WO2014013099A1 - Device and method for measuring a coating comprising bituminous binders - Google Patents

Description

 IRRIGATION MEASUREMENT DEVICE AND METHOD WITH BITUMINOUS BINDERS

FIELD OF THE INVENTION

The present invention belongs to the field of construction in civil engineering works and, more specifically, to devices and methods for measuring the provision of risks with bituminous binders

BACKGROUND OF THE INVENTION

In civil engineering works it is usual to apply on the surface being treated (building or reforming) irrigation with bituminous binders. For example, adhesion irrigation is the application of a bituminous emulsion on a layer treated with hydrocarbonate binders or hydraulic binders, prior to placing on it any type of bituminous layer that is not a gravel surface treatment, or a bituminous grout . Said treatment is necessary to avoid possible damages that can cause a bad union between the layers of the pavement (cracks, undulations, sliding of layers, ...), extending its useful life. To achieve a correct union between layers it is essential to apply the appropriate dosage of irrigation, since a lower provision than recommended does not manage to join the layers correctly, reducing their adhesion, and an excessive provision can cause slips between the layers or pass part of the binder to the upper layer, reducing the gaps, with the consequent increase in deformations.

Regarding adhesion irrigation, there is a standardized method for measuring the irrigation equipment applied on site according to ASTM D2995 (ASTM Standard D2995 ASTM D2995, Standard Practice for Estimating Application Rate of Bituminous Distributors, 4th edn, West Conshohocken, PA, Pennsylvania, USA). This method consists of placing a square surface of geotextile, previously weighed, on the layer of the firm prior to the extension of adhesion irrigation. Once the adhesion irrigation is extended, either manually or through a watering device, the geotextile surface is removed and weighed again. By means of the weight difference, the applied adhesion irrigation endowment is obtained.

However, this method raises doubts about its reliability, due to the results shown in some research.

Tashman (Tashman, L., Nam, K. & Papagiannakis, AT 2006, Evaluation of the influence of tack coat constr ction factor are the bond strength between pavement layers, lst edn, Washington State Dept. of Transportation, Washington) used it in his studies on adhesion between layers. In them he made comparisons of different instruments and methods of measurement of tensile strength and shear stress that provided different amounts of emulsion to join layers of the pavement. To measure the amount of residual bitumen applied on the surface, a layer of geotextile was placed on the base surface before the application of adhesion irrigation, in the same manner as indicated by ASTM D2995. However, instead of measuring the amount of emulsion applied, the amount of residual bitumen after water evaporation was measured. The practical results obtained were significantly different from those calculated and expected theoretically, obtaining values too high for the lowest allocations and values too low for the highest allocations. In turn, between the highest and lowest target values, the theoretical endowment difference was around 250 g / m, while the actual measurements obtained the difference was only 40 g / m ² . This means that for your tests you had to use the theoretical values instead of the actual measurements.

These deviations may be caused by an erroneous measurement during the test, an inadequate test procedure, decalibration of the watering device or a combination of the aforementioned factors.

On the other hand, West {West, RC, Zhang, J. & Moore, J. 2005, "Evaluation of bond strength between pavement layers ", National Center for Asphalt Technology, Auburn University, Alabama, USA) states that this method is reliable in view of the results obtained during the performance of its shear resistance tests that provide adhesion risks at the junction between layers, they took samples of the adhesion irrigation in seven different projects, to then be able to compare results of different types of emulsion applied and different amounts of it.

However, Muench {Muench, ST ά Moomaw, T. 2008, De-bonding of hot mix asphalt pavements in Washington State: An initial investigation, I ^st edn, Washington State Dept. Of Transportation, Office of Research & Library Services, Washington ) expresses its doubts regarding the reliability of this method since, taking as reference the tests carried out by Tashman and West, the results show many variations. Although West adopts it as a valid method, Muench observes that in three of the seven projects analyzed by West, the amount of heavy adhesion irrigation is much less than the amount originally planned. This occurs in the three projects that use fast-breaking cationic emulsions, and it may be due to the fact that at the time of weighing the geotextiles a part of the water in the emulsion has evaporated. Another source of error may be the accuracy of the calibration of truck adhesion irrigation dispensers.

