CN101762451A - Concrete split test device being capable of controlling wind speed and humiture and climate sensitivity evaluation method - Google Patents

Abstract

The invention relates to a concrete split test device being capable of controlling wind speed and humiture and a concrete split climate sensitivity evaluation method; the device is formed by a sealing annular air channel which is provided with a fan and is divided into an experimental section and a temperature and humidity adjusting section; the experimental section of the air channel is provided with a wind speed sensor, a temperature sensor and a humidity sensor; the wind speed sensor, the temperature sensor and the humidity sensor are respectively connected with a central controller; the output of the central controller is respectively connected with a frequency changer in a power circuit of the fan, a temperature control mechanism and a drying mechanism in the temperature and humidity adjusting section of the air channel; the experimental section of the air channel is provided with a split test support; and simultaneously the experimental section of the air channel is made from the transparent material. The concrete split test device can preferably choose the concrete mix proportion with low split climate sensitivity to be used in the complex weather condition project; the split climate sensibility factor of the concrete can be obtained by comparing the split condition of the concrete in different wind speed humiture conditions; and the concrete with small climate sensibility factor has more stable anti-cracking performance in different climate conditions.

Description

The concrete cracking test unit and the climate sensitivity evaluation method of controlled wind speed humiture

Technical field

The present invention relates to a kind of concrete test device and a kind of concrete cracking climate sensitivity evaluation method, be specifically related to a kind of concrete cracking test unit and a kind of method of estimating the concrete cracking climatic sensitivity of controlled wind speed humiture.

Background technology

High performance concrete comes across beginning of the nineties late 1980s, it is a kind of novel High Technique Concrete, be to increase substantially on the basis of conventional concrete performance, adopt modern technologies, optimize concrete raw material and match ratio thereof, through the science construction, permanance, workability, various mechanical property, applicability, volume stability and economic rationality are guaranteed.

High performance concrete not only requires to have the intensity of higher (or satisfying the buildings requirement of strength design), more emphasize under specific environment for use, to have high cracking resistance permanance, the high stability of volume, and the high operability of construction and economical rationality, sustainable development.Concrete reaches the most important technological means of high-performance and is to use new and effective water reducer and mineral admixture.The former can reduce concrete water cement ratio, increase the slump and control slump-loss, promptly gives high packing of concrete and excellent workability; The latter fills the space of Binder Materials, participates in the hydration reaction of Binder Materials, improves concrete packing, improves concrete interfacial structure, improves concrete permanance and intensity.High performance concrete not only has very quantum jump with conventional concrete on performance, economize on resources, save the energy, improve working conditions, aspect such as economical rationality, especially environment is had crucial meaning, be a kind of green material of sustainable development therefore.Characteristics at south water to north large channel engineering, the science of answering designs that permanance height, volume stability are good, construction can be operated strong water conservancy project high performance concrete, guarantee the long-term safety operation of buildings, for design, construction provide according to very pressing for.

The cracking problem of high performance concrete is a question of common concern, and existing split test method has all adopted comparatively harsh test condition in order to guarantee the test specimen cracking, can not reflect the climatic sensitivity of concrete capacity against cracking.The concrete cracking test unit of exploitation controllable temperature humidity wind friction velocity can be simulated concrete cracking resistance under the different weather conditions.Can be in the weather conditions scope of broad the concrete of cracking resistance, can think the concrete that splitting resistance is more excellent.

Summary of the invention

At the above-mentioned situation of prior art, the purpose of this invention is to provide a kind of concrete cracking test unit of controlled wind speed humiture, and the concrete cracking climate sensitivity evaluation method that uses this concrete cracking test unit to carry out.This test unit and method, the concrete cracking situation is observed in the combination of different weather conditions such as energy wind speed setting, temperature, humidity.Carry out the concrete cracking test before can be implemented in construction, to obtain necessary data.Propose the concrete cracking climate sensitivity evaluation method based on this test unit and estimate the cracking sensitivity of different concrete under the climate change condition, the low concrete mix of climatic sensitivity that can preferably ftracture is used for the weather conditions complex engineering.

