CN116067822A - Method for measuring saturation and dry water absorption of concrete coarse aggregate - Google Patents
Method for measuring saturation and dry water absorption of concrete coarse aggregate Download PDFInfo
- Publication number
- CN116067822A CN116067822A CN202211620884.1A CN202211620884A CN116067822A CN 116067822 A CN116067822 A CN 116067822A CN 202211620884 A CN202211620884 A CN 202211620884A CN 116067822 A CN116067822 A CN 116067822A
- Authority
- CN
- China
- Prior art keywords
- sample
- engine oil
- beaker
- aggregate
- coarse aggregate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N5/00—Analysing materials by weighing, e.g. weighing small particles separated from a gas or liquid
- G01N5/02—Analysing materials by weighing, e.g. weighing small particles separated from a gas or liquid by absorbing or adsorbing components of a material and determining change of weight of the adsorbent, e.g. determining moisture content
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N5/00—Analysing materials by weighing, e.g. weighing small particles separated from a gas or liquid
- G01N5/02—Analysing materials by weighing, e.g. weighing small particles separated from a gas or liquid by absorbing or adsorbing components of a material and determining change of weight of the adsorbent, e.g. determining moisture content
- G01N5/025—Analysing materials by weighing, e.g. weighing small particles separated from a gas or liquid by absorbing or adsorbing components of a material and determining change of weight of the adsorbent, e.g. determining moisture content for determining moisture content
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
- Y02W30/91—Use of waste materials as fillers for mortars or concrete
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Or Analyzing Materials Using Thermal Means (AREA)
Abstract
The invention provides a method for measuring the saturated and dry water absorption of concrete coarse aggregate, which mainly utilizes tools such as an oven, a metal basket, a beaker, an electronic balance and the like to construct a quantitative relation model of relevant parameters according to the mass change condition of the coarse aggregate before and after being soaked in different liquids, so as to calculate the saturated and dry water absorption of the concrete coarse aggregate. The method for measuring the saturated and dry water absorption of the concrete coarse aggregate is designed based on the pore structure characteristics and capillary pore adsorption characteristics of the coarse aggregate, and by utilizing the difference of the coarse aggregate on different liquid absorption capacities and the difference of different liquid densities and viscosity coefficients, has the characteristics of simple steps, low cost, reliable test, stable data, easy popularization and the like, overcomes the defects of large human operation error, serious subjective experience influence and the like in the traditional method, can be used for the research and development of automatic equipment and the design of software algorithms, and has good popularization and application values.
Description
Technical Field
The invention belongs to the field of hydraulic engineering, and particularly relates to a method for measuring saturation and dry water absorption of concrete coarse aggregate.
Background
Coarse aggregate is also called coarse aggregate, and mainly refers to stones in concrete raw materials, including artificial broken stones and natural pebbles. According to the size of the particle size, the stones are further classified into small stones (5 mm-20 mm), medium stones (20 mm-40 mm), large stones (40 mm-80 mm) and extra large stones (80 mm-150mm or 120 mm). Saturation and dry water absorption are one of the main performance indexes of coarse aggregate, reflecting the maximum water amount that coarse aggregate can absorb when it can absorb water from a non-water absolute state to a saturated state. The saturated surface dry state is a state in which the coarse aggregate is saturated with water and the coarse aggregate is free of clear water, namely, the coarse aggregate is in a critical state in which water absorption and water release are balanced.
When the coarse aggregate is in a saturated surface dry state, the coarse aggregate can not absorb water from the surrounding environment and release water to the surrounding environment, so that the free water content of the concrete mixture is not affected. Therefore, the "design rule of hydraulic concrete mix ratio" (DL/T5330-2015) clearly requires that the "design and test of concrete mix ratio should be based on saturated surface dry state aggregate", and saturated surface dry water absorption is an important basis for adjusting water consumption and correcting the consumption of coarse aggregate in the actual mixing process, but when the concrete is mixed according to the recommended mix ratio in a few projects, problems such as unsatisfactory fluidity, large actual measurement strength fluctuation and the like still occur, and the reason is related to inaccurate measurement of saturated surface dry water absorption.
The traditional coarse aggregate saturation surface dry water absorption measuring method has the problems of more human factors, high subjective experience influence degree and the like. The stone saturation and dry water absorption rate measuring method provided by the hydraulic concrete test procedure (SL/T352-2020) is to use a enamel tray and a wet towel to measure, and the wet towel is used for sucking redundant water on the surface of a sample to a saturated surface dry state, but the technical experience of a tester in actual operation has great influence on the accuracy and stability of a data result, the difference of test results of different testers is obvious, and particularly, the influence on human subjective factors is obvious in the aspects of judging watermarks, marks and water stains. Therefore, there is a strong need for a more objective and reliable method for determining saturated and dry water absorption by a wide range of engineering and technological workers.
In order to search for a more accurate saturated surface dry water absorption measuring method, researchers develop a great deal of exploration in aspects of aggregate water absorption law, saturated water particle stacking property and the like. Kong Xiangzhi and the like, the saturation and the dry water absorption of the fine aggregate are indirectly calculated through finely recording the change characteristic of the water evaporation rate in the drying process after the fine aggregate fully absorbs water. Sun Renjuan and the like propose a quantitative measurement method of the saturated surface dry state of the fine aggregate based on the repose angle according to the change condition of the natural repose angle of the particles in the water loss drying process of the fine aggregate. However, these methods are effective only for fine aggregates having a smaller particle size, but for coarse aggregates having a larger particle size, there is still a lack of a more effective saturation and dry water absorption test method.
Disclosure of Invention
The method for measuring the saturated and dry water absorption of the concrete coarse aggregate can remarkably improve the reliability and objectivity of a test result, eliminate the influence of human factors and subjective experience, meanwhile, does not need to increase new test equipment or test cost, is convenient for engineering site use, and provides a new approach for representing the water absorption performance of the concrete coarse aggregate.
