CN103954557B - The image analysis method of Comprehensive Assessment concrete carbonization velocity coefficient - Google Patents

Abstract

An image analysis method for Comprehensive Assessment concrete carbonization velocity coefficient, comprises the steps: 1, carries out concrete carbonation test; 2, concrete carbonization situation digital picture is obtained; 3, carbonization relevant range is chosen and pixel value analysis; 4, concrete carbonization velocity coefficient model is set up; 5, concrete carbonization velocity coefficient is calculated.The method can carry out two-dimentional carbonization test, and calculate concrete carbonization velocity coefficient according to the carbonization situation of the whole section of concrete, overcome classic method can only simulate one-dimensional condition under concrete carbonization process, and the defect such as precision is poor, for the anti-carbonation properties of Comprehensive Assessment concrete entirety provides analysis means and foundation.

Description

The image analysis method of Comprehensive Assessment concrete carbonization velocity coefficient

One, technical field

The present invention relates to a kind of analytical approach of building materials, particularly a kind of image analysis method of Comprehensive Assessment concrete carbonization velocity coefficient.

Two, background technology

Concrete is a kind of alkaline building materials, and the reinforcing bar in concrete is owing to being in alkaline environment, and its surface can form the passivating film of one deck densification, and the existence of stablizing passivating film can protect reinforcing bar not corroded.Sour gas CO in air ₂enter into inside concrete by concrete microfracture and hole and react with inside concrete alkaline matter, cause concrete alkalescence to reduce, this process is called concrete carbonization.When concrete carbonization depth reaches rebar surface, because the degree of alkalinity around reinforcing bar reduces, the passivating film of rebar surface can be destroyed, thus causes the corrosion of reinforcing bar.Therefore, accurately evaluate concrete carbonization velocity coefficient contribute to accurately evaluating the permanance of reinforced concrete structure and predict its service life.

At present, the method analyzing concrete carbonization velocity coefficient the most frequently used mainly utilizes one side or opposite carbon steel dipstick metering to get concrete one dimension carbonation depth, then solves concrete carbonization velocity coefficient.The method is the concrete prism test specimen that preparation length breadth ratio is not less than 3, by the concrete sample of 28 days curing age except staying the next one or relative two sides, remaining surface adopts the paraffin of heating or epoxy resin to seal, and parallel lines are drawn with pencil with 10mm spacing along its length in exposed side, then put into CO ₂concentration is 17 ~ 23%, relative humidity is 65 ~ 75%, and temperature is that in the carbonization case of 18 ~ 22 DEG C, carbonization is to predetermined number of days, during as 28 days, take out test block, broken type measures carbonation depth, brushes away powder remaining on concrete cross section subsequently, then on section, spray the alcoholic solution containing 20% distilled water that concentration is the phenolphthalein+99% of 1%, about after 30s, measure each point carbonation depth by original every 10mm measurement point steel ruler demarcated, measurement should be accurate to 0.5mm.Then the carbonation depth value recorded by each point is averaged as carbonation depth, then carbonation depth is opened radical sign value divided by carbonization number of days, calculates concrete carbonation rate coefficient.

Because concrete is heterogeneous material, only get concrete sample one side or relatively two sides carry out carbonization can only simulate one-dimensional condition under concrete carbonization process, be difficult to the anti-carbonation properties fully characterizing concrete entirety, and measuring carbonation depth by subjective operating influence comparatively greatly with steel ruler, precision is poor.But if the anti-carbonation properties of two-dimentional carbonization test, comprehensively sign concrete entirety will be carried out, carbonization is carried out under then needing that four of concrete sample sides are all exposed to Carbonization Conditions, like this, there will be two-dimentional carbonizing zone in the corner positions of two adjacent surfaces, existing steel ruler measures depth method and cannot measure accurately this region and analyze.

