CN111595663A - Research method for concrete resiliometer subsection calibration measuring point - Google Patents
Research method for concrete resiliometer subsection calibration measuring point Download PDFInfo
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Abstract
The invention discloses a research method for a concrete resiliometer subsection calibration measuring point, which is characterized in that the relationship between the fixed value of the rate of a medium-sized concrete resiliometer on a light steel needle and the hardness and weight of a steel anvil in a calibration period is researched, the calibration value of the concrete resiliometer is 40 +/-1 when the Rockwell hardness of the steel anvil is 60 +/-2 and the weight is 1.03kg, the fixed value of the rate of the resiliometer is reduced, the stability and the use precision of the rebound rate of the resiliometer in a common concrete strength interval are improved, meanwhile, an optimization processing method for evaluating the calibration result is designed, the calibration precision is improved, the blank in the field at home and abroad is filled, and the use precision of the resiliometer in the common concrete strength interval is improved.
Description
Technical Field
The invention relates to the technical field of building equipment detection, in particular to a research method for sectionalizing calibration measuring points of a concrete resiliometer.
Background
The rebound tester is used for detecting the compressive strength of concrete, mortar and bricks, and the principle is that a rebound value is obtained by bouncing the surface of a detected object, the rebound value is taken as a parameter related to the compressive strength of the detected object to estimate the compressive strength of the detected object, and as a simplest and most convenient nondestructive detection means, the rebound method for detecting the compressive strength of the concrete becomes a most widely applied concrete entity field detection method;
the standard state of the resiliometer and whether the metrological verification is accurate are the first major factors influencing the precision of the resiliometer, and the regulations of the national metrological verification regulation 'resiliometer' 817 and the industry standard 'technical regulation for detecting the compressive strength of concrete by a rebound method' JGJ/T23 on the verification of the resiliometer and the application of the rebound method all make detailed regulations on the standard state, verification and maintenance of the instrument; the standard steel anvil with the rebound rate of HRC60 +/-2 and the weight of 16.0 (+ -0.3 and-0.1) kilograms is qualified when the fixed value of the rebound rate of the standard steel anvil is 80 +/-2, and the standard is used for checking whether the impact stability and the indication value repeatability of the instrument meet the requirements when the first 9 indexes of the instrument meet the requirements in a standard state; the rebound instrument is bounced on a high-hardness steel anvil, elastic deformation is almost generated on an impact point, the rebound value is 80 +/-2, and the rebound interval value on concrete is skipped, so that the stability of the impact surface of an instrument impact rod and an impact hammer in four directions can be better reflected, and the verticality of a central guide rod is reflected; because the resiliometer is a mechanical instrument which is repeatedly used in a verification period, the instrument can be repeatedly flicked thousands of times and thousands of times in the half-year verification period, the performance of the instrument is influenced by multiple factors such as detection environment, flicking times, spring fatigue, pointer abrasion, fouling in a machine body and the like, and the standard state is easy to change, the application rule of the rebound method also requires that the instrument needs to be subjected to steel anvil calibration before and after detection so as to ensure the stability of the indication value of the instrument in the verification period; however, in the research, we find that different resiliometers which are qualified by verification and have the daily rate fixed value of the steel anvil within the range of 80 +/-2 in the verification period still have the rebound values on certain concrete members which are different by 3-4 division values, and the reason is that the resiliometers are subjected to elastic-plastic deformation on the surface of the concrete, the elastic deformation is different from the nearly elastic deformation of the steel anvil rate fixed time, and a linear relation does not exist between the two deformations; 3-4 division values of the resiliometer in a 20-60 indication range which is commonly used for indication values of the resiliometer can cause the strength value difference of a concrete measuring area to be 3-4 MPa, and further the engineering detection precision is directly influenced;
how to enable the rebound apparatus qualified in the verification to be used can overcome the problem that the accidental detection precision of the rebound apparatus is not high in the actual detection, and further improve the stability and the precision of the measurement value of the rebound apparatus in the verification period is an important subject of research in the field.