In order to achieve the technical aim, the invention provides a method for measuring the saturation and dry water absorption of concrete coarse aggregate, which comprises the following steps:
(1) Taking mg of coarse aggregate in a natural state, drying, controlling the drying temperature to be 105-110 ℃, weighing the mass of the sample for a plurality of times during the drying, calculating the water content of the sample until the difference between the water content of the sample and the water content of the sample is not more than 0.2%, stopping drying, and storing the coarse aggregate in a dampproof mode after natural cooling, wherein the calculation formula of the water content of the sample and the water content difference is as follows:
Δq＝q j -q j-1 (j＝2·N) ②
wherein: m is m 0 G, the mass of the coarse aggregate in a natural state before drying;
m i weighing the mass of the sample for the ith time in the drying process, and g;
q i 、q j 、q j-1 the water content calculated in the ith, jth and jth-1 th times respectively,%;
Δq is the difference between the water content of the front and the rear times,%;
n is the total times of sample mass weighing in the drying process;
i is the weighing times of the aggregate sample mass;
j is the number of times of calculation of the water content of the aggregate sample;
(2) Uniformly dividing the dried aggregate sample into 2 parts, respectively numbering the parts as A and B, and weighing the mass of the sample A as m by using an electronic balance A Sample B has a mass of m B The method comprises the steps of carrying out a first treatment on the surface of the For standby application;
(3) Taking 2 beakers and 2 metal basket, wherein the number of the beakers is 1# and 2# respectively, the number of the metal basket is 3# and 4# respectively, pouring distilled water into the 1# beakers, and weighing the total mass m of the beakers and the distilled water 10 The method comprises the steps of carrying out a first treatment on the surface of the Pouring engine oil into a No. 2 beaker, and weighing the total mass m of the beaker and the engine oil 20 ；
(4) Immersing a 3# metal basket in a 1# beaker, keeping the basket lifted and immersed below the liquid level, and weighing the total mass m of the beaker and distilled water 11 The method comprises the steps of carrying out a first treatment on the surface of the Then the metal basket is lifted up and removed completely, and the total mass m of the No. 1 beaker and distilled water is weighed again 12 ；
(5) Immersing a No. 4 metal basket in a No. 2 beaker, keeping the basket lifted and immersed below the liquid level, and weighing the total mass m of the beaker and the engine oil 21 The method comprises the steps of carrying out a first treatment on the surface of the Then the metal basket is completely lifted and removed, and the total mass m of the No. 2 beaker and the engine oil is weighed again 22 ；
(6) Loading a sample A into a 3# metal basket, loading a sample B into a 4# metal basket, and then soaking the 3# metal basket loaded with the sample A in a 1# beaker, and fully soaking; immersing a No. 4 metal basket filled with a sample B in a No. 2 beaker;
(7) The metal basket was lifted up but kept submerged in distilled water and motor oil, and the total mass m of the 1# beaker and distilled water was again weighed 13 Weigh the total mass m of the 2# beaker and the engine oil 23 And calculating the saturation and dry water absorption P of the coarse aggregate according to the following formula:
Δm 1 ＝m 13 -m 12 -m 11 +m 10 ③
Δm 2 ＝m 23 -m 22 -m 21 +m 20 ④
wherein: p is the saturation and dry water absorption of coarse aggregate,%;
ρ c the density of the engine oil is g/cm 3 ；
Δm 1 G, stress of the aggregate sample in distilled water;
Δm 2 g, stress of the aggregate sample in engine oil;
k is the mass ratio of the dried aggregate sample A to the dried aggregate sample B.
The invention has the preferable technical scheme that: the water content difference deltaq in the step (1) refers to the difference between two adjacent water contents, and the time interval between the two times of sample weighing is 1.5-2.0 h.
The invention has the preferable technical scheme that: the viscosity index of the engine oil in the step (3) is 30-50, and the engine oils with different indexes can be mixed and blended, and the density rho of the mixed engine oil is calculated when the engine oil is used c The engine oil can be reused after being filtered, and the density ρ of the mixed engine oil is higher c The calculation method of (1) is as follows:
wherein: m is M i The mass ratio of the ith engine oil in the mixed engine oil is percent;
ρ i and ρ j To mix the density of the ith and j kinds of engine oils in the engine oil, g/cm 3 ；
n is the total number of different engine oil types.
The invention has the preferable technical scheme that: the adequate soaking in the step (6) means that the soaking time is 24-30 hours, and the sample B does not need to be adequately soaked.
The invention has the preferable technical scheme that: the operation steps are all carried out in an environment with the temperature of 20-22 ℃ and the humidity of 80% -85%.
Because the surface of the concrete aggregate is provided with micro cracks and air holes, channels for external liquid to permeate can be formed, but the liquid permeation quantity and the permeation rate are related to factors such as the structural characteristics of the aggregate hole, the width of the crack, the ambient temperature, the viscosity coefficient and the like. According to the similar compatibility principle, the aggregate and the water are both inorganic materials, the aggregate has good water absorption performance, but the aggregate has poor organic solvent absorption performance, and the saturated water absorption rate of the aggregate can be calculated by utilizing the difference of the absorption characteristics of the aggregate to different liquids.
The inventors of the present application found through studies that the absorption characteristics of the aggregate to the organic solvent are related to the viscosity coefficient of the organic solvent. Organic solvents with lower viscosity coefficients are easier to invade into pores and microcracks of the aggregate, while organic solvents with higher viscosity coefficients have extremely limited infiltration amount and infiltration rate due to strong adhesion between the surface of the aggregate and the solvent. Therefore, the present application contemplates the use of an organic solvent having certain viscosity coefficient requirements as a control. The organic solvent should be selected in consideration of convenience of purchase, safety of use, environmental protection after use, etc. Although the chemical solvent has high purity and good effect, the engineering site purchase difficulty is high, a certain health risk exists in the operation of a tester, and the material treatment after the completion of the operation also faces the pollution problem. Therefore, the engine oil is finally selected as a comparison sample by taking the common materials such as engine oil, hydraulic oil, cooling oil, heavy oil and the like into consideration factors such as the absorption characteristics, test errors, influence degrees and the like of common aggregates. The viscosity index of the engine oil reflects the viscosity characteristics of the engine oil, which in turn are directly related to the permeation quantity and permeation rate. In the early test process, the application finds that the use of the engine oil with smaller viscosity index can lead to large permeation quantity and cause higher result error; the engine oil with larger viscosity index can cause larger adhesion between the metal basket and the surface of the aggregate, increase the material loss and reduce the economy of the method. Therefore, the method combines the aggregate characteristics of basalt, granite, sandstone, gneiss and the like which are common in engineering and the production characteristics of a sandstone processing system, and only selects engine oil with specific viscosity marks for testing in consideration of the result deviation and the data stability requirements.
