CN106442947A

CN106442947A - Nondestructive (quasi-nondestructive) testing method for concrete after high temperature treatment

Info

Publication number: CN106442947A
Application number: CN201610892027.5A
Authority: CN
Inventors: 赵东拂
Original assignee: Beijing University of Civil Engineering and Architecture
Current assignee: Beijing University of Civil Engineering and Architecture
Priority date: 2016-10-12
Filing date: 2016-10-12
Publication date: 2017-02-22

Abstract

The invention provides a nondestructive (quasi-nondestructive) testing method for concrete after high temperature treatment. The method comprises the step of determining residual strength of the concrete after high temperature treatment as well as the following steps: a, nondestructive/quasi-nondestructive testing is performed on the concrete after high temperature treatment; b, the microscopic characteristic change rule of the concrete under different temperature treatment conditions is determined according to results of nondestructive/quasi-nondestructive testing, the high temperature process applied to the concrete is judged qualitatively, and a high temperature process-microscopic damage relation model is built, wherein determination of the residual strength of the concrete after high temperature treatment is implemented by the following step: c, the residual strength of the concrete is determined based on the obtained high temperature process of the concrete. With the adoption of the technical scheme, the influence of the highest temperature applied to the concrete and time of highest temperature treatment on the microstructure and the residual strength of the concrete can be comprehensively considered, damage to the concrete after high temperature treatment for a certain period of time can be truly reflected, and a valid reference is provided for repair and reinforcement of the structure.

Description

(micro-) the damage detection method of nothing after a kind of concrete high temperature

Technical field

The invention belongs to material tests field, in particular it relates to detection of the concrete after high temperature, especially, The present invention relates to no (micro-) after a kind of concrete high temperature damage detection method.

Background technology

Concrete is the construction material of purposes most wide, consumption maximum in engineering construction, and is considered as excellent fire proofing wood Material, can residual intensity of the concrete after high temperature directly affects which and be continuing with, and its service life how long, therefore, mix The residual intensity of concrete of the solidifying soil after high temperature becomes the focus for thinking to pay close attention to.

But in actually detected, multiple test points may not accurate evaluation test point with the damage status of external position, Damage range after not to overdoing does total evaluation.

Content of the invention

In order to overcome above problem above of the prior art, the present invention is no (micro-) after providing a kind of concrete high temperature to damage inspection Survey method, the detection method can do total evaluation to the damage range for experiencing the xoncrete structure after high temperature, can be by concrete Temperature history, microstructure and macro-mechanical property are connected well.The present invention establishes model, both can be qualitative with science Microstructure characteristic of the description material in ground under the comprehensive function that high temperature and stress are damaged, again can be with quantitative response microstructure phase Related parameter and temperature and the relation that damages.

In order to reach object above, the present invention is adopted the following technical scheme that：After a kind of concrete high temperature, no (micro-) damage is detected Method, including determining the residual intensity of concrete after high temperature, further comprising the steps of：

A. lossless/Non-destructive test is carried out to the concrete after high temperature；

B. the microscopic feature Changing Pattern of concrete under different temperatures operating mode is determined according to lossless/Non-destructive test result, fixed Property judge concrete institute through high temperature course；Set up high temperature course microscopic damage relational model；

Wherein it is determined that the residual intensity of concrete is achieved by the steps of after high temperature：C. using the height of gained concrete Warm course determines the residual intensity of concrete.

Using above technical scheme, lossless/Non-destructive test is carried out to xoncrete structure, determine coagulation under different temperatures operating mode The microscopic feature Changing Pattern of soil, determines that concrete institute, through high temperature course, then determines the residue of concrete according to high temperature course Intensity, such detection method, total evaluation can be done to experiencing the impaired of xoncrete structure after high temperature.

Preferably, in step a, the lossless/Non-destructive test is comprised the following steps：

A. to experiencing the xoncrete structure after high temperature, ultrasound examination is carried out；

B. to experiencing the xoncrete structure after high temperature, micro-hardness testing is carried out；

C. to experiencing the xoncrete structure after high temperature, ultramicroscope (SEM) analysis is scanned, to concrete after high temperature Structure is scanned, and observes hydrated cementitious paste structure；

D. mercury pressure test being carried out to experiencing the xoncrete structure after high temperature, analyzes the hole state after concrete high temperature；

E. to experiencing the xoncrete structure after high temperature, X ray diffracting spectrum detection is carried out, in observation XRD spectrum, crystalline phase is divided Cloth and the change of peak value.

Any of the above-described scheme is preferably, in step A, using to the sound of weld defect control when, first wave amplitude (wave amplitude) and frequency Three parameters,acoustics of rate are analyzed to concrete damage situation after high temperature.

Any of the above-described scheme is preferably, in step A, uniform application medical ventolin at the test point.

Any of the above-described scheme is preferably, and in step A, ultrasonic emitting frequency is 50kHz.

Any of the above-described scheme is preferably, in step A, in order to obtain more accurately result, each test point retest, The test result that averages as the test point.

Any of the above-described scheme is preferably, and in step A, using to surveying method, is surpassed using single channel ultrasonic wave detector Sonic test.Described to surveying method, will two pop one's head in and will be arranged in the correspondence position of opposite face and survey ultrasound wave, rather than any two Individual face.

Any of the above-described scheme is preferably, in step A, with sound when, first wave amplitude (wave amplitude) and frequency values change be turned to The foundation of test specimen quality evaluation.

Any of the above-described scheme is preferably, and in step B, test specimen that ultrasonic tesint is finished, before and after during heating Face cuts, makes detection sample.Thermal field assumes law of symmetry distribution in each cross section, after sample is prepared, in conjunction with to surveying Method, it is possible to measure the high-temperature damage of diverse location, is conducive to more accurately evaluating high-temperature damage.

Any of the above-described scheme is preferably, and in step B, detects the concrete after experience high temperature using Vickers hardness measurement method The Vickers hardness number (HIV) of structure, evaluates to experiencing high temperature concrete damage.

Any of the above-described scheme is preferably, and in step D, device measuring aperture is 360 microns～3.2 nanometers.

Any of the above-described scheme is preferably, and in step E, is scanned using continuous scan mode.

Any of the above-described scheme is preferably, and in step E, during scanning, step-length is 0.02 degree/step.

Any of the above-described scheme is preferably, and in step E, when scanning, speed is 2 degree/min.

Any of the above-described scheme is preferably, and in step E, when scanning, sweep limitss are 10 °～80 °.

Any of the above-described scheme is preferably, in step b, using hydrated product, water of crystallization, gel morphology change, hydroxide Calcium, dolomite, entringite peak change, porosity, pore size change, concrete institute is qualitatively judged through high temperature course.These Be all finish analysis of experiments after, the crucial effect parameter that extracts, can be qualitatively judged by the change of these material parameters The high temperature course of concrete.

Any of the above-described scheme is preferably, when the high temperature course microscopic damage relational model includes high temperature course sound Model, high temperature course wave amplitude model, high temperature course microhardness model, high temperature course hydrargyrum intrusion model.

Any of the above-described scheme is preferably, and during the high temperature course sound, model is v=b₁T+b₂t+C.Gone through using the high temperature Model during Cheng Sheng, has considered the time of maximum temperature that concrete experienced and experience maximum temperature to concrete microcosmic The impact of structure, can truly reflect the damage of concrete after the high temperature of certain time, be that reparation, the reinforcing of structure is provided with Effect reference.