The scheme of finishing the foregoing invention task is, a kind of concrete cracking test unit of controlled wind speed humiture is characterized in that, this device is made of the annular passage of sealing, is provided with blower fan in the described air channel, and be divided into experimental section, temperature and humidity is regulated section;

Be provided with air velocity transducer, temperature sensor and humidity sensor (constituting monitoring system jointly) at the air channel experimental section; This air velocity transducer, temperature sensor and humidity sensor are connected with central controller respectively, and the output of this central controller frequency converter in the mechanomotive force circuit of giving a dinner for a visitor from afar respectively is with the temperature-controlling mechanism in described wind duct temperature and the humidity regulation section and the mechanism of drying;

Be provided with cracking examination frame in the experimental section of described air channel; This air channel experimental section adopts transparent material to make simultaneously.

That is, controllable temperature humidity wind speed concrete cracking test unit of the present invention mainly is made up of air channel, blower fan, cracking examination frame, temperature regulating device, moisture-catcher, monitoring system etc.

The air velocity transducer of monitoring system, temperature sensor and humidity sensor can be arranged on the place ahead (direction of the wind comes from) of air channel experimental section.

More specifically and more in the scheme of optimizing, described air channel is adopted diameter 500mm galvanized sheet iron pipe and organic glass pipe respectively, and plexi-glass tubular is used for test section, and the surface of observing the cracking test specimen in being convenient to test changes; The axial fan of blower fan selection and wind speed, air channel coupling; Cracking examination frame is used for support cracking test specimen, places the air channel test section; Temperature-controlling system adopts cooling and heating air conditioner; The employing moisture-catcher dries; Monitoring system can dynamic monitoring and temperature, humidity and the wind speed of controlling test section.

In the prioritization scheme, also be provided with temperature, recording thermometer in the air channel.

The concrete cracking climate sensitivity evaluation method that uses above-mentioned concrete cracking test unit to carry out, step is as follows:

(1), the concrete experiments sample is placed on the cracking examination frame of air channel experimental section, and close the air channel;

(2), set wind speed, the temperature and humidity numerical value of this time experiment, by wind speed, the temperature and humidity numerical value of central controller controls experimental provision;

(3), after wind speed, temperature and humidity numerical value reach requirement, the opening entry time;

(4), reach the stipulated time after, take out the concrete experiments sample, observe its cracking situation;

(5), calculate the weather sensitive factor of this concrete cracking, estimate the anti-crack ability of this concrete under these weather conditions;

(6), reset wind speed, the temperature and humidity numerical value of experiment, repeat above step (1)～step (5).

In other words, the present invention adopts the concrete cracking test unit of this cover controllable temperature humidity wind speed to carry out: under specific humiture and wind friction velocity, test crack on concrete situation is estimated the anti-crack ability of this concrete under these weather conditions;

Adopt the parameter combinations of different temperature, humidity and wind speed for same group of concrete, test crack on concrete situation is calculated the weather sensitive factor of this concrete cracking.

First kind of test can be adopted method among the CCES 01-2004 to the assessment for Anti-Crack Performance of Concrete method, and wherein the Several Parameters method is as follows:

1) area that on average splits in crack

$a=\frac{1}{2N}\underset{i}{\overset{N}{\mathrm{\Σ}}}{W}_i\·L_i$

2) the cracking crack number of unit area

$b=\frac{N}{A}$

3) area that always splits on the unit area

C＝a·b

In the formula:

Wi---the breadth extreme in i root crack, mm;

Li---the length in i root crack, mm;

N---total crack number, root;

A---dull and stereotyped area 0.36m2.

The early stage splitting resistance interpretational criteria of test specimen has following four:

1) very thin crack is only arranged;

2) area＜10mm2 that on average splits;

3) unit area cracking crack number＜10/m2;

4) area＜100mm2/m2 that always splits on the unit area.

According to above-mentioned criterion, splitting resistance is divided into five grades:

I level: all satisfy above-mentioned four conditions;

II level: satisfy 3 in above-mentioned four conditions;

III level: satisfy 2 in above-mentioned four conditions;

IV level: satisfy any one in above-mentioned four conditions;

V level: all do not satisfy.

