HK1081272A - Material segregation, density, and moisture analyzing apparatus and method - Google Patents

Description

Apparatus and method for analyzing segregation, density and moisture of material

This patent application is a continuation-in-part of co-pending U.S. application 09/864,050 entitled "apparatus and method for analyzing segregation, density and moisture of materials" filed on 5/23/2001.

Technical Field

The present invention relates generally to a material analysis apparatus and method for measuring the density, segregation (i.e., non-uniformity), and moisture content of a test material.

Background

The present invention relates to a material segregation and density analyzing apparatus and method for analyzing a segregation and density of a material. In particular, the present invention relates to a material segregation degree and density analysis apparatus and method for analyzing at least one of density and segregation degree of asphalt.

96% of the surface covering roads and streets (nearly two million miles) in the united states is asphalt. Asphalt is a relatively low cost paving material, particularly as compared to other paving materials such as concrete. Another characteristic that makes asphalt superior to concrete in paving is its elasticity. Asphalt is also generally less expensive to maintain than concrete.

The properties of asphalt paving material are non-uniform. It is very difficult to obtain a non-segregated and completely uniform bituminous mixture for paving. Furthermore, it is difficult to apply the bituminous mixture in a substantially uniform layer of pavement. Accordingly, there is a need to determine the properties of the paving material by measuring material variation and/or segregation. These variations or segregation are often visible on the surface of the paving material, however, quantifying the amount of paving material segregation is a very subjective and difficult process. The paving material segregation degree represents the density of the paving material.

Segregation can be defined as the separation of coarse and fine aggregate particles in a hot mix asphalt mixture. Alternatively, segregation is described as the separation and consolidation of larger aggregate asphalt particles that can break away from the asphalt mass and float up to the surface of the mixture. Segregation may occur in the mixed material before it is laid on a road, or it may occur when it is laid on a road surface. Studies have shown that segregation has a direct effect on the long-term performance of asphalt-coated pavements, as segregation increases the air content of the mix, thereby increasing the potential for moisture damage, spalling, cracking and overall chipping of the affected pavement. Therefore, the degree of segregation of the paving material needs to be determined.

In paving a particular road, the mixing characteristics of the asphalt mixture to be used are routinely checked in asphalt mixing devices. This inspection attempts to verify the integrity and homogeneity of the bituminous mixture, thereby controlling the final density of the bituminous mixture as it is applied and rolled. The inspection of the bituminous mixture correlates with the resulting paving material density and segregation at the time of application. Thus, the paving material sample used for control may be used for calibration of a density device that may be used or as a reference for a paving material density indicating device.

When an asphalt paving machine is placed on a layer of asphalt mixture to roll a road, the quality of the asphalt will be related to the life of the new road. Such lifetime influencing factors include (but are not limited to): the density of the bituminous mixture when rolled on a pavement, and the homogeneity and segregation of the bituminous mixture. Although the degree of segregation of the liquid asphalt mixture and the rock material may be desirable in an asphalt plant, the quality of the mixture applied to the pavement surface cannot be guaranteed. The lack of uniformity can be described as segregation.

Paving material (paved roads) typically laid by pavers is approximately 75% of its required compaction. During subsequent compaction (e.g., by roller compaction), it is highly desirable to compact the paving material to near the final desired paving compaction without changing segregation. The paved road should be close to the desired density to avoid material changes such as, but not limited to, air voids, which are believed to create defects in the final paved structure.

It is difficult to determine the level of compaction of the pavement without using complex measurement methods. These complex paving material measurement methods may not be accurate. In the past, these complex paving material measurement methods typically included drilling a portion of the rolled paved road (hereinafter also referred to as "extraction") and then measuring its density in the laboratory. This process creates a hole in the paved road, which is of course undesirable. Such holes are undesirable because they compromise the integrity of the paved road.

To address these problems associated with asphalt, various sophisticated asphalt paving material measuring systems and devices have been proposed and developed. For example, but not by way of limitation, it has been proposed to measure the dielectric properties of paving material to determine the density of the paving material, using the density of the paving material as an indicator of the level of compaction of the paving material.

Such a known paving material density indicating device is disclosed in U.S. patent No.3,784,905 to Blackwell. The Blackwell apparatus can measure the dielectric properties of applied and milled asphalt, where the dielectric properties are considered to be representative of the change in paving material or asphalt density. The Blackwell device may be used at low frequencies, and its operation may be affected by moisture and temperature changes, thus causing errors. Although a Blackwell may be sufficient in some cases, the Blackwell apparatus must be moved extremely slowly over the material being tested to take a density reading. Thus, the Blackwell device may require a longer operating time to determine density, which is undesirable as described above. Furthermore, the Blackwell device is very heavy, which requires large supports to support and transport the Blackwell device. This large support may need to be hauled across the applied pavement surface, thus possibly causing damage to the pavement that is typically just laid.

Another possible disadvantage of the Blackwell device is its limited depth adjustability in the measurement. This limited depth adjustability is due to the fact that the depth of measurement can only be changed by changing the height of the Blackwell electrode. This electrode configuration is undesirable because it limits the depth adjustability in the measurement.

Another known paving material indicating device includes a radioactive source (nuclear source) for determining the density of the paving material. The radiation source device has various disadvantages. Some of the disadvantages of radiation source devices include the need for licensed operators, control equipment, and radiation shielding (e.g., lead shielding). Of course, the disadvantages of these radiation source devices result in increased cost of the radiation source device, increased use costs, and the hazards inherent in radioactive materials. Furthermore, the radioactive source device is not adjustable to the area and depth of the paving material, requires a long time to move, and is very heavy and difficult to move. Moreover, the radiation source device is also very expensive, due at least in part to the radioactive material of the radiation source device. In addition, these radioactive density devices need to be frequently correlated with core density (core density) taken from the same location as the radioactive standard being tested. The association should be made for each mixture that may be used. These steps are of course time-consuming and costly, thus making the use of these radiation devices less than ideal.