In addition, by analyzing the described technique, several drawbacks related to its application have been detected. An important drawback is that the geotextile is simply placed on the surface of the layer on which the irrigation is applied, and lacks support, so it can be folded or moved by the wheels of the watering device at the time when apply irrigation.

It has also been observed that, in the areas where the irrigation application must be carried out manually, the operator can apply a different amount to the geotextile than the one previously being applied in other parts of the surface, distorting the results obtained. Another important factor that is not considered in this test is the time between the application of irrigation and the weighing of the impregnated geotextile. This can cause disparate results because, after some time, the water included in the irrigation will have evaporated.

Finally, it is appreciated that part of the irrigation applied to the surface of the geotextile could be drained if the applied dosage is high and the geotextile cannot fully absorb said amount.

GENERAL DESCRIPTION OF THE INVENTION

The present invention tries to solve the aforementioned drawbacks by means of a device and method of measuring irrigation with bituminous binders that allows to absorb a percentage of the irrigation applied on the surface of a layer of the firm.

Specifically, in a first aspect of the present invention, a device for measuring a bituminous binder irrigation is provided on a surface on which said bitiiminous binder irrigation has previously been applied, comprising a plate attached to a bar and covered by an absorbent material, the assembly consisting of the bar, the plate and the absorbent material configured to exert pressure on said surface. Said absorbent material covers the side of the plate intended to be in contact with said surface so that, by exerting pressure on said bituminous binder impregnated surface, said material absorbs an amount of the applied irrigation.

In a possible embodiment, the plate is made of a rigid material.

In a possible embodiment, the absorbent material is a non-woven geotextile. In a possible embodiment, the device of the invention further comprises a means for exerting pressure guided by said bar.

In one possible embodiment, said bar has a through hole configured to house a pin to hold the plate and the means for exerting pressure in suspension.

Preferably, the means for exerting pressure is a weight.

In a possible embodiment, between the plate, which is adapted to be covered by an absorbent material, and said absorbent material there is located a waterproof and deformable layer configured to mold said device to possible surface irregularities. Preferably, said waterproof and deformable layer is a polyethylene foam with at least one of its impermeable faces.

In a possible embodiment, the device of the invention comprises a support configured to keep said plate parallel to the surface. Preferably, said support is a tripod. In addition, in a preferred embodiment, said support comprises a plurality of support points, which in turn comprise fastening means for regulating the height of the support points.

In another aspect of the invention, a method of measuring an irrigation with bituminous binder is provided on a surface on which said irrigation has previously been applied, using the device defined above. The method comprises the steps of:

- Weigh an absorbent material.

 - Place said absorbent material covering the plate side of said device intended to be in contact with the surface.

- Place the device on the surface where the measurement is to be performed. - Apply pressure on the surface with said device, so that the absorbent material absorbs irrigation applied on said surface.

 - Remove the absorbent material from the device.

 - Weigh the absorbent material.

 - Compare the weight of the absorbent material comprising said irrigation with bituminous binder, with the weight of the absorbent material without the absorption of said irrigation.

The advantages of the invention will become apparent in the following description.

BRIEF DESCRIPTION OF THE FIGURES

In order to help a better understanding of the characteristics of the invention, in accordance with a preferred example of practical realization thereof, and to complement this description, a set of drawings is attached as an integral part thereof, whose character is Illustrative and not limiting. In these drawings:

Figures 1 A and IB show a schematic of a device according to a first embodiment of the invention.

Figures 2 A and 2B show a schematic of a device according to a second embodiment of the invention.

Figure 2C shows a detail related to the embodiment of Figures 2A and 2B. Figure 2D shows another detail related to the embodiment of Figures 2A and 2B. Figure 2E shows another detail related to the embodiment of Figures 2A and 2B. Figure 2F shows another detail related to the embodiment of Figure 2A. DETAILED DESCRIPTION OF THE INVENTION

In this text, the term "comprises" and its variants should not be understood in an exclusive sense, that is, these terms are not intended to exclude other technical characteristics, additives, components or steps.

In addition, the terms "approximately", "substantially", "around", "ones", etc. they should be understood as indicating values close to which these terms accompany, since due to calculation or measurement errors, it is impossible to achieve those values with total accuracy.