Any of the above-described scheme is preferably, and during the high temperature course sound, model is v=0.153T+8.822t-26.301.

Any of the above-described scheme is preferably, and the high temperature course wave amplitude model is A=c₁T+c₂T+C, wherein C are constant. Using the high temperature course wave amplitude model, the concrete maximum temperature for being experienced and the time for experiencing maximum temperature has been considered Impact to concrete microstructure, can truly reflect the damage of concrete after the high temperature of certain time, be repairing for structure Multiple, reinforcing is provided and is effectively referred to.

Any of the above-described scheme is preferably, and the high temperature course wave amplitude model is A=-0.066T-1.731t+ 137.415.

Any of the above-described scheme is preferably, and the high temperature course microhardness model is H=d₁T+d₂T+C, wherein C are Constant.Using the high temperature course microhardness model, maximum temperature and experience highest that concrete is experienced has been considered Impact of the time of temperature to concrete microstructure, can truly reflect the damage of concrete after the high temperature of certain time, For the reparation of structure, reinforce offer effectively reference.

Any of the above-described scheme is preferably, and the high temperature course microhardness model is H=-0.018T+0.707t+ 92.614.

Any of the above-described scheme is preferably, and the high temperature course hydrargyrum intrusion model is M=e₁T+e₂T+C, wherein：e₁、 e₂For regression coefficient, C is constant.Using the high temperature course hydrargyrum intrusion model, concrete is considered and has been experienced most Impact of the time of high-temperature and experience maximum temperature to concrete microstructure, can truly reflect the high temperature through certain time The damage of concrete afterwards is the reparation of structure, reinforce offer effectively refers to.

Any of the above-described scheme is preferably, and the high temperature course hydrargyrum intrusion model is M=-3.884 × 10^-5T+ 0.010t+0.066.

Any of the above-described scheme is preferably, in step c, to experiencing the residual intensity of concrete and experienced highest after high temperature Temperature and the relation through the time of maximum temperature carry out regression analyses, set up high temperature course Residual Strength Model.Using this High temperature course Residual Strength Model is calculated after high temperature during the residual intensity of concrete, has considered what concrete was experienced Maximum temperature and the time of experience maximum temperature, can truly reflect the residual intensity of concrete after the high temperature of certain time Value is the reparation of structure, reinforce offer effectively refers to.

Any of the above-described scheme is preferably, and the high temperature course Residual Strength Model is

Any of the above-described scheme is preferably, and the test specimen is cube specimen.

Using the detection method of the present invention, comprehensively, high temperature course surrounding and watching damage, remaining to xoncrete structure is considered comprehensively The impact of residual strength, does total evaluation to the damage range for experiencing the xoncrete structure after high temperature, can go through the temperature of concrete Journey, microstructure and macro-mechanical property are connected well.The present invention establishes a model, both can with science qualitatively Microstructure characteristic of the description material under the comprehensive function that high temperature and stress are damaged, again can be with quantitative response microstructure correlation Parameter and temperature and the relation that damages.

Description of the drawings

Fig. 1 is the residual intensity and heating-up temperature, constant temperature time graph of a relation for being obtained using universal hydraulic testing machine.

Fig. 2 is the residual intensity ratio for being obtained using universal hydraulic testing machine and temperature and the constant temperature time graph of a relation of overdoing.

Fig. 3 is according to the flow chart of (micro-) preferred embodiment for damaging detection method of nothing after the mixed concrete high temperature of the present invention.

Fig. 4 is no (micro-) after mixed concrete high temperature as shown in Figure 3 damage in detection method after the high-temperature damage of ultrasound examination The graph of a relation during sound of different test specimens with experience maximum temperature.

Fig. 5 is no (micro-) ripple for damaging different test specimens after detection method high temperature is damaged after mixed concrete high temperature as shown in Figure 3 The graph of a relation of width and experienced maximum temperature.

Fig. 6 is no (micro-) frequency for damaging different test specimens after detection method high temperature is damaged after mixed concrete high temperature as shown in Figure 3 The graph of a relation of rate and experienced maximum temperature.

Fig. 7 is that no (micro-) damage experiences the micro- hard of test specimen after high temperature in detection method after mixed concrete high temperature as shown in Figure 3 Degree and the graph of a relation of institute's experience maximum temperature.

Fig. 8 is that no (micro-) damage experiences the micro- hard of test specimen after high temperature in detection method after mixed concrete high temperature as shown in Figure 3 Degree and the graph of a relation of institute's experience maximum temperature time.

Fig. 9 is the SEM picture of test specimen under room temperature as shown in Figure 3 after mixed concrete high temperature no in (micro-) damage detection method.

Figure 10 is as shown in Figure 3 after mixed concrete high temperature no in (micro-) damage detection method, through maximum temperature be Temperature, and constant temperature after 1 hour at the maximum temperature, the SEM picture of test specimen.

Figure 11 is as shown in Figure 3 after mixed concrete high temperature no in (micro-) damage detection method, through maximum temperature be Temperature, and constant temperature after 1 hour at the maximum temperature, the SEM picture of test specimen.

Figure 12 is as shown in Figure 3 after mixed concrete high temperature no in (micro-) damage detection method, through maximum temperature be Temperature, and constant temperature after 1 hour at the maximum temperature, the SEM picture of test specimen.

Figure 13 is as shown in Figure 3 after mixed concrete high temperature no in (micro-) damage detection method, through maximum temperature be Temperature, and constant temperature after 1 hour at the maximum temperature, the SEM picture of test specimen.

Figure 14 is as shown in Figure 3 after mixed concrete high temperature no in (micro-) damage detection method, through maximum temperature be Temperature, and constant temperature after 1 hour at the maximum temperature, the SEM picture of test specimen.

Figure 15 is as shown in Figure 3 after mixed concrete high temperature no in (micro-) damage detection method, through maximum temperature be Temperature, and constant temperature after 1 hour at the maximum temperature, the SEM picture of test specimen.

Figure 16 is as shown in Figure 3 after mixed concrete high temperature no in (micro-) damage detection method, through maximum temperature be Temperature, and constant temperature after 1 hour at the maximum temperature, the SEM picture of test specimen.

Figure 17 is as shown in Figure 3 after mixed concrete high temperature no in (micro-) damage detection method, through maximum temperature be Temperature, and constant temperature after 1 hour at the maximum temperature, the SEM picture of test specimen.

Figure 18 is as shown in Figure 3 after mixed concrete high temperature no in (micro-) damage detection method, through maximum temperature be Temperature, and constant temperature after 1 hour at the maximum temperature, the SEM picture of test specimen.

Figure 19 is as shown in Figure 3 after mixed concrete high temperature no in (micro-) damage detection method, through maximum temperature be Temperature, and constant temperature after 0.5 hour at the maximum temperature, the SEM picture of test specimen.

Figure 20 is as shown in Figure 3 after mixed concrete high temperature no in (micro-) damage detection method, through maximum temperature be Temperature, and constant temperature after 2 hours at the maximum temperature, the SEM picture of test specimen.

Figure 21 is as shown in Figure 3 after mixed concrete high temperature no in (micro-) damage detection method, through maximum temperature be Temperature, and constant temperature after 3 hours at the maximum temperature, the SEM picture of test specimen.