Disclosure of Invention
Aiming at the existing problems, the invention aims to provide a research method for a concrete rebound instrument subsection calibration measuring point, which is characterized in that the calibration value of the rebound instrument is 40 +/-1 when the Rockwell hardness of a steel anvil is 60 +/-2 and the weight of the steel anvil is 1.03kg by researching the relation between the calibration value of the middle-sized concrete rebound instrument on a light steel needle and the hardness and the weight of the steel anvil in a calibration period, so that the calibration value of the rebound instrument is reduced, and the stability and the use precision of the rebound instrument in a common concrete strength interval are improved.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
a research method for calibrating a metering point by a concrete resiliometer subsection calibration, comprising the following steps:
s1: researching the relation between the constant value of the rebound instrument rate and the hardness and the quality of the steel anvil, and determining the influence factors of the constant value of the rebound instrument rate;
s2: after determining the influence factors of the constant value of the rebound instrument rate, searching the optimal measuring point of the constant value of the rebound instrument rate by using a measuring method of sectional calibration, and defining the standard steel anvil of the measuring point as a light steel anvil;
s3: evaluating the allowable error value of the concrete resiliometer by using the light steel anvil of the optimal metering point;
s4: and researching the allowable deviation of the light steel anvil at the optimal metering point by utilizing a classification research method, and determining the allowable deviation of the light steel anvil at the optimal metering point.
Preferably, the step S1 is a specific process of studying the relationship between the constant rebound resilience and the hardness and mass of the standard steel anvil and determining the influence factors of the constant rebound resilience, wherein the specific process is as follows:
s1.1 study on influence of hardness change of steel anvil on constant value of rebound tester
The influence of the hardness change of the low-hardness light steel anvil on the rate setting value of the resiliometer is researched by controlling the hardness of the low-hardness light steel anvil, and the result shows that the hardness of the steel anvil is reduced by 22 degrees from HRC60 to HRC38, the rate setting average value is reduced by only 2 divisions from 40 to 38, and the change amplitude is very limited;
s1.2 study on influence of weight change of steel anvil on constant value of rebound tester
The influence of the weight change of the standard steel anvil on the constant value of the rebound instrument is researched by controlling the weight of the steel anvil, and the result shows that when the weight of the standard steel anvil is 697g, 1032.5g, 1443.5g and 2286.5g, the corresponding constant values of the steel anvil are respectively 30, 40, 50 and 60, and the weight change has a remarkable influence on the constant value of the steel anvil.
Preferably, the specific process of finding the optimal segment metering point by using the segment calibration metering method in step S2 is as follows:
s2.1, after the change of the weight of the steel anvil is obviously influenced on the fixed value of the rate of the steel anvil, the optimal metering point is searched, specifically, 16.0kg of standard steel anvil is turned to remove the weight, 1.0kg of standard steel anvil is turned each time, and the fixed value of the rate is measured;
s2.2 comparing the weight of the light steel anvil with the fixed value of the corresponding rate in the step S2.1, wherein the fixed value of the initial selection rate is 30, 40, 50 and 60 respectively, the light steel anvil with the fixed value of the corresponding rate is found to be not suitable for being used as a sectional measuring point, and the light steel anvil with the fixed value of the selection rate is 40 is used as the sectional measuring point.
Preferably, the specific process of evaluating the allowable error value of the concrete rebound device by using the light steel anvil with the optimal metering point in step S3 is as follows:
s3.1, selecting a steel anvil with a measuring point of 40, stably placing the steel anvil on a cement ground with high rigidity for testing, selecting 5 resiliometers in a standard state with a fixed value of 80 on the standard steel anvil for testing, and carrying out cumulative rate determination on 3600 times by 6 testers within 3 months;
s3.2, the 3600 data are processed and evaluated, the probability of the occurrence of the display rate fixed value [39,41] is the maximum, and the fact that the optimal segmentation rate fixed metering point is set to be 40 is proved to be reasonable and feasible.