In addition, geotextile is understood as a flat synthetic textile material formed by polymeric fibers (polypropylene, polyester or polyamides), similar to a fabric, of great deformability, used for engineering works (in contact with earth and rocks), whose mission is to make separation or filtration, drainage, reinforcement or waterproofing functions. Within the geotextiles there are woven and nonwoven types. In the tissues, the fibers are oriented in two directions (weft and warp), while in the nonwovens, the fibers that make up the geotextile are arranged randomly.

In addition, bituminous binder means any adhesive material that contains asphaltic bitumen. It can be presented in pure, modified, oxidized, fluidized, fluxed, emulsified form [UNE 12597]. Its main field of use is the construction of bituminous pavements. There are several types of irrigation with bituminous binders such as surface treatments: primer watering, adhesion watering, curing watering and gravel watering. The instrument and procedure described is valid, for example, for adhesion risks, curing risks and for measuring the binder applied in the first layer of gravel watering, making the measurement of the binder before the extension of the first layer of gravel

The characteristics of the method and apparatus of the invention, as well as the advantages derived therefrom, may be better understood with the following description, made with reference to the drawings listed above.

The following preferred embodiments are provided by way of illustration, and are not intended to be limiting of the present invention. In addition, the present invention covers all possible combinations of particular and preferred embodiments indicated herein. For those skilled in the art, other objects, advantages and features of the invention will be derived partly from the description and partly from the practice of the invention.

Next, the device of the invention for measuring irrigation with bituminous binders on a surface, for example a firm layer, is described in accordance with the scheme thereof in Figure 1A. The device is portable and is designed to measure different types of applied watering, such as adhesion watering, curing watering or the binder applied in the first layer of the gravels. All these risks are made with bituminous binders, but one skilled in the art will understand that the specific amount, type and bituminous binders will depend on the type of irrigation.

The surface can be a layer of firm, a bridge, a terrace, a roof or any other surface that an expert in the field considers to be applied in civil engineering. The materials from which said surface may be formed are those conventional in this type of surfaces, such as bituminous pavements or concrete pavements.

The device of Figure 1A comprises a substantially flat plate 1 1. The plate material can be any that is rigid. In a particular embodiment stainless steel has been used, although other alternative materials may be employed, such as aluminum, and alloys of said materials. The plate 1 1 must have a thickness such that it guarantees its rigidity. One skilled in the art will understand that the appropriate thickness that ensures the rigidity of the plate 1 1 depends on the characteristics of the surfaces and the material of the plate 11. Said plate 11 is covered with an absorbent material 12. Possible absorbent materials 12 are geotextiles, fabrics, sponges or foams of polymeric materials. As absorbent materials, both woven and nonwoven materials can be used as long as they ensure adequate absorption of the applied emulsion. In a particular embodiment, a non-woven polypropylene geotextile with a weight of 500 g / m ² (PP-500) has been used. Alternatively, another type of geotextile can be used as long as it has a higher density (PP-600, PP-700, PP-800, etc.).

The plate 11 is preferably joined transversely to a bar 13. Through the plate assembly 11, bar 13 and absorbent material 12, pressure is exerted on the surface.

To measure the irrigation with bituminous binders, it is necessary to weigh the absorbent material 12 before placing it covering the plate 1 1. This weight is compared at the end of the test, with the weight of the absorbent material 12 once a percentage of applied binder.

Irrigation is applied to the surface to subsequently place the measuring device of Figure 1 A, and exert pressure on said surface. Preferably, if the density of the absorbent material is increased, the pressure exerted must also be increased so that said material can absorb the emulsion for the lowest endowments. One skilled in the art will understand that the time required between the application of irrigation and the placement of the device depends on the type of bituminous binder used. For fast break emulsions, the waiting time should be shorter than in cases of slow break emulsions. In any case, it is necessary to place the device before the breaking of the emulsion begins, so a waiting time is recommended from the application of irrigation depending on the rate of breakage of the emulsion. As Figure IB shows, in one embodiment, at least one means for exerting pressure 14 on the surface, such as a weight, is introduced along the bar.

