CN112666200B - Concrete frost resistance evaluation method - Google Patents
Concrete frost resistance evaluation method Download PDFInfo
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- CN112666200B CN112666200B CN202011479890.0A CN202011479890A CN112666200B CN 112666200 B CN112666200 B CN 112666200B CN 202011479890 A CN202011479890 A CN 202011479890A CN 112666200 B CN112666200 B CN 112666200B
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- 238000011156 evaluation Methods 0.000 title claims abstract description 14
- 238000007710 freezing Methods 0.000 claims abstract description 183
- 230000008014 freezing Effects 0.000 claims abstract description 180
- 238000010257 thawing Methods 0.000 claims abstract description 144
- 239000002893 slag Substances 0.000 claims abstract description 37
- 238000000034 method Methods 0.000 claims abstract description 24
- 239000002689 soil Substances 0.000 claims abstract description 13
- 238000012360 testing method Methods 0.000 claims abstract description 5
- 238000001514 detection method Methods 0.000 claims description 14
- 238000007664 blowing Methods 0.000 claims description 9
- 239000011159 matrix material Substances 0.000 claims description 8
- 238000012854 evaluation process Methods 0.000 claims description 3
- 238000005259 measurement Methods 0.000 claims description 3
- 238000004364 calculation method Methods 0.000 claims description 2
- 238000004088 simulation Methods 0.000 claims 3
- 238000005286 illumination Methods 0.000 abstract 1
- 238000010276 construction Methods 0.000 description 3
- 230000002528 anti-freeze Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 238000006467 substitution reaction Methods 0.000 description 2
- 238000004781 supercooling Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 230000001678 irradiating effect Effects 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
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- 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
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A90/00—Technologies having an indirect contribution to adaptation to climate change
- Y02A90/10—Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation
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Abstract
The invention relates to a method for evaluating the frost resistance of concrete, which is characterized by comprising the following steps: the first part of the sample to be detected is put into a freeze thawing bin for pre-freeze thawing, the elastic modulus of the sample is determined, and scoring parameters of cracks and falling slag soil are generated according to the elastic modulus; three samples, namely one sample, are placed in a freeze thawing chamber, one sample is placed in a freeze compartment, one sample is placed in a freeze illumination chamber, and corresponding tests are carried out on the samples so as to score cracks and falling slag soil generated by the samples in different environments; and calculating the comprehensive score of the sample, and evaluating the freezing resistance of the sample. The invention is used for simulating the use environment with large temperature difference between day and night of the concrete by arranging the freeze thawing chamber; the air freezing chamber is arranged for simulating the use environment of the concrete in high and cold weather and high wind; the freezing and shining chamber is arranged for simulating the service environment of the concrete with high and cold and long sunlight, comprehensively simulates the service environment of the concrete, reduces the error of the evaluation result of the freezing resistance of the concrete, and increases the safety performance of building facilities.
Description
Technical Field
The invention relates to the technical field of concrete, in particular to a method for evaluating the frost resistance of concrete.
Background
At present, a large amount of foundation construction in China is continuously carried out, and concrete is widely applied to civil engineering due to the characteristics of rich raw materials, excellent construction performance, economy, practicability and the like. And concrete is used as one of main raw materials of foundation construction engineering, so that the influence of natural environment and climate characteristics on the frost resistance of the concrete is particularly important to be studied. In western regions of China, especially in Qinghai-Tibet plateau regions, the environment is severe, the temperature difference between day and night is large, the temperature difference between high and cold, the gust and the sunshine are long, and the damage to the durability of concrete is large. Concrete is exposed to such environments for a long period of time and may be damaged, thereby bringing hidden danger to the safety performance of buildings, roads and bridge facilities. At present, a plurality of methods for evaluating the frost resistance of a concrete material in the civil engineering field are mainly a quick freezing method and a slow freezing method (GB/T50082-2009 Standard for test methods for the long-term performance and durability of common concrete, and a fourth chapter of frost resistance test), and the two methods consider the influence of the number of freeze thawing cycles on the frost resistance of the concrete, but cannot accurately reflect the frost resistance level in the actual environment of the concrete, so that calculation and consideration in the actual engineering environment are difficult, the evaluation result error is large, and the potential safety hazard of building facilities is increased.
Disclosure of Invention
Therefore, the invention provides a concrete frost resistance evaluation method which is used for solving the problems of single concrete frost resistance evaluation method and increased potential safety hazards of building facilities caused by poor pertinence in the prior art.