Another conventional paving material density indicating device is set forth in U.S. Pat. No.5,900,736, assigned to TransTech Systems. The TransTechSystems paving material density indicating device is a non-radioactive asphalt density measuring device. The TransTech System pavement density indicating device is based on electric fields or capacitance.

More recently, current developments in paving technology have allowed paving using thinner layers than have been used in the past. For example, for a test core, a thinner pavement reduces the amount of pavement that can be drilled from a crushed pavement (described later). Accordingly, there is a need for a reliable, convenient pavement density, compaction, and segregation determination device that provides the desired results wherein the upper surface of a paved road is not adversely affected by the operation of the device and method for analyzing material density and segregation, particularly if used on paving materials employing thick or thin pavers.

Moreover, paving material application can vary from one underlying infrastructure of roadway to another, resulting in variations in paving material depth, area, shape, and volume. Of course, the density, compaction, and segregation of the paving material need to be determined. It is therefore desirable to provide paving material density, compaction and segregation determination devices that are capable of measuring paving material densities at different depths, areas, shapes and volumes.

Moreover, conventional devices for measuring paving material density, compaction, and segregation are often slow to operate and require complex operations to achieve proper device function. The lack of speed often does not facilitate the determination of paving material density and compactness. The measurement of density, compaction and segregation is therefore often a tedious and tedious process that slows down the final paving material application operation. Accordingly, there is a need to provide an asphalt paving material density analyzer or a convenient paving material density, compaction, and segregation determination device for determining paving material density in a faster, more convenient process than prior devices.

Another possible disadvantage of conventional pavement density indicating devices is the inability to accommodate various configurations, such as shapes and areas. Conventional devices often do not allow for movement or replacement of the sensing area and cannot be configured such that the paving material density indicating device can be conveniently moved to determine density and solidity. Accordingly, there is a need for a paving material density indicating device that is capable of determining the paving material density of a particular construction of paving material.

Disclosure of Invention

The present invention is directed to an apparatus for analyzing material density and segregation. The material analysis device comprises: an analyzer body comprising a substantially insulative material housing; a material analyzing circuit including a transmitting device, a receiving device, and a control device; an antenna system including a transmitting antenna, a receiving antenna, and a ground plane; a connection structure connecting the antenna system to the material analysis circuit. The transmitter means of the material analysis circuit generates a VHF electromagnetic wave signal suitable for transmission by the transmitting antenna and directed into the material to be analyzed. The receiving antenna receives any signal returned from the material and sends it to the receiving and control devices. The control means may then analyze the signal to obtain a property of the material.

Moreover, the present invention sets forth a material analyzing apparatus. The material analysis device comprises: an analyzer body comprising a substantially insulative material housing; a material analyzing circuit including a transmitting device, a receiving device, and a control device; an antenna system including a transmitting antenna, a receiving antenna, and a ground plane; a connection structure connecting the antenna system to the material analysis circuit. The transmitter means of the material analysis circuit generates a VHF electromagnetic wave signal suitable for transmission by the transmitting antenna and directed into the material to be analyzed. The receiving antenna receives any signal returned from the material and sends it to the receiving and control devices. The control means may then analyze the signal to obtain a property of the material. The material property includes at least one of density and material segregation.

The present invention is directed to an apparatus for analyzing material density and segregation. The material analysis device comprises: an analyzer body comprising a substantially insulative material housing; a material analyzing circuit including a transmitting device, a receiving device, and a control device; an antenna system including a transmitting antenna, a receiving antenna, and a ground plane; a connection structure connecting the antenna system to the material analysis circuit. The transmitter means of the material analysis circuit generates a VHF electromagnetic wave signal suitable for transmission by the transmitting antenna and directed into the material to be analyzed. The receiving antenna receives any signal returned from the material and sends it to the receiving and control devices. The control means may then analyze the signal to obtain a property of the material. The material density may be linearly related to the returned signal. In terms of D m × V + b, the control device determines that the density D is substantially equal to the measured return voltage V multiplied by a constant slope m, plus an offset b.

The present invention is directed to an apparatus for analyzing material density and segregation. The material analysis device comprises: an analyzer housing comprising a substantially insulative material housing; a material analyzing circuit including a transmitting device, a receiving device, and a control device; an antenna system including a transmitting antenna, a receiving antenna, and a ground plane; a connection structure connecting the antenna system to the material analysis circuit. The transmitter means of the material analysis circuit generates a VHF electromagnetic wave signal suitable for transmission by the transmitting antenna and directed into the material to be analyzed. The receiving antenna receives any signal returned from the material and sends it to the receiving and control devices. The control means may then analyze the signal to obtain a property of the material. The control means may analyse the signal to obtain a characteristic of the material, i.e. the degree of segregation of the material:

where k is a constant, ρ is the paving material density, and s is the distance moved across the surface.

Another aspect of the invention provides a method of analyzing a material. The method comprises the following steps: providing an analyzer body comprising a substantially insulative material housing; providing a material analysis circuit comprising a transmitting device, a receiving device and a control device; providing an antenna system, wherein the antenna system comprises a transmitting antenna, a receiving antenna and a grounding layer; connecting the antenna system to a material analysis circuit; generating a VHF electromagnetic wave signal; transmitting the VHF electromagnetic wave signal by the transmitting antenna; introducing a signal to be analyzed; receiving any signal returned from the material; sending the return signal to the receiving device and the control device; the signal is then analyzed to obtain material properties.