Figure 22 is the XRD spectrum of test specimen under room temperature as shown in Figure 3 after mixed concrete high temperature no in (micro-) damage detection method.

Figure 23 is as shown in Figure 3 after mixed concrete high temperature no in (micro-) damage detection method, through maximum temperature be Temperature, and constant temperature after 1 hour at the maximum temperature, the XRD spectrum of test specimen.

Figure 24 is as shown in Figure 3 after mixed concrete high temperature no in (micro-) damage detection method, through maximum temperature be Temperature, and constant temperature after 1 hour at the maximum temperature, the XRD spectrum of test specimen.

Figure 25 is as shown in Figure 3 after mixed concrete high temperature no in (micro-) damage detection method, through maximum temperature be Temperature, and constant temperature after 1 hour at the maximum temperature, the XRD spectrum of test specimen.

Figure 26 is as shown in Figure 3 after mixed concrete high temperature no in (micro-) damage detection method, through maximum temperature be Temperature, and constant temperature after 1 hour at the maximum temperature, the XRD spectrum of test specimen.

Figure 27 is as shown in Figure 3 after mixed concrete high temperature no in (micro-) damage detection method, through maximum temperature be Temperature, and constant temperature after 1 hour at the maximum temperature, the XRD spectrum of test specimen.

Figure 28 is as shown in Figure 3 after mixed concrete high temperature no in (micro-) damage detection method, through maximum temperature be Temperature, and constant temperature after 1 hour at the maximum temperature, the XRD spectrum of test specimen.

Figure 29 is as shown in Figure 3 after mixed concrete high temperature no in (micro-) damage detection method, through maximum temperature be Temperature, and constant temperature after 1 hour at the maximum temperature, the XRD spectrum of test specimen.

Figure 30 is as shown in Figure 3 after mixed concrete high temperature no in (micro-) damage detection method, through maximum temperature be Temperature, and constant temperature after 1 hour at the maximum temperature, the XRD spectrum of test specimen.

Figure 31 is as shown in Figure 3 after mixed concrete high temperature no in (micro-) damage detection method, through maximum temperature be Temperature, and constant temperature after 1 hour at the maximum temperature, the XRD spectrum of test specimen.

Figure 32 is as shown in Figure 3 after mixed concrete high temperature no in (micro-) damage detection method, through maximum temperature be Temperature, and constant temperature after 0.5 hour at the maximum temperature, the XRD spectrum of test specimen.

Figure 33 is as shown in Figure 3 after mixed concrete high temperature no in (micro-) damage detection method, through maximum temperature be Temperature, and constant temperature after 2 hours at the maximum temperature, the XRD spectrum of test specimen.

Figure 34 is as shown in Figure 3 after mixed concrete high temperature no in (micro-) damage detection method, through maximum temperature be Temperature, and constant temperature after 3 hours at the maximum temperature, the XRD spectrum of test specimen.

Specific embodiment

In order to become apparent from, more accurately understand the content of the invention of the present invention, with reference to specific embodiment and accompanying drawing to this The content of the invention of invention is further explained, illustrates.

Embodiment 1

In the present embodiment, including test the selection of test block, experimental temperature be related to etc. some, be described in detail below The content of the invention of the present invention.

(1) selection of experiment test block makes standard cube test specimen with C60 concrete as test material.

(2) selection of concrete sample amount and operating mode.EXPERIMENTAL DESIGN heating temperature range is 100 DEG C～900 DEG C, at interval of 100 DEG C is a small group；Constant temperature 0.5h, 1h, 2h, 3h respectively are heated up to after assigned temperature per group's test specimen.

(3) the step of testing.Test is broadly divided into：First stage is hot test, and second stage is tested for residual intensity Test, the phase III is the concrete NDT stage after high temperature of the present invention.

(3.1) the hot test stage carries out high-temperature heating test using chamber type electric resistance furnace, size of burner hearth be 300mm × 500mm × 200mm, it is allowed to 1000 DEG C of maximum temperature, temperature control precision ± 1 DEG C.During raising temp and loading, test specimen is put to resistance furnace Interior, initial temperature is room temperature, to rise to design temperature with international standard heating curve, for examination of the temperature for setting more than 600 DEG C Block, for prevent in temperature-rise period occur explosion damage instrument, wrap up high temperature resistant wire gauze outside which, constant temperature to the scheduled time, Cut off the electricity supply, fire door is opened, make fire box temperature that room temperature is down to, test block is taken out, parcel preservation is carried out with preservative film, because high temperature examination After testing, if placed in the air, steam entrance is had, affect content (the scanning electricity of Free water in follow-up microscopic test Mirror), it is ensured that the accuracy of result.

(3.2) the residual intensity testing experiment stage.Using hydraulic servo universal testing machine, the test block after high temperature is carried out by force Degree test.In order to increase the reliability of data, taking 3 test specimens per group carries out residual intensity test, takes average as representative value, surveys Amount result is as shown in table 1.

1 investigation of strength of concrete at elevated temperature static(al) of table tests table

Note：P-X-X represents：Fatigue test-warm temperature-constant temperature time, P-1-0.5 represents fatigue test-maximum temperature It it is 0.5 hour for constant temperature time at 100 DEG C-maximum temperature.

Through residual intensity test, measure do not experience high temperature course test block pressure resistance intensity be 61.2Mpa, each worst hot case The residual intensity of lower concrete sample and residual intensity ratio change pass with the difference of test block heating-up temperature and constant temperature time System's figure is as shown in Figures 1 and 2.From table 1, Fig. 1 and Fig. 2 as can be seen that experience high temperature after concrete residual intensity not only with The maximum temperature for being experienced is relevant, but also relevant with the constant temperature time in maximum temperature.

(3.3) universal testing machine measures the residual intensity of test specimen, only several test points, it is impossible to which W-response is mixed comprehensively The damage situations of Xtah Crude Clay structure, for the damage situations of comprehensive, overall evaluation concrete after high temperature, the present embodiment provides a kind of (micro-) the damage detection method of nothing after concrete high temperature, flow chart as shown in figure 3, specifically, according to enforcement order, includes following successively Step：

B. determine the microscopic feature Changing Pattern of concrete under different temperatures operating mode according to lossless/Non-destructive test result, really Concrete institute is determined through high temperature course；

C. the residual intensity of concrete is determined using the high temperature course of gained concrete.

Wherein, in step a, the lossless/Non-destructive test is comprised the following steps：

In step A-E, first implementation steps A, step B, C, D and E is then carried out, and the enforcement of step B-D order is not done Limit, can be arranged according to practical situation.

During implementation steps A, ultrasonic emitting frequency is 50kHz, uniform application medical ventolin at test point, using to surveying Method, carries out ultrasonic testing using single channel ultrasonic wave detector, with the range finding of vernier caliper measurement cube specimen, transmitting frequency Rate is 50KHz.Each measuring point retest 6 times, the test result that averages as the point, using the sound to weld defect control When, first wave amplitude (wave amplitude) and three parameters,acoustics of frequency are analyzed to concrete damage situation after high temperature.