In order to achieve the above object, the present invention provides a method for evaluating the frost resistance of concrete, comprising:
s1, placing a first part of a sample to be detected into a freeze thawing chamber for pre-freeze thawing, determining the elastic modulus of the sample, and calculating scoring parameters of generated cracks and falling slag soil according to the elastic modulus;
s2, placing three samples into a freeze thawing chamber, placing one sample into the freeze compartment, placing one sample into a freezing chamber, and performing corresponding tests on the samples to score cracks and falling slag generated by the samples in different environments;
s3, calculating a comprehensive score of the sample, and evaluating the freezing resistance of the sample;
and a central control module is arranged in the process of implementing the concrete frost resistance evaluation method and is used for controlling the evaluation process and analyzing the evaluation result.
Further, a sample with the volume of C and the mass of E in the environment of 20 ℃ is placed into a freezing and thawing chamber for pre-freezing and thawing, a first image pickup device for detecting the deformation quantity of the sample is arranged at the upper part of the freezing and thawing chamber, a freezing and thawing mode is started, and when the freezing and thawing chamber reaches the minimum temperature W1 for the first time and the freezing time length T1 is passed, the image pickup device detects the volume D1 of the sample; when the freezing and thawing chamber reaches the highest temperature W2 for the first time and the thawing time period T2 passes, the camera device detects the sample volume Y1; when the freezing and thawing chamber reaches the lowest temperature W1 for the second time and the freezing duration T1 passes, the image pickup device detects the sample volume D2; when the freeze thawing chamber reaches the highest temperature W2 for the second time and the thawing time period T2 passes, the camera device detects the sample volume Y2; when the freezing and thawing chamber reaches the lowest temperature W1 for the third time and the freezing duration T1 passes, the image pickup device detects the sample volume D3; when the freezing and thawing chamber reaches the highest temperature W2 for the third time and the thawing time length T2 passes, the camera device detects the sample volume Y3; the central control module calculates the sample volume change elastic modulus X:
alpha is the elastic modulus compensation parameter.
Further, calculating a concrete crack length scoring parameter L, a concrete crack width scoring parameter S and a concrete slag quantity scoring parameter V by the central control module according to the sample volume change elastic modulus X;
L＝X×l
S＝X×s
V＝X×v
wherein L is the compensation parameter of the elastic modulus X to the concrete crack length scoring parameter L, S is the compensation parameter of the elastic modulus X to the concrete crack width scoring parameter S, and V is the compensation parameter of the elastic modulus X to the concrete slag drop scoring parameter V.
Further, three samples with the volume of C and the mass of E at 20 ℃ are put into a freeze thawing chamber, one sample is put into the freeze chamber, and one sample is put into a freezing chamber; carrying out freeze thawing cycle treatment on a sample in the freeze thawing chamber, wherein in the freeze thawing cycle process, the highest temperature of the freeze thawing chamber is W2, the lowest temperature is W1, the freeze thawing cycle times are N times, and the single freeze thawing cycle time is T3; performing freezing and blowing treatment on the sample in the freezing chamber, wherein the freezing temperature in the freezing chamber is W3, the blowing wind speed is F, and the freezing treatment time is T4; and (3) performing freezing and ultraviolet irradiation treatment on the sample in the freezing chamber, wherein the freezing temperature in the freezing chamber is W3, the ultraviolet irradiation intensity is G, and the freezing treatment time is T4.
Further, when the freeze thawing cycle treatment is completed on the sample in the freeze thawing chamber, the first camera device detects the surface state of the sample, when a crack is generated on the surface of the sample, a crack is selected, the total length of the crack is measured to be A1, the widest part of the crack is B1, the first camera device transmits the measurement result to the central control module, and the central control module calculates the score K1 of the crack, wherein K1=A1×L+B1×S; the central control module calculates residual crack scores K2, K3 and … … Kn of the sample surface, and the central control module calculates total crack scores Kx, kx=K1+K2+ … +Kn of the sample surface.
Further, when the crack on the surface of the concrete is branched, the first camera device measures the longest path of the crack as A1, one branch is selected, the distance from the tail end of the branch to the branching position of the crack is measured as A11, the first camera device transmits the detection result to the central control module, the central control module calculates the ratio A1 of the branch length to the total length of the crack,scoring the branch according to the A1 and a11 central control module:
when a1 is less than or equal to 0.1, the central control module judges that the branch is an invalid branch and does not score the branch;
when a1 is more than 0.1 and less than or equal to 0.3, the central control module calculates the branch length score k11, wherein k11=A11×L×0.5;
when a1 > 0.3, the central control module calculates the branch length score k11, k11=a11×l×0.8.
Further, when a secondary branch is generated on the branch, the first camera device measures the distance from the tail end of the secondary branch to the branch outlet as A111, the first camera device transmits the detection result to the central control module, the central control module calculates the ratio a11 of the secondary branch length to the total length of the crack,scoring the secondary branches according to a11 and a111 central control module:
when a11 is less than or equal to 0.1, the central control module judges that the secondary branch is an invalid branch and does not score the invalid branch;
when a11 is more than 0.1 and less than or equal to 0.3, the central control module calculates the secondary branch length score k111, k11=a111×l×0.3;
when a11 > 0.3, the central control module calculates the branch length score k111, k111=a111×l×0.6;
the central control module divides the branch into a plurality of branch scores k112, k113, … … k11n;
the central control module calculates a branch length score k11, k11=k11=a11×l×i+k111+k112+ … +k11n, i=0.5 or 0.8;
the central control module calculates residual branch scores k12, k13 and … … k1n of the crack;
the central control module calculates the crack score K1, k1=a1×l+b1×s+k11+k12+ … +k1n.