Preferably, the calibration process and calibration conditions in step S3.1 are:
(1) the calibration test is carried out at the room temperature of 5-35 ℃;
(2) the surface of the steel anvil is required to be dry and clean, and is required to be stably and horizontally placed on an object with high rigidity;
(3) the rebound value is the stable rebound result of five times of continuous downward flicking, and the average value after a maximum value and a minimum value are removed;
(4) the calibration test is carried out in four directions, the tapping rod is rotated by 90 degrees before tapping in each direction, and the average value of resilience in each direction is 40 +/-1.
Preferably, the specific process of exploring the allowable deviation of the light steel anvil at the optimal metering point by using the classification research method in step S4 is as follows:
s4.1 study of the relationship between hardness. + -. 2 and the rating. + -. 2
(1) Adopting a standard steel anvil and a light steel anvil with the weight of 16.0kg to respectively manufacture steel cores with the hardness of 58, 60 and 62 for rating tests;
(2) the result shows that when the hardness of the steel anvil is in the range of HRC [58,62], the hardness change has little influence on the rating result, namely, the hardness +/-2 and the rating value +/-2 have no necessary connection, and no error transmission exists;
s4.2 determining allowable deviation of light steel anvil of optimal metering point
As can be seen from the experimental results of step S3, the probability that the light gauge point constant value falls within the interval 40 ± 1 is 95% or more, and therefore, it is possible to prove that the accuracy of the allowable deviation for the light gauge point constant value is ± 1.
Preferably, the resiliometer used in the research method is a digital display medium-sized resiliometer.
The invention has the beneficial effects that: the invention discloses a research method for concrete resiliometer subsection calibration measuring point, compared with the prior art, the improvement of the invention is that:
(1) aiming at the problems in the background art, the invention designs a research method for the concrete resiliometer subsection calibration measuring point, by researching the relation between the fixed value of the middle-sized concrete resiliometer on a light steel needle and the hardness and weight of a steel anvil in a calibration period, the calibration value of the concrete resiliometer is 40 +/-1 when the Rockwell hardness of the steel anvil is 60 +/-2 and the weight is 1.03kg, the fixed value of the resiliometer is reduced, and the stability and the use precision of the rebound rate of the resiliometer in a common concrete strength interval are improved;
(2) meanwhile, the invention designs an optimization processing method for evaluating the rating result on the basis of the current specification, after the steel anvil with the rating value of 40 is processed by the method, the probability that the rebound instrument rating value 40 plus or minus 1 falls in the interval is more than 95 percent, the light steel anvil rating value allowable deviation precision is proved to be feasible to be plus or minus 1, and the invention combines the rating method of a standard steel anvil to give specific operation and method for rating and metering the light steel anvil;
(3) the method proves that the rebound tester is completely feasible to carry out subsection calibration measurement by adopting the light steel anvil in the common interval.
Drawings
FIG. 1 is a graph of the change in weight of the steel anvil of the present invention versus the rate set value.
FIG. 2 is a graph showing the relationship between constant value of anvil rate and frequency of the light steel anvil of the present invention.
FIG. 3 is a graph of the relationship between the constant value of the anvil rate and the probability of the light steel of the present invention.
Wherein: in fig. 1: (a) an M-R curve chart of the weight change and the calibration value of the steel anvil; (b) ln (M) -R curve graph of steel anvil weight change and rate value.
Detailed Description
In order to make those skilled in the art better understand the technical solution of the present invention, the following further describes the technical solution of the present invention with reference to the drawings and the embodiments.
