A simple method for detecting the exposed cement concrete pavement during fine milling.

Abstract

The invention discloses a simple method for detecting the exposed grout rate of fine milling construction of cement concrete pavement; the method mainly comprises the steps of test point selection, test point cleaning, shaping and weighing measurement; during shaping operation, a cuttable sheet is laid on the contour of an area that has not been milled or has not been completely milled, and the contour is drawn before cutting or the contour is directly cut on site based on the contour shape; during weighing measurement operation, the cut standard paper is placed on a weighing device to weigh the mass; the total mass parameter of the standard paper is converted into the exposed grout rate of three test points, and they are marked as X respectively. 1 , X 2 , X 3 The average value is used as the exposed grout rate of the fine milling construction of the cement concrete section to judge the quality of the fine milling construction. The present invention relies on topography and weighing measurement to realize the exposed grout rate measurement, has strong operability, simple and convenient operation process and low cost, and can relatively accurately know the exposed grout rate of the fine milling construction of the cement pavement.

Description

Technical Field

[0001] The invention belongs to the technical field of cement pavement construction quality detection, and in particular relates to a simple method for detecting the slurry exposure rate of cement concrete pavement fine milling construction. Background Art

[0002] The exposed mortar rate (also known as the nominal exposed rate) is an important basis for judging the quality of fine milling construction of cement concrete pavement, and the accuracy of its test results is particularly important. At present, there are many methods for testing the exposed mortar rate of fine milling of cement concrete pavement at home and abroad, but most of them are based on visual inspection, which is too subjective and cannot provide accurate exposed mortar rate data. Secondly, China is also studying the use of image acquisition technology and analysis technology to inspect the quality of fine milling of cement concrete pavement, but this method has many operating processes, expensive equipment, high detection cost, and it is not easy to quickly detect the quality of on-site construction. It is currently not suitable for on-site detection. Summary of the invention

[0003] The purpose of the present invention is to provide a simple method for detecting the exposed mortar rate of fine milling construction of cement concrete pavement, so as to solve the problems in the existing detection process of exposed mortar rate of fine milling construction of cement concrete pavement: the visual method cannot provide accurate exposed mortar rate data, and the image acquisition technology and analysis technology methods are high in cost and cumbersome in operation.

[0004] To achieve the above object, the technical solution adopted by the present invention is:

[0005] A simple method for detecting the exposed slurry rate of cement concrete pavement fine milling construction includes the following steps:

[0006] (1) Test site selection: Refer to the method of T 0902-2019 in the "Site Test Procedure for Highway Roadbed and Pavement" JTG 3450-2019, every 2000m 2 Randomly select 3 locations to conduct the slurry exposure test, each with a size of 100cm×100cm;

[0007] (2) Cleaning of test points: After selecting a point, use a brush and ear bulb to carefully remove dust from the test site and surrounding areas. If necessary, scrub with water and wait until it is dry before testing. In case of strong winds, a wind shield can be placed;

[0008] (3) Shape rubbing: Use standard sheets that can be cut to lay the contour of the area that has not been milled or has not been completely milled. Use a marker to draw the contour and place it indoors to cut the standard sheets. Alternatively, you can directly cut the standard sheets on site based on the contour shape to obtain the contour sheet.

[0009] (4) Weighing measurement: Place the cut standard sheet on the weighing equipment and weigh the mass. Obtain the total mass parameters of the three standard sheets at the three test points. Use the total mass parameters of the standard sheets to convert into the grout exposure rate of the three test points and mark them as X1, X2, and X3 respectively. The average value is used as the grout exposure rate of the fine milling construction of this section of cement concrete to judge the quality of the fine milling construction.

[0010] The average exposure rate is ; =(X1+X2+X3) / 3.

[0011] Furthermore, the cuttable standard sheet material is A4 paper and a hard transparent plastic sheet or other rectangular thin sheets. When the unmilled or incompletely milled area of ​​the cuttable standard sheet material cannot be filled with a single cuttable sheet material, multiple cuttable sheets are laid flat and spliced ​​together.