Further, a first concrete slag-falling collecting device is arranged below the freeze thawing chamber and used for collecting falling slag, when the freeze thawing cycle treatment of the sample in the freeze thawing chamber is completed, the mass e of the slag in the collecting device is detected and the detection result is transmitted to the central control module, the central control module calculates the score Qx of the concrete slag-falling amount,
the central control module calculates the total score Px of the samples in the freeze thawing chamber,wherein, p1 is the weight parameter of the total score Kx of the crack to the total score Px of the sample in the freeze thawing chamber, and p2 is the weight parameter of the score Qx of the slag drop amount of the concrete to the total score Px of the sample in the freeze thawing chamber.
Further, according to the algorithm, the central control module calculates a total score Pz of the sample in the freezing chamber and a total score Py of the sample in the freezing chamber, and calculates a total score H of the frost resistance of the concrete to be detected according to Px, pz and Py:
H＝Px×β+Pz×δ+Py×γ
wherein, beta is the weight parameter of the total score Px of the sample in the freezing and thawing chamber to the total score H of the freezing resistance, delta is the weight parameter of the total score Pz of the sample in the freezing and thawing chamber to the total score H of the freezing resistance, and gamma is the weight parameter of the total score Py of the sample in the freezing and thawing chamber to the total score H of the freezing resistance.
Further, a total freezing resistance score matrix H0 (H1, H2, H3) is further arranged in the central control module, wherein H1 is a first preset total freezing resistance score, H2 is a second preset total freezing resistance score, H3 is a third preset total freezing resistance score, the scores are sequentially increased, and the freezing resistance is stronger when the score is lower; the central control module compares the total freezing resistance score H of the concrete with the internal parameters of the total freezing resistance score matrix H0:
when H is less than or equal to H1, the central control module judges that the frost resistance of the concrete to be detected is first-level;
when H1 is more than H and less than or equal to H2, the central control module judges that the frost resistance of the concrete to be detected is two-stage;
when H1 is more than H and less than or equal to H2, the central control module judges that the anti-freezing performance of the concrete to be detected is three-level;
when H is more than H2, the central control module judges that the frost resistance of the concrete to be detected is four-level.
Compared with the prior art, the invention has the beneficial effects that the freezing and thawing chamber is arranged to simulate the use environment with large temperature difference between day and night of the concrete; the air freezing chamber is arranged for simulating the use environment of the concrete in high and cold weather and high wind; the freezing and shining chamber is arranged for simulating the service environment of the concrete with high and cold and long sunlight, comprehensively simulates the service environment of the concrete, reduces the error of the evaluation result of the freezing resistance of the concrete, and increases the safety performance of building facilities.
Further, before the concrete freezing resistance performance is formally evaluated, a sample with the volume of C and the mass of E in a 20 ℃ environment is put into a freezing and thawing chamber for pre-freezing and thawing, a first image pickup device for detecting the deformation quantity of the sample is arranged at the upper part of the freezing and thawing chamber, a freezing and thawing mode is started, and when the freezing and thawing chamber reaches the minimum temperature W1 for the first time and the freezing time length T1 is passed, the image pickup device detects the sample volume D1; when the freezing and thawing chamber reaches the highest temperature W2 for the first time and the thawing time period T2 passes, the camera device detects the sample volume Y1; when the freezing and thawing chamber reaches the lowest temperature W1 for the second time and the freezing duration T1 passes, the image pickup device detects the sample volume D2; when the freeze thawing chamber reaches the highest temperature W2 for the second time and the thawing time period T2 passes, the camera device detects the sample volume Y2; when the freezing and thawing chamber reaches the lowest temperature W1 for the third time and the freezing duration T1 passes, the image pickup device detects the sample volume D3; when the freezing and thawing chamber reaches the highest temperature W2 for the third time and the thawing time length T2 passes, the camera device detects the sample volume Y3; the central control module calculates the volume-changing elastic modulus X of the sample; and calculating a concrete crack length scoring parameter L, a concrete crack width scoring parameter S and a concrete slag quantity scoring parameter V by the central control module according to the sample volume change elastic modulus X. And the grading parameters of the concrete are determined pertinently, so that the error of the antifreeze performance evaluation result of the concrete is further reduced, and the safety performance of building facilities is improved.