Perhaps,

Adopt concrete cracking weather sensitive factor Kc to carry out for the evaluation of second kind of test, the size reflection crack on concrete of Kc is subjected to the influence degree of climate change, the big more explanation of Kc is affected by climate change remarkable more, otherwise it is not remarkable to represent that then concrete cracking is affected by climate change.Kc adopts following formula to calculate:

$K_c=\left|\frac{\mathrm{dK}}{\mathrm{dT}+\mathrm{dH}-\mathrm{dV}}\right|$

In the formula: K _c---concrete cracking weather sensitive factor;

Area of cracks rate of change under dK---two kinds of weather conditions on the concrete unit area;

Rate of temperature change under dT---two kinds of weather conditions;

Humidity rate of change under dH---two kinds of weather conditions;

Wind speed rate of change under dV---two kinds of weather conditions.

The cracking resistance evaluation of first kind of test can be used for the optimization of match ratio cracking resistance, selects the higher concrete of splitting resistance opinion rating to be used for engineering in a plurality of proportionings; The result of second kind of test reflects that concrete cracking is subjected to the influence degree of climate change, should pay attention to the heat and moisture preserving maintenance for the concrete that the Kc value is bigger.

The present invention has filled up the blank of prior art, a kind of concrete cracking test unit of controlled wind speed humiture is provided, and the concrete cracking climate sensitivity evaluation method that uses this concrete cracking test unit to carry out, the concrete cracking situation is observed in the combination of different weather conditions such as energy wind speed setting, temperature, humidity.Carry out the concrete cracking test before can be implemented in construction, to obtain necessary data.Propose the concrete cracking climate sensitivity evaluation method based on this test unit and estimate the cracking sensitivity of different concrete under the climate change condition, the low concrete mix of climatic sensitivity that can preferably ftracture is used for the weather conditions complex engineering.

Description of drawings

Fig. 1 is a controllable temperature humidity wind speed concrete cracking test unit structural drawing;

Fig. 2 is the controllable temperature humidity wind speed concrete cracking test mould structural drawing of embodiment 1;

Fig. 3 is embodiment 1 medium frequency and wind speed graph of relation.

Embodiment

Embodiment 1, controllable temperature humidity wind speed split test.

The concrete cracking test unit of controlled wind speed humiture is made of the annular passage that seals, and is divided into experimental section 1, adopts diameter 500mm plexi-glass tubular, and the surface of observing the cracking test specimen in being convenient to test changes; Temperature and humidity is regulated section 2, adopts diameter 500mm galvanized sheet iron pipe.Be provided with blower fan 3 in the described air channel, and in air channel experimental section 1, be provided with air velocity transducer, temperature sensor and humidity sensor 6; This air velocity transducer, temperature sensor and humidity sensor are connected with central controller 4 respectively, and the output of this central controller 4 frequency converter 5 in the mechanomotive force circuit of giving a dinner for a visitor from afar respectively is with the temperature-controlling mechanism in described wind duct temperature and the humidity regulation section and the mechanism of drying; Be provided with cracking examination frame in the experimental section of described air channel.

Critical piece:

The axial fan of blower fan selection and wind speed, air channel coupling; Cracking examination frame is used for support cracking test specimen, places the air channel test section; Temperature-controlling system adopts cooling and heating air conditioner; The employing moisture-catcher dries; Monitoring system can dynamic monitoring and temperature, humidity and the wind speed of controlling test section.

T40 profile shaft circulation blower fan has adopted novel cylindrical shape wheel hub structure, thereby makes the air efficient of blower fan bring up to 84%, and has strengthened the intensity at blade root place.T40 profile shaft circulation blower fan can be used as general factory, warehouse, office, residential ventilation ventilation or strengthens the usefulness of heating installation heat radiation, also can be installed in series at interval in longer gas exhaust duct, to improve the blast in the air channel.Product is divided into into ten plane No. by the impeller diameter difference, is followed successively by № 2.5,3,3.5,4.5,5,6,7,8,9,10.The blade of each plane No. can be mounted to 15 °, 20 °, 25 °, 30 °, 35 ° five kinds of angles again.These series of products all adopt impeller directly to be contained in direct connection structure on the motor shaft, are no more than at impeller circumferential speed and are equipped with three kinds of revolution: 2900r/min, 1450r/min, 960r/min under the 60m/s condition.Seeing in the face of the air inlet direction impeller is is rotated counterclockwise.Because differences such as impeller diameter size, blade angle degree, speed of mainshaft speeds, so its air quantity, blast and consumption of power are also different thereupon, blast is by 31Pa～473Pa, and air quantity is by 564m3/h～48200m3/h.This blower fan is made up of impeller, casing two parts.Impeller portion: be made up of blade, wheel hub etc., blade is an arc thin plate, is stamped to form by sheet steel. is welded on the wheel hub cylindrical by required established angle.Casing portion: form by air duct, base and support plate etc., all adopt sheet steel and section bar to make.Air duct is a straight cylinder shape, and certain clearance is arranged between the impeller.