Example 1: referring to fig. 1-3, a method for researching the sectional calibration measurement of a lightweight resiliometer calibration steel anvil comprises the following steps:
s1: researching the relation between the constant value of the rebound instrument rate and the hardness and the quality of the steel anvil, and determining the influence factors of the constant value of the rebound instrument rate, the specific process is as follows:
according to the principle of the resiliometer, the calibration value of the resiliometer in the standard state is mainly determined by two major factors: firstly, the hardness of the steel anvil, secondly, the weight of the steel anvil, the content that this step was mainly explored is exactly the influence of hardness and weight to the steel anvil rate definite value, seeks the best measurement point of segmentation rating according to its influence adversity, its concrete process is:
s1.1 study on influence of hardness change of steel anvil on constant value of rebound tester
In order to explore the feasibility of adjusting the constant value of the steel anvil rate by hardness, two groups of steel anvils with different hardness are designed and tested, and the test results are shown in table 1:
table 1: comparison of the results of the evaluation of different hardness Steel anvils
The experimental results in table 1 show that the hardness of two light steel anvils with the same weight is reduced by 22 degrees from HRC60 to HRC38, the average rating value is reduced by only 2 graduations from 40 to 38, the variation range is very limited, the visible rating is not sensitive to the hardness variation, if the hardness of the steel anvil is reduced continuously, the steel anvil needs to be searched in a non-metal material, but the stability and the reusability of the low-hardness non-metal material are poor, and therefore, the effect of adjusting the rating of the steel anvil by adjusting the hardness is not ideal;
s1.2 study on influence of weight change of steel anvil on constant value of rebound tester
4 kinds of light steel anvils with the hardness of HRC60 +/-2 are designed, the concrete resiliometer is calibrated, and the obtained calibration values are shown in a table 2:
table 2: specification parameters of light steel anvil
As can be seen from table 2, the weight change of the steel anvil has a significant effect on the rate value;
s2: after determining the influence factors of the rebound instrument rate fixed value, searching the optimal metering point of the rebound instrument rate fixed value by using a metering method of sectional calibration, and the specific process is as follows:
s2.1, selecting a standard steel anvil of 16.0kg, turning and removing the weight from the standard steel anvil of 16.0kg, wherein 1.0kg is turned each time, the rule that the fixed value of the search rate changes along with the weight is found, and the test result is shown in Table 3:
table 3: exploration condition of steel anvil weight and corresponding rate fixed value
As can be seen from the experimental data in Table 3, the results demonstrate that the constant rate value varies non-linearly with the weight of the steel anvil; the fixed value of the description rate is influenced by the weight of the steel anvil, the stability of the steel anvil contacting the ground, the shaking of the steel anvil during impact, the verticality of personnel during impact and other factors; in addition, in the exploration process, the light steel anvil is found to be light in weight and poor in fit with the ground, and the light steel anvil is more sensitive to the rigidity and the flatness of the lower base layer of the steel anvil during instrument calibration and the verticality of an instrument during operation of personnel; therefore, a special rubber base is specially designed for the light steel anvil, the base is made of rubber and silica gel soft rubber, the Shore hardness is 70, the steel anvil can be better wrapped by the smooth inner surface of the rubber base, the bottom surface of the rubber base is designed with anti-skid lines, the adhesion force and the ground gripping force are better, the steel anvil is further ensured to be stably contacted with the ground, and the stability of the rate fixed value is ensured;
s2.2, because the common scale interval of the resiliometer is 20-60, the light steel anvil with the rate setting values of 30, 40, 50 and 60 is supposed to be initially, but through the comparison of the test (the result is shown in figure 1) and the measurement result (table 3) of the step S2.1, the stability of the rate setting value is poor when the steel anvil is 0.7kg in mass, and the rate setting value is very sensitive to the weight of the steel anvil when the weight is close to 2.4kg, so that the two points of the rate setting value 30 corresponding to 0.7kg and the rate setting value 60 corresponding to 2.4kg are not suitable for being taken as sectional measuring points; the two points with the constant rate values of 40 and 50 are stable, but the use frequency of the rebound value of about 40 is considered to be large in the common range of the concrete strength, the numerical value is characterized by comparison and is just positioned in the middle of the linear section, so that the sectional metering point is more reasonable to be 40, and the relation curve of the weight change of the steel anvil and the constant rate value is shown in the graph in fig. 1(a) and (b);