Further, when the crack on the surface of the concrete is branched, the first camera device measures the longest path of the crack as A1, one branch is selected, the distance from the tail end of the branch to the branching position of the crack is measured as A11, the first camera device transmits the detection result to the central control module, the central control module calculates the ratio A1 of the branch length to the total length of the crack,scoring the branch according to the A1 and A11 central control modules; when a secondary branch is generated on the branch, the first camera device measures that the distance from the tail end of the secondary branch to the branch outlet is A111, the first camera device transmits the detection result to the central control module, and the central control module calculates the ratio a11 of the length of the secondary branch to the total length of the crack, and the first camera device calculates the total length of the secondary branch>Scoring the secondary branches according to the a11 and A111 central control modules; setting multi-grade grading, accurately grading the generated cracks, further reducing the error of the concrete antifreeze performance evaluation result,the safety performance of the building facilities is increased.
Further, when scoring the total score of a single sample in the freeze thawing chamber, the freeze plenum and the freezing chamber, a crack and falling slag soil scoring weight is set; when the total freezing resistance score of the concrete is scored, a weight parameter of the total freezing resistance score of the sample in the freezing and thawing chamber is set, and a weight parameter of the total freezing resistance score of the sample in the freezing chamber is set; by setting the multilevel weight scoring parameters, the concrete frost resistance is precisely scored, the error of the concrete frost resistance evaluation result is further reduced, and the safety performance of building facilities is improved.
Drawings
FIG. 1 is a schematic structural diagram of equipment used in the method for evaluating the frost resistance of concrete;
FIG. 2 is a flow chart of the method for evaluating the frost resistance of the concrete.
Detailed Description
In order that the objects and advantages of the invention will become more apparent, the invention will be further described with reference to the following examples; it should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.
Preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are merely for explaining the technical principles of the present invention, and are not intended to limit the scope of the present invention.
It should be noted that, in the description of the present invention, terms such as "upper," "lower," "left," "right," "inner," "outer," and the like indicate directions or positional relationships based on the directions or positional relationships shown in the drawings, which are merely for convenience of description, and do not indicate or imply that the apparatus or elements must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention.
Furthermore, it should be noted that, in the description of the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention can be understood by those skilled in the art according to the specific circumstances.
Referring to fig. 1, a schematic structural diagram of an apparatus for evaluating the frost resistance of concrete according to the present invention is shown; when the method for evaluating the frost resistance of the concrete is used, a central control module 1, a freeze thawing chamber 2, a freeze chamber 3 and a freezing chamber 4 are arranged; the freezing and thawing chamber 2 is used for simulating the use environment with large temperature difference between day and night of concrete, the freezing and thawing chamber 3 is used for simulating the use environment with high and cold level and high and strong wind of concrete, and the freezing and thawing chamber 4 is used for simulating the use environment with high and cold level and long sunshine time of concrete.
The freezing and thawing chamber 2 comprises a first camera device 21, a first refrigerator 22, a heater 23 and a first slag-off collecting device 24, wherein the first camera device 21 is positioned at the top of the freezing and thawing chamber 2 and is connected with the central control module 1, and is used for detecting the deformation of a sample volume and the generation of a sample crack in the freezing and thawing chamber when pre-freezing and thawing, and the first refrigerator 22 is positioned at one side of the freezing and thawing chamber 2 and is used for freezing the sample in the freezing and thawing chamber; the heater 23 is located at the opposite side of the first freezer 22 in the freezing and thawing chamber 2, and is used for thawing the sample frozen in the freezing and thawing chamber 2; the first slag-falling collecting device 24 is located at the bottom of the freeze thawing chamber 2 and connected to the central control module 1, and is used for collecting slag soil falling from samples in the freeze thawing chamber 2, and a quality sensor is arranged on the first slag-falling collecting device 24, so that the quality of the falling slag soil can be detected, and the detection result can be transmitted to the central control module 1.
The freezing chamber 3 comprises a second camera device 31, a second refrigerator 32, a blowing machine 33, a second slag-off collecting device 34 and an air outlet 35, wherein the second camera device 31 is positioned at the top of the freezing chamber 3 and is connected with the central control module 1 to detect the generation condition of a sample crack in the freezing chamber, and the second refrigerator 32 is positioned at one side of the freezing chamber 3 to freeze the sample in the freezing chamber; the blower 33 is located above the second refrigerator 32 in the freezing chamber 3 and is used for blowing air to the sample frozen in the freezing chamber 3; the second slag collecting device 34 is located at the bottom of the air chamber 3 and connected to the central control module 1, and is used for collecting the slag soil falling from the sample in the air chamber 3, the second slag collecting device 34 is provided with a mass sensor, and can detect the mass of the slag soil falling and transmit the detection result to the central control module 1, and the air outlet 35 is located at the opposite side of the air chamber 3, where the second refrigerator 32 is located, and is used for discharging the blown cold air.