After high temperature during the sound of different test specimens, the constant temperature time of the maximum temperature and maximum temperature of wave amplitude and frequency and experience Graph of a relation is as shown in Figures 4 to 6 (that does not wherein indicate temperature retention time is 1 hour).There it can be seen that not experiencing high temperature C60 normal concrete, is 19.2 μ s during its sound；And after experiencing high temperature, in 24.12-124.53 μ s during the sound of C60 concrete, with Normal concrete is compared, and increased 4.92-105.33 μ s during sound；Under conditions of same high temperature lasts, the concrete of high temperature is experienced Sound when increase with the increase of high-temperature temperature, indivedual test specimens occur data bounce situation and sample itself test position Defect is relevant, may be more serious in the lucky local failure of test position, causes data bigger than normal than test specimen basic condition, or exists Reverse situation.In turn can using sound when show the degree of crackle and hole defect in concrete；The benchmark of high temperature is not experienced Concrete, its wave amplitude is 159.8dB；Experience high temperature after, the wave amplitude of C60 concrete in 158.38-127.36dB, with benchmark coagulation Soil is compared, and wave amplitude reduces 32.44-1.42dB；100 DEG C of high temperature of experience, 200 DEG C, 300 DEG C, 400 DEG C of test specimen, high temperature lasts When identical, its wave amplitude is 156-159dB or so, is more or less the same；From 400 DEG C, with the rising of high-temperature temperature, under wave amplitude is rapid Drop, during to 900 DEG C, wave amplitude is reduced to 127.70dB or so, it is believed that 400 DEG C be wave amplitude produce significant change flex point；Equally Under hot conditionss, difference is lasted (0.5h, 1h, 2h, 3h) and the wave amplitude of concrete is affected less, consistent with result during sound；Not The frequency of the normal concrete of experience high temperature is 48.48KHz；After experience high temperature, the frequency of C60 concrete is 47.10- 12.88kHz, compared with normal concrete, frequency reduces 1.38-35.60kHz；Experience 100 DEG C of high temperature, 200 DEG C, 300 DEG C, 400 DEG C of test specimen, high temperature lasts and is all 1h, and its frequency is 45-47kHz or so, and wherein 300 DEG C of frequency values are low, should be with survey Examination position is just at weakness zone, and defect is on the high side relation, or there may be big crack or hole, is similar to and surveys with acoustics Open circuit is pinged, causes the data perturbation that tests；From 400 DEG C, with the rising (400-900 DEG C) of high-temperature temperature, frequency Rapid decline, during to 900 DEG C, wave amplitude is reduced to 12.88dB, it is believed that 400 DEG C is flex point that frequency produces significant change, this Point is consistent with the change of wave amplitude；Under same hot conditionss, as high temperature lasts the increase of (0.5h, 1h, 2h, 3h), frequency reduces, This point be different from sound when and wave amplitude result.

During implementation steps B, cube specimen that ultrasonic tesint is finished, cut along centrage parallel to front-back during heating Equal-sized two parts are cut into, are taken a portion and 1cm thin slice is cut into, the thickness error of thin slice is within 1mm.By sample Firm is positioned on a rigid mount, so that pressure head is contacted with specimen surface, applies test force perpendicular to test face, until applying To setting.Finishing from loading beginning to the applying of total Test power should be between 1s～5s.During the holding of maximum constant test force Between should be 15s.Microhardness detection is evaluated to experiencing high temperature concrete damage using Vickers hardness number HIV, different test specimens Vickers hardness and experience maximum temperature (constant temperature time be 1 hour, maximum temperature difference) and maximum temperature temperature retention time The relation of (as a example by 400 DEG C, constant temperature time difference) is as shown in Figure 7 and Figure 8.It can be seen from figure 7 that concrete is micro- hard Degree totally assumes downward trend with the rising of temperature, does not experience the normal concrete of high temperature, and its Vickers hardness is 52.50.High Under the conditions of 100 DEG C～300 DEG C of temperature, with the rising of temperature, Vickers hardness is continuously increased, and the Vickers of the test specimen that 300 DEG C of high temperature is hard Degree reaches highest, is 98.25GPa.From 300 DEG C～900 DEG C, with high-temperature temperature raise, Vickers hardness reduce, Vickers hardness it So starting to reduce from 300 DEG C, reason is that now hydrated product starts to decompose, and structure starts deterioration；Can from Fig. 8 Go out, with the increase that high temperature lasts, Vickers hardness reduces, and is reduced to 45.5GPa from 138.25GPa.With experience 400 DEG C of high temperature, Constant temperature 1h is compared, and the test block heating-up temperature of 300 DEG C of constant temperature 1h of high temperature reduces by 100 DEG C, and Vickers hardness increases 11.75GPa；But high temperature 400 DEG C, the high temperature of constant temperature 0.5h lasts reduction 0.5h, and Vickers hardness increases 51.75GPa, illustrates that high temperature lasts at 400 DEG C Impact of the change to microhardness bigger.

During implementation steps C, surface topography is carried out to material using 250 environmental scanning electron microscope of Quanta FEG and is divided Analysis, accelerating potential is 20KV.The SEM picture of the test specimen of different maximum temperatures and different constant temperature time as shown in Fig. 9-21, from In can draw, do not experience the normal concrete test specimen of high temperature, SEM photograph show in concrete combine between hydrated cementitious slurry tight Close, structural integrity, hydrated product is in good condition, degree is high, undecomposed, closely knit, continuous between each thing phase, has no the funeral of water of crystallization Lose, paste structure is intact, SiO₂Surface of aggregate is intact, there is CH crystal in slurry, there is entringite acicular crystal in slurry.Water There is gel in slurry body in a large number, it is seen that calcium hydroxide (Ca (OH)₂Or CH) and entringite (Aft) acicular crystal.Experience is not The microscopic feature of synthermal and different constant temperature times is summarized as shown in table 2 to table 4.

2 100 DEG C～500 DEG C Concrete At High Temperature microscopic feature tables of table

3 600 DEG C～900 DEG C Concrete At High Temperature microscopic feature tables of table

The different high temperature of table 4 last lower concrete microscopic feature table (400 DEG C)

During implementation steps D, pore structure study is carried out to sample using the full-automatic mercury injection apparatus of 9500 type of AutoPore IV, if Standby measurement pore diameter range is that 360 μm～3.2nm, as a result as shown in table 5, that does not wherein indicate constant temperature time is 1 hour.

5 Mercury injection test test result of table

The different maximum temperature constant temperature time of different maximum thermometers be can be seen that from hydrargyrum pressure experimental result, to test specimen Hydrargyrum pressure experimental result all have an impact, reflect different degree of impairments.

There is the sharp peaks 0.04142mL/g of a hydrargyrum intrusion under room temperature at the 32.4nm of aperture, other peak values are general All in below 0.013mL/g.Mercury injection method result of the test shows, the pore structure for not experiencing the normal concrete of high temperature is distributed in Between 1nm～1mm, below 100nm is distributed mainly on, integrated distribution occurs in 30nm or so in 30nm or so, peak value.

After 100 DEG C of high temperature of experience 1h, it is seen that have the peak value 0.06846mL/g of a hydrargyrum intrusion at the 95.6nm of aperture, And the width at peak is that 7.2～2233.1nm, far above normal concrete, other peak values are respectively less than 0.012mL/g.Mercury injection method Result of the test shows, what the pore structure distribution for experiencing the concrete that 100 DEG C of high temperature reach 1h presented that nanoscale hole increases shows As, starting loose phenomenon occur have relation with paste structure, concrete reason has a small amount of gel to start to decompose；Micron order hole and base Quasi- concrete is very close to this hot conditionss in surface are no affected on the hole in micron order aperture.