Since the viscosity of the liquid is related to the ambient temperature. Typically, an increase in ambient temperature will result in a decrease in the viscosity coefficient, which will result in an increase in the aggregate penetration and an increase in the penetration rate. The environmental temperature is set to be 20-22 ℃ by considering the characteristic of the change of the engine oil viscosity along with the environmental temperature and the influence degree of the engine oil viscosity change on the test result. The moisture absorption phenomenon exists in the aggregate storage process, the greater the ambient humidity is, the more obvious the moisture absorption phenomenon of the aggregate is, and the lower the ambient humidity is, the strict requirement is also put on the test condition. Meanwhile, in the aggregate soaking process, the beaker moisture also has an evaporation phenomenon, and the test result is lower due to the loss of the moisture. In practice, the rate of moisture evaporation is related to the ambient humidity. The lower the ambient humidity, the faster the moisture evaporation rate; while the higher the ambient humidity, the lower the rate of moisture evaporation. The environmental humidity is limited to 80% -85% by considering the influences of site environmental conditions, humidity ranges of a conventional laboratory, moisture evaporation rates under different humidities, aggregate hygroscopic characteristics and the like.
According to the water absorption dynamic characteristics of the material, the water absorption rate of the aggregate in the initial stage of soaking is high, but the water absorption rate of the aggregate is continuously reduced along with the extension of the soaking time. The full soaking is to ensure that the water absorption of the aggregate is stable, improve the accuracy and the reliability of test results, and the previous test of the applicant shows that the water absorption rate of the aggregate is greatly changed within 1h from the beginning of soaking, and is basically stable after 24 h. Therefore, the water absorption time of the aggregate is set to be 24-30h. Sample B did not require adequate soaking because of the limited absorption capacity of the aggregate for the oil and in order to reduce the impact of the soak time in the oil on the results. The dehydration and drying of the aggregate are slow processes, the dehydration rate of the aggregate at the initial stage of drying is high, and the change of the water content is high; the water loss rate of the aggregate in the later drying stage is smaller, the change of the water content is slower, the weighing time of the sample mass of the front and the back times is limited, and the time interval of the front and the back times of weighing is required to be set mainly for avoiding the false image that the water content meets the requirement due to the shorter interval.
The invention aims to ensure the stability of test results and avoid errors caused by human factors by keeping the metal net lifted but still immersed below the liquid level. The stress of the metal basket in the liquid mainly comprises lifting force, buoyancy and gravity. Under the condition of complete immersion, the buoyancy of the metal basket is irrelevant to the relative position, the immersion depth and other factors, so that the overall quality is stable, and errors caused by human factors are avoided
Saturation dry water absorption is one of main technical indexes of coarse aggregate, and is also an important parameter for determining the actual water consumption of concrete and the consumption of coarse aggregate before mixing. The invention provides a method for measuring the saturation and dry water absorption rate of concrete coarse aggregate by comparing the quality change condition of the coarse aggregate in different media by utilizing the difference of the absorption capacity of the coarse aggregate to different liquids and the difference of viscosity coefficients of different liquids based on the pore structure characteristics of the coarse aggregate and capillary adsorption principle and combining the viscosity characteristics of the liquids at different temperatures. Compared with the prior art, the method has the following advantages:
(1) The method has more objective test results, reduces the influence of human factors, and solves the problems of strong subjectivity, serious operation experience dependence and the like in the traditional means.
(2) The method can be developed by means of the existing equipment and devices, does not need to purchase or add new test instruments, is low in economic investment, has low technical requirements for personnel, and is convenient for popularization and application of the method.
(3) The test result of the method has good stability and replay, the difference between test results of different batches is small, the discrete degree of data is reduced, the fluctuation range of the data is improved, and the method can be used for the research and development of automatic equipment and the design of software algorithms.
The invention has the characteristics of simple steps, low cost, high test reliability, good data stability, easy popularization and the like, remarkably improves the reliability and objectivity of the test result, eliminates the influence of artificial factors and subjective experience, does not need to increase new test equipment or test cost, has better popularization and application value, and is convenient for engineering field use.
Drawings
FIG. 1 is a graph of the variation of oil viscosity coefficient at different ambient temperatures;
FIG. 2 is a graph showing the absorption of kerosene and motor oil by aggregates with different viscosity coefficients;
FIG. 3 is a view of a sample of water electrician Cheng Luandan from example 1;
FIG. 4 is a view of the artificial rubble of the hydro-electric engineering of example 2;
FIG. 5 is a view of the artificial macadam of the hydro-electric engineering in example 3.
Detailed Description
The invention is further described below with reference to the drawings and examples. Fig. 1 to 5 are drawings of embodiments, which are drawn in a simplified manner, for the purpose of clearly and concisely illustrating embodiments of the present invention. The following technical solutions presented in the drawings are specific to embodiments of the present invention and are not intended to limit the scope of the claimed invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
The invention provides a method for measuring the saturation and dry water absorption of concrete coarse aggregate, which specifically comprises the following steps of:
(1) Drying mg of coarse aggregate in a natural state, controlling the drying temperature to be 105-110 ℃, weighing the mass of the sample for a plurality of times during the drying, calculating the water content of the sample until the difference between the water content of the sample and the water content of the sample is not more than 0.2%, stopping drying, and storing the coarse aggregate in a dampproof mode after natural cooling, wherein the calculation formula of the water content of the sample and the water content difference is as follows:
Δq＝q j -q j-1 (j＝2·N) ②
wherein: m is m 0 G, the mass of the coarse aggregate in a natural state before drying;
m i weighing the mass of the sample for the ith time in the drying process, and g;
q i 、q j 、q j-1 the water content calculated in the ith, jth and jth-1 th times respectively,%;
Δq is the difference between the water content of the front and the rear times,%;
n is the total times of sample mass weighing in the drying process;
i is the weighing times of the aggregate sample mass;
j is the number of times of calculation of the water content of the aggregate sample;
the aggregate drying process is necessary, and the sufficiently dried aggregate can be further subjected to a subsequent water absorption test. The water content is a parameter for representing the drying condition of the aggregate, and is the percentage of the water content of the aggregate in the total mass in a natural state, wherein the water content is 0, which indicates that the aggregate is in a fully dried state; the water content is stable, which indicates that the water content in the aggregate is basically unchanged. Formulas (1) and (2) are mathematical formulas constructed according to the physical meaning of the water content; the determination of the water content limit value is determined by considering the influences of the water loss characteristic, the drying efficiency, the test period, the result precision and the like of common aggregates, and under the condition that the water loss characteristic, the drying efficiency, the test period, the result precision and the like of the aggregate sample are not more than 0.2%, the error fluctuation of the saturated surface dry water absorption of the aggregate sample meets the precision requirement.