it can be seen from the experimental data and the relation curve of fig. 1 that when the weight of the steel anvil is between 7.0kg and 16.0kg, the calibration result is still in the range of 80 ± 2, and the calibration value is not sensitive to the change of the weight of the steel anvil; the constant value is relatively stable and uniformly changed in the range of 6 kg-2.5 kg; when 2.5kg is reduced to 2.4kg, the rate set value is suddenly reduced to about 60, which shows that when the weight of the steel anvil is around 2.4kg, the rate set value is very sensitive to the weight change of the steel anvil; in the wave band of 2.4kg-1.4kg-1.0kg-0.7kg, the influence of the weight of the steel anvil on the rate setting value is close to a linear relation and is relatively stable; when the weight of the steel anvil is 0.7kg, the rating result is between 22 and 35, because the steel anvil is light in weight, the steel anvil is easy to bounce in the impact process, and thus the data fluctuation is large;
through analysis of the test data and its relationship curve for the steel anvil weight and rate rating values, it is reasonably feasible to set the optimal segment rating gauge point to 40 for the following reasons:
(1) the strength of the concrete measuring area corresponding to the rebound value 40 is found by measuring area curves of industry standards and local standards of each area, is exactly about 40MPa which is most commonly used in daily life, and a measuring point is determined for an ideal daily rate;
(2) according to the test curves (fig. 1(a) and (b)), the linear relation of three points of the rate setting values 30, 40 and 50 is better, 40 is positioned in the middle of the linear section, and the steel anvil weight and rate setting values are better in stability in the section;
(3) according to the exploration test, when the rate is below 30, the stability of the measured rate is poor because the steel anvil is too light;
(4) according to exploration tests, when the rate setting value is in a 50-70 section, the change curve linearity of the weight of the steel anvil and the rate setting value is poor, the rate setting value is sensitive to the weight change of the steel anvil, and the weight of the steel anvil is not easy to control;
(5) the standard steel anvil rate is 80, the light steel anvil rate is 40, which is just half of the standard steel anvil rate, and the data comparison has the characteristics of convenient use and memory;
s3: the method comprises the following steps of evaluating the allowable error value of the concrete rebound tester by using a light steel anvil with an optimal metering point, wherein the specific process comprises the following steps:
s3.1 in order to ensure the precision and accuracy of the resiliometer, the allowable error of the calibration result of the instrument at each metering point is subjected to test analysis, a light steel anvil with the metering point of 40 is selected for the test, the light steel anvil is stably placed on a cement ground with higher rigidity for testing, 5 instruments in a standard state with the fixed value of 80 on the standard steel anvil are selected for the test in order to reduce the error caused by the instruments and personnel, and 3600 times are cumulatively calibrated by 6 detection personnel in 3 months;
s3.2, processing and evaluating the 3600 times of data, wherein the evaluation method comprises a standard evaluation method and an improved evaluation method:
(1) the standard evaluation method comprises the following steps: evaluating according to a rating method of JGJ/T23 technical Specification for detecting the compressive strength of concrete by a rebound method;
the improved evaluation method and the operation specification thereof comprise the following steps:
(1) the method comprises the following steps: the calibration test operation is consistent with the requirements of the current specification, the calibration test operation is carried out in four directions, each direction flicks for 3 times, but the extreme difference of the flicking result of each direction for 3 times is not more than 1, otherwise, the calibration data of the direction is invalidated;
(2) the second method comprises the following steps: the calibration test operation is consistent with the current standard requirement, and is carried out in four directions, each direction is flicked for 5 times, and a maximum value and a minimum value are removed;
the steel anvil rating results shown in table 4 were obtained:
table 4: comparison of evaluation methods of Steel anvil rating results