A material analysis apparatus for measuring segregation of a material. The device comprises: an analyzer body comprising a substantially insulative material housing; a material analysis circuit including a transmitting device, a receiving device, and a control device; an antenna system including a transmission antenna, a reception antenna, and a ground plane; a connection structure connecting the antenna system to the material analysis circuit. The transmitter means of the material analysis circuit generates a VHF electromagnetic wave signal suitable for transmission by the transmitter antenna and directed into the material to be analyzed, the receiver antenna receives any signal returned from the material and transmits it to the receiver means and control means, and the control means can then analyze the signal for material properties, the degree of segregation (Seg or segregation level) of the material being determined by the following equation: seg ═ constant × SD + offset, where SD is the standard deviation of the measurement.

Another aspect of the invention provides a method of analyzing a material. The method comprises the following steps: providing an analyzer body comprising a substantially insulative material housing; providing a material analysis circuit comprising a transmitting device, a receiving device and a control device; providing an antenna system, wherein the antenna system comprises a transmitting antenna, a receiving antenna and a grounding layer; connecting the antenna system to a material analysis circuit; generating a VHF electromagnetic wave signal; transmitting the VHF electromagnetic wave signal by the transmitting antenna; introducing a signal to be analyzed; receiving any signal returned from the material; sending the return signal to the receiving device and the control device; the signal is then analyzed to obtain material properties. The step of analyzing said signal to obtain segregation characteristics of the material is determined by the following formula:

where k is a constant, ρ is the paving material density, and s is the distance moved across the surface.

Another aspect of the invention provides a method of analyzing a material. The method comprises the following steps: providing an analyzer body comprising a substantially insulative material housing; providing a material analysis circuit comprising a transmitting device, a receiving device and a control device; providing an antenna system, wherein the antenna system comprises a transmitting antenna, a receiving antenna and a grounding layer; connecting the antenna system to a material analysis circuit; generating a VHF electromagnetic wave signal; transmitting the VHF electromagnetic wave signal by the transmitting antenna; introducing a signal to be analyzed; receiving any signal returned from the material; sending the return signal to the receiving device and the control device; the signal is then analyzed to obtain material properties. The material density is linearly related to the returned signal, and the determined density D is substantially equal to the measured return voltage V multiplied by a constant slope m, plus an offset b, as follows:

D＝m×V+b

another aspect of the present invention provides a material analyzing apparatus for measuring a segregation degree of a material. The device comprises: an analyzer body comprising a substantially insulative material housing; the material analysis circuit comprises a transmitting device, a receiving device and a control device; an antenna system including a transmitting antenna, a receiving antenna, and a ground plane; a connection structure connecting the antenna system to the material analysis circuit. The transmitter of the material analysis circuit generates a VHF electromagnetic wave signal. The VHF electromagnetic wave signal is adapted to be transmitted by the transmitting antenna and directed into the material to be analyzed. The receiving antenna receives any signal returned from the material and transmits the received signal to the receiving means and control means. The control means may then analyze the signal to obtain a property of the material. The material segregation degree (Seg) is determined by the following formula: seg ═ constant × SD + offset, where SD is the standard deviation of the measurement.

Another aspect of the invention provides a method of measuring segregation of a material. The method comprises the following steps: providing an analyzer body comprising a substantially insulative material housing; providing a material analysis circuit comprising a transmitting device, a receiving device and a control device; providing an antenna system comprising a transmit antenna, a receive antenna and a ground plane; connecting the antenna system to a material analysis circuit; generating a VHF electromagnetic wave signal; transmitting the VHF electromagnetic wave signal by the transmitting antenna; the method comprises the steps of introducing a signal to be analyzed, receiving any signal returned from the material, sending said return signal to said receiving means and control means, and analyzing said signal to obtain the material property. The material segregation degree (Seg) was determined by the following formula: seg ═ constant × SD + offset, where SD is the standard deviation of the measurement.

Drawings

FIG. 1 is a schematic diagram of a material segregation and density analysis apparatus of a specific example of the present invention;

FIG. 2 is a schematic diagram of an electrical circuit for a material segregation and density analysis apparatus of a specific example of the present invention;

FIG. 3 is a schematic diagram of an antenna for a material segregation and density analysis apparatus of a specific example of the present invention;

FIG. 4 is a graph of non-average density versus paving material position;

FIG. 5 is a second graph of non-average density versus paving material position;

fig. 6 is a schematic view of an antenna used for a material property analysis apparatus of a specific example of the present invention;

fig. 7 is a schematic diagram of an electric circuit for a moisture content analysis device of a specific example of the present invention.

Detailed Description

The present invention includes a material segregation and density analysis apparatus and method (hereinafter "material analysis apparatus") for analyzing the density and segregation of a material. For example, the present invention includes a material analysis device for measuring and determining at least one of density, solidity, and segregation of asphalt. The bitumen may be a freshly applied bitumen.

The material analysis device according to the present embodiment includes a portable material analysis device. The term "portable" as used herein refers to: in operation as described below, the material analysis apparatus may be conveniently moved by a standard operator of the material analysis apparatus.

The material analysis apparatus according to the present embodiment may be supported by a user of the material analysis apparatus. For example, and not by way of limitation, the material analysis device described herein is a handheld material analysis device. A material analysis apparatus according to the present embodiment may be placed on a target test location on a newly paved road to measure the density of asphalt. The measurements may be made in any suitable units, such as, but not limited to, pounds per cubic foot.

The material analysis apparatus 1 (fig. 1) as specifically described herein is relatively lightweight (e.g., about 3/4 to 1 pound) and the body and base (also referred to as a "foot") have perimeter dimensions of about 5 inches by about 5 inches. These shapes and weights are merely examples of the size, shape and weight of a material analysis apparatus as specifically described herein and are not intended to limit the present invention in any way. The material analyzing apparatus may be composed of any structure and weight as long as the function and operation of the material analyzing apparatus can be maintained.

The material analysis device 1 according to the present embodiment comprises a "relative" reading device. The term "relative reading device" as used herein means: the material analysis device should be calibrated to a material of known density. The calibration or reference of the material analysis device is typically performed prior to use at the draping location.