Therefore, the carbonation depth that depth method only can analyze concrete sample regional area is got in existing one side or opposite carbon steel dipstick metering, and precision is poor, is difficult to the anti-carbonation properties of Comprehensive Assessment concrete entirety.

Three, summary of the invention

The object of the present invention is to provide a kind of image analysis method of Comprehensive Assessment concrete carbonization velocity coefficient, it accurately, intuitively comprehensively can be analyzed two-dimentional carbonization Under Concrete test specimen tunneling boring carbonization situation by computing machine and image processing software, and then evaluation concrete carbonization velocity coefficient, provide convenient effective method for evaluating concrete anti-carbonation properties better.

Technical scheme of the present invention is: a kind of image analysis method of Comprehensive Assessment concrete carbonization depth, comprises the steps:

(1) carry out concrete carbonation test: preparation length breadth ratio is not less than the concrete prism test specimen of 3, adopt the paraffin of heating or epoxy resin to seal the end face of the concrete sample of 28 days curing age and bottom surface, then put into CO ₂concentration is 17 ~ 23%, and relative humidity is 65 ~ 75%, and temperature is in the carbonization case of 18 ~ 22 DEG C, under being exposed to carbonization environment, carries out carbonization test by four oblong lateral surface,

(2) concrete carbonization situation digital picture is obtained: when carbonization is to the stipulated time in carbonization case for concrete sample, with dry sawing or split the law concrete sample cut open or rive, remove remaining disintegrating slag and powder on section, section is sprayed the alcoholic solution containing 20% distilled water that concentration is the phenolphthalein+99% of 1%, after 30s, when color vary stable, with digital camera, concrete sample section is vertically taken, obtain concrete carbonization situation digital picture

(3) carbonization relevant range is chosen and pixel value analysis: utilize Computer Image Processing software to obtain to step (2) the non-carbonized region that concrete carbonization situation digital picture chooses the whole cross sectional area of concrete sample and test specimen section, and analyze the pixel value of the whole cross sectional area of concrete sample and the pixel value of the non-carbonized region of test specimen section

(4) concrete carbonization velocity coefficient model is set up: based on the scale model of the non-carbonized region of concrete and the whole cross sectional area of concrete, set up the relational model between the pixel value of the whole cross sectional area of concrete carbonization velocity coefficient and concrete sample and the pixel value of the non-carbonized region of test specimen section

(5) concrete carbonization velocity coefficient is calculated: the pixel value of whole cross sectional area of the concrete sample obtained according to step (3) and the pixel value of the non-carbonized region of test specimen section, and the relational model between the pixel value of the whole cross sectional area of the concrete carbonization velocity coefficient that obtains of step (4) and concrete sample and the pixel value of the non-carbonized region of test specimen section, calculate concrete carbonization velocity coefficient.

The scale model of the non-carbonized region of described concrete and the whole cross sectional area of concrete is

$\frac{A_u}{A_t}=\frac{P_u}{P_t}$

Wherein A _trepresent the area of the whole cross sectional area of concrete sample; A _urepresent the area of the non-carbonized region of concrete sample section; P _trepresent the pixel value of the whole cross sectional area of concrete sample; P _urepresent the pixel value of the non-carbonized region of concrete sample section.

Relational model between the pixel value of the whole cross sectional area of described concrete carbonization velocity coefficient and concrete sample and the pixel value of the non-carbonized region of test specimen section is

$\mathrm{\α}=\frac{b/2}{\sqrt{2(1+\sqrt{1-\frac{1}{4}{\left(\frac{P_t-P_u}{P_t}\right)}^2})\·\sqrt{t}}}\·\frac{P_t-P_u}{P_t}$

Wherein α represents concrete carbonization velocity coefficient, and unit is mm/d ^0.5; B represents the length of side of concrete sample, and unit is millimeter; T represents concrete sample carbonization time, and unit is sky.

The present invention will have the region in graphics process accurately choose with pixel read function image processing software in complete, in advance this type of software must be installed in personal computer.