The freezing chamber 4 comprises a third camera device 41, a third refrigerator 42, a third slag-off collecting device 43 and an ultraviolet lamp 44, wherein the third camera device 41 is positioned at the top of the freezing chamber 4 and is connected with the central control module 1 for detecting the generation condition of sample cracks in the freezing chamber; the third refrigerator 42 is located at one side of the freezing chamber 4, and is used for freezing the sample in the freezing chamber; the third slag-falling collecting device 43 is located at the bottom of the freezing chamber 4 and connected with the central control module 1, and is used for collecting the slag soil falling from the sample in the freezing chamber 4, and the third slag-falling collecting device 43 is provided with a quality sensor, and can detect the quality of the falling slag soil and transmit the detection result to the central control module 1; the ultraviolet lamp 44 is located at the top of the freezing chamber 4 for irradiating ultraviolet rays to the sample in the freezing chamber.
Please continue to refer to fig. 2, which is a flowchart of the method for evaluating the frost resistance of concrete according to the present invention, the method for evaluating the frost resistance of concrete according to the present invention comprises:
s1, placing a first part of a sample to be detected into a freeze thawing chamber 2 for pre-freeze thawing, determining the elastic modulus of the sample, and calculating scoring parameters of generated cracks and falling slag soil according to the elastic modulus;
s2, placing three samples into a freeze thawing chamber 2, placing one sample into a freeze compartment 3, placing one sample into a freezing chamber 4, and performing corresponding tests on the samples to score cracks and falling slag soil generated by the samples in different environments;
s3, calculating a comprehensive score of the sample, and evaluating the freezing resistance of the sample;
the method for evaluating the frost resistance of the concrete is characterized in that a central control module 1 is arranged in the process of implementing the method for evaluating the frost resistance of the concrete and is used for controlling the evaluating process and analyzing the evaluating result.
Specifically, a sample with the volume of C and the mass of E in an environment of 20 ℃ is placed into a freezing and thawing chamber 2 for pre-freezing and thawing, a first image pickup device 21 for detecting the deformation amount of the sample is arranged at the upper part of the freezing and thawing chamber 2, a freezing and thawing mode is started, and when the freezing and thawing chamber 2 reaches the minimum temperature W1 for the first time and the freezing time length T1 is passed, the image pickup device detects the volume D1 of the sample; when the freezing and thawing chamber 2 reaches the highest temperature W2 for the first time and the thawing time period T2 passes, the camera device detects the sample volume Y1; when the freezing and thawing chamber 2 reaches the lowest temperature W1 for the second time and the freezing duration T1 passes, the camera device detects the sample volume D2; when the freeze thawing chamber 2 reaches the highest temperature W2 for the second time and the thawing time period T2 elapses, the camera device detects the sample volume Y2; when the freezing and thawing chamber 2 reaches the lowest temperature W1 for the third time and the freezing duration T1 passes, the camera device detects the sample volume D3; when the freezing and thawing chamber 2 reaches the highest temperature W2 for the third time and the thawing time period T2 passes, the camera device detects the sample volume Y3; the central control module 1 calculates the sample volume change elastic modulus X:
alpha is the elastic modulus compensation parameter.
Specifically, calculating a concrete crack length scoring parameter L, a concrete crack width scoring parameter S and a concrete slag quantity scoring parameter V by the central control module 1 according to the sample volume change elastic modulus X;
L＝X×l
S＝X×s
V＝X×v
wherein L is the compensation parameter of the elastic modulus X to the concrete crack length scoring parameter L, S is the compensation parameter of the elastic modulus X to the concrete crack width scoring parameter S, and V is the compensation parameter of the elastic modulus X to the concrete slag drop scoring parameter V.
Specifically, three samples with the volume of C and the mass of E at 20 ℃ are put into a freeze thawing chamber 2, one sample is put into a freeze chamber 3, and one sample is put into a freezing chamber 4; carrying out freeze thawing cycle treatment on a sample in the freeze thawing chamber 2, wherein in the freeze thawing cycle process, the highest temperature of the freeze thawing chamber 2 is W2, the lowest temperature is W1, the number of freeze thawing cycles is N, and the single freeze thawing cycle time is T3; freezing and blowing treatment are carried out on the sample in the freezing chamber 3, the supercooling freezing temperature in the freezing chamber 3 is W3, the blowing wind speed F is the blowing treatment time is T4; and freezing and ultraviolet irradiation treatment are carried out on the sample in the freezing chamber 4, the supercooling freezing temperature in the freezing chamber 3 is W3, the ultraviolet irradiation intensity is G, and the freezing wind treatment time is T4.