Once the pressure on the surface is exerted, the means for exerting pressure are removed, if any. One skilled in the art will understand that the pressure time of the device on the surface depends on the type of bituminous binder used, since the higher the percentage of water in the emulsion, the less time it will take for absorption. Preferably, the pressure application time should be approximately 5 minutes from the beginning of the pressure application.

Next, the measuring device 1 is removed from the ground, the absorbent material 12 is removed from the device and weighed at that same time, to finally compare the final weight with the initial weight of the absorbent material 12 without irrigation of bituminous binders.

Figures 2A, 2B, 2C, 2D, 2E and 2F show an alternative embodiment in which the device includes optional elements that facilitate its use.

As Figure 2C shows, an impervious and deformable layer 25, preferably polyethylene foam with at least one of its impermeable faces, can optionally be placed between the plate 21 and the absorbent material 22. Said waterproof and deformable layer 25 allows the device 2 to be molded to possible irregularities of the surface on which it is worked. In addition, if the absorbent material 22 is not thick enough to regularly absorb the applied emulsion, the inclusion of said impermeable and deformable layer 25 makes it possible to increase the reliability in the measurements made in the field.

Also optionally, and as shown in Figures 2A and 2B, the device 2 includes a support 26, preferably a tripod, which is responsible for maintaining the plate 21 parallel to the surface before and during the application of the test, while facilitating the process of placing the plate on the surface.

To perform the irrigation measurement with the device 2 when it includes the support 26, the support 26 must be leveled to keep the plate 21 substantially parallel with respect to the surface on which to apply the irrigation. In a possible embodiment of the invention, each support point 27 of the support includes fastening means 28 such as screws, to regulate the height of each of the support points 27.

As in the device of Fig. IB, at least one means for exerting pressure 24 is introduced along the bar 23 at the surface of the bar 23.

As Figure 2F illustrates, optionally, and in order to hold said means for exerting pressure 24 before the application of the load, the bar 23 that is attached to the plate 21 has a through hole in which a pin 29 is placed which maintains the plate 21 and the means for exerting pressure 24 in suspension.

After the necessary time has elapsed since the application of the irrigation with bituminous binders on the surface, the measuring device 2 is placed, the pin 29 is removed and the means for exerting pressure (or weight) 24 to apply the load is released.

After a while, the weight 24 and the measuring device 2 are removed, the absorbent material 22 is removed, and weighed at that same time, to finally compare the final weight with the initial weight of the absorbent material 22 without irrigation.

The portable device 1, 2 of the invention solves the drawbacks detected in the current state of the art. The device is used once irrigation with bituminous binders has been applied, and the absorbent material 12, 22 is subject to said device 1, 2, so there is no possibility that the absorbent material 12, 22 will wrinkle or double, always obtaining the precise values of binder absorption. In turn, being a portable device that is used once the irrigation with bituminous binders is extended, said device 1, 2 can be placed anywhere on the surface 20, for example pavement, avoiding the false results that can cause an operator in the manual application of irrigation.

It is a method that allows, quickly, to verify the dosage of irrigation with bituminous binders used, since the results are obtained instants after the application of said irrigation. Another important factor is the control over the absorbent material 12, 22 used and the load applied, always obtaining results comparable to previously obtained tables.

The device 1, 2 is suitable for use in the construction of, for example, pavements or bridges, either in the construction of new terraces or in the rehabilitation of existing ones, being useful to control the correct endowment of applied binder.

A concrete example of embodiment of the invention and the results obtained are shown below.

To verify the correct functioning of the designed device, tests have been carried out in the laboratory applying adhesion irrigation between 250 and 500 gm ² of residual bitumen. Bituminous mixing track specimens of various types (AC16D, AC16S, BBTM11A) with different surface roughnesses of surface dimensions of 265x310 mm have been used.

A device consisting of a 2 mm thick steel plate and a surface dimension of 250x250 mm, covered with a PP-500 non-woven geotextile with a polyethylene foam of the same dimensions (250x250 mm) has been used to conform to possible irregularities of the surface. Said plate is connected perpendicularly and in its center to a steel bar 20 mm in diameter. The type of geotextile indicated (PP-500) is very suitable due to the significant differences obtained between the percentages absorbed for the different dosages analyzed, although alternatively other geotextiles may be suitable such as PP-600, PP-700, PP-800 or PP-1000

The test device incorporates a tripod that is responsible for keeping the plate parallel to the surface before and during the application of the test. For this, in each support point of the support there are some thymes to regulate the height of each of the support points.