As can be seen from Table 4, the constant value interval of the anvil ratio of the No. II steel directly measured according to the standard mode is 37-42, the average value is 39.78, the standard deviation is 0.950 (which is the standard deviation compared with the standard rebound value), and the coefficient of variation is 0.024 (which is the coefficient of variation compared with the standard rebound value); the first method and the second method are results obtained by processing data which do not meet the requirements according to an improved evaluation method, and in the table, the first method and the second method remove points with larger dispersion, so that a calibration interval, a standard deviation and a variation coefficient are slightly reduced, and the average value is not changed greatly; the three methods are shown in fig. 2 and fig. 3, and the calibration values and the frequency and probability curves of the occurrence are shown in the figure;
as can be seen from fig. 2 and 3, the frequency of occurrence rules of the steel anvil frequency setting values corresponding to the three modes are basically consistent, the frequency of occurrence is 39,41, 40, 38, 42 and 37 in sequence from high to low, and the probability of occurrence of the frequency setting value [39,41] is the maximum, wherein the probability of occurrence of the standard method, the first method and the second method is 93.86%, 95.10% and 96.44% in sequence, 6.14% of the frequency setting value of the standard method falls outside the [39,41] interval, 4.90% and 3.56% of the frequency setting value of the first method and the second method respectively fall outside the [39,41] interval, which indicates that the method for evaluating the first method and the second method can ensure that the guarantee rate setting value tolerance ± 1 can reach more than 95%, and the second method is superior to the first method;
step S4: the allowable deviation of the light steel anvil at the optimal metering point is researched by utilizing a classification research method, and the allowable deviation of the light steel anvil at the optimal metering point is determined, wherein the classification research method comprises the following specific steps:
s4.1 study of the relationship between hardness. + -. 2 and the rating. + -. 2
(1) Whether the standard steel anvil hardness for the calibration of the medium-sized resiliometer is HRC60 and the allowable deviation is +/-2, and the allowable deviation of the rate-setting value of the resiliometer is accurate to +/-1 is feasible or not, a standard steel anvil and a light steel anvil with the weight of 16.0kg are adopted, steel cores with the hardness of 58, 60 and 62 are respectively manufactured to carry out calibration tests, and the hardness calibration test results of the steel anvil are shown in tables 4 and 5:
table 5: comparison of the results of different hardness anvil calibrations (16kg Standard anvil)
Table 6: comparison of the results of different hardness anvil calibrations (light anvil)
As can be seen from the test data in Table 5, the rate setting values of the 16.0kg standard steel anvil with the hardness of 58, 60 and 62 are between 78 and 82, and the hardness change has almost no influence on the rate setting result;
as can be seen from the test data in Table 6, the light steel anvil has the rating values of between 38 and 41 when the hardness is 58, 60 and 62, and the hardness change has almost no influence on the rating result;
therefore, it can be seen from the results in tables 5 and 6 that, when the hardness is in the range of [58,62] in both the standard steel anvil and the light steel anvil, the hardness has little influence on the rating result of the common medium-sized rebound tester; because the hardness of the steel anvil is equivalent to that of the striking rod, when the hardness of the steel anvil is in the range of HRC (58, 62), the deformation of the steel anvil and the striking rod is approximately elastic deformation, and the influence of the slight change of the hardness on the fixed value is very limited, namely the allowable deviation of the hardness +/-2 cannot be transmitted to the fixed value of the ratio or amplified accordingly, namely the hardness +/-2 is not necessarily connected with the fixed value of the ratio +/-2, and no error is transmitted;
s4.2 determination of allowable deviation of fixed value of anvil ratio of light steel
As can be seen from the experimental results of the standard evaluation method of step S3, the stable interval of the constant value of the light steel anvil rate is [37-42], and the interval of the constant value of the rate after the steel anvil having the constant value of 40 is processed by the second method of step three (improved rate method) is [38-42], and the probability that the rate constant value 40 ± 1 falls in the interval is 95% or more, and therefore, it is feasible that the accuracy of the allowable deviation of the constant value of the light steel anvil rate is ± 1.