Specifically, when the freeze-thawing cycle processing is completed on the sample in the freeze-thawing chamber 2, the first image capturing device 21 detects the surface state of the sample, and when a crack is generated on the surface of the sample, a crack is selected, the total length of the crack is measured to be A1, the widest part of the crack is B1, the first image capturing device 21 transmits the measurement result to the central control module 1, and the central control module 1 calculates the score K1 of the crack, wherein k1=a1×l+b1×s; the central control module 1 calculates residual crack scores K2, K3 and … … Kn of the sample surface, and the central control module 1 calculates total crack scores Kx, kx=K1+K2+ … +Kn of the sample surface.
Specifically, when the crack on the concrete surface has branches, the first camera device 21 measures the longest path of the crack as A1, selects one of the branches and measures the distance from the tail end of the branch to the branching position of the crack as a11, the first camera device 21 transmits the detection result to the central control module 1, the central control module 1 calculates the ratio A1 of the branch length to the total length of the crack,the branch is scored according to A1 and a11 central control module 1:
when a1 is less than or equal to 0.1, the central control module 1 judges that the branch is an invalid branch and does not score the branch;
when 0.1 < a1 is less than or equal to 0.3, the central control module 1 calculates the branch length score k11, k11=a11×l×0.5;
when a1 > 0.3, the central control module 1 calculates the branch length score k11, k11=a11×l×0.8.
Specifically, when a secondary branch is generated on the branch, the first camera device 21 measures the distance from the tail end of the secondary branch to the branch outlet as a111, the first camera device 21 transmits the detection result to the central control module 1, the central control module 1 calculates the ratio a11 of the length of the secondary branch to the total length of the crack,the secondary branches were scored according to a11 and a111 central control module 1:
when a11 is less than or equal to 0.1, the central control module 1 judges that the secondary branch is an invalid branch and does not score the invalid branch;
when a11 is more than 0.1 and less than or equal to 0.3, the central control module 1 calculates the secondary branch length score k111, k11=a111×l×0.3;
when a11 > 0.3, the central control module 1 calculates the branch length score k111, k111=a111×l×0.6;
the central control module 1 divides the branch to the remaining secondary branch scores k112, k113, … … k11n;
the central control module 1 calculates a branch length score k11, k11=k11=a11×l×i+k111+k112+ … +k11n, i=0.5 or 0.8;
the central control module 1 calculates residual branch scores k12, k13 and … … k1n of the crack;
the central control module 1 calculates the crack score K1, k1=a1×l+b1×s+k11+k12+ … +k1n.
Specifically, a first concrete slag-dropping collecting device 24 is arranged below the freeze thawing chamber 2 to collect dropped slag, when the freeze thawing cycle treatment is completed on the sample in the freeze thawing chamber 2, the mass e of the slag in the collecting device 24 is detected and the detection result is transmitted to the central control module 1, the central control module 1 calculates a concrete slag-dropping amount score Qx,
the middle partThe control module 1 calculates the total score Px of the samples in the freeze thawing chamber 2,wherein, p1 is the weight parameter of the total score Kx of the crack to the total score Px of the sample of the freeze thawing chamber 2, and p2 is the weight parameter of the total score Qx of the concrete slag drop amount to the total score Px of the sample of the freeze thawing chamber 2.
Specifically, according to the algorithm, the central control module 1 calculates a total score Pz of the sample in the freezing chamber 3 and a total score Py of the sample in the freezing chamber 4, and the central control module 1 calculates a total score H of the frost resistance of the concrete to be detected according to Px, pz and Py:
H＝Px×β+Pz×δ+Py×γ
wherein, beta is the weight parameter of the total score Px of the sample in the freezing and thawing chamber 2 to the total score H of the freezing resistance, delta is the weight parameter of the total score Pz of the sample in the freezing and thawing chamber 3 to the total score H of the freezing resistance, and gamma is the weight parameter of the total score Py of the sample in the freezing and thawing chamber 4 to the total score H of the freezing resistance.
Specifically, a total freezing resistance score matrix H0 (H1, H2, H3) is further arranged in the central control module 1, wherein H1 is a first preset total freezing resistance score, H2 is a second preset total freezing resistance score, H3 is a third preset total freezing resistance score, the scores are sequentially increased, and the freezing resistance is stronger when the score is lower; the central control module 1 compares the total freezing resistance score H of the concrete with the internal parameters of the total freezing resistance score matrix H0:
when H is less than or equal to H1, the central control module 1 judges that the frost resistance of the concrete to be detected is first-level;
when H1 is more than H and less than or equal to H2, the central control module 1 judges that the frost resistance of the concrete to be detected is two-stage;
when H1 is more than H and less than or equal to H2, the central control module 1 judges that the anti-freezing performance of the concrete to be detected is three-level;
when H is more than H2, the central control module 1 judges that the frost resistance of the concrete to be detected is four-level.