After 200 DEG C of high temperature of experience 1h, it is seen that have the peak value 0.06206mL/g of a hydrargyrum intrusion at the 50.3nm of aperture, Far above normal concrete, and the width at peak is 9.1～351.1nm；There is the sharp peak value of a pole tip at 370.4438 μm 0.2443mL/g, peak width is very narrow, shows now with the presence of larger porosity defects；Other peak values are respectively less than 0.04mL/ g.Mercury injection method result of the test shows, the pore structure distribution for experiencing the concrete that 200 DEG C of high temperature reach 1h presents micron order hole The phenomenon that uprushes, starts larger porosity defects occur have relation with paste structure, concrete reason have gel decomposition concentration of local, plus Acute.

After 300 DEG C of high temperature of experience 1h, it is seen that have the peak value 0.09077mL/g of a hydrargyrum intrusion at the 50.3nm of aperture, Far above normal concrete and M-1-1-1.5 and M-2-1-3, and the width at peak is 5.2～551.5nm；At 369.7101 μm There is the sharp peak value 0.3464mL/g of a pole tip at place, and peak width is very narrow, shows now with the presence of larger porosity defects, with M- 2-1-3 is compared, and position is constant, and peak height is slightly higher, is represented that defect is raised with temperature and is developed further；Other peak values are respectively less than 0.02mL/g.Mercury injection method result of the test shows, the pore structure distribution for experiencing the concrete that 300 DEG C of high temperature reach 1h presents micron The level phenomenon uprushed of hole, larger porosity defects occur with paste structure has relation, concrete reason have gel decomposition concentration of local, Aggravation.

After 400 DEG C of high temperature of experience 1h, it is seen that have the peak value 0.06813mL/g of a hydrargyrum intrusion at the 77.1nm of aperture, Far above normal concrete, and the width at peak is 4.5～1046.9nm；Other peak values are respectively less than 0.012mL/g.Mercury injection method Result of the test shows, the pore structure distribution for experiencing the concrete that 400 DEG C of high temperature reach 1h presents that nanoscale hole is on the high side to be showed As scattering and disappearing mainly due to gel decomposition or water of crystallization.

After 500 DEG C of high temperature of experience 1h, it is seen that have the peak value 0.06191mL/g of a hydrargyrum intrusion at the 77.1nm of aperture, Far above normal concrete, and the width at peak is 13.7～225.8nm；There is pole tip sharp at 368.6182 μm, 783.2nm Peak value 0.1230mL/g, 0.08337mL/g, peak width is very narrow, shows that the porosity defects in this aperture are more；Other peak values are respectively less than 0.015mL/g.Mercury injection method result of the test shows, experience the concrete that 500 DEG C of high temperature reach 1h pore structure distribution present micro- Certain aperture of meter level and the notable many phenomenons of certain aperture hole of nanoscale, this is produced due to gel decomposition.

600 DEG C of experience high temperature 0.5 hour, it is seen that the peak value 0.2451mL/g for having pole tip sharp at 366.6957 μm, peak width is very Narrow, show that the porosity defects in this aperture are more；Other peak values are respectively less than 0.05mL/g.Mercury injection method result of the test shows, experience 600 DEG C of high temperature reaches the pore structure distribution of the concrete of 0.5h and presents the notable many phenomenons of certain aperture hole of micron order, this It is to be produced due to gel decomposition, in addition, in whole pore structure distribution, holes at different levels significantly increase.

700 DEG C of high temperature 0.5h of experience, the concrete sample at test specimen high temperature surface 5cm.It can be seen that at 362.1355 μm The peak value 0.1005mL/g for having pole tip sharp, peak width is very narrow, shows that the porosity defects in this aperture are more；Other peak values are respectively less than 0.05mL/g.Mercury injection method result of the test shows, experience the concrete that 700 DEG C of high temperature reach 0.5h pore structure distribution present micro- The notable many phenomenons of certain aperture hole of meter level, this is produced due to gel decomposition.

800 DEG C of high temperature 0.5h of experience, the concrete sample at test specimen high temperature surface 5cm.It can be seen that no particularly pertinent Peak, the peak height at each peak is more or less the same, and peak value is respectively less than 0.025mL/g.Mercury injection method result of the test shows, experiences 800 DEG C of high temperature Reach the concrete of 0.5h pore structure distribution present each aperture hole quantitative difference little, no certain aperture hole is concentrated point The phenomenon of cloth.

900 DEG C of high temperature 0.5h concrete samples are experienced, its microcosmic feature is：In concrete, aperture is in 370 μm or so of hole Gap is significantly many, and in addition overall hole all increases.

Different constant temperature times press the impact of experimental result to hydrargyrum：

After 400 DEG C of high temperature of experience 0.5h, it is seen that have the peak value 0.1043mL/g of a hydrargyrum intrusion at the 77.1nm of aperture, Far above normal concrete, and the width at peak is that 12.3～1627.1nm, nanoscale hole is dramatically increased；At 335.4365 μm With 308.1835 μm at have sharp peak value 0.05049mL/g, 0.01550mL/g, peak width is very narrow, shows now to have had larger Porosity defects exist；Other peak values are respectively less than 0.012mL/g.Mercury injection method result of the test shows, 400 DEG C of high temperature of experience reach The pore structure distribution of the concrete of 0.5h presents the phenomenon that hole integrally significantly increases, and shows slurry deterioration aggravation, and Nanoscale hole is dramatically increased, and is shown that gel decomposition or water of crystallization scatter and disappear and is accelerated.

After 400 DEG C of high temperature 2h of experience, it is seen that have the peak value 0.08273mL/g of a hydrargyrum intrusion at the 77.2nm of aperture, far Higher than normal concrete, and the width at peak is 17.1～1871.1nm；Other peak values are respectively less than 0.02mL/g.Mercury injection method is tried Test result to show, the pore structure distribution for experiencing the concrete that 400 DEG C of high temperature reach 2h presents nanoscale hole phenomenon on the high side, Scatter and disappear mainly due to gel decomposition or water of crystallization.

After 400 DEG C of high temperature of experience 3h, it is seen that have the peak value 0.06813mL/g of a hydrargyrum intrusion at the 95.4nm of aperture, Far above normal concrete, and the width at peak is 4.0～347.2nm；There is the sharp peak value of a pole tip at 366.9672 μm 0.1209mL/g, peak width is very narrow, shows now with the presence of larger porosity defects；Other peak values are respectively less than 0.015mL/g.Pressure Hydrargyrum method result of the test shows, the pore structure distribution for experiencing the concrete that 400 DEG C of high temperature reach 3h presents the minimizing of nanoscale hole Phenomenon, this be as, under long-time hot conditionss, gel is melted into entirety.

During implementation steps E, using XRD7000 type X-ray diffractometer, using continuous scan mode, 0.02 degree of step-length/walk, 2 degree/min of speed, 10 °～80 ° of sweep limitss, using hydrated product, water of crystallization, gel morphology change, calcium hydroxide, white clouds Stone, entringite peak change, porosity, pore size change, concrete institute is qualitatively judged through high temperature course, the different highests of experience The XRD spectrum of temperature and different constant temperature time test specimens is as shown in Figure 22-34.