Frequency converter is used for the stepless speed regulation of three-phase AC asynchronous motor.Its principle is: drag the character and the state of load according to motor, change machine operation power source voltage (380V or middle and high pressure) and frequency (being generally 50HZ), make motor reach optimum Working when dragging different loads.Its effect is: (1) energy savings: its power saving rate can reach (20～80) %; (2) protection motor and load equipment are avoided the impact of instantaneous starting, prolong its mission life; (3) operating accuracy of raising motor and load equipment.

The frequency conversion speed-adjusting development is ripe day by day so far, and it is that some other mode of speed regulation is incomparable at aspects such as frequency range, dynamic response, accuracy requirement, operation and maintenances.It also has the power savings of highly significant except that having remarkable speed adjusting performance, therefore, be widely used in all trades and professions.

Utilize frequency converter to realize automatic, level and smooth speedup or deceleration according to the variation of motor load, the basic little characteristics of asynchronous machine inherent characteristic revolutional slip that keep, have efficient height, wide ranges, precision height and the infinite variable speed advantage of energy, this is for water pump, and equipment such as blower fan are very suitable.

The combination of variable-frequence governor and squirrel cage motor is again the outstanding person of speed regualtion of AC motor system; this system has excellent performance; the speed adjustable range of its significant power savings, higher adjusting speed accuracy, broad, perfect defencive function, easy maintenance and using method, be easy to realize control and process control automatically, be subjected to users' popular welcome and commendation.Variable-frequence governor has following principal feature:

1. easy and simple to handle, only need to regulate control panel and just can carry out frequency adjustment;

2. volume is little, and is in light weight, can adopt wall built-up to install, and floor area is little;

3. the frequency numeral shows that frequency resolution is accurate;

4. can realize remote operation, easy to be reliable;

5. have abundant defencive function, and can numeral show guilty culprit, easy maintenance;

6. have international external interface terminal at present, can be connected, be convenient to carry out closed-loop control with III type table, Programmable Logic Controller and computing machine;

7. start can realize soft start, and shutdown realizes soft stop, makes the motor start-stop steady, and starting current is little, reduces the impact to electrical network and equipment;

8. high-speed response, low noise, high retarding torque.

According to the request for utilization of the blower fan outfit rating of electric machine and controllable temperature humidity wind friction velocity split test device, the 7200MA series of selecting the first motor in east, Taiwan to produce, 3HP horsepower, voltage level are 380V, this product has following characteristic:

1. the new general vector converter of using of high function from generation to generation;

2. adopt dialog mode LCD manipulater, have multi-lingual setting and parameter copy function;

3. input terminal can be selected SINK or SOURCE interface mode (OPTION);

4. standard includes RS-485 (MODBUS) communication function (PROFIBUS communication card: OPTION);

5. include PG back coupling interface standard, add PG and can do the control of V/F closed loop, to improve velocity accuracy;

6. include PID, simple and easy PLC, clocking capability and pulse wave output, the application of applicable difference;

7. the simulation output interface is 2 groups, can set 11 kinds of different analog output signals respectively;

8. have the accumulation duration of runs and intelligent unusual resume function, be easy to the maintenance management of system;

9. have two specified (deciding torque and the torque load(ing) of successively decreasing) overload protection functions and automatic energy-saving source function;

10. high starting torque has full-automatic torque magnification of universe and automatic slippage revisal function.