The material analysis device 1 is a portable unit for density and segregation measurements. (in the following description, a material analyzing apparatus according to the present invention refers to a measuring apparatus for one or both of density and resolution, and the use of one indirectly indicates the use of the other). The device relies on a technique of penetrating the asphalt layer to make density measurements. However, segregation measurement differs from simple density measurement in that the segregation level is automatically calculated by the device from a plurality of density measurements, giving the user the density and segregation level numbers. Moreover, a material analysis apparatus as specifically described herein uses VHF electromagnetic wave signals that are directed into the paving material, where high frequencies may include, but are not limited to, VHF signals. Such VHF electromagnetic wave signals are merely examples of signals given within the scope of the present invention and are not intended to limit the present invention in any way. The following description refers to VHF electromagnetic wave frequencies.

A material analysis apparatus according to the present invention is shown in fig. 1-3. The material analyzing apparatus 1 illustrated in fig. 1 includes an analyzer body 10 and a handle 12. As described herein, the handle 12 is used to move and manipulate the material analysis device 1 for paving material analysis. At least a portion of the handle 12 is non-conductive or insulative. For example, and in no way limiting of the present invention, a first portion of the handle 12 (e.g., the front 12 inches of the handle) comprises an insulating material, and the remaining portion can be made of any material. The foregoing is merely exemplary and the scope of the present invention includes any other structure and configuration of the handle. The analyzer body 10 includes the above-described configuration.

The analyzer body 10 includes a substantially insulative material housing 14 in which a circuit 50 of a material analyzing apparatus 1, which will be described later, is placed. The analyzer body 10 includes a base or seating surface 16 made of a non-metallic material. The base surface 16 of the analyzer body 10 is made of a non-metallic material to prevent interference and shield the circuit 50 of the material analyzing apparatus 1.

The upper surface 18 of the analyzer body 10 of the material analyzing apparatus 1 includes at least one display 51 connected to the circuit 50 of the material analyzing apparatus 1. The at least one display 51 is used to provide real-time or near real-time analysis instructions of the material analysis apparatus 1 to an operator or user of the material analysis apparatus 1. The at least one display 51 may also provide an indication of at least one of pitch density, solidity, and segregation as determined by the material analysis apparatus 1. The method of providing the results of the material analysis apparatus 1 using the display 51 may be the only method of providing the results to the user or operator of the material analysis apparatus 1; alternatively, a method of using the display 51 to give the results of the material analysis apparatus 1 may be provided in conjunction with a communication link structure, which will be described in detail later.

The material analysis apparatus 1 according to the present embodiment may include a second data transmission apparatus to transmit the signal generated by the material analysis apparatus 1. The signals generated and transmitted by the material analysis device 1 may be received by any suitable receiving device, such as, but not limited to, a computer, for example, via a modem or a wireless modem. These are merely examples and are not intended to limit the present invention in any manner. The receiving device may be located in close proximity to the paving material being analyzed by the material analyzing device 1. If the sending system (not shown) of the material analysis device 1 is sufficiently powered, the receiving device need not be located in close proximity to the paving material being analyzed by the material analysis device 1. Regardless of the position of the receiving device and the paving material analyzed by the material analysis device 1, the material analysis device 1 can transmit the signal generated by the material analysis device 1 to a receiving device remote from the material analysis device 1.

The insulated handle 12 of the material analysis apparatus 1 includes a structure that allows a user or operator of the material analysis apparatus 1 to easily move the material analysis apparatus 1 during use. Insulated handle 12 may be used to move material analysis apparatus 1 for determining at least one of density, solidity, and segregation during operation. The insulated handle 12 may include an actuator 120 at a location on the insulated handle 12 that may be conveniently accessed by an operator or user of the material analysis apparatus 1.

The actuator 120 may be used to operate the circuit 50 of the material analysis apparatus 1 so that at least one of the density, compactness and segregation of the paving material may be determined. The actuator 120 may operate the circuit 50, the circuit 50 for calibration or reference of the material analysis apparatus 1 as described herein and to transmit a signal representative of at least one of density, compaction and segregation of the paving material in accordance with operation of the material analysis apparatus 1 as specifically described herein.

The material analysis device 1 according to the present embodiment includes a circuit 50 for determining at least one of paving material density, compaction, and segregation. The circuit 50 of the material analysis apparatus 1 is placed in the substantially insulating material housing 14 of the material analysis apparatus 1. The circuit 50 may transmit the signal in the form of a simple continuous wave, for example, but not in any way limiting to the invention, the signal frequency being about 50MHz in the form of a simple continuous wave.

The material analyzing apparatus 1 according to the present embodiment may include a base (not shown for the purpose of simplifying the explanation). The base includes a structure that protects the bottom structure of the material analysis apparatus 1. The mount prevents the material analysis device 1 from wearing in use, for example, when moving the material analysis device 1 over paving material in operation of the material analysis device 1 as specifically described herein. The base may comprise any non-conductive and non-interfering material such as, but not limited to, rubber, composite material (LEXAN), and other similar materials. The base may comprise a flexible member that is attached to the analyzer body 10 of the material analysis apparatus 1, for example by VELCRO or other similar attachment means. The base should be thin enough so as not to interfere with the generation and return of signals. For example, and in no way limiting of the invention, the base may be about 10 mils thick.

Fig. 2 shows details of the circuit 50. The circuit 50 includes a transmitting device 52 and a receiving device 54. A simple continuous wave of approximately 50MHz generated by the circuit 50 may be generated by a transmitting device 52, such as but not limited to a micro-power transmitting device 52 and a receiving device 54. The receiving device 54 may be equipped with a tuning diode detector. The transmission device 52 and the reception device 54 may both be installed in the analyzer body 10 of the material analyzing apparatus 1.

