocity, with the unit of m / s; v τ =vcosα represents the tangential residual velocity after the concrete surface is eroded by the sediment-laden water flow, with the unit of m / s, and when the tangential residual velocity v τ is lower than the critical velocity v τ,lim , the material does not cause mass loss; v n =vsinα represents the normal residual velocity after the concrete surface is eroded by the sediment-laden water flow, with the unit of m / s, and when the normal residual velocity v n is lower than the critical velocity v n,lim , the material does not cause mass loss; v represents the water flow erosion velocity, with the unit of m / s; represents the water flow erosion angle, and n and m are the tangential and normal coefficients of the water flow erosion angle. In the above formula, the tangential critical velocity v τ,lim , the normal critical velocity v n,lim , the tangential coefficient n of the water flow erosion angle, the normal coefficient m of the water flow erosion angle, the energy κ required for tangential cutting to cause unit mass loss, and the energy ε required for normal impact to cause unit mass loss are unknown quantities.

[0043] S2, through the abrasion acceleration test, the saturated surface dry mass loss of the concrete test piece before and after the liquid-solid abrasion effect under different erosion velocities, erosion angles and sediment concentrations is obtained, the concrete mass loss rate is calculated, and the calculation formula is as follows:

[0044]

[0045] wherein M t represents the saturated surface dry mass of the concrete test piece after the erosion time t, and M0 represents the initial saturated surface dry mass of the concrete test piece before the erosion and after the water sealing treatment.

[0046] S3, the calculated value of the concrete mass loss rate is substituted into the concrete mass loss rate prediction model in S1, and the to-be-solved parameters, including the tangential critical velocity v τ,lim , the normal critical velocity v n,lim, tangential coefficient n of water flow scouring angle, tangential coefficient m of water flow scouring angle, energy required for unit mass loss caused by tangential cutting κ, energy required for unit mass loss caused by normal impact ε.

[0047] S4, the to-be-solved parameters obtained by fitting in S3 are substituted into the concrete mass loss rate prediction model in S1, and the model in step 1 is used to predict the mass loss rate of concrete under liquid-solid erosion of different scouring rates, scouring angles, scouring times and sediment concentrations.

[0048] In a specific implementation of the present application, before the erosion acceleration test described in S2 is performed, the concrete test piece is subjected to water saturation treatment by using a vacuum water saturation machine, and a side surface of the water-saturated concrete test piece is used as the scouring surface, and the remaining surfaces are packaged using epoxy resin to achieve water-saturated packaging treatment of the concrete test piece; during the erosion acceleration test, the water flow scouring angle ranges from 0° to 90°, the scouring rate ranges from 0 m / s to 20 m / s, and the scouring time can be set according to the test requirements, and in this embodiment, the adjustment precision of the scouring time is 1 s.

[0049] As shown in Figure 1 , the present application proposes a device for realizing the above-mentioned erosion acceleration test, and the main components thereof include an erosion reaction box 1, a wear-resistant sand slurry pump 4, a water-sand mixing pump 5, an impeller 13, a water flow power control system 6 and a test piece clamp 10.

[0050] The top of the erosion reaction box 1 is provided with a box cover plate 2, the bottom is provided with a water outlet hole 11, and the outer wall surface is welded with a box reinforcing steel belt 3.

[0051] The water-sand mixing pump 5 is connected with the impeller 13 installed in the inside of the erosion reaction box 1, and is used to drive the impeller to stir the water-sand mixture in the erosion reaction box 1, the number of the water-sand mixing pump 5 and the impeller 13 is 2-4, and the impellers are evenly distributed at the bottom of the erosion reaction box 1, and the installation position of the impeller is referred to Figure 2 .

[0052] The wear-resistant sand slurry pump 4 forms a circulating path with the inside of the erosion reaction box 1 through the water-sand transportation pipeline 7 and the circulating water pipeline 12, and is used to draw the water flow in the erosion reaction box 1 from one side through the circulating water pipeline 12 and flow into the top through the water-sand transportation pipeline 7; as Figure 1As shown, the inlet of the wear-resistant sand slurry pump 4 is connected to the inside of the erosion reaction box 1 through the circulating water pipeline 12 from the side of the erosion reaction box 1, and the water and sand mixture in the inside of the erosion reaction box 1 can be pumped out under the action of the in-pump motor; the outlet of the wear-resistant sand slurry pump 4 is connected to the inside of the erosion reaction box 1 through the water and sand transportation pipeline 7 from the top of the erosion reaction box 1, and the pumped water flows into the top, the flushing nozzle 9 is installed at the outlet of the water and sand transportation pipeline 7 to realize the flushing function of the water flow, and the flow meter 8 is installed at the flow surface of the water and sand transportation pipeline 7, and the flushing rate of the water flow at the flushing nozzle can be calculated by measuring the flow Q of the flow surface S represents the flow area of the flow section during the water flow flushing process.