The humiture register

Rotronic is famous in the world humidity product producer, the history in 40 years, and unique sensor technology makes it be in leadership in humidity.This humiture register has following characteristics:

-compact standard standalone module

-humiture one bulk measurement shows (optional)

-warning function

-accurate temperature and humidity measurement and good short-term and long-time stability

-can connect the various interchangeable digital sensors of ROTRONIC

-degree of protection: IP65

-have certain anti-vibration ability

-9V laminated cell (can use rechargeable battery) or the power supply of external power supply

-CF card storage memory, the infinite memory of realization data

-FDA CFR21/11 and GAMP 4 authentications

-optional spread footing: can expand the input of 4 way word Temperature Humidity Sensors or 4 road PT100 and 2 way switch amounts

The humiture register system is by forming with lower member:

(1) register table body HygroLog NT

The split type humiture register of triple channel HygroLog NT 3

The split type humiture register of-triple channel;

But-split connects the various interchangeable digital sensors of ROTRONIC;

-accurate temperature and humidity measurement and good short-term and long-time stability;

-storage medium: the CF card, the storage data volume is big, standard configuration 16MB;

-with card reader, PDA or by HW4 software PC reading of data;

Can set between 5 seconds to 24 hours-writing time at interval;

-triple channel independently is provided with writing time at interval and recording status;

-9V laminated cell or rechargeable battery also can external power supplies;

-battery life was greater than 1 year (depending on configuration and setting);

-logging mode is optional: start/stop;

-working environment: 0...100%RH;-30...70 ℃;-10...60 ℃ (band shows);

-measurement range: 0...100%RH;-50...200 ℃ (depending on the selection of probe);

-precision: ± 1.5%RH/ ± 0.3 ℃ (depending on the selection of probe);

-optional demonstration and guidance panel directly is provided with panel and calibration etc.;

-alarm;

-optional spread footing: outer power supply source adapter, RS485 and RS232 interface, can expand 4 road HygroClip digitizings probes or 4 road PT100 and the input of 2 way switch amounts (as door status switch).

(2) universal Temperature Humidity Sensor HygroClip S

The standard atmosphere sensor is common to the temperature and humidity measurement of environmental gas.

Measurement range :-40...85 ℃, 0...100%RH;

Accuracy: ± 1.5%RH, ± 0.3 ℃ (in the time of 23 ± 2 ℃);

Repeatability: be better than 0.5%RH and 0.1 ℃;

Stability: be better than 1.0%RH and 0.1 ℃ every year;

During time constant: τ=63,23 ℃, under the 1m/s wind friction velocity, humiture is 15 seconds;

Output: simulation output :-0.4...+0.85V →-40...85 ℃

0...1V→0...100％RH；

Numeral output: DIO number bus;

Filtrator: metal cloth filter, hole 20...25 μ;

Physical dimension: Φ 15 * 100mm;

Degree of protection: IP65.

(3) switching extended line

Can directly receive on the first passage of table body, realize that if desired split or prolongation can be matched MOK-02-DAT05 (2 meters) or MOK-05-DAT05 (5 meters) receives on the first passage of table body, also can match MOK-02-B5 (2 meters) or MOK-05-B5 (5 meters) and receive on second, third passage of showing body.

(4) HW4 software and connection

(5) spread footing DS-NT

DS-U-2RS485 and USB interface can connect outer power supply source adapter, can expand input of 4 way words or Analogue probe signal and the input of 2 way switch amount signals.

(6) power supply adaptor AC1211

The AC1211 AC power source adapter, 220VAC changes 9VDC, is the DS-NT power supply, thereby is register table body HygroLogNT power supply, perhaps is the rechargeable battery charging.

Anemoscope

Adopt Taiwan safe bodyguard AVM-07 anemoscope as air velocity transducer.

This anemoscope has following characteristics:

(1) 52mm separate type fan;

(2) high sensitivity/high wind speed is measured;

(3) ergonomic designs;

(4) moment, average, 2/3 maximum quantity of wind measurement;

(5) wind speed m/s, ft/min, knots, Km/hr, mph;

(6) LCD is two shows;

(7) temperature survey ℃/switching;

(8) RS-232 connects the computing machine transmission.

Table 1 AVM-07 Taiwan safe bodyguard anemoscope physical specification

Humiture adjuster, employing power are that 1 family expenses air conditioner transformation obtains.

Central controller can adopt computing machine to connect frequency converter, humiture register, anemoscope and air conditioner and gather and control.

Frequency and wind speed relation: employing Frequency Converter Control rotation speed of fan can be realized the control to wind speed, by testing the relation that can determine between frequency and test section wind speed.Respectively the frequency converter output frequency be set to 10Hz, 15Hz, 20Hz ... 55Hz, 60Hz, by anemoscope viewing test section actual measurement wind speed, test findings sees Table 2 and mistake! Do not find Reference source.。

Table 2 frequency and wind speed relation

As can be seen from the figure, output frequency and respective relationships are close to straight line, and the relational expression that draws between frequency and the wind speed through numerical fitting is as follows:

V＝0.08727+0.34945f

Can calculate the output frequency of correspondence when satisfying certain wind speed by this formula.