Thus far, the technical solution of the present invention has been described in connection with the preferred embodiments shown in the drawings, but it is easily understood by those skilled in the art that the scope of protection of the present invention is not limited to these specific embodiments. Equivalent modifications and substitutions for related technical features may be made by those skilled in the art without departing from the principles of the present invention, and such modifications and substitutions will be within the scope of the present invention.
Claims (3)
1. The method for evaluating the frost resistance of the concrete is characterized by comprising the following steps of:
s1, placing a first part of a sample to be detected into a freeze thawing bin for pre-freeze thawing, determining the elastic modulus of the sample, and calculating scoring parameters of generated cracks and fallen slag soil according to the elastic modulus;
s2, placing three samples into a freeze thawing chamber, placing one sample into the freeze compartment, placing one sample into a freezing chamber, and performing corresponding tests on the samples to score cracks and falling slag generated by the samples in different environments;
s3, calculating a comprehensive score of the sample, and evaluating the freezing resistance of the sample;
a central control module is arranged in the process of implementing the concrete frost resistance evaluation method and is used for controlling the evaluation process and analyzing the evaluation result;
in the step S1, freeze thawing is carried out on a sample to be detected for a plurality of times, and the elastic modulus of the sample is calculated by taking an average value so as to ensure the accuracy of a calculation result; calculating a concrete crack length scoring parameter, a concrete crack width scoring parameter and a concrete slag removal amount scoring parameter in the evaluation process according to the elastic modulus;
in the step S2, the freeze thawing chamber is used for simulating a use environment with large temperature difference between day and night of concrete; the air freezing chamber is used for simulating the use environment of the concrete in high and cold weather and high wind; the freezing and shining chamber is used for simulating the use environment of concrete with high and cold property and long sunlight time; when the sample to be detected completes the corresponding environment simulation, detecting the surface state of the sample in each simulation environment, grading the generated cracks when the surface of the sample is cracked, grading the concrete slag drop amount when the sample falls off the slag, and calculating the total score of the sample to be detected in the corresponding simulation environment according to the total score of the surface cracks and the concrete slag drop amount grading;
in the step S3, a weight parameter of the total score of the sample in the freezing and thawing chamber to the total score of the freezing and thawing chamber is arranged in the central control module, the weight parameter of the total score of the sample in the freezing and thawing chamber to the total score of the freezing and thawing chamber is set, and the freezing resistance of the concrete is accurately scored by setting the weight scoring parameter; the central control module is also provided with an antifreezing total score matrix H0, compares the antifreezing total score with parameters in the antifreezing total score matrix H0, and determines the antifreezing performance grade of the sample to be detected;
a sample with the volume of C and the mass of E in the environment of 20 ℃ is placed into a freezing and thawing chamber for pre-freezing and thawing, a first image pickup device for detecting the deformation amount of the sample is arranged at the upper part of the freezing and thawing chamber, a freezing and thawing mode is started, and when the freezing and thawing chamber reaches the minimum temperature W1 for the first time and the freezing time length T1 is passed, the image pickup device detects the volume D1 of the sample; when the freezing and thawing chamber reaches the highest temperature W2 for the first time and the thawing time period T2 passes, the camera device detects the sample volume Y1; when the freezing and thawing chamber reaches the lowest temperature W1 for the second time and the freezing duration T1 passes, the image pickup device detects the sample volume D2; when the freeze thawing chamber reaches the highest temperature W2 for the second time and the thawing time period T2 passes, the camera device detects the sample volume Y2; when the freezing and thawing chamber reaches the lowest temperature W1 for the third time and the freezing duration T1 passes, the image pickup device detects the sample volume D3; when the freezing and thawing chamber reaches the highest temperature W2 for the third time and the thawing time length T2 passes, the camera device detects the sample volume Y3; the central control module calculates the sample volume change elastic modulus X:
alpha is an elastic modulus compensation parameter;
calculating a concrete crack length scoring parameter L, a concrete crack width scoring parameter S and a concrete slag quantity scoring parameter V by the central control module according to the sample volume change elastic modulus X;
L＝X×l
S＝X×s
V＝X×v
wherein L is a compensation parameter of the elastic modulus X to the concrete crack length scoring parameter L, S is a compensation parameter of the elastic modulus X to the concrete crack width scoring parameter S, and V is a compensation parameter of the elastic modulus X to the concrete slag removal scoring parameter V; in the step S2, three samples with the volume of C and the mass of E at 20 ℃ are put into a freeze thawing chamber, one sample is put into the freeze compartment, and one sample is put into a freezing chamber; carrying out freeze thawing cycle treatment on a sample in the freeze thawing chamber, wherein in the freeze thawing cycle process, the highest temperature of the freeze thawing chamber is W2, the lowest temperature is W1, the freeze thawing cycle times are N times, and the single freeze thawing cycle time is T3; performing freezing and blowing treatment on the sample in the freezing chamber, wherein the freezing temperature in the freezing chamber is W3, the blowing wind speed is F, and the freezing treatment time is T4; freezing and ultraviolet irradiation treatment are carried out on the sample in the freezing chamber, the freezing temperature in the freezing chamber is W3, the ultraviolet irradiation intensity is G, and the freezing treatment time is T4;