[0012] Furthermore, the cuttable standard sheet should be calibrated before the test, and the calibration method is as follows:

[0013] Before on-site testing, the standard sheets for testing must be calibrated indoors in advance. In principle, 10 sheets of each package of standard sheets are calibrated, and the average value is taken as the standard density of the standard sheets for testing, and the coefficient of variation of density should not be greater than 1%;

[0014] Randomly select 10 sheets from a pack of standard sheets for density calibration, measure their dimensions (length × width) one by one with a vernier caliper, and calculate their area A i , and then weigh each sheet on an analytical balance. i Then the density of each standard sheet is i The calculation formula is:

[0015] (1)

[0016] Average density for:

[0017] (2)

[0018] Density coefficient of variation C V for:

[0019] (3)

[0020] In the formula, A i The area of ​​the standard sheet for single test, mm 2 ;m i is the mass of the standard sheet for single test, mg; S is the density sample deviation, mg / cm 2 ; n is the number of standard sheet samples used in the calibration test, n=10.

[0021] Furthermore, the slurry exposure rate of each test point is calculated according to the following formula:

[0022] (4)

[0023] Where, X i — is the exposed bone ratio of cement concrete pavement, also known as exposed slurry ratio (%);

[0024] M i —Total mass (mg) of the test standard sheet representing the area of ​​cement concrete pavement that has not been milled or has not been completely milled;

[0025] A m — is the total area at the detection point, which is 100cm×100cm=10000 (cm 2 );

[0026] — is the standard sheet density for testing (mg / cm 2 ).

[0027] Furthermore, when the unmilled and incompletely milled area is completely covered by four or more standard sheets laid flat and spliced, a rectangle of the size shown after four or more standard sheets are laid flat and spliced ​​is drawn in the area, and then the cuttable sheet is aligned with the edge of the drawn rectangle and the unmilled and incompletely milled area is paved.

[0028] Furthermore, during the shaping process of step (3), when encountering extreme weather or other conditions that are not suitable for on-site shaping of the cuttable standard sheet, a 100 cm×100 cm transparent plate can be added to cover the contour of the unmilled or incompletely milled area, and an outline is drawn on the transparent plate with a marker pen and placed indoors. Then, the cuttable standard sheet is laid on the transparent plate, and the cuttable standard sheet is cut according to the drawn outline.

[0029] The beneficial effects of the present invention are:

[0030] The present invention lays transparent cuttable sheets or paper sheets on the road surface of the selected test point to cover the unmilled or incompletely milled areas, and cuts out standard paper of a size corresponding to the outline, obtains necessary parameters by weighing, and then obtains the exposed slurry rate of the road surface; this method is highly operational, easy to operate on site, and has a simple and convenient operation process and low cost, and can relatively accurately obtain the exposed slurry rate of the cement road surface during fine milling construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram for demonstrating the on-site application of the present invention.

[0032] Among them, 1-unmilled part of cement concrete pavement; 2-milled part of cement concrete pavement; 3-standard cuttable sheet for test. DETAILED DESCRIPTION

[0033] The preferred embodiments of the present invention are described below with reference to the accompanying drawings.

[0034] Please refer to the application process for Figure 1 .

[0035] 1. Preparation of equipment and tools before the test

[0036] (1) Analytical balance: accuracy not less than 1 mg;

[0037] (2) Digital display vernier caliper: measuring range 500mm, accuracy 0.1mm;

[0038] (3) Transparent cuttable sheet: rectangular transparent PC, PVC sheet or rectangular plastic shed film; size is 210mm×297mm, other suitable sizes can also be used, preferably the same size as A4 paper, easy to carry, and its density needs to be calibrated before each use;

[0039] (4) A4 paper: 210mm×297mm, 80g / m 2 , 85g / m 2 or 90g / m 2 , its density needs to be calibrated before each use;

[0040] (5) Transparent sheet (100cm×100cm), windshield, wallpaper knife, scissors, brush, ear bulb, marker, ruler and other auxiliary tools.

[0041] 2. Calibration of standard sheets for testing

[0042] Before on-site testing, the standard sheets for the test must be calibrated indoors in advance. In principle, 10 sheets of each package of standard sheets should be calibrated, and the average value should be used as the standard density of the standard sheets for the test, and the density variation coefficient should not be greater than 1%.