South water to north east line first phase engineering is worn engineering South Area, the Yellow River and is built pipe office and provide the Shandong Province to conquer east nearly 2 years 8 of county to Dec extreme temperature and wind speed data, sees Table 3.The construction time of south trunk canal lining concrete estimate will spring 2 to May, build pipe office suggestion by the South Area, construction time extreme temperature and wind speed data can be got by looking into for 8 to Dec, extreme temperature during this period and wind speed range generally can not surpass 8 to Dec.Flood season 6 to July, general uneasiness applied the worker, put aside.

Table 3 extreme temperature and wind speed data

Adopt the controllable temperature humidity wind speed concrete cracking test unit of development that following three groups of concrete have been carried out split test.His-and-hers watches 4 listed three groups of concrete have carried out the contrast test under 20 ℃ of temperature, humidity 60%, the wind speed 21m/s condition respectively, and SP2 group and SP3 group concrete have been carried out the test of cracking climatic sensitivity.Split test the results are shown in Table 5.

Table 4 controllable temperature humidity wind speed concrete cracking test match ratio

From three groups of crack on concrete test comparing results as can be seen, three groups of concrete splitting resistance opinion ratings are the I level, content of stone powder is that 6.0% and 11.4% two groups cracking situation is approaching, total area of cracks on the unit area is 3.0mm2/m2～3.6mm2/m2, and that content of stone powder is 18.0% the every cracking parameter of concrete is all higher, and the total area of cracks on the unit area reaches 21.7mm2/m2.

Table 5 split test result

Be calculated as follows the weather sensitive factor of SP2 group concrete cracking:

$K_c=\left|\frac{\mathrm{dK}}{\mathrm{dT}+\mathrm{dH}-\mathrm{dV}}\right|=\left|\frac{-0.4444}{0.2500+0.08333-(-0.2857)}\right|=0.718$

$\mathrm{dK}=\frac{2.0-3.6}{3.6}=-0.4444;$

$\mathrm{dT}=\frac{25-20}{20}=0.2500;$

$\mathrm{dH}=\frac{65-60}{60}=0.08333;$

$\mathrm{dV}=\frac{15-21}{21}=-0.2857.$

Be calculated as follows the weather sensitive factor of SP3 group concrete cracking:

$K_c=\left|\frac{\mathrm{dK}}{\mathrm{dT}+\mathrm{dH}-\mathrm{dV}}\right|=\left|\frac{-0.5760}{0.2500+0.08333-(-0.2857)}\right|=0.931$

$\mathrm{dK}=\frac{9.2-21.7}{21.7}=-0.5760;$

$\mathrm{dT}=\frac{25-20}{20}=0.2500;$

$\mathrm{dH}=\frac{65-60}{60}=0.08333;$

$\mathrm{dV}=\frac{15-21}{21}=-0.2857.$

Content of stone powder is that 11.4% SP2 group concrete cracking weather sensitive factor is 0.718, content of stone powder is that 18.0% SP3 group concrete cracking weather sensitive factor is 0.931, the higher SP3 group crack on concrete of content of stone powder is more vulnerable to climatic influences, therefore, want strict and strengthen maintenance by the rules code requirement and could satisfy demand of anti-crack building curing period for the higher concrete of content of stone powder.

Claims (8)

1. the concrete cracking test unit of a controlled wind speed humiture is characterized in that, this device is made of the annular passage of sealing, is provided with blower fan in the described air channel, and is divided into experimental section, temperature and humidity adjusting section;

Be provided with air velocity transducer, temperature sensor and humidity sensor at the air channel experimental section; This air velocity transducer, temperature sensor and humidity sensor are connected with central controller respectively, and the output of this central controller frequency converter in the mechanomotive force circuit of giving a dinner for a visitor from afar respectively is with the temperature-controlling mechanism in described wind duct temperature and the humidity regulation section and the mechanism of drying;

Be provided with cracking examination frame in the experimental section of described air channel; This air channel experimental section adopts transparent material to make simultaneously.