The circuit 50 of the material analysis apparatus 1 according to the present embodiment further comprises an antenna system 60. The antenna system 60 is placed on the material analysis apparatus 1 and generally contacts the paving material 5 (fig. 3) during operation of the material analysis apparatus 1. The antenna system 60 includes a transmit antenna 62 connected to the transmitting device 52. The antenna system 60 also includes a receiving antenna 64 connected to the receiving device 54.

The connection of the transmit antenna 62 to the transmit device 52 and the connection of the receive antenna 64 to the receive device 54 may be made in any suitable manner, such as the illustrated connection configuration 65. The connection structure 65 between the transmit antenna 62 and the transmit device 52 and between the receive antenna 64 and the receive device 54 may include direct hard-wired wiring as shown. The connection structure 65 wiring for connecting the transmit antenna 62 to the transmit device 52 and connecting the receive antenna 64 to the receive device 54 may also include various electronic components, such as capacitors and inductors (as shown). The illustrated construction and what is described herein is merely illustrative of a material analysis apparatus 1 as specifically described herein and is not intended to limit the present invention. Other features of the invention are also within the scope of the invention.

The antenna system 60 (fig. 1) of the circuit 50 in the material analysis device 1 as specifically described in the present invention may transmit radio frequency, electromagnetic waves (E × H), where E is an electric field and H is a magnetic field. In addition, the insulation (dielectricity) and permeability of the material under test can affect the propagation of electric and magnetic field components, respectively. Radio frequency, electromagnetic waves (used herein as "signals") are transmitted from transmitting antenna 62 into paving material 5. When a signal is returned from paving material 5, receiving antenna 64 may acquire or receive the signal.

The antenna system 60 includes a transmit antenna 62 and a receive antenna 64. The transmitting antenna 62 and the receiving antenna 64 form a two-conductor transmission line. The two-conductor transmission line is bent in a zigzag fashion (two parallel segments and one oblique segment connecting opposite ends of the two parallel segments), however, the description of the two-conductor transmission line is merely exemplary and many other configurations of two-conductor transmission lines can be formed as specifically described in the present invention. The description is not intended to limit the invention in any way.

The material analysis device 1 maintains contact between the antenna system 60 and the paving material 5. The amount of contact may be considered to be the maximum surface area of contact between the paving material 5 and the antenna system 60 of the material analysis device 1 (including the coverage of the middle of the base or bed surface 16).

Note that the structure of the antenna system on the base or chassis surface 16 is intended to cause the two-conductor transmission line portion of the antenna system 60 to lay flat on the paving material 5. The transmitting antenna 62 and the receiving antenna 64 are placed substantially parallel to each other. The strength of the signal generated by transmit antenna 62 and received by receive antenna 64 is proportional to paving material density.

The antenna system 60, as embodied by the invention, further includes a ground plane 68. A ground plane 68 is disposed substantially parallel between the transmit antenna 62 and the receive antenna 64. The ground plane 68 is "in the middle" of the zigzag, where the transmit antenna 62 and the receive antenna 64 form the outside of the zigzag to sandwich the ground plane 68 between them.

As shown in fig. 1, ground plane 68 is also located on base or bottom surface 16 of body 14 of material analysis device 1. Ground plane 68 extends a first distance from base or underlying surface 16, while transmit antenna 62 and receive antenna 64 extend a second distance from base or underlying surface 16. The first distance is greater than the second distance so that the ground plane 68 extends further from the base or bottom surface 16 than the transmit antenna 62 and the receive antenna 64. Thus, the signals (both electric and magnetic field components) entering and exiting paving material 5 tend to be deeper into paving material 5. These signals are less adversely affected by paving material 5 near the roadway. Thus, this configuration makes the returned signal less susceptible to the surface properties, characteristics and configuration of the paving material. For example, and in no way limiting of the invention, the ground plane 68 may be closer to the paving material 5 than the transmit antenna 62 and the receive antenna 64, which may be up to about 0.030 ". This orientation and configuration would cause the first approximately 0.125 "of the paving material to not send a signal to the material analysis device 1. This neglecting effect is desirable because surface irregularities and unwanted surface moisture due to the draping operation can affect the density reading.

The material analyzing apparatus 1 includes a relative reading device, which will be described later. The paving industry has standardized test cores (test core) of 6 inches in diameter taken from roadways. In addition, the core may be fabricated in the laboratory from paving material mixtures to determine the maximum theoretical density of a particular mixture. The core is used to give a standardized reading of at least one of density, compaction and segregation of the paving material. For example, in paving a road, the asphalt mix is inspected daily in an asphalt plant, which inspection may be contractually required. The density (and compactness and segregation) of these cores or samples can thus be obtained for calibration of the material analysis device 1. The material analysis device 1 as embodied by the present invention is small enough in size to calibrate an industry standard 6 inch diameter test core. Previous devices were not considered small enough to calibrate industry standard 6 inch diameter test cores.

The material analysis apparatus 1 according to the present invention also has reference features that allow a user or operator to calibrate the material analysis apparatus 1 to a reference standard prior to each field measurement. This calibration or reference characteristic is included in the circuit 50 and can be controlled by the insulated handle actuator 120 described above. As specifically described in the present invention, this reference characteristic allows the material analysis apparatus 1 to have a faster reference speed and higher reproducibility.

The reference characteristics as described above will be further described with reference to fig. 2. In fig. 2, the transmitting device 52 is connected to the antenna system 60, for example, by a non-resonant LC on a connecting structure 65. The connection structure 65 may include a tuning connection structure for performing a receiving function of the material analysis apparatus 1. The detector 54 may comprise a single diode detector for converting the signal to Direct Current (DC).

In operation of the reference characteristic, the signal is converted to direct current and compared to an internal reference signal. The internal reference signal may be stored in a memory or in a control device in the material analysis device 1. Alternatively, the internal reference signal may be stored in a remote memory, such as, but not limited to, a memory installed in a computer with which the material analysis apparatus 1 may communicate.