[0043] Specific operation: Randomly select 10 sheets from a pack of standard sheets for density calibration, use a vernier caliper to measure their size (length × width) one by one, and calculate their area A i , and then weigh each sheet on an analytical balance. i Then the density of each standard sheet used in the test is i The calculation formula is:

[0044] (1)

[0045] Average density for:

[0046] (2)

[0047] Density coefficient of variation C V for:

[0048] (3)

[0049] In the formula, A i The area of ​​the standard sheet for single test, mm 2 ;m i is the mass of the standard sheet for single test, mg; S is the density sample deviation, mg / cm 2 ; n is the number of standard sheet samples used in the calibration test, n=10.

[0050] The density variation coefficient C V If the density is greater than 1%, the density is recalibrated twice. After the last two calibrations, there is still a set of density variation coefficients C V If it is greater than 1%, replace the entire package of standard sheets until the calibration meets the requirements.

[0051] 3. Slurry exposure rate calculation process

[0052] (1) Test site selection: Refer to the method of T 0902-2019 in the "Site Test Procedure for Highway Roadbed and Pavement" JTG 3450-2019, every 2000m 2 Three locations were randomly selected to conduct slurry exposure rate tests, each with a size of 100cm×100cm.

[0053] (2) Cleaning of test points: After selecting the test points, use a brush and ear bulb to carefully remove dust from the test site and surrounding areas to prevent the edges of transparent cuttable sheets from becoming unclear due to dust sticking to them. If necessary, scrub with water and conduct the test after drying. If the wind is strong during the test, place a wind shield around the test point.

[0054] (3) Shape extension: Use cuttable sheets to lay the contours of the unmilled or incompletely milled areas. The cuttable sheets are preferably hard transparent plastic sheets and A4 paper. Other rectangular sheets, such as polycarbonate PC sheets and PVC sheets, can also be used in the shape extension process. Take the commonly used hard transparent plastic sheets as an example. The size of the hard transparent plastic sheets is controlled to be the same as that of A4 paper, which is convenient for carrying and storage. After laying the contours of the unmilled or incompletely milled areas and achieving full coverage, use a marker to draw the contours, and use wallpaper knives, scissors and other cutting tools to cut along the contours. Cut the sheet according to the contour shape; if the unmilled or incompletely milled area cannot be filled with a single cuttable sheet, multiple cuttable sheets will be laid flat and spliced ​​together; when the unmilled or incompletely milled area completely covers four or more cuttable sheets by laying flat and splicing, draw a rectangle of the size shown after four or more cuttable sheets are laid flat and spliced ​​in the area, then align the cuttable sheet with the edge of the drawn rectangle and lay the unmilled or incompletely milled area, which can avoid cutting size errors caused by uneven splicing of multiple sheets and also increase the convenience of operation.

[0055] When encountering extreme weather, such as sudden strong winds, rain, or the ground is not dry after rain, the site is difficult to clean, and other situations that are not suitable for on-site shaping operations of cuttable standard sheets, a 100cm×100cm transparent plate can be added for auxiliary use; when using it, cover the transparent plate on the contour of the unmilled or incompletely milled area, use a marker to draw the outline on the transparent plate and place it indoors, then lay the cuttable standard sheet on the transparent plate, and cut the cuttable standard sheet according to the drawn outline.

[0056] (4) Weighing and measurement: After the topography is completed, the cuttable pieces are cut according to the size; when the outline is larger than the size of a single standard sheet, multiple standard sheets can be laid flat and cut. The cut standard sheets are placed on the weighing equipment and weighed. The total weight of the standard sheets at the three test points representing the unmilled and incompletely milled areas is recorded as M1, M2, and M3 respectively; the slurry exposure rate at the three locations is measured and calculated according to the slurry exposure rate calculation formula and marked as X1, X2, and X3 respectively. The average of the three slurry exposure rates is used as the slurry exposure rate of the fine milling construction of this section of cement concrete to judge the quality of the fine milling construction;

[0057] The average exposure rate is ; =(X1+X2+X3) / 3.

[0058] The grout exposure rate of the test point is calculated according to the following formula:

[0059] (4)

[0060] Where, X i — is the exposed bone ratio of cement concrete pavement, also known as exposed slurry ratio (%);

[0061] M i —Total mass (mg) of the test standard sheet representing the area of ​​cement concrete pavement that has not been milled or has not been completely milled;

[0062] A m — is the total area at the detection point, which is 100cm×100cm=10000 (cm 2 );

[0063] — is the standard sheet density for testing (mg / cm 2 ).