Preferably, the resiliometer used in the present study method is a digital display medium resiliometer.
Through the above-described research methods, the specific operating methods and requirements for determining the resiliometer calibration of the present invention are as follows (selected evaluation method):
the concrete operation method of the rebound tester subsection calibration measurement refers to the regulations of technical specification for detecting the concrete compressive strength by rebound method JGJ/T23-2011 item 3.2.2 and rebound tester JJJG 817-2011 item 7.2.3.10, and the concrete requirements are as follows:
(1) the calibration test is carried out at the room temperature of (5-35) DEG C;
(2) the surface of the steel anvil is required to be dry and clean, and is required to be stably and horizontally placed on an object with high rigidity;
(3) the rebound value is a stable rebound result of five times of continuous downward impacts, and an average value after a maximum value and a minimum value is removed (method one); a range method: the rebound value should be stable rebound result of three consecutive downward impacts and should be extremely different from 1 (method two)
(4) The calibration test is carried out in four directions, the tapping rod is rotated by 90 degrees before tapping in each direction, and the average value of resilience in each direction is 40 +/-1.
And through the exploration process of the research method, we determine that:
(1) the specific parameters of the light-duty rebound tester calibration steel anvil according to the invention comprise the hardness and the weight of the light-duty steel anvil for the calibration of the rebound tester, namely the Rockwell hardness of 60 +/-2 and the weight of 1.03 kg;
(2) determining a sectional metering point of a common interval in the range of the resiliometer, namely a point with a rating value of 40 on a light steel anvil researched herein;
(3) determining that the calibration value allowable deviation of the resiliometer on a light steel anvil with the hardness of HRC60 +/-2 is feasible to be +/-1, and providing an optimization processing method for evaluating the calibration result;
(4) the specific operation and method of the light steel anvil rating measurement are provided by combining the rating method of the standard steel anvil;
(5) research and application of the rebound tester subsection calibration measurement fill the blank in the field at home and abroad, and improve the use precision of the rebound tester in the common concrete strength interval;
(6) the rebound tester adopts a light steel anvil to carry out subsection calibration measurement in a common interval.
The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.
Claims (7)
1. A research method for calibrating measuring points by sections of a concrete resiliometer is characterized by comprising the following steps: the method comprises the following steps:
s1: researching the relation between the constant value of the rebound instrument rate and the hardness and the quality of the steel anvil, and determining the influence factors of the constant value of the rebound instrument rate;
s2: after determining the influence factors of the constant value of the rebound instrument rate, searching the optimal measuring point of the constant value of the rebound instrument rate by using a measuring method of sectional calibration, and defining the standard steel anvil of the measuring point as a light steel anvil;
s3: evaluating the allowable error value of the concrete resiliometer by using the light steel anvil of the optimal metering point;
s4: and researching the allowable deviation of the light steel anvil at the optimal metering point by utilizing a classification research method, and determining the allowable deviation of the light steel anvil at the optimal metering point.
2. The method for researching the concrete rebound instrument subsection calibration measuring point according to claim 1, wherein the method comprises the following steps: step S1, researching the relation between the constant rebound instrument rate and the hardness and the quality of the standard steel anvil, and determining the influence factors of the constant rebound instrument rate comprises the following specific processes:
s1.1 study on influence of hardness change of steel anvil on constant value of rebound tester
The influence of the hardness change of the low-hardness light steel anvil on the rate setting value of the resiliometer is researched by controlling the hardness of the low-hardness light steel anvil, and the result shows that the hardness of the steel anvil is reduced by 22 degrees from HRC60 to HRC38, the rate setting average value is reduced by only 2 divisions from 40 to 38, and the change amplitude is very limited;
s1.2 study on influence of weight change of steel anvil on constant value of rebound tester
The influence of the weight change of the standard steel anvil on the constant value of the rebound instrument is researched by controlling the weight of the steel anvil, and the result shows that when the weight of the standard steel anvil is 697g, 1032.5g, 1443.5g and 2286.5g, the corresponding constant values of the steel anvil are respectively 30, 40, 50 and 60, and the weight change has a remarkable influence on the constant value of the steel anvil.