Calibration of a material analysis apparatus according to the present invention as embodied herein can be performed by at least two methods (in clear contrast to the above references). A first calibration method according to the invention comprises extracting road data using a material analysis device according to the invention and additionally coring from the paving material. Next, the core is analyzed in a laboratory for at least one of density, solidity, and segregation. Accordingly, the specification of the material analyzing apparatus as specifically described in the present invention can be set to be accurately read out from the data of the core.

A second calibration method comprises the evaluation and analysis of test cores prepared in the laboratory using a material analysis apparatus according to the invention in which the cores are prepared from an earlier bituminous mixture using vibratory forming of the bitumen, the bituminous mixture used being able to be sampled from the bituminous apparatus. A material analysis device as specifically described herein is placed directly on a laboratory core. Thus, the material analysis device may be used to calibrate to the asphalt mixture laid as paving material in rapid or near real-time. Several department of transportation (DOT) and federal department of transportation have indicated that this method is ideal for calibration purposes.

It will be appreciated by those skilled in the art that the control device 70 may also be implemented using a variety of separate dedicated or programmable integrated or other electronic circuits or devices, such as hardwired electronic or logic circuits including discrete element circuits or programmable logic devices, such as PLDs, PALs, PLAs or the like. The control device 70 may also be implemented using a suitably programmed general-purpose computer, such as a microprocessor or microcontrol element, or other processor device, such as a CPU or MPU, alone or in combination with one or more peripheral data and signal processing devices. In general, any device or the like can be used as a control device as long as a finite state machine can implement the flowcharts described in the application on the device. As shown, a distributed processing architecture is preferred for maximum data/signal processing capability and speed.

In operation, a measurement of the degree of segregation of paving material may be made using the material analyzing apparatus 1 as specifically described herein. Measurement of the degree of segregation of paving material using the material analyzing apparatus 1 can be achieved by placing the material analyzing apparatus 1 on the surface of paving material, activating the circuit 50 of the material analyzing apparatus 1, sending and receiving signals, analyzing the signals, and displaying the measured value of the degree of segregation of paving material to an operator.

As specifically described herein, the density measurement function of the material analysis device 1 may include at least one paving material density measurement using the material analysis device 1. In order to determine a cross-sectional analysis of the paving material using the material analysis device 1, a plurality of tests of the paving material density may be performed and averaged. Averaging is desirable because paving material is non-uniform no matter how carefully it is applied.

The measurement is usually performed by moving, for example by rotating or moving the material analysis device 1 back and forth relative to the paving material. The number of measurements ranges, for example, from about 4 density measurements to about 8 density measurements. The standard deviation of the density measurement for a given location is directly related to the degree of segregation of the material in the paving material.

For purposes of illustration and not intended to limit the invention, in paving materials where higher segregation is expected, the standard deviation of the paving material zone will be high, for example, but not limited to, exceeding about 3.0. For low segregation paving or even paving zones, there is a relatively low standard deviation, approximately 1.0. Such standard deviation is due to the close proximity of a set of density values. The display of the material analysis device 1 according to the invention indicates the degree of segregation, which is derived from the standard deviation of the density of the set of paving materials tested.

The operation of the material analyzing apparatus 1 according to the present invention will now be described. This operation will describe the operation of the material segregation and density analysis apparatus and method as specifically described herein to analyze the density and segregation of the material. Specifically, the operation will be described of the operation of the material segregation and density analysis apparatus and method according to the present embodiment to analyze the density and segregation of the paving material. The following description of the operation of the present invention is intended only to describe exemplary operation of the present invention and is not intended to limit the present invention in any way. It is clear that other operations are also within the scope of the invention.

In the operation of determining the segregation level of the paving material, the material analyzing apparatus 1 according to the embodiment of the present invention analyzes the generated paving material density signal by the control device 70 of the material analyzing apparatus 1. The degree of segregation is proportional to the standard deviation of the density values. Therefore, the temperature of the molten metal is controlled,

standard deviation of k × density

Wherein k is a constant.

Examples of the use and operation of the material analysis apparatus 1, as specifically described herein, include making multiple density measurements at multiple test locations. The standard deviation can then be calculated using a spreadsheet software program with mathematical functions (e.g., EXCEL). In the first step, a number of density measurements are made at 2 independent locations. Position 1 has a higher visible resolution and position 2 has a lower visible resolution. A plurality of measurements are performed by rotating the material analysis device 1 according to the invention as specified around a circular peripheral geometry. The graph shown in fig. 4 shows the data obtained from such an operation. As is evident from the figure, the standard deviation of the high resolution locations is about 2.2, or about 2.6 times the standard deviation of the low resolution locations of about 0.86.

Next, a section of paving material is taken, the width being slightly in excess of 15 feet. The material analysis apparatus 1 as specifically described herein records a plurality of density values in 1 foot increments. For each set of measured densities, the standard deviation and average density were calculated and plotted in fig. 5. The left ordinate of the graph shows the segregation level and the right ordinate shows the density.

A material analyzing apparatus measuring system and related operation using the material analyzing apparatus 1 as specifically described in the present invention will now be further described. The measurement system and associated operations using the material analysis apparatus 1 include at least 2 (and in other embodiments at least 4) material analysis apparatus 1 units. The material analyzing apparatus 1 may be arranged in an appropriate structure. The structure may be placed on a paving material area of unknown resolution. Multiple measurements are made, such as but not limited to 4 density measurements. These measurements may be made simultaneously. These measurements are used to determine at least one of a standard deviation and an average of the density.

The determination value can be calculated by the control device 70 of the circuit 50 of the material analyzing apparatus 1 according to the present invention. With these determined values, the density standard deviation can be calculated by the control device 70 and can be displayed on the display 51 of the insulating material casing 14. Each material analysis device 1 of the set of material analysis devices 1 described above can be moved rapidly from one paving material position to another. This movement can provide a readout of both the resolution and the average density. By this method, each individual material analysis apparatus 1 unit corresponds to a manual rotation of a single material analysis apparatus 1 unit for checking different volume segments of paving material.