[0064] Finally, a test report can be formed, which should indicate the information such as the test location pile number, purpose, average value, and calibration density of the standard sheet used in the test.

Claims

1. A simple method for detecting the slurry exposure rate of cement concrete pavement fine milling construction, characterized in that: The steps include: (1) Test site selection: Refer to the method of T 0902-2019 in the "Site Test Procedure for Highway Roadbed and Pavement" JTG 3450-2019, every 2000m 2 Randomly select 3 locations to conduct the slurry exposure test, each with a size of 100cm×100cm; (2) Cleaning of the test point: After selecting a point, use a brush and ear bulb to carefully remove dust from the test site and surrounding areas, scrub with water, and wait for it to dry before testing. In case of strong winds, a wind shield can be placed; (3) Shape extension: Use a standard cuttable sheet to lay the contour of the unmilled or incompletely milled area, draw the contour with a marker pen and place it indoors for cutting the standard sheet, or cut the standard sheet directly on site based on the contour shape; wherein the standard cuttable sheet is a uniform hard transparent plastic sheet, paper sheet or other uniform thin sheet of a regular shape. When the unmilled or incompletely milled area cannot be filled with a single cuttable sheet, multiple cuttable sheets are laid flat and spliced; the standard cuttable sheet should be calibrated in advance before the test, and the calibration method is as follows: Before on-site testing, the standard sheets need to be calibrated indoors in advance. In principle, 10 sheets of each package of standard sheets are calibrated, and the average value is used as the density of the standard sheets for testing, and the density variation coefficient should not be greater than 1%; Randomly select 10 sheets from a pack of standard sheets for density calibration, use a vernier caliper to measure the size of each sheet, length × width, and calculate its area A i , and then weigh each sheet on an analytical balance. i ; Then the density of each standard sheet is ρ i The calculation formula is: （1） Average density for: （2） Density coefficient of variation C V for: （3） In the formula, A i — is the area of ​​standard sheet for single test, mm 2 ; m i — is the mass of a single standard sheet for testing, mg; S—density sample deviation, mg / cm 2 ; n—is the number of standard sheet samples used for calibration test, n=10; (4) Weighing measurement: Place the cut standard sheet on the weighing equipment, weigh the mass, and obtain the total mass parameters of the standard sheet at the three test points; convert the total mass parameters of the standard sheet into the grout exposure rate of the three test points, and mark them as X1, X2, and X3 respectively. The average value is used as the grout exposure rate of the fine milling construction of this section of cement concrete to judge the quality of fine milling construction; the average grout exposure rate is X; X=(X1+X2+X3) / 3; where the grout exposure rate of each test point is calculated according to the following formula: （4） Where, X i — is the exposed bone ratio of cement concrete pavement, also known as exposed slurry ratio, %; M i —Total mass of the test standard sheet representing the area of ​​cement concrete pavement that has not been milled or has not been completely milled, mg; A m — is the total area at the detection point, 100cm×100cm=10000, cm 2 ; — is the standard sheet density for testing, mg / cm 2 .

2. A simple method for detecting the exposed slurry rate of cement concrete pavement fine milling construction as claimed in claim 1, characterized in that: When the un-milled and incompletely milled area is completely covered by four or more standard sheets laid flat and spliced, a rectangle of the size shown after four or more standard sheets are laid flat and spliced ​​is drawn in the area, and then the standard sheets are aligned with the edge of the drawn rectangle and the un-milled and incompletely milled area is laid.

3. A simple method for detecting the exposed slurry rate of cement concrete pavement fine milling construction as claimed in claim 1, characterized in that: During the shaping process of step (3), when encountering extreme weather or other conditions that are not suitable for on-site shaping of cuttable standard sheets, a 100 cm×100 cm transparent plate can be added to cover the contour of the unmilled or incompletely milled area. The outline is drawn on the transparent plate with a marker pen and placed indoors. Then, the cuttable standard sheets are laid on the transparent plate and cut according to the drawn outline.

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