2. the concrete cracking test unit of controlled wind speed humiture according to claim 1 is characterized in that, the described temperature-controlling mechanism and the mechanism of drying adopt cooling and heating air conditioner jointly.

3. the concrete cracking test unit of controlled wind speed humiture according to claim 1 is characterized in that, also is provided with thermometrograph and recording thermometer in the air channel.

4. the concrete cracking test unit of controlled wind speed humiture according to claim 1 is characterized in that, described air channel adopts diameter 500mm galvanized sheet iron pipe and organic glass pipe to constitute respectively, and plexi-glass tubular wherein is used for test section.

5. according to the concrete cracking test unit of the described controlled wind speed humiture of one of claim 1～4, it is characterized in that described blower fan adopts axial fan.

6. the concrete cracking test unit of controlled wind speed humiture according to claim 5 is characterized in that,

Described axial fan adopts T40 profile shaft circulation blower fan;

Described central controller adopts computing machine to connect frequency converter, humiture register, anemoscope and air conditioner and gathers and control.

7. concrete cracking climate sensitivity evaluation method that uses the described concrete cracking test unit of claim 1 to carry out is characterized in that step is as follows:

(1), the concrete experiments sample is placed on the cracking examination frame of air channel experimental section, and close the air channel;

(2), set wind speed, the temperature and humidity numerical value of this time experiment, by wind speed, the temperature and humidity numerical value of central controller controls experimental provision;

(3), after wind speed, temperature and humidity numerical value reach requirement, the opening entry time;

(4), reach the stipulated time after, take out the concrete experiments sample, observe its cracking situation;

(5), calculate the weather sensitive factor of this concrete cracking, estimate the anti-crack ability of this concrete under these weather conditions;

(6), reset wind speed, the temperature and humidity numerical value of experiment, repeat above step (1)～step (5).

8. concrete cracking climate sensitivity evaluation method according to claim 7 is characterized in that, calculates the weather sensitive factor of concrete cracking in the step (5), and the method for estimating the anti-crack ability of this concrete under these weather conditions is:

Adopt the method among the CCES 01-2004, wherein the Several Parameters method is as follows:

1) area that on average splits in crack

$a=\frac{1}{2N}\underset{i}{\overset{N}{\mathrm{\Σ}}}{W}_i\·L_i$

2) the cracking crack number of unit area

$b=\frac{N}{A}$

3) area that always splits on the unit area

C＝a·b

In the formula:

Wi---the breadth extreme in i root crack, mm;

Li---the length in i root crack, mm;

N---total crack number, root;

A---dull and stereotyped area 0.36m2;

The early stage splitting resistance interpretational criteria of test specimen has following four:

1) very thin crack is only arranged;

2) area＜10mm2 that on average splits;

3) unit area cracking crack number＜10/m2;

4) area＜100mm2/m2 that always splits on the unit area;

According to above-mentioned criterion, splitting resistance is divided into five grades:

I level: all satisfy above-mentioned four conditions;

II level: satisfy 3 in above-mentioned four conditions;

III level: satisfy 2 in above-mentioned four conditions;

IV level: satisfy any one in above-mentioned four conditions;

V level: all do not satisfy;

Perhaps,

Adopt concrete cracking weather sensitive factor Kc to carry out for the evaluation of second kind of test, the size reflection crack on concrete of Kc is subjected to the influence degree of climate change, the big more explanation of Kc is affected by climate change remarkable more, otherwise it is not remarkable to represent that then concrete cracking is affected by climate change.Kc adopts following formula to calculate:

$K_c=\left|\frac{\mathrm{dK}}{\mathrm{dT}+\mathrm{dH}-\mathrm{dV}}\right|$

In the formula: K _c---concrete cracking weather sensitive factor;

Area of cracks rate of change under dK---two kinds of weather conditions on the concrete unit area;

Rate of temperature change under dT---two kinds of weather conditions;

Humidity rate of change under dH---two kinds of weather conditions;

Wind speed rate of change under dV---two kinds of weather conditions.

The cracking resistance evaluation of first kind of test can be used for the optimization of match ratio cracking resistance, selects the higher concrete of splitting resistance opinion rating to be used for engineering in a plurality of proportionings; The result of second kind of test reflects that concrete cracking is subjected to the influence degree of climate change, should pay attention to the heat and moisture preserving maintenance for the concrete that the Kc value is bigger.

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