A plurality of density values are determined to calculate paving material segregation. Such as, but not limited to, the material analysis apparatus 1 being moved by at least one hand of an operator or other simple mechanical means. The movement may be rotational or longitudinal. Using this method, the generated signal may include the density level plus the density change (DC + AC) as the material analysis device 1 moves. First, the resulting signal is AC coupled to give a density variation, and then the resulting signal is a full wave corrected and filtered to get a DC level. The DC level is proportional to the amount of density change.

As specifically described herein, the analog processing of the material analysis device 1 can produce a signal proportional to the degree of separation. The resulting signal proportional to the degree of separation will be displayed to the user. A toggle switch associated with the actuator allows a user or operator to switch between the segregation and density modes.

Unlike some known devices of the prior art, the material analysis apparatus 1 as embodied by the present invention is not adversely affected by moisture and temperature. The material analyzing apparatus 1 and the operation thereof are not adversely affected because the frequency of the signal generated by the material analyzing apparatus 1 is very high, or VHF electromagnetic waves. An exemplary frequency is about 50 MHz. At such frequencies, the signal or field generated by the material analysis apparatus 1 as specifically described herein is actually an electromagnetic field. The material analysis apparatus 1 sends signals into one side of the antenna system 60 while the other side of the antenna system 60 receives the received/returned signals. The receiving device detects the received signal, the output of which is a dc electrical signal proportional to the bitumen density.

Also, the zigzag antenna system 60 has a uniform structure. Due to this structure, the antenna system 60 has no dead space in the middle thereof. The prior art circular array of analyzers exhibits dead zones that ignore important paving material zones. The electromagnetic field generated by the material analysis device 1 described above and in the detailed description of the invention follows Maxwell and Poynting equations, where the propagating wave is affected by both the dielectric (dielectric) and the magnetic permeability of the medium.

For example, by generating a VHF electromagnetic wave field, a material analysis apparatus 1 as specifically described herein may determine the density of a material (such as, but not limited to, paving material). The field is passed through the material to measure its density. The density is linearly related to the returned/returned signal measured as a voltage measurement. The density D can be determined to be equal to the measured voltage V multiplied by a constant slope m, plus an offset b, as follows:

D＝m×V+b

as described above, moisture and temperature do not affect the material analyzing apparatus 1.

The material analysis apparatus 1 according to the present embodiment generates VHF electromagnetic wave energy that enables measurement of material segregation of a test surface, particularly an asphalt road. Segregation is measured by taking about 7 or more density measurements at one test location and then using the statistical Standard Deviation (SD) to determine the material segregation level (segregation level, Seg). Thus, the resolution level is equal to a constant times the standard deviation plus some offset, as follows:

SL ═ constant × SD + offset

Furthermore, the material analyzing apparatus 1 according to the present embodiment generates VHF electromagnetic wave energy, which is capable of measuring material segregation of materials such as, but not limited to, paving materials and asphalt. Another segregation measurement method, as embodied by the invention, may determine a Segregation Level (SL) (also referred to as material segregation) as follows:

where k is a constant, ρ is the paving material density, and s is the distance moved across the surface. In other words, SL is equal to the constant multiplied by the average of the absolute values of the density variations for each distance variation between distances s1 and s 2. The above equation is realized by moving the material analyzing apparatus 1 according to the present embodiment. The manner of movement may be at least one of rotational or linear motion. In this method, the signal obtained is the density level plus the density change (DC + AC) as the unit moves.

First, the signal is AC coupled, only the density variation is available, then the signal is a full wave that is corrected and filtered, resulting in a DC level that is proportional to the density variation. This processing, which may be analog, will produce a signal proportional to the degree of separation. The value is displayed to the user by the material analyzing apparatus 1.

The material analysis device 1 as specifically described herein may also calculate the segregation level by rapidly measuring small variations in spatial density across the paving material zone. The signal is reported to the operator in real time or near real time values.

Fig. 6 is a schematic view of an antenna for a material property analysis apparatus according to the present invention. Fig. 6 includes the cross-section labeled 3-3 in fig. 2. Fig. 6 also shows the seating surface 16 of the analyzer body 10 (see fig. 1). Fig. 6 also shows a movable base 200 positioned between the base surface 16 and the surface being analyzed 202. Ground layer 68 with structural insulation 201 on both sides forms layer 71. Layer 72, above layer 71, includes transmit antenna 62, insulating layer 201, and receive antenna 64. The layer above layer 72 is a continuous insulating layer 203. A conductive structure top layer component 204 is located above the continuous insulating layer 203 and is also electrically connected to ground. Note that fig. 6 is an exploded view, partially shown, and therefore the gaps between the following layers are shown for clarity of illustration only and are not present in the device of the present invention: between paving material 5 and movable base member 200, between layer 72 and insulation 203, and between insulation 203 and structural topper member 204.

Fig. 7 is a schematic diagram of an electrical circuit for a moisture content analyzing apparatus according to the present invention. Fig. 7 is similar to fig. 2 as previously described, with the primary difference being that fig. 7 shows a phase module for determining moisture content, and a moisture display 221 for displaying the moisture content so determined.