(2) The dried coarse aggregate sample is evenly divided into 2 parts for test, the serial numbers are A and B respectively, and the mass of the sample A is m by using an electronic balance A Sample B has a mass of m B The method comprises the steps of carrying out a first treatment on the surface of the For standby application;
(3) Taking 2 beakers and 2 metal basket, wherein the number of the beakers is 1# and 2# respectively, the number of the metal basket is 3# and 4# respectively, pouring a proper amount of distilled water into the 1# beakers, and weighing the total mass m of the beakers and the distilled water 10 The method comprises the steps of carrying out a first treatment on the surface of the Pouring a proper amount of engine oil into a No. 2 beaker, and weighing the total mass m of the beaker and the engine oil 20 The method comprises the steps of carrying out a first treatment on the surface of the The viscosity index of the engine oil is 30-50, and the engine oil with different indexes can be mixed, and the density rho of the mixed engine oil is calculated when the engine oil is used c The engine oil can be reused after being filtered, and the density ρ of the mixed engine oil is higher c The calculation method of (1) is as follows:
wherein: m is M i The mass ratio of the ith engine oil in the mixed engine oil is percent;
ρ i and ρ j The density of the ith engine oil and the j engine oils in the mixed engine oil;
n is the total number of different engine oil types.
The formula (7) is a mathematical formula constructed by considering the mass proportion of the engine oils with different labels and combining the densities of the engine oils with different labels, and is used for calculating the density of the mixed engine oil. In the calculation, the phenomenon that the components of the engine oil are mutually dissolved is assumed, namely the integral volume composite superposition principle, and the density of the mixed engine oil is as follows:
the finishing deformation is as follows:
the further finishing deformation is as follows:
thus, the density of the mixed oil is:
the mixed engine oil can improve the utilization rate of materials, solve the problem of insufficient oil reserves of specific viscosity mark marks of engineering sites, and improve the economy of the method.
(4) Immersing a 3# metal basket in a 1# beaker, keeping the basket lifted and immersed below the liquid level, and weighing the total mass m of the beaker and distilled water 11 The method comprises the steps of carrying out a first treatment on the surface of the Then the metal basket is lifted up and removed completely, and the total mass m of the No. 1 beaker and distilled water is weighed again 12 ；
(5) Immersing a No. 4 metal basket in a No. 2 beaker, keeping the basket lifted and immersed below the liquid level, and weighing the total mass m of the beaker and the engine oil 21 The method comprises the steps of carrying out a first treatment on the surface of the Then the metal basket is completely lifted and removed, and the total mass m of the No. 2 beaker and the engine oil is weighed again 22 ；
(6) Loading a sample A into a 3# metal basket, loading a sample B into a 4# metal basket, and then soaking the 3# metal basket loaded with the sample A in a 1# beaker, and fully soaking; immersing a No. 4 metal basket filled with a sample B in a No. 2 beaker; the adequate soaking means that the soaking time is 24-30 hours, and the sample B does not need to be adequately soaked;
(7) The metal basket was lifted up but kept submerged in distilled water and motor oil, and the total mass m of the 1# beaker and distilled water was again weighed 13 Weigh the total mass m of the 2# beaker and the engine oil 23 And calculating the saturation and dry water absorption P of the coarse aggregate according to the following formula:
Δm 1 ＝m 13 -m 12 -m 11 +m 10 ③
Δm 2 ＝m 23 -m 22 -m 21 +m 20 ④
wherein: p is the saturation and dry water absorption of coarse aggregate,%;
ρ c the density of the engine oil is g/cm 3 ；
Δm 1 G, stress of the aggregate sample in distilled water;
Δm 2 g, stress of the aggregate sample in engine oil;
k is the mass ratio of the dried aggregate sample A to the dried aggregate sample B.
The immersion of the aggregate sample and the metal basket in the liquid will result in a change in the overall stress state, which is related to the density of the liquid on the one hand and the volume of the aggregate sample on the other hand. The change is shown in the macroscopic sense as fluctuation of the total mass of the beaker and the liquid, and the saturation and dry water absorption rate of the aggregate sample is calculated by accurately measuring the fluctuation of the total mass and combining the absorption characteristics of the aggregate sample to different liquids. Equations (3), (4) and (5) are the case of calculating the change in the overall mass. The formula (6) is a model formula which is proposed by physical modeling and mathematical deduction by utilizing the difference of the adsorption characteristics of aggregate to different liquids at room temperature according to the mass change condition of the different liquids, and the calculation process of the formula (6) is as follows:
according to the water absorption condition and stress of the aggregate sample in water, the mass changes of the beaker and distilled water are as follows:
according to the stress condition of the aggregate sample in the engine oil, the mass changes of the beaker and the engine oil are as follows:
after finishing and bringing the publication (9) into the publication (8), the following formula (6) is obtained:
the organic solvent is selected through extensive experiments, so that the absorption characteristics of stones on different liquids are mastered, and the liquid type is preferably selected by taking the absorption characteristics of stock materials and aggregates of a concrete laboratory on different solvents, the safety, volatility, performance stability and other factors of the different solvents into consideration. For its selection process, the inventors of the present application conducted the following experiments, in which solvents, which are routinely used in concrete laboratories, were selected as shown in table 1. Among them, absolute ethanol, acetone, engine oil and kerosene are common, but acetone is toxic and volatilized at a high rate, so that it is generally rarely used.