As can be seen from Figure 22, to not experiencing the normal concrete test specimen of high temperature, after hydrated cementitious, cement ore is mutually basic Reaction is completed.The peak value of hydrated product calcium hydroxide is relatively low, shows that calcium hydroxide has certain content.Hydrated product entringite Peak value is very low, shows that although entringite has, but content is little.From the thing phase of XRD, quartz content is very high, this be from In gathering materials；It is emerylite and dolomite to take second place, and may be from gathering materials

The XRD result of the test specimen of the different maximum temperatures (constant temperature time is 1 hour) of experience：

As can be seen from Figure 23, concrete sample of 100 DEG C of high temperature at test specimen high temperature surface 1.5cm, XRD are experienced Collection of illustrative plates shows, after hydrated cementitious, cement ore phase fundamental reaction is completed, tricalcium silicate, dicalcium silicate, tricalcium aluminate, tetra calcium aluminoferrite Content is little, and almost reaction is finished.The feature peak-to-peak value of hydrated product calcium hydroxide is relatively low, shows that calcium hydroxide is present and necessarily contains Amount.The characteristic peak of hydrated product entringite does not almost have, and shows almost not finding the presence of entringite.From the thing phase of XRD See, the content of quartz is very high, comes from and gathers materials；Next to that albite, cordierite, calcium hydroxide, albite and cordierite may Come from and gather materials, calcium hydroxide is hydrolysis product of cement；It is finally dolomite and hydrated calcium silicate gel, hydrated calcium silicate conduct Main hydrolysis product of cement, therefore its peak value, maintains the hot conditionss of 1 hour higher than the peak value of normal concrete at 100 DEG C Under, hydration reaction is promoted, and the growth of hydrated product is accelerated, and now, the growth to concrete crushing strength is favourable.

As can be seen from Figure 24, concrete sample of 200 DEG C of high temperature at test specimen high temperature surface 3cm, XRD figure are experienced Spectrum shows, through hydrated reaction of cement, cement ore phase fundamental reaction is completed, tricalcium silicate, dicalcium silicate, tricalcium aluminate, ferrum aluminum Sour four calcium contents are little, and almost reaction is finished.The feature peak-to-peak value of hydrated product calcium hydroxide is relatively low, shows that calcium hydroxide is present Certain content.The characteristic peak of hydrated product entringite does not almost have, and shows almost not finding the presence of entringite.From XRD's See in thing phase, the content of quartz is very high, comes from and gathers materials；Next to that albite, clinoenstatite, plus rattan stone, may be from collection Material；It is finally calcium hydroxide and hydrated calcium silicate gel, calcium hydroxide is hydrolysis product of cement, and hydrated calcium silicate gel is main Hydrolysis product of cement, the peak value of hydrated calcium silicate gel higher than the peak value of normal concrete, the peak value less than 100 DEG C, therefore, Under the hot conditionss of 200 DEG C of maintenance 1h, gel growth remains promotion compared with normal concrete, but not as 100 DEG C are tieed up Hold obvious under conditions of 1h.

As can be seen from Figure 25, concrete sample of 300 DEG C of high temperature at test specimen high temperature surface 3cm, XRD figure are experienced Spectrum shows, through hydrated reaction of cement, cement ore phase fundamental reaction is completed, tricalcium silicate, dicalcium silicate, tricalcium aluminate, ferrum aluminum Sour four calcium contents are little, and almost reaction is finished.The feature peak-to-peak value of hydrated product calcium hydroxide is relatively low, shows that calcium hydroxide is present Certain content.The characteristic peak of hydrated product entringite does not almost have, and shows almost not finding the presence of entringite.From XRD's See in thing phase, the content of quartz is very high, comes from and gathers materials；Next to that albite, calcium hydroxide, albite is may be from collection Material, calcium hydroxide is hydrolysis product of cement；It is finally dolomite and many calcium syngenite.

As can be seen from Figure 26, concrete sample of 400 DEG C of high temperature 1h at test specimen high temperature surface 3cm, XRD are experienced Collection of illustrative plates shows, through hydrated reaction of cement, cement ore phase fundamental reaction is completed, tricalcium silicate, dicalcium silicate, tricalcium aluminate, ferrum Four calcium content of aluminic acid is little, and almost reaction is finished.The feature peak-to-peak value of hydrated product calcium hydroxide is relatively low, shows that calcium hydroxide is deposited In certain content.The characteristic peak of hydrated product entringite does not almost have, and shows almost not finding the presence of entringite.From XRD Thing phase on see, quartz content very high, come from and gather materials；Next to that dolomite, plus rattan stone, calcium silicates, albite；It is finally Emerylite, calcium hydroxide, Calcium Carbonate.

As can be seen from Figure 27, concrete sample of 500 DEG C of high temperature at test specimen high temperature surface 3cm, XRD figure are experienced Spectrum shows, through hydrated reaction of cement, cement ore phase fundamental reaction is completed, tricalcium silicate, dicalcium silicate, tricalcium aluminate, ferrum aluminum Sour four calcium contents are little, and almost reaction is finished.The feature peak-to-peak value of hydrated product calcium hydroxide is relatively low, shows that calcium hydroxide is present Certain content.The characteristic peak of hydrated product entringite does not almost have, and shows almost not finding the presence of entringite.From XRD's See in thing phase, the content of quartz is very high, comes from and gathers materials；Next to that dolomite, albite, calcium hydroxide；It is finally calcium sulfate Potassium, tilleyite.

As can be seen from Figure 28, concrete sample of 600 DEG C of high temperature at test specimen high temperature surface 3cm, XRD figure are experienced Spectrum shows, through hydrated reaction of cement, cement ore phase fundamental reaction is completed, tricalcium silicate, dicalcium silicate, tricalcium aluminate, ferrum aluminum Sour four calcium contents are little, and almost reaction is finished.The feature peak-to-peak value of hydrated product calcium hydroxide is relatively low, shows that calcium hydroxide is present Certain content.The characteristic peak of hydrated product entringite does not almost have, and shows almost not finding the presence of entringite.From XRD's See in thing phase, the content of quartz is very high, comes from and gathers materials；Next to that albite, microcline；It is finally calcium hydroxide, white clouds Stone, tilleyite.

As can be seen from Figure 29, concrete sample of 700 DEG C of high temperature at test specimen high temperature surface 5cm, XRD figure are experienced Spectrum shows, through hydrated reaction of cement, cement ore phase fundamental reaction is completed, tricalcium silicate, dicalcium silicate, tricalcium aluminate, ferrum aluminum Sour four calcium contents are little, and almost reaction is finished.Hydrated product calcium hydroxide, the feature peak-to-peak value of entringite almost do not have, and show The almost presence without calcium hydroxide, entringite.From the thing phase of XRD, the content of quartz is very high, comes from and gathers materials；Secondly It is albite.

As can be seen from Figure 30, concrete sample of 800 DEG C of high temperature 0.5h at test specimen high temperature surface 5cm is experienced, XRD spectrum shows, through hydrated reaction of cement, cement ore phase fundamental reaction is completed, tricalcium silicate, dicalcium silicate, tricalcium aluminate, Tetra calcium aluminoferrite content is little, and almost reaction is finished.Hydrated product calcium hydroxide, the feature peak-to-peak value of entringite almost do not have, Show the presence almost without calcium hydroxide, entringite.From the thing phase of XRD, the content of quartz is very high, comes from and gathers materials； Next to that albite, microcline.Dolomite is not found, dolomite is a kind of carbonate, main component is CaMg (CO₃)₂, receive Heat can decompose generation Calcium Carbonate, according to Chinese engineering construction association criterion《Fire-damaged building structure standard of perfection》 (CECS252：2009), characteristic temperature during dolomite decomposition should be 720 DEG C～740 DEG C, whether can decompose judgement according to which high The temperature of temperature, and dolomite is not now found, dolomite may decompose, consistent with standard.