On the one hand, the steel plate with the bar, the geotextile, the polyethylene foam and a low density polyethylene layer between the geotextile and the polyethylene foam have been placed to prevent the latter from getting dirty with the emulsion.

On the other hand, a tripod and 4 weights of 4.5 kg each have been placed, which together with the weight of the bar and the steel plate add a total weight of 20 kg (3.14 kPa). In order to hold the weights before the load is applied, the bar that is attached to the plate has a through hole in which a pin that holds the plate and the suspended weights is placed.

The desired amount of irrigation with bituminous binders is spread on the surface of the test specimen and, after 5 minutes from said emulsion extension, the device is placed and the load is applied on the surface of the specimen.

After another 5 minutes from the application of the load, the load and the device are removed, the geotextile is removed from the steel plate and weighed on a portable precision balance within 2 minutes after the geotextile has been removed. of the steel plate. Geotextile provides different absorption percentages for each of the dosages used. So for the lowest dosage, 250 g / rn ² , the percentage absorbed is around 60%, while for the highest, 2

of 500 g / m, it is approximately 90%. These percentages correspond to the amount absorbed with respect to the total applied.

Claims

1. Measuring device for an irrigation with bituminous binder on a surface (20) on which said irrigation with bituminous binder has previously been applied, comprising a plate (11, 21) attached to a bar (13, 23) and coated by an absorbent material (12, 22), the assembly being formed by the bar (13, 23), the plate (1 1, 21) and the absorbent material (12, 22) configured to exert pressure on said surface (20 ), the device being characterized in that said absorbent material (12, 22) covers the side of the plate (11, 21) intended to be in contact with said surface (20) so that, by exerting pressure on said surface (20 ) impregnated with bituminous binder, said material (12, 22) absorbs an amount of irrigation applied. 2. The device of claim 1, wherein said plate (11, 21) is made of a rigid material. 3. The device of any of the preceding claims, wherein said absorbent material (12, 22) is a nonwoven textile geo. 4. The device of any of the preceding claims, further comprising a means for exerting pressure (14, 24) guided by said bar (13, 23). 5. The device of any one of the preceding claims, wherein said bar (13, 23) has a through hole configured to house a pin (29) to hold the plate (11, 21) and the means for exerting pressure (14) , 24). 6. The device of any one of claims 4 or 5, wherein the means for exerting pressure (14, 24) is a weight. 7. The device of any of the preceding claims, wherein between the plate (11, 21), which is adapted to be covered by an absorbent material (12, 22), and said absorbent material (12, 22) is located a waterproof layer and deformable (25) configured to mold said device to possible surface irregularities. 8. The device of claim 7, wherein the waterproof and deformable layer (25) is a polyethylene foam with at least one of its waterproof faces. 9. The device of any of the preceding claims, comprising a support (26) configured to keep said plate (1, 21) parallel to the surface (20). 10. The device of claim 9, wherein said support (26) is a tripod. 1 1. The device of any of claims 9 or 10, wherein said support (26) comprises a plurality of support points (27), which in turn comprise fastening means (28) to regulate the height of the support points (27). 12. Method of measuring an irrigation with bituminous binder on a surface (20) on which said irrigation has previously been applied, using the device according to any of the preceding claims, characterized in that it comprises the steps of: - Weigh an absorbent material (12, 22).  - Place said absorbent material (12, 22) covering the side of the plate (1, 21) of said device intended to be in contact with the surface (20).  - Place the device on the surface (20) on which you want to measure. - Apply pressure on the surface (20) with said device, so that the absorbent material (12, 22) absorbs irrigation applied on said surface (20).  - Remove the absorbent material (12, 22) from the device. - Weigh the absorbent material (12, 22). - Compare the weight of the absorbent material (12, 22) comprising said irrigation with bituminous binder, with the weight of the absorbent material (12, 22) without the absorption of said irrigation.