Table 1 stock solvents for concrete laboratories
The inventor selects absolute ethyl alcohol, engine oil and kerosene as comparison to test, and analyzes the absorption condition of the dry aggregate to the solvents, and the viscosity coefficient and evaporation rate of each solvent at different temperatures, and the test results are shown in tables 2 to 4; wherein the absorptivity of the aggregate in different solvents is shown in table 2:
TABLE 2 absorption of aggregates in different solvents
The absorption rate of the aggregate in different solvents in table 2 shows that the characteristics of absorbing water and absolute ethyl alcohol are relatively close, which is also in accordance with the characteristic that alcohol and ethanol can be mutually dissolved, the absolute ethyl alcohol can be removed through the absorption rate in table 2, and the applicant further screens in engine oil and kerosene.
Table 3 shows the evaporation characteristics of different solvents, and the flash point in Table 3 can represent the volatile condition of the reagent and the ignition temperature can represent the safety of the reagent in combination with the screening result of the early absolute ethyl alcohol. In combination, the stability and safety of the used engine oil are higher than those of kerosene, but reagent screening also requires further comparison and analysis, in particular the absorption of the engine oil and kerosene by the aggregate sample.
TABLE 3 physical Property parameters of different solvents
As can be seen from a comparison of the absorption characteristics of the aggregate samples in Table 2 for engine oil and kerosene, the absorption capacity of the aggregate for both kerosene and engine oil is significantly weaker than that of water and absolute ethyl alcohol, and differs by about 100 times. Meanwhile, the absorption capacity of the aggregate to the engine oil is slightly smaller than that of kerosene, and the absorption capacity of the aggregate to the engine oil is 0.01% lower than that of the kerosene under the condition of soaking for 30 hours. The error analysis is used to determine that:
wherein delta is the absorptivity of the aggregate sample to engine oil or kerosene;
the total error of the test results is:
due to the density of kerosene and engine oil of 0.85-0.98g/cm 3 Range. The application finds that the absorptivity of the aggregate sample to kerosene is 0.02% -0.04%, and the saturation and dry water absorption error caused by the absorption of kerosene by the aggregate is 0.02% -0.05%. Meanwhile, the application finds that the absorption rate of the aggregate sample to engine oil is 0.01% -0.03%, and the saturation and dry water absorption error caused by the absorption of the aggregate to engine oil is 0.01% -0.03%. This indicates that the results of the oil test have higher accuracy.
TABLE 4 viscosity coefficients (mPa.S) of the solvents at different temperatures
The stability of motor oil and kerosene at different temperatures is also an important factor for application considerations. The reason why the ambient temperature causes the change in the absorption rate of the aggregate to the engine oil and the kerosene is mainly related to the fluctuation of the viscosity coefficient of the reagent, and the viscosity coefficients of the respective solvents at different temperatures are shown in table 4. Fig. 1 shows the change of the viscosity coefficient of engine oil at different ambient temperatures, and fig. 2 shows the absorption of kerosene and engine oil by aggregates at different viscosity coefficients. Overall, the thermal stability of engine oil is much higher than that of kerosene. The application of the engine oil is good in effect from the change of viscosity coefficient and absorptivity.
When the environmental temperature is set to 20-25 ℃ for test by using an error analysis method, the variation range of the viscosity coefficient of engine oil is 0.05 mPa.S, the variation range of the absorption rate is 0.01%, and the corresponding error range is 0.02%. Meanwhile, the application limits the ambient temperature to 20-22 ℃ by further considering the measurement precision of the thermometer. In practice, the error analysis should also take into account the effects of weighing errors, as well as the amplification effects of error accumulation, which are all taken into account comprehensively in the design of the method.
As can be seen from the test data in the above part, the absorption capacity of the aggregate to water and alcohol is far higher than that of engine oil and kerosene, and the fluctuation range of the viscosity of the engine oil under the temperature change is smaller than that of the kerosene. Meanwhile, the flash point of engine oil is far higher than that of kerosene and absolute ethyl alcohol, which shows that the volatility is far lower than that of kerosene. Therefore, the engine oil is selected as a comparison solvent, and further researches are conducted on the temperature characteristics of engine oils with different labels, so that a proper range is preferable.
Besides the test, the method also analyzes the influence of the ambient temperature and the humidity on the test result, and evaluates the fluctuation range of the test result so as to limit the test conditions. According to the method, the relation between the saturated and dry water absorption of the coarse aggregate and the relevant quality parameters is constructed by utilizing tools such as an oven, a metal basket, a beaker and an electronic balance according to the mass change condition of the coarse aggregate before and after being soaked in different liquids and combining with an Archimedes buoyancy principle, so that the saturated and dry water absorption of the coarse aggregate of the concrete is calculated, and the accurate measurement of the saturated and dry water absorption of the stone is realized.
The invention will be further illustrated with reference to specific examples.
Example 1 the saturation and dry water absorption measurements of a sample of a certain hydropower engineered pebble from Jilin, jilin City, example 1 was carried out at a test temperature of 20℃and a humidity of 80% as shown in FIG. 3.
Weighing 10314.6g of sample in natural state, drying at 105deg.C for 10 hr, weighing 10263.4g of sample 1 st time, and controlling water content q 1 The mass of the sample is 10254.7g after weighing 0.50 percent and the 2 nd time, and the corresponding water content q 2 0.58%, the time interval between two times of weighing is 1.5h, and the water content difference delta q is 2-1 0.08%, meeting deltaq is less than or equal to 0.2 percent, and can be used for further experiments.
Uniformly dividing the dried coarse aggregate into 4 parts, optionally performing test on 2 parts, respectively numbering A and B, and weighing the sample mass m of the number A A 2467.5g, sample mass m B 2531.2g, k 0.975; then two beakers with a volume of 5000mL were taken, numbered 1# and 2# respectively. Into a # 1 beaker was poured 2467.5g of distilled water, into a # 2 beaker was poured 2531.2g of engine oil, the viscosity index of the engine oil was 30, and the density was 0.946g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the Then the total mass m of the No. 1 beaker and distilled water is weighed 10 2812.9g, total mass m of 2# beaker and engine oil 20 2873.8g.