As can be seen from Figure 31,900 DEG C of high temperature 0.5h of experience, the concrete sample at test specimen high temperature surface 5cm, XRD spectrum shows, through hydrated reaction of cement, cement ore phase fundamental reaction is completed, tricalcium silicate, dicalcium silicate, tricalcium aluminate, Tetra calcium aluminoferrite content is little, and almost reaction is finished.Hydrated product calcium hydroxide, the feature peak-to-peak value of entringite almost do not have, Show the presence almost without calcium hydroxide, entringite.From the thing phase of XRD, the content of quartz is very high, comes from and gathers materials； Next to that albite；It is finally the product calcium silicates (Ca of gel decomposition₂SiO₄), it is seen that calcium silicates have lost crystallization completely Water.

The XRD result of the test specimen of different maximum temperature (as a example by the 400 DEG C) constant temperature times of experience：

As can be seen from Figure 32,400 DEG C of high temperature 0.5h of experience, the concrete sample at test specimen high temperature surface 3cm, XRD spectrum shows, through hydrated reaction of cement, cement ore phase fundamental reaction is completed, tricalcium silicate, dicalcium silicate, tricalcium aluminate, Tetra calcium aluminoferrite content is little, and almost reaction is finished.The feature peak-to-peak value of hydrated product calcium hydroxide is relatively low, shows calcium hydroxide There is certain content.The characteristic peak of hydrated product entringite does not almost have, and shows almost not finding the presence of entringite.From See in the thing phase of XRD, the content of quartz is very high, comes from and gathers materials；Next to that plus rattan stone, albite；It is finally calcium hydroxide, white Marble.

As can be seen from Figure 26, the XRD spectrum of constant temperature 1h, ore deposit phase reaction with constant temperature 0.5h, hydrated product and each The content of material is all essentially unchanged.

As can be seen from Figure 33, the XRD spectrum of constant temperature 2h, compared with first two operating mode, Mineralogical changes are basically identical, only It is that the content of quartz is very high, comes from and gathers materials from the thing phase of XRD；Next to that albite, emerylite, anorthite, hydrogen-oxygen Change calcium；It is finally dolomite, calcium silicates, silicon calcite, lawsonite, adds rattan stone.

As can be seen from Figure 34, the XRD spectrum of constant temperature 3h, compared with first three operating mode, Mineralogical changes are basically identical, from See in the thing phase of XRD, the content of quartz is very high, comes from and gathers materials；Next to that albite, emerylite, microcline；It is finally Calcium hydroxide, Calcium Carbonate.

Can draw from XRD result, the maximum temperature experienced by concrete and the constant temperature time of maximum temperature all can be right The damage of concrete has relation.

During actually detected, the result that obtained using above five kinds of lossless/Non-destructive test, determine concrete institute warp The high temperature course that goes through, determines the constant temperature time of experienced maximum temperature and maximum temperature.On the other hand, since the highest of experience Temperature, maximum temperature constant temperature time all can to after high temperature during the sound of xoncrete structure, wave amplitude, microstructure, residual intensity cause Impact, it is necessary to take both into consideration and could consider damage of the high temperature course to each side of xoncrete structure rationally, comprehensively.

During implementation steps b, to sound when, wave amplitude, microhardness, aperture, hydrargyrum intrusion, residual intensity and temperature history (most High-temperature and maximum temperature constant temperature time) correlation analysiss are carried out, and regression analyses are carried out, set up high temperature course microscopic damage Relational model, including model, high temperature course wave amplitude model, high temperature course microhardness model, height during high temperature course sound Warm course hydrargyrum intrusion model.The foundation of these models, it is also possible to just carry out after each test is completed.

Analyze through SPSS, during sound, the regression analyses of wave amplitude and temperature and constant temperature time the result such as table 6, table 7 derived, its Middle T represents maximum temperature, and t represents constant temperature time, and during v expression sound, A represents wave amplitude.As can be seen that during sound with temperature and constant temperature when Between correlation coefficient be respectively 0.782,0.167, its uncorrelated two-sided significance value be respectively 0.00 and 0.165, during explanation sound To have a significance related and for positive correlation to temperature, also has positive correlation with constant temperature time, by obtaining in the result of variance analyses The F value (significance test of regression model) for returning part is 29.355, and corresponding probit is 0.00, less than significant level 0.05, illustrate that temperature and constant temperature time explain highly significant to linear regression during sound.Therefore high temperature course sound can be drawn When relational model be formula：V=b₁T+b₂T+C, wherein：b₁、b₂For regression coefficient, C is constant.The regression coefficient of this test 0.153,8.822 can be taken respectively, constant measures -26.301, that is, obtain model v=0.153T+8.822t- during high temperature course sound 26.301.

Analyze with the correlation regression of temperature, time during 6 sound of table

(a) dependency

(b)Anova^b

(c) regression coefficient^a

A. dependent variable:v；A. predictor variable:(constant), t, T.

As table 7, wave amplitude is respectively -0.853 and -0.083 with the correlation coefficient of temperature and constant temperature time, two-sided significance value Respectively 0.00 and 0.315, illustrate that wave amplitude and temperature have a significance related and for negative correlation, with constant temperature time have general Dependency, it is 0.00 that F value is 45.323, corresponding probit, less than significant level 0.05.Illustrate temperature and constant temperature time to ripple The linear regression of width explains highly significant.Therefore high temperature course wave amplitude model can be drawn for formula：A=c₁T+c₂T+C, its In：c₁、c₂For regression coefficient, C is constant.The regression coefficient of this test can take -0.066, -1.731 respectively, and constant is measured 137.415, that is, obtain high temperature course wave amplitude model A=-0.066T-1.731t+137.415.

The correlation regression of 7 wave amplitude of table and temperature, time is analyzed

(a) dependency

(b)Anova^b

(c) regression coefficient^a

A. dependent variable:A；A. predictor variable:(constant), t, T.

The foundation of high temperature course microhardness model：In mixcrohardness test, such as table 8, microhardness H and temperature and perseverance The correlation coefficient of warm time is respectively -0.27 and 0.063, and corresponding two-sided significance value is respectively 0.187 and 0.418, represents Microhardness has general negative correlation with temperature, and microhardness has general positive correlation with constant temperature time, and F value is 0.187, Corresponding probit is 0.682, less than significant level 0.05.Illustrate that temperature and constant temperature time are explained to the linear regression of wave amplitude aobvious Write.Therefore can show that wave amplitude is formula with the relational model of temperature history：H=d₁T+d₂T+C, wherein：d₁、d₂For returning system Number, C is constant.The regression coefficient of this test can take -0.018,0.707 respectively, and constant measures 92.614, that is, obtain high temperature and go through Journey microhardness model is H=-0.018T+0.707t+92.614.