[0053] In the embodiment, the flow meter is connected to the water flow power control system 6, the flow of the water and sand mixture can be converted into the flushing rate of the water flow at the flushing nozzle through the built-in program, the dynamic adjustment of the flushing rate and the flushing time of the water and sand mixture can be realized, the adjustment range of the flushing rate is 0 m / s-20 m / s, and the flushing time can be set according to the test requirements, and in the embodiment, the adjustment accuracy of the flushing time is 1 s.

[0054] Referring to Figure 2 , the test piece clamp 10 is installed in the erosion reaction box 1 and located below the outlet of the water and sand transportation pipeline 7, and the angle of the test piece clamp 10 can be adjusted; in the embodiment, the number of the test piece clamp 10 is 4, which is uniformly distributed at the four corners of the erosion reaction box 1, and the angle of each test piece clamp 10 can be adjusted independently. The outlet of the water and sand transportation pipeline 7 adopts a multi-outlet design, and the number of outlets is 4, which is consistent with the number of test piece clamps 10, and the accelerated test under four groups of working conditions can be carried out at the same time.

[0055] The water flow power control system 6 is used to control the in-pump motor power and running time of the wear-resistant sand slurry pump 4 and the water and sand stirring pump 5.

[0056] In a specific implementation of the present application, the erosion reaction box 1, the box cover plate 2 and the box reinforcing steel belt 3 are welded by 315 stainless steel, the external dimensions of the reaction box are 2100 mm x 1400 mm x 2000 mm, and the internal wall dimensions are 2000 mm x 1400 mm x 2000 mm. Four test piece clamps are installed in the erosion reaction box 1, and the clamp size is 120 mm x 120 mm x 120 mm, the rotation angle of the test piece clamp can be flexibly adjusted through the clamp bolt, and the angle adjustment range is 0°-90°.

[0057] The working process of the above-mentioned device for carrying out the abrasion acceleration test is as follows:

[0058] (1) The concrete specimen with a size of 100mm*100mm*100mm is subjected to saturated encapsulation treatment, and in this embodiment, the specimen is subjected to saturated treatment by using a full-automatic vacuum saturated machine, and is taken out after 4 hours of dry pumping, 2 hours of wet pumping and 18 hours of static stopping. A side surface of the specimen during molding is selected as an abrasion surface, and the other five surfaces are encapsulated by using epoxy resin, and after 24 hours, it is ensured that the epoxy resin is completely cured to avoid the influence of the side surface of the concrete specimen on the chloride ion transmission during the scouring and abrasion process.

[0059] (2) The water on the surface of the concrete specimen is wiped off, and the initial saturated surface dry mass M0 of the concrete specimen is weighed, in units of g.

[0060] (3) The scouring speed condition of the sand-carrying water flow is set to 10m / s, the scouring time is 12d, the angle condition of the concrete specimen is adjusted to 15°, 30°, 45°, 60° and 90° by using a specimen clamp, and water and sand are added in the erosion reaction box to keep the sand content to 10kg / m 3 , the impeller of the water-sand stirring pump 5 is controlled to continuously stir at a speed of 2900r / min to ensure that the water and sand in the test box are uniformly mixed.

[0061] (4) The concrete specimen is taken out after the scouring and abrasion t time, the water on the surface of the concrete specimen is wiped off, and the saturated surface dry mass M t of the concrete specimen is weighed, and the mass loss rate w of the concrete under the scouring and abrasion is calculated:

[0062]

[0063] In the formula, A is the scouring area of the concrete specimen.

[0064] The accelerated test results of step (4) are as follows:

[0065]

[0066] (5) The cumulative sand mass M s in the accelerated test is the total amount of sand mass of the flow section during the scouring and abrasion process, that is, M s =vSQ s t, S is the flow section area, m 2 , Q s is the sand content of the water flow, kg / m 3 , and v is calculated by real-time monitoring of the sand-carrying water flow rate through the water-sand conveying pipeline by using a flowmeter, and the evaluation method is arranged as follows:

[0067]

[0068] (6) The entraining water flow scouring rate v, the scouring time t, the scouring angle a and the mass loss rate w under the scouring and abrasion effect obtained in step S5 in the scouring and abrasion test are substituted into the liquid-solid abrasion mass loss rate evaluation method of concrete to obtain n=1.6, m=0.6, v τ,lim =1.5 m / s, v n,lim =1.0 m / s, κ=333300 (kg·m 2 ) / (g·s 2 ), ε=96150 (kg·m 2 ) / (g·s 2 ), the relationship curve between the calculated value and the test value is shown in Figure 3 , and it can be seen from the curve in Figure 3 that the most unfavorable working condition of the scouring effect is at 68°.

[0069] (7) When the test needs to be stopped at any time, the motor in the pump is turned off through the power switch in the water flow power control system; if the water flow sediment concentration needs to be adjusted during the test, the motor in the pump is first turned off through the power switch in the water flow power control system, and then the required materials are added to the erosion reaction box after the box cover is opened.