2 metal basket are taken, and the numbers are 3# and 4# respectively; immersing a 3# metal basket in distilled water of a 1# beaker, immersing a 4# metal basket in engine oil of a 2# beaker, keeping the metal basket lifted and the top end below the liquid level, and weighing the total mass m of the 1# beaker and the distilled water 11 2818.1g, total mass m of 2# beaker and engine oil 21 2878.1g; then the metal basket is taken out from the distilled water and the engine oil, and the total mass m of the No. 1 beaker and the distilled water is weighed again 12 2807.5g, total mass m of 2# beaker and engine oil 22 2869.9g;
after the metal basket is wiped clean, a sample A is placed in a 3# metal basket, a sample B is placed in a 4# metal basket, then the 3# metal basket is soaked in a 1# beaker, and after 24 hours of soaking, the metal basket is lifted and kept below the liquid level; the No. 4 metal basket is soaked in the No. 2 beaker, and the metal basket is lifted and kept below the liquid level; the mass of the # 1 beaker and distilled water 3682.7g, and the mass of the # 2 beaker and engine oil 3747.0g are weighed.
According to the quality parameters in the test process, the saturation and dry water absorption P of the sample can be calculated to be 1.19%. The results obtained by repeating the test several times are shown in Table 5, and the average value of the results is 1.19%, the standard deviation is 0.02%, and the coefficient of variation is 0.01. The saturation and dry water absorption of the samples, determined manually using conventional methods, are shown in table 6, with an average of 1.26%, a standard deviation of 0.07% and a coefficient of variation of 0.06.
TABLE 5 test results of saturation and Dry Water absorption of aggregate for certain Power station engineering in Jilin City of Jilin province
| Number of |
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| Test results | 1.19 | 1.16 | 1.16 | 1.18 | 1.21 | 1.20 | 1.19 | 1.18 | 1.19 | 1.20 |
TABLE 6 test results of engineering of certain power stations in Jilin City, jilin, using conventional methods
| Number of |
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| Test results | 1.12 | 1.26 | 1.34 | 1.28 | 1.18 | 1.29 | 1.19 | 1.27 | 1.3 | 1.32 |
As can be seen from the comparison of the tables, the method has the advantages that the result is smaller than that of the traditional method, the fluctuation amplitude of the data is smaller than that of the traditional method, and the stability of the result in the application is higher and the discrete degree is smaller.
Example 2 saturation and dry water absorption measurements of a sample of a hydroelectric engineering artificial stone in the city of underway in Hebei province the sample is shown in figure 4. The test temperature was 21℃and the humidity was 83%.
Weighing 12460.3g of sample in natural state, drying at 110deg.C for 12 hr, weighing 12320.6g of sample 1 st time, and controlling water content q 1 The mass of the sample is 12281.8g after weighing 1.12 percent and the 2 nd time, and the corresponding water content q 2 1.43%, the time interval between two times of weighing is 1.7h, and the water content difference delta q is 2-1 0.31 percent, the requirement that deltaq is less than or equal to 0.2 percent is not met, the sample is continuously dried for 2 hours, the mass of the sample is 12276.2g when the sample is weighed for the third time, and the corresponding water content q is obtained 3 1.48% of the water content delta q 3-2 0.05 percent, meets the requirement that deltaq is less than or equal to 0.2 percent, and can be used for further experiments.
Uniformly dividing the dried coarse aggregate into 4 parts, optionally performing test on 2 parts, respectively numbering A and B, and weighing the sample mass m of the number A A 2983.7g, sample mass m B 3011.6g and k of 0.991; then two metal barrels with the capacity of 5000mL are taken, and the numbers are 1# and 2# respectively. Into a # 1 beaker was poured 2088.6g of distilled water, into a # 2 beaker was poured 2108.1g of engine oil, the viscosity index of the engine oil was 40, and the density was 0.966g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the Then the total mass m of the No. 1 beaker and distilled water is weighed 10 2434.0g of total mass m of 2# beaker and oil 20 2450.7g.
2 metal baskets are taken, and the numbers are 3# and 4# respectively. Metal 3#The basket is immersed in distilled water of the No. 1 beaker, the No. 4 metal basket is immersed in engine oil of the No. 2 beaker, and the metal basket is kept lifted and the top end of the metal basket is below the liquid level; the total mass m of the 1# beaker and distilled water at this time was weighed 11 2439.2g, total mass m of 2# beaker and oil 21 2455.0g; then the metal basket is taken out from the distilled water and the engine oil, and the total mass m of the No. 1 beaker and the distilled water is weighed again 12 2428.6g, total mass m of 2# beaker and oil 22 2446.8g;
after the metal basket is wiped clean, a sample A is placed in a 3# metal basket, a sample B is placed in a 4# metal basket, then the 3# metal basket is soaked in a 1# beaker, and after 26 hours of soaking, the metal basket is lifted and kept below the liquid level; the No. 4 metal basket is soaked in the No. 2 beaker, and the metal basket is lifted and kept below the liquid level; the mass of the 1# beaker and distilled water 3469.9g, and the mass of the 2# beaker and engine oil 3512.5g were weighed.
According to the quality parameters in the test process, the saturation and dry water absorption P of the sample can be calculated to be 1.76%. The results obtained by repeating the test several times are shown in Table 7, and the average value of the results is 1.78%, the standard deviation is 0.03%, and the coefficient of variation is 0.01. The saturation and dry water absorption of the samples, determined manually using conventional methods, are shown in Table 8, with an average of 1.84%, a standard deviation of 0.26% and a coefficient of variation of 0.14.
TABLE 7 test results of saturation and Dry Water absorption of certain hydropower engineering aggregates in the Maillard City of Hebei province
| Number of |
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| Test results | 1.81 | 1.79 | 1.76 | 1.75 | 1.79 | 1.74 | 1.76 | 1.79 | 1.8 | 1.75 |
TABLE 8 test results of a hydropower project in the Maillard City of Hebei province measured using the conventional method
| Number of |
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| Test results | 1.53 | 2.11 | 1.97 | 2.26 | 1.67 | 1.53 | 1.61 | 1.94 | 2.06 | 1.69 |
As can be seen from the comparison of the tables, the method has the advantages that the result is smaller than that of the traditional method, the fluctuation amplitude of the data is smaller than that of the traditional method, and the stability of the result in the application is higher and the discrete degree is smaller.