The correlation regression of 8 microhardness of table and temperature, time is analyzed

(a) dependency

(b)Anova^b

(c) regression coefficient^a

A. dependent variable:H；A. predictor variable:(constant), t, T

The foundation of high temperature course hydrargyrum intrusion model：In Mercury injection test, as shown in table 9, when aperture is with temperature and constant temperature Between correlation coefficient be respectively -0.349,0.630, corresponding two-sided significance be respectively 0.242 and 0.021, hydrargyrum intrusion Peak value is respectively -0.558,0.583 with the correlation coefficient of temperature and constant temperature time, and corresponding two-sided significance value is respectively 0.048th, 0.036, the significance probability of contrast aperture and peak value and temperature history, select the peak value of hydrargyrum intrusion as with temperature Parameter with constant temperature time opening relationships model.Therefore can show that hydrargyrum intrusion is formula with the relational model of temperature history：M =e₁T+e₂T+C, wherein：e₁、e₂For regression coefficient, C is constant.The regression coefficient of this test can take respectively -3.884 × 10-5, 0.010, constant measures 0.066, that is, obtain high temperature course hydrargyrum intrusion model M=- 3.884 × 10^-5T+0.010t+0.066.

The correlation regression of 9 hydrargyrum intrusion of table and temperature, time is analyzed

(a) dependency

(b)Anova^b

(c) regression coefficient^a

A. dependent variable:M；A. predictor variable:(constant), t, T

The achievement in research of residual intensity after the existing high temperature to concrete, be all only and through maximum temperature phase in high temperature course Close, but in fact, experience high temperature after concrete residual intensity except with experience high temperature course maximum temperature phase outside the Pass, Time correlation also with its experience maximum temperature.

During implementation steps c, according to the high temperature course for qualitatively judging, and high temperature course Residual Strength Model is set up, come really The residual intensity of fixed concrete after high temperature, the foundation of high temperature course Residual Strength Model：As table 10, residual intensity and temperature The correlation coefficient of degree, residual intensity and constant temperature time is respectively -0.805 and -0.110, represents between the two there is negative correlation, its Incoherent two-sided significance value is respectively 0.00 and 0.05, and it is incoherent that expression rejects both on 0.05 significance level It is assumed that so all there is significance dependency relation in residual intensity and heating-up temperature, constant temperature time.The R side of regression model adjustment (is returned Return the equation coefficient of determination) it is 0.938, illustrate that the degree of fitting for returning is very high, by recurrence part being obtained in the result of variance analyses F value (significance test of regression model) be 145.820, corresponding probit be 0.00, less than significant level 0.05, explanation The explanation highly significant of temperature and constant temperature time to residual intensity.

Therefore residual intensity is can be set as with the linear regression model (LRM) of temperature history：F=a₁T+a₂T+C, wherein：a1、a2 For regression coefficient, C is constant.

From residual intensity test phase it is recognised that after high temperature the residual intensity of concrete can be divided into 100 DEG C～500 DEG C With 500 DEG C～900 DEG C two stages, therefore respectively with temperature and time, regression is carried out to the residual intensity in two stages and divides Analysis, draws corresponding regression coefficient, and coefficient given herein is applied to C60 standard cube test block, with certain reference price Value.

Residual intensity is formula with the relational model of temperature history：

The correlation regression of Figure 10 residual intensity and temperature, time is analyzed

(a) correlation coefficient

B () model collects^b

(c)Anova^b

(d) 500 DEG C～900 DEG C regression coefficients^a

(e) 100 DEG C～500 DEG C regression coefficients^a

A. dependent variable:f；A. predictor variable:(constant), t, T.

High temperature course Residual Strength Model model is undermined by setting up high temperature above course microcosmic, can quantitative Analysis When obtaining the sound of xoncrete structure after high temperature, wave amplitude, microhardness, hydrargyrum pressure amount and residual intensity, then overall merit concrete Damage situations.

For the building that concrete on fire sustains damage, directly take the small pieces of its surface or certain depth and powder enters Row analysis, implements residual intensity detection method after the kind concrete high temperature of the present invention, will not structure be caused to damage.

Embodiment 2

As different from Example 1, in the present embodiment, the test specimen is prism.

It should be noted that various embodiments above is only in order to illustrate technical scheme, rather than a limitation；Although With reference to foregoing embodiments, the present invention is described in detail, it will be understood by those within the art that：Which is still Technical scheme described in foregoing embodiments can be modified, or which part or all technical characteristic are carried out Equivalent；And these modifications or replacement, do not make the essence of appropriate technical solution depart from various embodiments of the present invention technical side The scope of case.

Claims

1. after a kind of concrete high temperature no（Micro-）Detection method is damaged, including determining the residual intensity of concrete after high temperature, its feature It is：Further comprising the steps of：

B. determine the microscopic feature Changing Pattern of concrete under different temperatures operating mode according to lossless/Non-destructive test result, qualitative sentence Disconnected concrete institute is through high temperature course；Set up high temperature course microscopic damage relational model；

Wherein it is determined that the residual intensity of concrete is achieved by the steps of after high temperature：C. gone through using the high temperature of gained concrete Journey determines the residual intensity of concrete.

2. nothing after concrete high temperature is mixed as claimed in claim 1（Micro-）Damage detection method, it is characterised in that：In step a, described Lossless/Non-destructive test is comprised the following steps：

C. electron-microscopic analysis are scanned to experiencing the xoncrete structure after high temperature, xoncrete structure after high temperature is carried out Scanning, observes hydrated cementitious paste structure；

E. carry out X ray diffracting spectrum detection to experiencing the xoncrete structure after high temperature, crystallize in observation XRD spectrum distributed mutually and The change of peak value.

3. nothing after concrete high temperature is mixed as claimed in claim 2（Micro-）Damage detection method, it is characterised in that：In step A, adopt To the sound of weld defect control when, first wave amplitude and three parameters,acoustics of frequency are analyzed to concrete damage situation after high temperature.

4. nothing after concrete high temperature is mixed as claimed in claim 3（Micro-）Damage detection method, it is characterised in that：In step A, surveying Uniform application medical ventolin at pilot.

5. nothing after concrete high temperature is mixed as claimed in claim 4（Micro-）Damage detection method, it is characterised in that：In step A, ultrasound Ripple tranmitting frequency is 50kHz.

6. nothing after concrete high temperature is mixed as claimed in claim 5（Micro-）Damage detection method, it is characterised in that：In step A, in order to Obtain more accurately result, each test point retest, the test result that averages as the test point.

7. nothing after concrete high temperature is mixed as claimed in claim 6（Micro-）Damage detection method, it is characterised in that：In step A, adopt To method is surveyed, ultrasonic testing is carried out using single channel ultrasonic wave detector.

8. nothing after concrete high temperature is mixed as claimed in claim 7（Micro-）Damage detection method, it is characterised in that：In step A, with sound When, the change of first wave amplitude and frequency values be turned to the foundation of test specimen quality evaluation.

9. nothing after concrete high temperature is mixed as claimed in claim 2（Micro-）Damage detection method, it is characterised in that：In step B, will be super The test specimen that sound test is finished, cuts, makes detection sample parallel to front-back during heating.

10. nothing after concrete high temperature is mixed as claimed in claim 9（Micro-）Damage detection method, it is characterised in that：In step B, adopt The Vickers hardness number HIV of the xoncrete structure after experience high temperature is detected with Vickers hardness measurement method, to experiencing high temperature concrete damage Wound is evaluated.