[0070] After the test is completed, the water and sand in the erosion reaction box are discharged in time through the bottom drain hole 11, and the erosion reaction box 1, the water and sand conveying pipeline 7, the wear-resistant sand slurry pump 4 and the water and sand stirring pump 5 are cleaned by flushing with clean water to avoid the residue of sand particles.

[0071] Based on the above working process, the water and sand in the box are uniformly mixed through water and sand stirring, the abrasion effect is generated on the concrete surface by driving the entraining water flow to scour the concrete surface through the water flow power control system, and the motor power of the wear-resistant sand slurry pump is automatically adjusted to realize the dynamic control of the water flow scouring rate by collecting the flow data of the flow surface through the flow meter. Based on the above device, the scouring and abrasion mass loss rate of the concrete test piece is derived based on the measurable indexes such as the scouring rate, the scouring angle, the scouring time and the mass of the test piece, the undetermined coefficients v τ,lim , v n,lim , v τ , v n , κ and ε in the prediction method are fitted, so as to predict the actual scouring mass loss w of the actual component in the marine environment under any scouring rate, scouring angle and scouring time, and the anti-scouring and abrasion performance of the concrete is quantitatively evaluated according to the mass loss.

[0072] In one specific embodiment of the present application, the hydrological data of the north navigation hole, the middle approach bridge, the offshore platform and the Aindong beach of Hangzhou Bay Sea-Crossing Bridge are investigated, the average sediment concentration is 1.25 kg / m 3, the maximum vertical average flood flow velocity is 3.77 m / s, the flood flow duration is 5.5 h / d, and the calculated scouring erosion mass loss rate w2=1.88×10 -5 (g / s·m 2 )) at the position with a scouring angle of 60° under the flood working condition. According to the calculation result of step (4), the ratio of the scouring erosion mass loss rate of the accelerated test to that of the Hangzhou Bay working condition is 92, indicating that one day of the indoor accelerated test is equivalent to 92 days of the scouring erosion under the flood working condition of the Hangzhou Bay.

[0073] The above only describes the preferred embodiments of the present application, and it should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application.

Claims

1. A method for assessing the rate of loss of mass of concrete under liquid-solid abrasion, characterized in that, The method comprises the following steps: Step 1, defining the tangential cutting mass loss rate and the normal impact mass loss rate of concrete under liquid-solid erosion of different scouring rates, scouring angles, scouring times and sediment concentrations, and obtaining a concrete mass loss rate prediction model based on the sum of the two; ； wherein: represents the rate of concrete mass loss, represents the cumulative sand mass eroded by the water flow abrasion process, represents the energy required to cause unit mass loss by tangential cutting, represents the energy required to cause unit mass loss by normal impact, represents the area of the concrete subject to erosion, represents the time of the concrete subject to erosion, represents the tangential residual velocity after the sand-laden water flow has eroded the concrete surface, represents the normal residual velocity after the sand-laden water flow has eroded the concrete surface, represents the erosion velocity, represents the tangential critical velocity, represents the normal critical velocity, represents the water flow erosion angle, , are the tangential and normal coefficients of the water flow erosion angle; Step 2, obtaining the saturated surface dry mass loss of the concrete test piece before and after liquid-solid erosion of different scouring rates, scouring angles and sediment concentrations through an erosion acceleration test, and calculating the concrete mass loss rate; Step 3, the calculated value of the concrete mass loss rate is substituted into the concrete mass loss rate prediction model in step 1 to fit the to-be-solved parameters, including the tangential critical rate , the normal critical rate , the tangential coefficient of the water flow scouring angle , the normal coefficient of the water flow scouring angle , the energy required for unit mass loss caused by tangential cutting , the energy required for unit mass loss caused by normal impact ; Step 4, substituting the to-be-solved parameters fitted in step 3 into the concrete mass loss rate prediction model in step 1, and predicting the concrete mass loss rate under liquid-solid erosion of different scouring rates, scouring angles, scouring times and sediment concentrations by using the model in step 1.

2. The method of claim 1, wherein the method further comprises: In step 2, the calculation formula of the concrete mass loss rate is as follows: ； wherein, the time of flushing the saturated surface dry mass of the concrete specimen after the flushing, the initial saturated surface dry mass of the concrete specimen after the water-logged encapsulation treatment before the flushing.

3. The method of claim 2, wherein the method further comprises: The saturated water packaging treatment specifically comprises the following steps: a vacuum saturated water machine is used to saturate the concrete test piece, and a certain side surface of the saturated concrete test piece is used as the scouring surface, and the remaining surfaces are packaged with epoxy resin.

4. The method of claim 1, wherein the method further comprises: The calculation formula of the cumulative sand mass in the water flow scouring and erosion process is as follows: ； wherein, A denotes the cross-sectional area of the flow during the scouring process, C denotes the sediment concentration of the flow.

5. The method of claim 1, wherein the method further comprises: The water flow scouring angle ranges from 0° to 90°, and the scouring rate ranges from 0 m / s to 20 m / s.

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