Outstanding advantages of the present invention is:

A kind of image analysis method of Comprehensive Assessment concrete carbonization velocity coefficient is proposed first, the method can carry out two-dimentional carbonization test, carbonization test is carried out under four of concrete sample sides are all exposed to Carbonization Conditions, and irregular, under shaggy concrete cross section condition, computing machine and image processing software is utilized to carry out accurately, analyze the carbonized region of the whole section of concrete intuitively, and then utilize the area ratio of whole cross sectional area of concrete sample and the non-carbonized region of test specimen section to solve concrete carbonization velocity coefficient, avoid traditional one side or concrete one dimension carbonation depth is got in opposite carbon steel dipstick metering, solve again the one side of only getting concrete sample in the method for concrete carbonization velocity coefficient or relatively two sides carry out carbonization can only simulate one-dimensional condition under concrete carbonization process, be difficult to the anti-carbonation properties fully characterizing concrete entirety, and with steel ruler measure carbonation depth by subjective operating influence larger, the defects such as precision is poor, for the anti-carbonation properties of Comprehensive Assessment concrete entirety provides analysis means and foundation.

Four, accompanying drawing explanation

Fig. 1 is the concrete carbonization situation digital picture of concrete test block section.

Fig. 2 is the numerical analysis image after concrete test block cross section regulation color range.

Fig. 3 analyzes the whole cross sectional area of concrete sample obtained.

Fig. 4 is the non-carbonized region analyzing the concrete sample section obtained.

Fig. 5 is the histogram of concrete sample whole cross sectional area pixel analysis.

Fig. 6 is the histogram of the non-carbonized region pixel analysis of concrete sample section.

Fig. 7 is that Matlab solves the concrete carbonization region obtained and the comparison diagram of testing the carbonized region recorded.

Five, embodiment

By the following examples technical scheme of the present invention is described in further detail.

Graphical analysis in embodiment mainly exists complete in CS5.0 image processing software, in advance this software must be installed in personal computer.

Embodiment 1

An example of the image analysis method of Comprehensive Assessment concrete carbonization depth of the present invention, comprises the steps:

1, concrete carbonation test is carried out:

The concrete prism test specimen of preparation 100mm × 100mm × 300mm, adopts the paraffin of heating or epoxy resin to seal the end face of the concrete sample of 28 days curing age and bottom surface, then puts into CO ₂concentration is 17 ~ 23%, and relative humidity is 65 ~ 75%, and temperature is in the carbonization case of 18 ~ 22 DEG C, under being exposed to carbonization environment, carries out carbonization test by four oblong lateral surface.

2, concrete carbonization situation digital picture is obtained:

When concrete sample is in carbonization case during carbonization to 28 day, with split the law, concrete sample is rived, remove remaining disintegrating slag and powder on section, section is sprayed the alcoholic solution containing 20% distilled water that concentration is the phenolphthalein+99% of 1%, after 30s, when color vary stable, with digital camera, concrete sample section is vertically taken, obtain concrete carbonization situation digital picture, as shown in Figure 1.

3, carbonization relevant range is chosen and pixel value analysis:

Open cS5.0 image processing software, selects " image → adjustment → color range " instrument in menu bar, drags the color range bar at two ends in dialog box, note observing picture situation of change simultaneously, until obvious carbonization boundary appears in picture, get final product clear differentiation carbonizing zone and non-carbonizing zone, as shown in Figure 2.With " Magic wand " in CS5.0 toolbar blank space single left button mouse click beyond cross-section image, then a mouse click right button, whole concrete test block section can be chosen by " selecting oppositely ", " newly-built layer " button is clicked under groundwork district panel, obtain layer 2, in toolbar, set a kind of foreground arbitrarily, and with " filling " button in toolbar, foreground filling is carried out to the region chosen in layer 2, the whole cross sectional area of concrete sample can be obtained, as shown in Figure 3.Select layer 1, hide Layers 2, use " Polygonal Lasso Tool " instrument in CS5.0 toolbar is chosen the non-carbonizing zone on concrete sample section, choose in process to click along the spacing that the carbonization boundary amount of exhausting is little and choose, and finally make area closes, as run into rubble, should pass in the middle part of rubble with reference to the carbonized region on rubble both sides, to make border, whole carbonized region continuously smooth.Newly-built layer 3, sets another kind of foreground in toolbar, fills the selected non-carbonized region of test specimen section, as shown in Figure 4.Choose layer 2, layer 3 respectively, read the pixel value gained of layer 2, layer 3 in the information on " layer chosen " hurdle in " histogram " window respectively, as shown in Figure 5, Figure 6, its data are listed in table 1.

The pixel value of the whole cross sectional area of table 1 concrete sample and the non-carbonized region of section

Analyzed area	Pixel value
		Whole cross sectional area	276138
Non-carbonized region	163350

4, concrete carbonization velocity coefficient model is set up:

The scale model of the non-carbonized region of concrete and the whole cross sectional area of concrete is

$\frac{A_u}{A_t}=\frac{P_u}{P_t}$

Wherein A _trepresent the area of the whole cross sectional area of concrete sample; A _urepresent the area of the non-carbonized region of concrete sample section; P _trepresent the pixel value of the whole cross sectional area of concrete sample; P _urepresent the pixel value of the non-carbonized region of concrete sample section.

Based on the scale model of the non-carbonized region of concrete and the whole cross sectional area of concrete, the relational model set up between the pixel value of whole cross sectional area of concrete carbonization velocity coefficient and concrete sample and the pixel value of the non-carbonized region of test specimen section is

$\mathrm{\α}=\frac{b/2}{\sqrt{2(1+\sqrt{1-\frac{1}{4}{\left(\frac{P_t-P_u}{P_t}\right)}^2})\·\sqrt{t}}}\·\frac{P_t-P_u}{P_t}$

Wherein α represents concrete carbonization velocity coefficient, and unit is mm/d ^0.5; B represents the length of side of concrete sample, and unit is millimeter; T represents concrete sample carbonization time, and unit is sky.

5, concrete carbonization velocity coefficient is calculated:

The pixel value 276138 of whole cross sectional area of concrete sample step 3 obtained, the pixel value 163350 of the non-carbonized region of test specimen section, 100 millimeters, concrete sample limit and concrete sample carbonization time substitute into the relational model between the pixel value of whole cross sectional area of concrete carbonization velocity coefficient that step 4 obtains and concrete sample and the pixel value of the non-carbonized region of test specimen section for 28 days, and calculating this concrete carbonation rate coefficient is 1.94mm/d ^0.5.

Embodiment 2

The present embodiment is the instantiation of the validity of checking the inventive method, namely according to analyzing the concrete carbonization velocity coefficient obtained in embodiment 1, business numerical analysis software Matlab is utilized to set up concrete carbonization model, and carbonization situation when solving 28 days in concrete, then with embodiment 1 test the carbonized region recorded and contrast:

Based on Fick First Law, utilize business numerical analysis software Matlab to set up concrete carbonization model, its concrete region is the square area of 100mm × 100mm, and carbonization direction is that the circumferential inside concrete in carbonized region four carries out carbonization.According to the concrete carbonization velocity coefficient that embodiment 1 Comprehensive Assessment obtains, setting concrete carbonization velocity coefficient is 1.94mm/d ^0.5, utilize business numerical analysis software Matlab to solve carbonized region when carbonization time is 28 days in concrete.

Fig. 7 is that business numerical analysis software Matlab solves the comparison diagram of testing the carbonized region recorded in the concrete carbonization region and embodiment 1 obtained, the region that in figure, solid line surrounds is that business numerical analysis software Matlab solves the non-carbonized region of the concrete obtained, and the red area that in figure, dotted line surrounds is test the non-carbonized region of the concrete recorded in embodiment 1.