Example 3 saturation and dry water absorption measurements of a hydroelectric engineering artificial lithotripte sample in Fukang, xinjiang, the sample is shown in FIG. 5. The test temperature was 22℃and the humidity was 85%.
Weighing 15527.4g of sample in natural state, drying at 108 deg.C for 9 hr, weighing 15477.2g of sample 1 st time, and controlling water content q 1 The mass of the sample is 15469.3g after weighing 0.32 percent and the 2 nd time, and the corresponding water content q 2 0.37%, the time interval between two times of weighing is 2h, and the water content difference delta q is 2-1 0.05 percent, meets the requirement that deltaq is less than or equal to 0.2 percent, and can be used for further experiments.
Uniformly dividing the dried coarse aggregate into 4 parts, optionally performing test on 2 parts, respectively numbering A and B, and weighing the sample mass m of the number A A 3288.6g, sample mass m B 3197.1g and a k value of 1.029; then two plastic deep concave basins are taken, and the numbers are 1# and 2# respectively. Adding 4932.9g of distilled water into a No. 1 beaker, adding 4795.7g of engine oil into a No. 2 beaker, wherein the engine oil is formed by mixing two engine oils with viscosity numbers of 30 and 50, and the mass ratio of the engine oil is m 30 :m 50 =40%: 60%, 30 engine oil density of 0.946g/cm 3 The density of the engine oil with the reference number of 50 is 0.987g/cm 3 The density of the mixed engine oil is 0.970g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the Then the total mass m of the No. 1 beaker and distilled water is weighed 10 5278.3g, total mass m of 2# beaker and oil 20 5138.3g.
2 metal baskets are taken, and the numbers are 3# and 4# respectively. Immersing a 3# metal basket in distilled water of a 1# beaker, immersing a 4# metal basket in engine oil of a 2# beaker, keeping the metal basket lifted and the top end below the liquid level, and weighing the total mass m of the 1# beaker and the distilled water at the moment 11 5283.5g, total mass m of 2# beaker and oil 21 5142.6g; then the metal basket is taken out from the distilled water and the engine oil, and the total mass m of the No. 1 beaker and the distilled water is weighed again 12 Is 5292.9 g, total mass m of 2# beaker and engine oil 22 5134.4g;
after the metal basket is wiped clean, a sample A is placed in a 3# metal basket, a sample B is placed in a 4# metal basket, then the 3# metal basket is soaked in a 1# beaker, and after soaking for 30 hours, the metal basket is lifted and kept below the liquid level; the No. 4 metal basket is soaked in the No. 2 beaker, and the metal basket is lifted and kept below the liquid level; the mass of the 1# beaker and distilled water 6432.1g, the mass of the 2# beaker and the mass of the engine oil 6270.5g were weighed.
According to the quality parameters in the test process, the saturation and dry water absorption P of the sample can be calculated to be 1.40%. The results obtained by repeating the test several times are shown in Table 9, and the average value of the results is 1.43%, the standard deviation is 0.07%, and the coefficient of variation is 0.05. The saturation and dry water absorption of the samples, determined manually using conventional methods, are shown in table 10, with an average of 1.56%, a standard deviation of 0.15% and a coefficient of variation of 0.09.
Table 9 test results of saturation and Dry Water absorption of certain hydropower engineering aggregates in Fukang City of Xinjiang
| Number of |
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| Test results | 1.46 | 1.28 | 1.37 | 1.43 | 1.48 | 1.51 | 1.42 | 1.43 | 1.44 | 1.48 |
TABLE 10 test results of a hydropower project in Fukang, xinjiang, using conventional methods
| Number of |
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| Test results | 1.53 | 1.59 | 1.61 | 1.67 | 1.22 | 1.67 | 1.53 | 1.72 | 1.42 | 1.59 |
As can be seen from the comparison of the tables, the method has the advantages that the result is smaller than that of the traditional method, the fluctuation amplitude of the data is smaller than that of the traditional method, and the stability of the result in the application is higher and the discrete degree is smaller.
Claims (5)
1. A method for determining saturation and dry water absorption of concrete coarse aggregate, characterized in that the method comprises the following steps:
(1) Taking mg of coarse aggregate in a natural state, drying, controlling the drying temperature to be 105-110 ℃, weighing the mass of the sample for a plurality of times during the drying, calculating the water content of the sample until the difference between the water content of the sample and the water content of the sample is not more than 0.2%, stopping drying, and storing the coarse aggregate in a dampproof mode after natural cooling, wherein the calculation formula of the water content of the sample and the water content difference is as follows:
Δq＝q j -q j-1 (j＝2·N)②
wherein: m is m 0 For the quality of the coarse aggregate in a natural state before drying,g；
m i weighing the mass of the sample for the ith time in the drying process, and g;
q i 、q j 、q j-1 the water content calculated in the ith, jth and jth-1 th times respectively,%;
Δq is the difference between the water content of the front and the rear times,%;
n is the total times of sample mass weighing in the drying process;
i is the weighing times of the aggregate sample mass;
j is the number of times of calculation of the water content of the aggregate sample;
(2) Uniformly dividing the dried aggregate sample into 2 parts, respectively numbering the parts as A and B, and weighing the mass of the sample A as m by using an electronic balance A Sample B has a mass of m B The method comprises the steps of carrying out a first treatment on the surface of the For standby application;
(3) Taking 2 beakers and 2 metal basket, wherein the number of the beakers is 1# and 2# respectively, the number of the metal basket is 3# and 4# respectively, pouring distilled water into the 1# beakers, and weighing the total mass m of the beakers and the distilled water 10 The method comprises the steps of carrying out a first treatment on the surface of the Pouring engine oil into a No. 2 beaker, and weighing the total mass m of the beaker and the engine oil 20 ；
(4) Immersing a 3# metal basket in a 1# beaker, keeping the basket lifted and immersed below the liquid level, and weighing the total mass m of the beaker and distilled water 11 The method comprises the steps of carrying out a first treatment on the surface of the Then the metal basket is lifted up and removed completely, and the total mass m of the No. 1 beaker and distilled water is weighed again 12 ；
(5) Immersing a No. 4 metal basket in a No. 2 beaker, keeping the basket lifted and immersed below the liquid level, and weighing the total mass m of the beaker and the engine oil 21 The method comprises the steps of carrying out a first treatment on the surface of the Then the metal basket is completely lifted and removed, and the total mass m of the No. 2 beaker and the engine oil is weighed again 22 ；
(6) Loading a sample A into a 3# metal basket, loading a sample B into a 4# metal basket, and then soaking the 3# metal basket loaded with the sample A in a 1# beaker, and fully soaking; immersing a No. 4 metal basket filled with a sample B in a No. 2 beaker;
(7) The metal basket was lifted up but kept submerged in distilled water and motor oil, and the total mass m of the 1# beaker and distilled water was again weighed 13 Weighing the No. 2 burnTotal mass m of cup and engine oil 23 And calculating the saturation and dry water absorption P of the coarse aggregate according to the following formula:
Δm 1 ＝m 13 -m 12 -m 11 +m 10 ③
Δm 2 ＝m 23 -m 22 -m 21 +m 20 ④
wherein: p is the saturation and dry water absorption of coarse aggregate,%;
ρ c the density of the engine oil is g/cm 3 ；
Δm 1 G, stress of the aggregate sample in distilled water;
Δm 2 g, stress of the aggregate sample in engine oil;
k is the mass ratio of the dried aggregate sample A to the dried aggregate sample B.