when the freeze thawing cycle treatment is completed on the sample in the freeze thawing chamber, the first camera device detects the surface state of the sample, when a crack is generated on the surface of the sample, one crack is selected, the total length of the crack is measured to be A1, the widest part of the crack is B1, the first camera device transmits the measurement result to the central control module, and the central control module calculates the score K1 of the crack, wherein K1=A1×L+B1×S; the central control module calculates residual crack scores K2, K3 and … … Kn of the sample surface, and calculates total crack scores Kx, kx=K1+K2+ … +Kn of the sample surface;
a concrete slag-off collecting device is arranged below the freeze thawing chamber and used for collecting the fallen slag, when the freeze thawing cycle treatment is completed on the sample in the freeze thawing chamber, the mass e of the slag in the collecting device is detected and the detection result is transmitted to the central control module, the central control module calculates the score Qx of the slag-off amount of the concrete,the central control module calculates a total score Px of the sample in the freeze thawing chamber:
wherein, p1 is the weight parameter of the total score Kx of the crack to the total score Px of the sample in the freeze thawing chamber, and p2 is the weight parameter of the total score Qx of the slag drop amount of the concrete to the total score Px of the sample in the freeze thawing chamber;
when the crack on the surface of the concrete generates branches, the first camera device measures the longest path of the crack as A1, selects one branch and measures the distance from the tail end of the branch to the branching position of the crack as A11, the first camera device transmits the detection result to the central control module, the central control module calculates the ratio A1 of the branch length to the total length of the crack,scoring the branch according to the A1 and a11 central control module:
when a1 is less than or equal to 0.1, the central control module judges that the branch is an invalid branch and does not score the branch;
when a1 is more than 0.1 and less than or equal to 0.3, the central control module calculates the branch length score k11, wherein k11=A11×L×0.5;
when A1 > 0.3, the central control module calculates the branch length score k11, k11=a11×l×0.8;
when a secondary branch is generated on the branch, the distance from the tail end of the secondary branch to the branch outlet is measured as A111 by the first camera device, the detection result is transmitted to the central control module by the first camera device, the ratio a11 of the secondary branch length to the total length of the crack is calculated by the central control module,scoring the secondary branches according to a11 and a111 central control module:
when a11 is less than or equal to 0.1, the central control module judges that the secondary branch is an invalid branch and does not score the invalid branch;
when a11 is more than 0.1 and less than or equal to 0.3, the central control module calculates the secondary branch length score k111, k11=a111×l×0.3;
when a11 > 0.3, the central control module calculates the branch length score k111, k111=a111×l×0.6;
the central control module divides the branch into a plurality of branch scores k112, k113, … … k11n;
the central control module calculates a branch length score k11, k11=k11=a11×l×i+k111+k112+ … +k11n, i=0.5 or 0.8;
the central control module calculates residual branch scores k12, k13 and … … k1n of the crack;
the central control module calculates the crack score K1, k1=a1×l+b1×s+k11+k12+ … +k1n.
2. The method for evaluating the frost resistance of the concrete according to claim 1, wherein the total score Pz of the samples in the freezing chamber and the total score Py of the samples in the freezing chamber are calculated according to the central control module, and the central control module calculates the total score H of the frost resistance of the concrete to be detected according to Px, pz and Py:
H＝Px×β+Pz×δ+Py×γ
wherein, beta is the weight parameter of the total score Px of the sample in the freezing and thawing chamber to the total score H of the freezing resistance, delta is the weight parameter of the total score Pz of the sample in the freezing and thawing chamber to the total score H of the freezing resistance, and gamma is the weight parameter of the total score Py of the sample in the freezing and thawing chamber to the total score H of the freezing resistance.
3. The method for evaluating the frost resistance of the concrete according to claim 2, wherein the central control module is further internally provided with a total frost resistance score matrix H0 (H1, H2 and H3), wherein H1 is a first preset total frost resistance score, H2 is a second preset total frost resistance score, H3 is a third preset total frost resistance score, the scores of the total scores are sequentially increased, and the lower the score is, the stronger the frost resistance is; the central control module compares the total freezing resistance score H of the concrete with the internal parameters of the total freezing resistance score matrix H0: when H is less than or equal to H1, the central control module judges that the frost resistance of the concrete to be detected is first-level;
when H1 is more than H and less than or equal to H2, the central control module judges that the frost resistance of the concrete to be detected is two-stage;
when H1 is more than H and less than or equal to H2, the central control module judges that the anti-freezing performance of the concrete to be detected is three-level;
when H is more than H2, the central control module judges that the frost resistance of the concrete to be detected is four-level.
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