As can be seen from Figure 7, the region of the carbonized region that Matlab calculates and actual carbonization is substantially identical, illustrates that the concrete carbonization velocity coefficient utilizing the inventive method Comprehensive Assessment to obtain is rational, demonstrates the validity of the inventive method.

Claims (2)

1. an image analysis method for Comprehensive Assessment concrete carbonization velocity coefficient, is characterized in that, comprises the steps:

(1) carry out concrete carbonation test: preparation length breadth ratio is not less than the concrete prism test specimen of 3, adopt the paraffin of heating or epoxy resin to seal the end face of the concrete sample of 28 days curing age and bottom surface, then put into CO ₂concentration is 17 ~ 23%, and relative humidity is 65 ~ 75%, and temperature is in the carbonization case of 18 ~ 22 DEG C, under being exposed to carbonization environment, carries out carbonization test by four oblong lateral surface,

(2) concrete carbonization situation digital picture is obtained: when carbonization is to the stipulated time in carbonization case for concrete sample, with dry sawing or split the law concrete sample cut open or rive, remove remaining disintegrating slag and powder on section, section is sprayed the alcoholic solution containing 20% distilled water that concentration is the phenolphthalein+99% of 1%, after 30s, when color vary stable, with digital camera, concrete sample section is vertically taken, obtain concrete carbonization situation digital picture

(3) carbonization relevant range is chosen and pixel value analysis: utilize Computer Image Processing software to obtain to step (2) the non-carbonized region that concrete carbonization situation digital picture chooses the whole cross sectional area of concrete sample and test specimen section, and analyze the pixel value of the whole cross sectional area of concrete sample and the pixel value of the non-carbonized region of test specimen section

(4) concrete carbonization velocity coefficient model is set up: based on the scale model of the non-carbonized region of concrete and the whole cross sectional area of concrete, set up the relational model between the pixel value of the whole cross sectional area of concrete carbonization velocity coefficient and concrete sample and the pixel value of the non-carbonized region of test specimen section, the relational model between the pixel value of the whole cross sectional area of described concrete carbonization velocity coefficient and concrete sample and the pixel value of the non-carbonized region of test specimen section is:

$\mathrm{\α}=\frac{b/2}{\sqrt{2(1+\sqrt{1-\frac{1}{4}{\left(\frac{P_t-P_u}{P_t}\right)}^2})}\·\sqrt{t}}\·\frac{P_t-P_u}{P_t}$

Wherein α represents concrete carbonization velocity coefficient, and unit is mm/d ^0.5; B represents the length of side of concrete sample, and unit is millimeter; T represents concrete sample carbonization time, and unit is sky, P _trepresent the pixel value of the whole cross sectional area of concrete sample; P _urepresent the pixel value of the non-carbonized region of concrete sample section,

(5) concrete carbonization velocity coefficient is calculated: the pixel value of whole cross sectional area of the concrete sample obtained according to step (3) and the pixel value of the non-carbonized region of test specimen section, and the relational model between the pixel value of the whole cross sectional area of the concrete carbonization velocity coefficient that obtains of step (4) and concrete sample and the pixel value of the non-carbonized region of test specimen section, calculate concrete carbonization velocity coefficient.

2. the image analysis method of Comprehensive Assessment concrete carbonization velocity coefficient according to claim 1, is characterized in that, the scale model of the non-carbonized region of described concrete and the whole cross sectional area of concrete is

$\frac{A_u}{A_t}=\frac{P_u}{P_t}$

Wherein A _trepresent the area of the whole cross sectional area of concrete sample; A _urepresent the area of the non-carbonized region of concrete sample section; P _trepresent the pixel value of the whole cross sectional area of concrete sample; P _urepresent the pixel value of the non-carbonized region of concrete sample section.