The present invention generally measures material properties of a surface to be tested. One of the measured properties of the material is the moisture content of the material. As shown in fig. 7, the transmission signal from the transmission antenna 62 passes through the material to be measured, and is then received by the reception antenna 64. Moisture in the material, which may be due to external moisture, will affect the phase between the transmitted and received signals. The dry insulator has a relatively low phase shift (e.g., on the order of 2 degrees). A wet insulator will exhibit a phase shift significantly greater than 2 degrees, possibly up to 20 degrees for high humidity. Thus, by comparing the reference signal from the transmitter 52 with the measured received signal from the receiver 54, the phase of the received signal is sensed and calculated, and the resulting phase difference is then converted to a relative moisture content. The phase difference is determined by the phase module 220 and then the moisture content of the material to be measured is calculated from the determined phase offset. The calculated moisture content may be displayed on the moisture display 221. Moisture detection to which the present invention is applied may include moisture detection in insulating materials (e.g., electrical insulators on the generator stator), or in other materials (insulating or non-insulating) such as roofing materials or thermal insulators.

The signal transmitted by the transmitting antenna 62 in fig. 7 and fig. 1-3 and 6 is typically an electromagnetic wave signal, such as a VHF signal (e.g., about 50MHz), a signal having a frequency range of 1kHz to 50MHz, or the like.

Although embodiments have been described herein, it will be appreciated that various combinations of elements, variations and modifications will occur to those skilled in the art, within the scope of the present invention, in light of the specification.

Claims (11)

1. A material analysis apparatus comprising an analyzer body, the analyzer body comprising:

a material housing;

a material analysis circuit comprising a transmitting device, a receiving device and a control device,

the antenna system comprises a transmitting antenna, a receiving antenna and a grounding layer; and

a connection structure connecting said antenna system to said material analysis circuit,

wherein the transmitting means of the material analysis circuit generates an electromagnetic wave signal suitable for being transmitted by the transmitting antenna into the material to be analyzed, the receiving antenna receives a signal returned from the material and then transmits the returned signal to the receiving means and the control means, and then the control means analyzes the returned signal to obtain the material property of the material,

wherein the transmitting and receiving antennas of the antenna system and the ground plane form a two-conductor transmission line structure with a ground plane therebetween, an

The antenna system described therein has a uniform coverage, no dead zones, and can provide a field shape that makes the return signal less affected by material surface properties, characteristics, and material surface structure.

2. The material analysis apparatus of claim 1, wherein the material property comprises at least one of density, segregation, and moisture content.

3. The material analyzing apparatus according to claim 1, wherein the transmitting antenna and the receiving antenna of the antenna system and the ground layer constitute a zigzag structure.

4. A material analysis apparatus for measuring the density of a material, the apparatus comprising:

an analyzer body comprising a material housing;

a material analysis circuit comprising a transmitting device, a receiving device, and a control device;

the antenna system comprises a transmitting antenna, a receiving antenna and a grounding layer;

a connection structure connecting said antenna system to said material analysis circuit;

wherein the transmitting means of the material analysis circuit generates an electromagnetic wave signal adapted to be transmitted by the transmitting antenna into the material to be analyzed, the receiving antenna receives a signal returned from the material and then transmits the return signal to the receiving means and the control means, the control means then analyzes the returned signal to obtain a characteristic of the material, the density of the material is linearly related to the returned signal, the control means is adapted to determine a density D, the density D being substantially equal to a return voltage V measured on the antenna multiplied by a constant slope m, plus an offset b, as follows:

D＝m×V+b

wherein the transmitting and receiving antennas of the antenna system and the ground plane constitute a two-conductor transmission line structure with the ground plane therebetween, wherein the antenna system has a uniform coverage, has no dead space, and can provide a field shape that makes a return signal less affected by material surface properties, characteristics, and material surface structure.

5. The material analyzing apparatus as claimed in claim 4, wherein the transmitting and receiving antennas of the antenna system and the ground plane constitute a zigzag structure.

6. A method of analyzing a material, the method comprising:

providing an analyzer body comprising a material housing;

providing a material analysis circuit comprising a transmitting device, a receiving device and a control device;

providing an antenna system comprising a transmit antenna, a receive antenna, and a ground plane;

connecting the antenna system to the material analysis circuit;

generating an electromagnetic wave signal;

transmitting the electromagnetic wave signal by the transmitting antenna;

introducing a signal to be analyzed into the material;

receiving a signal returned from the material;

sending the returned signal to the receiving device and the control device; and

analyzing the returned signal to obtain a property of the material,

wherein the transmitting and receiving antennas of the antenna system and the ground plane constitute a two-conductor transmission line structure with a ground plane therebetween, wherein the antenna system has a uniform coverage area, is free from dead zones, and can provide a field shape such that the returned signal is less affected by material surface properties, characteristics, and material surface structure.

7. The method of claim 6, wherein the transmit and receive antennas of the antenna system and the ground plane form a zigzag structure.

8. The method of claim 6, wherein the characteristic of the material comprises a moisture content of the material.

9. The method of claim 8, wherein analyzing the returned signal comprises measuring a phase shift caused by a moisture content of the material.

10. A method of analyzing a material for measuring the density of the material, the method comprising:

providing an analyzer body comprising a material housing;

providing a material analysis circuit comprising a transmitting device, a receiving device and a control device;

providing an antenna system comprising a transmit antenna, a receive antenna, and a ground plane;

connecting the antenna system to the material analysis circuit;

generating an electromagnetic wave signal;

transmitting the electromagnetic wave signal by the transmitting antenna;

introducing a signal to be analyzed into the material;

receiving any signal returned from the material;

sending the returned signal to the receiving device and the control device; and

analyzing the signal to obtain a density characteristic of the material;

the density of the material is linearly related to the returned signal, and the determined density D is substantially equal to the measured return voltage V multiplied by a constant slope m, plus an offset b, as follows:

D＝m×V+b

wherein the transmitting and receiving antennas of the antenna system and the ground plane constitute a two-conductor transmission line structure with the ground plane therebetween, wherein the antenna system has a uniform coverage, no dead space, and can provide a field shape such that a returned signal is less affected by material surface properties, characteristics, and material surface structure.

11. The method of claim 10, wherein the transmit and receive antennas of the antenna system and the ground plane form a zigzag structure.