3. The method for researching the concrete rebound instrument subsection calibration measuring point according to claim 2, wherein the method comprises the following steps: the specific process of finding the optimal segment metering point by using the segment calibration metering method in step S2 is as follows:
s2.1, after the change of the weight of the steel anvil is obviously influenced on the fixed value of the rate of the steel anvil, the optimal metering point is searched, specifically, 16.0kg of standard steel anvil is turned to remove the weight, 1.0kg of standard steel anvil is turned each time, and the fixed value of the rate is measured;
s2.2 comparing the weight of the light steel anvil with the fixed value of the corresponding rate in the step S2.1, wherein the fixed value of the initial selection rate is 30, 40, 50 and 60 respectively, the light steel anvil with the fixed value of the corresponding rate is found to be not suitable for being used as a sectional measuring point, and the light steel anvil with the fixed value of the selection rate is 40 is used as the sectional measuring point.
4. The method for researching the subsection rating measurement of the light-duty rebound tester rating steel anvil according to claim 3, wherein the method comprises the following steps: the specific process of evaluating the allowable error value of the concrete rebound tester by using the light steel anvil at the optimal metering point in the step S3 is as follows:
s3.1, selecting a steel anvil with a measuring point of 40, stably placing the steel anvil on a cement ground with high rigidity for testing, selecting 5 resiliometers in a standard state with a fixed value of 80 on the standard steel anvil for testing, and carrying out cumulative rate determination on 3600 times by 6 testers within 3 months;
s3.2, the 3600 data are processed and evaluated, the probability of the occurrence of the display rate fixed value [39,41] is the maximum, and the fact that the optimal segmentation rate fixed metering point is set to be 40 is proved to be reasonable and feasible.
5. The method for researching the subsection rating measurement of the light-duty rebound tester rating steel anvil according to claim 4, wherein the method comprises the following steps: the calibration process and calibration conditions in step S3.1 are:
(1) the calibration test is carried out at the room temperature of 5-35 ℃;
(2) the surface of the steel anvil is required to be dry and clean, and is required to be stably and horizontally placed on an object with high rigidity;
(3) the rebound value is the stable rebound result of five times of continuous downward flicking, and the average value after a maximum value and a minimum value are removed;
(4) the calibration test is carried out in four directions, the tapping rod is rotated by 90 degrees before tapping in each direction, and the average value of resilience in each direction is 40 +/-1.
6. The method for researching the subsection rating measurement of the light-duty rebound tester rating steel anvil according to claim 4, wherein the method comprises the following steps: the specific process of researching the allowable deviation of the light steel anvil at the optimal metering point by using the classification research method in the step S4 is as follows:
s4.1 study of the relationship between hardness. + -. 2 and the rating. + -. 2
(1) Adopting a standard steel anvil and a light steel anvil with the weight of 16.0kg to respectively manufacture steel cores with the hardness of 58, 60 and 62 for rating tests;
(2) the result shows that when the hardness of the steel anvil is in the range of HRC [58,62], the hardness change has little influence on the rating result, namely, the hardness +/-2 and the rating value +/-2 have no necessary connection, and no error transmission exists;
s4.2 determining allowable deviation of light steel anvil of optimal metering point
As can be seen from the experimental results of step S3, the probability that the light gauge point constant value falls within the interval 40 ± 1 is 95% or more, and therefore, it is possible to prove that the accuracy of the allowable deviation for the light gauge point constant value is ± 1.
7. The method for segmented ratiometric study of a light-duty resiliometer ratiometric steel anvil according to any one of claims 1 to 6, wherein: the resiliometer used in the research method is a digital display medium resiliometer.
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