2. A method for determining saturation and dry water absorption of concrete coarse aggregate according to claim 1, wherein: the water content difference deltaq in the step (1) refers to the difference between two adjacent water contents, and the time interval between the two times of sample weighing is 1.5-2.0 h.
3. A method for determining saturation and dry water absorption of concrete coarse aggregate according to claim 1, wherein: the viscosity index of the engine oil in the step (3) is 30-50, and the engine oils with different indexes can be mixed and blended, and the density rho of the mixed engine oil is calculated when the engine oil is used c The engine oil can be reused after being filtered, and the density ρ of the mixed engine oil is higher c The calculation method of (1) is as follows:
wherein: m is M i The mass ratio of the ith engine oil in the mixed engine oil is percent;
ρ i and ρ j To mix the density of the ith and j kinds of engine oils in the engine oil, g/cm 3 ；
n is the total number of different engine oil types.
4. A method for determining coarse aggregate saturation and dry water absorption as set forth in claim 1, wherein: the adequate soaking in the step (6) means that the soaking time is 24-30 hours, and the sample B does not need to be adequately soaked.
5. A method for determining the saturation and dry water absorption of concrete coarse aggregate according to claim 1, wherein said operating steps are carried out at a temperature of 20-22 ℃ and in an environment of 80% -85% humidity.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211620884.1A CN116067822A (en) | 2022-12-16 | 2022-12-16 | Method for measuring saturation and dry water absorption of concrete coarse aggregate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211620884.1A CN116067822A (en) | 2022-12-16 | 2022-12-16 | Method for measuring saturation and dry water absorption of concrete coarse aggregate |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116067822A true CN116067822A (en) | 2023-05-05 |
Family
ID=86175971
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211620884.1A Pending CN116067822A (en) | 2022-12-16 | 2022-12-16 | Method for measuring saturation and dry water absorption of concrete coarse aggregate |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116067822A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117686378A (en) * | 2024-02-02 | 2024-03-12 | 中国电建集团西北勘测设计研究院有限公司 | Method for measuring saturation surface dry water absorption rate of artificial fine aggregate |
-
2022
- 2022-12-16 CN CN202211620884.1A patent/CN116067822A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117686378A (en) * | 2024-02-02 | 2024-03-12 | 中国电建集团西北勘测设计研究院有限公司 | Method for measuring saturation surface dry water absorption rate of artificial fine aggregate |
| CN117686378B (en) * | 2024-02-02 | 2024-05-03 | 中国电建集团西北勘测设计研究院有限公司 | Method for measuring saturation surface dry water absorption rate of artificial fine aggregate |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101477012B (en) | Method for wax-sealed measurement of asphalt mixture bulk density | |
| CN103592201B (en) | Measure volume displacement method and the equipment of soil bulk density | |
| CN116067822A (en) | Method for measuring saturation and dry water absorption of concrete coarse aggregate | |
| Biçer-Simsir et al. | Evaluation of lime-based hydraulic injection grouts for the conservation of architectural surfaces | |
| CN108535132B (en) | Weak cementation rock mass water absorption test device and test method | |
| CN101025394A (en) | Method and instrument for detecting aggregate relative density and water absorbing rate | |
| CN107917873B (en) | Method for testing oil corrosion resistance of asphalt mixture | |
| CN115096747B (en) | Method for measuring performance index of concrete continuous grading aggregate | |
| CN110646598A (en) | Test method for evaluating asphalt consumption of asphalt mixture | |
| CN105136603A (en) | Method for detecting diffusion coefficient of water vapor in bituminous mixture | |
| Gran | Fluorescent liquid replacement technique. A means of crack detection and water: binder ratio determination in high strength concretes | |
| Kucharczyková et al. | Determination and evaluation of the air permeability coefficient using Torrent Permeability Tester | |
| CN102226803A (en) | Detection method of early autogenous shrinkage of cement mortar | |
| CN110044809A (en) | A kind of concrete durability test device and its test method | |
| CN118010965A (en) | Concrete performance detection data processing method | |
| CN105938084B (en) | Method for evaluating permeability of chemical imbibition agent | |
| CN115290502A (en) | Method for rapidly determining gas content of coal seam under critical gas pressure | |
| CN110736675A (en) | sandstone aggregate saturated surface dry water absorption determination device and method | |
| CN111562194B (en) | Quick test method for MB value of machine-made sand | |
| CN110987709B (en) | Method for rapidly predicting dry density, water content and water absorption of aerated concrete discharged from kettle | |
| CN116539476A (en) | Specific gravity measuring method for soil with strong hygroscopicity | |
| CN110954443B (en) | Method for calculating dynamic contact angle of asphalt material by using plate inserting method | |
| Bomberg et al. | On validation of hygric characteristics for heat, air, moisture models | |
| CN113834840B (en) | Method for testing core imbibition efficiency | |
| CN109323891A (en) | A method of estimation lake euphotic zone depth |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |