Patent Publication Number: US-2017369383-A1

Title: Taggant for cement authentication

Description:
This application is a continuation of U.S. application Ser. No. 14/292,334, filed May 30, 2014, which is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND 
     Concrete is a mixture of cement and various other materials. The cement and other materials are often mixed at a concrete plant and transported (e.g., with concrete mixer trucks) to a jobsite. Concrete used in certain applications (e.g., for buildings, footings, etc.) may have a strength, ductility, or other characteristic that is specified by a customer, engineer, or still another person. The amount and grade of cement impacts the strength and other characteristics of the concrete. While certain characteristics of the concrete (e.g., slump, etc.) may be tested by an inspector, other characteristics (e.g., composition) may be more difficult to determine by an inspector in the field thereby making it difficult for an inspector to verify that the delivered concrete satisfies the identified specifications. 
     Traditionally, a driver delivers paperwork that identifies the composition and other characteristics of the concrete load (e.g., the identity of the mixing plant, etc.). Tracking a particular load requires monitoring the paperwork supplied by the driver. However, an inspector may not be able to independently authenticate various characteristics of the cement or the concrete (e.g., composition). The location of a particular concrete load may also be difficult for an inspector to track. Such load tracking may be particularly relevant during subsequent inspection of a structure after initial construction (e.g., during routine surveying, to determine the ability of a structure to withstand a storm or explosion, etc.). Despite these shortcomings, inspectors traditionally rely on paperwork provided upon delivery of the concrete load for initial authentication and subsequent inspection. 
     SUMMARY 
     One embodiment relates to a traceable cement mixture that includes a volume of cementitious material, a plurality of taggants disposed within the volume of cementitious material according to a taggant mix ratio that is specified based on a quality of the cementitious material, and a volume of an additional material mixed with the volume of cementitious material according an additional material mix ratio. 
     Another embodiment relates to a traceable cement mixture that includes a volume of cementitious material, a first taggant disposed within the volume of cementitious material, the first taggant indicating a first characteristic of the volume of cementitious material, and a second taggant disposed within the volume of cementitious material, the second taggant indicating a second characteristic of the volume of cementitious material. The first characteristic is different than the second characteristic. 
     Still another embodiment relates to a traceable cement mixture that includes a volume of cementitious material and a plurality of taggants disposed within the volume of cementitious material, at least one of the plurality of taggants including data relating to a number density of taggants within the volume of cementitious material. The number density of taggants is specified based on at least one of a quality, a strength, a grade, a manufacturer, a manufacture date, an inspection status, and an approval status of the cementitious material. 
     The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The invention will become more fully understood from the following detailed description taken in conjunction with the accompanying drawings wherein like reference numerals refer to like elements, in which: 
         FIG. 1  is a side plan view of a traceable cement mixture, according to one embodiment; 
         FIG. 2  is a side plan view of a traceable cement mixture, according to another embodiment; 
         FIG. 3  is a side plan view of a building including a concrete base, according to one embodiment; 
         FIG. 4  is a side plan view of a bridge including a concrete base, according to one embodiment; 
         FIGS. 5-6  are isometric views of a cement authentication apparatus, according to two embodiments; 
         FIG. 7  is a side plan view of a cement authentication apparatus, according to another embodiment; and 
         FIG. 8  is a flow diagram of a cement production process, according to one embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented here. 
     Taggants are intended to facilitate the authentication of a cementitious mixture. The taggants may be active (e.g., RFID, ultrasonic, etc.) and store authentication data or passive and be detected (e.g., with radiofrequency waves, with x-rays, etc.) to facilitate an authentication process. Active taggants may store energy (e.g., with a battery, etc.) or may be remotely powered (e.g., with an electromagnetic field, etc.). Such authentication reduces the risk that concrete having an improper composition will be used during construction. Authentication may ensure that a batch of concrete includes cement originating from an approved source. Taggants may be used to verify that the mix ratio of authenticated cement to other materials in a batch of concrete is within a specified range. Taggants also allow for the prospective or retrospective analysis of structures (e.g., buildings, bridges, etc.) to determine whether the appropriate concrete was poured during initial construction. 
     Referring to the embodiment shown in  FIG. 1 , a mixture, shown as traceable cement mixture  10 , includes cementitious material, shown as cement particles  20 , and a taggant, shown as cement taggant  30 . As shown in  FIG. 1 , traceable cement mixture  10  is disposed within a housing, shown as container  40 . Container  40  may have a variety of shapes and may be rigid (e.g., made of rigid plastic, metal, etc.) or flexible (e.g., a plastic or paper bag, etc.). In other embodiments, container  40  is a portion of a machine used during the production of cement (e.g., a mix hopper, etc.). 
     As shown in  FIG. 1 , traceable cement mixture  10  includes a volume of cement particles  20 . In one embodiment, cement particles  20  have a generally spherical shape. In other embodiments, cement particles  20  have another shape (e.g., ovular, discus, irregular, etc.). Cement particles  20  may be Portland cement composed primarily of hydraulic calcium silicates. In other embodiments, cement particles  20  may be another type of cement (e.g., a blended cement, another hydraulic cement, etc.) or still another material. Cement particles  20  may have a size of approximately 1 micron. In other embodiments, cement particles  20  are larger than one micron (e.g., 10 microns, 50 microns, 90 microns, etc.) or smaller than one micron (e.g., 0.5 microns, etc.). In use, cement particles  20  are hydrated (e.g., with water) and cure to form cured concrete. The shape, composition, size, and density of cement particles  20 , among other characteristics, may impact the strength, hardness, toughness, or other features of the cured concrete. The shape, composition, size, or other feature of cement particles  20  may be specified (e.g., by a structural engineer, by a designer, by a regulatory agency, etc.) to produce concrete having specified characteristics (i.e. specified concrete). 
     Various manufactures may produce cement particles  20 . According to one embodiment, mineral deposits are mined, and larger pieces are milled, ground, or otherwise processed to form cement particles  20 . The manufacturer of cement particles  20  is tasked with producing cement particles  20  having the specified features. Such specified features may be identified as an acceptable range (e.g., a density of between 830 and 1650 kilograms per cubic meter), as a mean value (e.g., an average particle size of thirty microns, etc.), or as still another requirement. Some manufacturers may produce cement particles  20  having specified features that are outside the acceptable range or otherwise fail to conform with the identified requirements. By way of example, some manufacturers may lack the quality control processes, equipment, know-how, or other skills needed to produce cement particles  20  having specified features within the identified requirements. In other instances, some manufacturers may disingenuously produce cement particles  20  that fail to meet the identified requirements (e.g., by failing to sufficiently grind cement particles  20  as a cost cutting measure, by cutting cement particles  20  with other, non-specified types of cement, contaminants, other materials, etc.). As the particular features of cement particles  20  relate to the strength, hardness, toughness, or other features of the cured concrete, selection and verification of a particular manufacturer may impact the quality, life, strength, or other features of a structure. 
     Referring again to the embodiment shown in  FIG. 1 , cement taggants  30  are disposed within a volume of cement particles  20 . Cement taggants  30  are intended to reduce the risk that improper cement particles  20  will be introduced into specified concrete. Cement taggants  30  are also intended to reduce the risk that cement particles  20  may be improperly processed or blended with other materials. In some embodiments, cement taggants  30  include data relating to a characteristic of the volume of cement particles  20 . The characteristic of the volume of cement particles  20  may be a grade, a quality, a manufacturer, a manufacture date, an inspection status, an inspection date, an approval status, or still other properties. Cement taggants  30  may be introduced at various points during the manufacture and use of cement particles  20 . In some embodiments, cement taggants  30  are introduced to traceable cement mixture  10  before the processing of the raw material (e.g., before cement particles  20  are formed through a grinding process, etc.). In other embodiments, cement taggants  30  are introduced to traceable cement mixture  10  after a cement particles  20  are processed (e.g., during a certification of cement particles  20 , etc.) or after cement particles  20  are introduced into concrete, among other alternatives. 
     In one embodiment, cement taggant  30  is a discrete object that is configured to be individually monitored, handled, or examined. In other embodiments, cement taggant  30  is configured to be monitored, handled, or examined in aggregate with other cement taggants  30 . By way of example, a scoop of cement taggants  30  may be monitored, handled, or examined as a group. Cement taggant  30  may have a size that is larger or smaller than one millimeter. In one embodiment, cement taggants  30  are nanoparticles and are configured to be monitored, handled, or examined in aggregate. 
     According to one embodiment, the size of cement taggant  30  corresponds with the size of cement particles  20 . In still other embodiments, the density of cement taggant  30  corresponds with the density of cement particles  20 . By way of example, cement taggant  30  may include a hollow shell having at least one of a specified weight and a specified volume such that the density of cement taggant  30  corresponds with the density of cement particles  20 . Corresponding a feature (e.g., size, density, etc.) of cement taggant  30  with that of cement particles  20  reduces the risk that cement taggants  30  will separate from cement particles  20 . By way of example, separation may otherwise occur during shipping, handling, due to an increase in viscosity of cement particles  20  post-hydration, or during another process. In other embodiments, the size, density, or other feature of cement taggants  30  is greater or less than the corresponding feature of cement particles  20  to encourage separation and facilitate detection of cement taggants  30  within traceable cement mixture  10 . In still other embodiments, cement taggant  30  is configured to react with water such that a property (e.g., density, etc.) of cement taggant  30  changes to facilitate post-hydration separation. By way of example, cement taggant  30  may absorb more water than cement particles  20  and sink post hydration. 
     In some embodiments, cement taggants  30  are secured (e.g., the data is secured according to an encryption scheme). Securing cement taggants  30  is intended to reduce the risk of forgery of cement taggants  30 . By way of example, a manufacturer may employ a certification process whereby an inspector evaluates cement particles  20 . After authenticating the characteristic of cement particles  20 , the inspector may introduce cement taggants  30  into a volume of cement particles  20 . Securing cement particles  20  reduces the risk that the cement manufacturer, an intermediate party (e.g., a concrete mixing plant, a concrete transportation company, etc.), or still others will introduce cement taggants  30  into the volume of cement particles  20  or concrete produced therewith. In one embodiment, cement taggants  30  are secured and are configured to respond only to a specified request signal. An operator may retrieve the data only if the specified request signal is sent. If the operator does not know the specified request signal, cement taggants  30  may not respond at all or may not provide the data. In other embodiments, the data relating to the characteristic of cement particles  20  may be retrieved (e.g., read, etc.) only by those with a decryption key. In still other embodiments, cement taggants  30  have a specified feature intended to provide security. By way of example, cement taggants  30  may be difficult to produce (e.g., replicatable biological information encoded molecule taggants, specified isotopes, etc.). In still other embodiments, cement taggant  30  includes an RFID device that provides security. By way of example, the RFID device may employ an algorithm or provide a different code (e.g., number) based on a date or day of the week of interest (e.g., the manufacture date of cement particles  20 , the mix date of cement mixture  10 , etc.). By way of another example, the RFID device may employ an algorithm to provide a code that varies based upon still other inputs. While RFID devices are explicitly discussed herein, it should be understood that acoustic devices (e.g., ultrasonic devices, etc.) may provide similar functionality. Securing cement taggants  30  thereby facilitates distinguishing legitimate and illegitimate cement taggants  30  and also facilitates authenticating at least one of cement mixture  10  and cement particles  20 . 
     In one embodiment, cement taggant  30  includes a storage device (e.g., a flash memory, a computer storage medium, etc.) having a memory configured to store the data. Such cement taggants  30  may include an integrated circuit to facilitate the storage or retrieval of the data from the memory. In some embodiments, the data is stored in the memory as ciphertext. Such ciphertext may vary based on the encryption scheme (e.g., symmetric-key, public key, etc.), the particular security protocol utilized, a date of encryption, or still other features of the encryption or data. 
     Cement taggants  30  have fluorescent properties, according to one embodiment. By way of example, cement taggant  30  may include a material having fluorescent properties, the material thereby configured to at least one of provide information and identify cement taggant  30  within the volume of cement particles  20 . In one embodiment, the material is polymeric. Cement taggants  30  having fluorescent properties may facilitate the inspection of traceable cement mixture  10  or concrete produced therewith. In one embodiment, the material fluoresces when exposed to ultraviolet light. In other embodiments, the material fluoresces when exposed to electricity, heat, or still another form of energy. An inspector may authenticate a mixture by exposing the traceable cement mixture  10  or concrete produced therewith to an ultraviolet light and evaluating (e.g., visually, with a sensor, etc.) the presence of cement taggants  30  (e.g., the color, the intensity of the fluorescence, the number of cement taggants  30  present in the sample, etc.). By way of example, the color cement taggant  30  fluoresces may facilitate identifying a particular volume of concrete mixture  10 , cement particles  20 , or cement taggants  30 . In other embodiments, cement taggants  30  are colored (e.g., painted, etc.) to and used to identify a particular volume of concrete mixture  10 , cement particles  20 , or cement taggants  30 . 
     In some embodiments, different cement taggants  30  fluoresce different colors. The different colors may correspond to different characteristics of cement particles  20 . By way of example, a blue fluorescence may indicate that the cement particles  20  were produced or mixed by a first manufacturer and a red fluorescence may indicate that the cement particles  20  were produced or mixed by a second manufacturer. In another embodiment, different color fluorescence may correspond to different grades of cement particles  20 . While manufacturer identity and grades have been explicitly discussed, cement taggants  30  fluorescing with different colors may be used to distinguish between samples of cement particles  20  according to still other characteristics. 
     In some embodiments, cement taggants  30  are layered ceramic chips. The layered ceramic chips may have a size that is larger than one millimeter. The cement taggants  30  may include microprocessors and other devices (e.g., sensors, timers, etc.) configured to evaluate a property of cement particles  20  (e.g., moisture content, duration since processing, etc.). By way of example, cement taggant  30  may include a RFID device. Such a RFID device may be configured to interface with a sensing device to facilitate retrieval of the data (e.g., during an authentication process). 
     In other embodiments, cement taggant  30  includes a replicatable biological information encoded molecule, such as at least one of DNA and RNA. By way of example, cement taggant  30  may include a marker disposed within a capsule. The capsule may prevent degradation or dehydration of the marker when cement taggant  30  is introduced into the volume of cement particles  20 . The replicatable biological information encoded molecule may be configured to fluoresce when exposed to a source of energy (e.g., ultraviolet light, electricity, heat, etc.). In some embodiments, the replicatable biological information encoded molecule or the organism containing the replicatable biological information encoded molecule is otherwise undetectable to an observer of traceable cement mixture  10 . Fluorescing replicatable biological information encoded molecules may facilitate the inspection of traceable cement mixture  10  or concrete produced therewith. By way of example, the fluorescing replicatable biological information encoded molecule may facilitate an inspector&#39;s efforts to locate cement taggant  30  or may be used as a preliminary marker. According to another embodiment, the replicatable biological information encoded molecule itself encodes data (e.g., a code that is designed to indicate or store particular information). The replicatable biological information encoded molecule or the organism containing the replicatable biological information encoded molecule may be disposed within a material having a density different than the density of cement particles  20 , or the replicatable biological information encoded molecule may be disposed within a capsule such that cement taggant  30  has a density different than the density of cement particles  20 . In another embodiment, the replicatable biological information encoded molecule or the organism containing the replicatable biological information encoded molecule is positioned within a material having a density different than the density of water. Such materials may be organic materials, inorganic materials (e.g., foam, etc.), or hollow shells, among other alternatives. Replicatable biological information encoded molecule positioned within materials having a different density may float or sink within traceable cement mixture  10  or hydrated concrete. Such floating or sinking may facilitate the authentication of traceable cement mixture  10  or concrete produced therewith. According to another embodiment, cement taggant  30  includes a ferromagnetic material. Cement taggants  30  that include a ferromagnetic material may be extracted from cement mixture  10  with a magnetic field, thereby facilitating an authentication process involving removal or in-situ examination. In other embodiments, magnetized cement taggants  30  may be extracted using a non-magnetic material (e.g., iron, etc.). In still other embodiments, cement taggants  30  including a ferromagnetic material may be at least one of examined and detected using a magnetic field, the presence or response thereof authenticating cement mixture  10 . 
     In still other embodiments, cement taggant  30  includes a material having a specified nuclear magnetic resonance spectrum. Such a material may absorb and re-emit electromagnetic radiation at a specific resonance frequency. The specific resonance frequency facilitates distinguishing cement taggant  30  from the various other materials within concrete (e.g., cement particles  20 , aggregates, etc.) thereby facilitating authentication. In one embodiment, cement taggant  30  includes a trace element that may be electromagnetically, chemically, or otherwise detected. The trace element facilitates authentication by identifying cement taggant  30  within a volume of cement particles  20 . 
     In another embodiment, cement taggant  30  includes an isotope configured to identify cement taggant  30  within a volume of cement particles  20 . The isotope may be a Mossbauer active isotope that produces a Mossbauer spectrum when exposed to a corresponding gamma-ray source. By way of example, the isotope may be iron-57. The isotope may be mixed with cement particles  20  on a certain date (e.g., a manufacture date, a mix date, etc.). The isotope may be short lived and degrade at a particular rate. An inspector may evaluate the age of at least one of cement mixture  10  and cement particles  20  based on the ratios of the different isotopes therein. Accordingly, secured cement taggants  30  that include an isotope may be used to authenticate at least one of cement mixture  10  and cement particles  20 . 
     According to another embodiment, cement taggant  30  includes a gamma-ray watermark having a combination of gamma-ray-emitting isotopes. Such gamma-ray watermarks are discussed in U.S. Pat. No. 6,740,875, granted on May 25, 2004, which is hereby incorporated by reference. A cement verification apparatus may include a sensor configured to interface with (e.g., detect, etc.) the electromagnetic radiation, the trace element, the Mossbauer spectrum, or the gamma-rays to identify cement taggant  30  within traceable cement mixture  10  or concrete produced therewith. 
     In some embodiments, cement taggant  30  changes upon exposure to a threshold level of water (e.g., exposed to any quantity of water, a specified humidity level, liquid water, etc.). In another embodiment, cement taggant  30  includes a RFID device configured to provide a response signal (e.g., to a request signal, etc.) that varies based on the moisture content of cement particles  20  or cement mixture  10 . In other embodiments, moisture changes at least one of the optical spectrum (e.g., color, etc.), the infrared spectrum, and the nuclear magnetic resonance spectrum of cement taggant  30 . The moisture content of cement may impact the strength, toughness, durability, or other features of concrete produced therewith. Where specified concrete is required, the moisture content of cement particles  20  must be controlled. While cement particles  20  may be dried to a preferred moisture content during initial manufacture (e.g., in a drying oven, etc.), subsequent storage may expose cement particles  20  to moisture. By way of example, storage outside of a climate-controlled environment (e.g., outside, etc.) exposes cement particles  20  to liquid water (e.g., due to rain) and water vapor (e.g., due to humidity in the surrounding air). Such subsequent storage may increase the moisture content of cement particles  20  and change a property of concrete produced therefrom (e.g., strength, toughness, etc.). The moisture content of cement particles  20  may also be greater than a preferred level due to insufficient drying during initial manufacture. A greater-than-preferred moisture content of cement particles  20  may be difficult to observe. While re-testing may occur when cement particles  20  are isolated (e.g., prior to mixing), determining the moisture content of cement particles  20  after hydrating and mixing the concrete may be difficult. Cement taggants  30  that change (e.g. permanently, temporarily, etc.) when exposed to water facilitates the authentication of cement particles  20 . By way of example, an inspector may evaluate cement taggants  30  (e.g., pre-hydration, within hydrated concrete, etc.) to determine whether cement particles  20  have been exposed beyond a threshold level. 
     According to one embodiment, cement taggant  30  includes a property that degrades at a specific rate in the presence of water. By way of example, the property of cement taggant  30  may be density, size, or magnetic permeability. In one embodiment, cement taggants  30  are introduced to cement particles  20  during initial manufacture, and the magnetic permeability of cement taggant  30  degrades as cement taggant  30  is exposed to water. Cement taggants  30  may include iron, and the magnetic permeability may change due to oxidation or reduction (i.e. the magnetic permeability of cement taggant  30  may degrade due to rusting) or by still another mechanism. Subsequent evaluation of the magnetic permeability of cement taggant  30  thereby allows an inspector to determine a water exposure level for cement particles  20 . 
     In another embodiment, cement taggant  30  includes a material that changes color when exposed to a threshold level of water (e.g., exposed to any quantity of water, a specified humidity level, liquid water, etc.). Such a color change may occur due to oxidation or reduction. By way of example, cement taggant  30  may include iron, which changes color as it rusts. In other embodiments, the material includes a water-sensitive dye configured to change color when exposed to water. In one embodiment, cement taggants  30  configured to change color are introduced to cement particles  20  during initial manufacture. 
     The exposure to water needed to produce the color change may be specified. The specified exposure may be identified in terms of at least one of a time, a threshold humidity, or another measurement of exposure. After the period of time, in the presence of the threshold humidity, or as the exposure condition occurs, the material changes color. The change in color may be binary (e.g., white below the threshold and red above the threshold, etc.) or may occur gradually (e.g., initially white, pink after thirty days, and red after sixty days). In some embodiments, the color change varies based on both the intensity of exposure (e.g., humidity in the air, liquid water, etc.) and based on the duration of exposure (i.e. the time cement taggant  30  is exposed to the particular intensity of water). An inspector may evaluate cement taggants  30  (e.g., pre-hydration, etc.) to determine whether cement particles  20  have been exposed beyond a threshold level. Such evaluation may occur visually (e.g., traceable cement mixture  10  is red, thereby indicating excess exposure to water or humidity, etc.) or may occur through the use of a sensor (e.g., an image sensor) and a processor configured to evaluate a sensor signal from the sensor, determine the color of traceable cement mixture  10  or cement taggants  30 , and correspond the color with a level of exposure to water. 
     Referring next to the embodiment shown in  FIG. 2 , a mixture, shown as cement mixture  100 , is positioned within a housing, shown as container  110 . As shown in  FIG. 2 , cement mixture  100  includes cementitious material, shown as cement particles  120 , a plurality of taggants, shown as cement taggants  130 , and an additional material, shown as supplementary particles  140 . Supplementary particles  140  may include aggregates, a reinforcement fiber, a chemical admixture, a mineral admixture (e.g., fly ash, sand, etc.), unauthenticated cement (i.e. wild cement), or still other materials. In one embodiment, taggants are added to supplementary particles  140  to indicate the presence thereof. Cement mixture  100  may be formed by mixing a volume of supplementary particles  140  with cement taggants  130  and a volume of cement particles  120 . According to an embodiment, the volume of supplementary particles  140  mixed with the volume of cement particles  120  is specified, the ratio forming an additional material mix ratio. The amount of supplementary particles  140  relative to cement particles  120  may impact the strength of the concrete. A volume of cement taggants  130  may be disposed within the volume of cement particles  120  according to a taggant mix ratio. 
     In some embodiments, an amount (e.g., volume, number, etc.) of cement taggants  130  are added according to the taggant mix ratio during the initial manufacture of cement particles  120  (e.g., upon grinding, upon authentication, etc.). The amount of cement taggants  130  added to cement particles  120  may be associated with the quality of the cement (e.g., more cement taggants  130  may be added to premium cement while fewer cement taggants  130  may be added to standard quality cement, etc.). Such a mixture of cement taggants  130  and cement particles  120  may form a traceable cement mixture. Supplementary particles  140  may be later introduced to the traceable cement mixture. In some embodiments, supplementary particles  140  are wild cement, the wild cement having properties (e.g., moisture content, size, shape, grade, etc.) that reduce the cost of supplementary particles  140  relative to cement particles  120 . Authenticating a cement mixture may include monitoring the taggant mix ratio to determine a dilution of tagged cement with wild cement. Supplementary particles  140  may be introduced into cement particles  120  during a mixing operation either inadvertently (e.g., a mixing plant may accidentally add grades of cement or other materials that are inappropriate for the specified concrete) or disingenuously (e.g., a mixing plant may add filler materials to increase the volume of concrete produced). 
     Specified concrete includes a preferred ratio of cement. Introducing cement taggants  130  according to the taggant mix ratio establishes a specified amount (e.g., volume, number, etc.) of cement taggants  130  that should be present within the specified concrete. A specified concrete including the preferred ratio of cement but less than the specified amount of cement taggants  130  suggests the introduction of supplementary particles  140 . 
     Strength testing, hardness testing, or observation of the mixing process, among other alternatives, may be used to verify that the specified concrete includes the preferred ratio of cement. An authentication process may be used to determine whether the specified concrete includes a sufficient amount of cement taggants  130 . The observed amount of cement taggants  130  within a volume of cement particles (i.e. cementitious material that has not been mixed) may be compared with a specified amount of cement taggants  130  (e.g., according to the taggant mix ratio used during authentication) to verify that supplementary particles  140  have not been introduced. According to one embodiment, a processor of an authentication apparatus is configured to compare the observed amount of cement taggants  130  with the specified amount. The processor may provide a confirmation signal when or if the observed amount of cement taggants  130  reaches or exceeds the specified amount of cement taggants  130 . In some embodiments, cement taggants  130  include a material that fluoresces, and the amount of cement taggants  130  may be determined by counting or otherwise measuring the fluorescence. In other embodiments, the cementitious material or concrete is otherwise evaluated (e.g., with scanning, through resonance imaging, etc.) to determine the amount of cement taggants  130  therein. 
     In one embodiment, cement mixture  100  includes a first taggant including data relating to a characteristic of cement particles  120  and a second taggant including different data relating to a characteristic of cement particles  120 . The data of the first taggant and the second taggant may relate to the same or different characteristics of cement particles  120 . By way of example, the first taggant may include data relating to an inspection status of cement particles  120  (e.g., inspected but did not meet specifications) and the second taggant may also include data relating to an inspection status of cement particles  120  (e.g., inspected and met specifications). Verification of the mixture may occur by scanning for taggants including data indicating that cement particles  120  were authenticated and met specifications. 
     In another embodiment, the first taggant includes data relating to the manufacturer of cement particles  120 , and the second taggant includes data relating to the manufacturing date of cement particles  120 . Taggants having data relating to different characteristics facilitates gathering more information during a subsequent authentication of cement particles  120  (e.g., by an inspector, etc.). According to one embodiment, cement taggants  130  include one piece of data. According to another embodiment, cement taggants  130  include multiple pieces of data. Including multiple pieces of data may facilitate subsequent verification efforts (e.g., an inspector may determine information about different characteristics of cement particles  120  from a single cement taggant  130 ). In still other embodiments, the ratio of the first taggant to the second taggant may code information (e.g., premium cement may have more of a first taggant, etc.). By way of example, a manufacturer may begin a period by adding a first taggant (e.g., a taggant including platinum such that an x-ray spectrum having a recognizable feature is produced, etc.) and incrementally (e.g., each day, each week, etc.) adding more of a second taggant (e.g., a taggant including rhodium such that an x-ray spectrum having a recognizable feature is produced, etc.), the ratio of the two taggants (e.g., a ratio of the two materials as indicated by the x-ray spectrum, etc.) relating to the date of manufacture. 
     In some embodiments, the first taggant and the second taggant include the same identification mechanism (i.e. both taggants are the same type). By way of example, the first taggant and the second taggant may be RFID devices or taggants that are responsive to x-rays. Such taggants may include or be configured to provide different data (e.g., the first taggant may indicate the manufacture name and the second taggant may indicate the date of manufacture, etc.). In other embodiments, the first taggant is a different type of identification device than the second taggant. By way of example, the first taggant may include at least one of a fluorescent material, a nanoparticle, a RFID device, a replicatable biological information encoded molecule, a material having a specified nuclear magnetic resonance spectrum, a trace element, an particular isotope, and a gamma-ray watermark whereas the second taggant may include another of a fluorescent material, a nanoparticle, a RFID device, a replicatable biological information encoded molecule, a material having a specified nuclear magnetic resonance spectrum, a trace element, an particular isotope, and a gamma-ray watermark. In one embodiment, the first taggant includes an RFID device, an x-ray type tag, or another type of taggant that may be examined after the concrete has set whereas the second taggant includes a replicatable biological information encoded molecule or another type of taggant that may be examined before the concrete has set. In another embodiment, the first taggant includes an additive (e.g., manganese, etc.) that is detectable within a spectrum (e.g., an x-ray spectrum) to identify a first piece of data (e.g., manganese may be associated with a particular manufacture of cement), and the second taggant may include an additive (e.g., platinum, etc.) that is detectable within a spectrum to identify a second piece of data (e.g., to indicate a premium grade cement, etc.). A single taggant may include both pieces of data, according to an alternative embodiment. In other embodiments, at least one of a plurality of identification mechanisms is different between the first taggant and the second taggant. 
     Referring next to the embodiment shown in  FIG. 3 , a structure, shown as building  200 , includes a base, shown as footing  210 , and a supported portion, shown as elevated portion  220 . 
     As shown in  FIG. 3 , footing  210  includes a column  212  and a lateral support portion  214 . While shown in  FIG. 3  as having two columns  212  coupled by lateral support portion  214 , building  200  may be otherwise shaped. In one embodiment, footing  210  includes concrete and a reinforcing material (e.g., rebar, etc.). Columns  212  interface with a ground volume, shown as ground surface  202 . Footing  210  supports elevated portion  220 . The weight of elevated portion  220 , forces due to wind acting on elevated portion  220 , forces due to seismic activity, and still other loads may be imparted on footing  210 . 
     In one embodiment, footing  210  is manufactured from authenticated concrete to reduce the risk that an inappropriate concrete mixture (e.g., inferior concrete) may be relied upon to support the loads imparted on footing  210 . As shown in  FIG. 3 , concrete including a taggant, shown as cement taggants  216 , is shaped (e.g., poured into forms, assembled using pre-formed concrete components, etc.) to produce footing  210 . Cement taggants  216  may remain within footing  210  during the life of building  200 , as shown in  FIG. 3 . In some embodiments, all of the concrete within footing  210  includes cement taggants  216 . In other embodiments, only a portion of the concrete within footing  210  includes cement taggants  216  (e.g., concrete within columns  212 , etc.). While footing  210  is explicitly discussed herein, still other portions of building  200  may be manufactured from concrete that includes cement taggants  216  (e.g., elevator shafts, floor support beams, other structural components, etc.). 
     In some embodiments, different portions of building  200  are manufactured from concrete and include different cement taggants  216 . Different cement taggants  216  may identify different portions of building  200 . By way of example, cement taggants  216  may include an RFID device that responds (e.g., to a request signal) with a design location for the corresponding concrete (i.e. a floor or portion of the building for which the concrete should have been or should be poured). An inspector may scan the concrete before pouring to verify that the concrete will be poured into a form for the appropriate portion of the building. An inspector may also scan the concrete after the concrete is poured (e.g., during a subsequent investigation where a portion of the building has failed) and retrieve the design location for the concrete to verify that the appropriate concrete was poured in the appropriate location. Such identification may reduce the risk that a particular portion of building  200  may be manufactured from concrete having properties other than those specified (e.g., by an architect or engineer, etc.). By way of example, concrete for columns  212  may have a characteristic (e.g., strength, grade, quality, manufacturer, manufacture date, inspection status, approval status, etc.) that is different than the characteristic of concrete for lateral support portion  214 . In one embodiment, column  212  includes concrete having a characteristic that is specified to facilitate compressive loading wherein lateral support portion  214  includes concrete having a characteristic that is specified to facilitate bending loading. Cement taggants  216  include data identifying such characteristics. In one embodiment, cement taggants  216  reduce the risk of applying (e.g., inadvertently, disingenuously, etc.) concrete intended to carry compressive loading in columns  212  at locations exposed primarily to bending stresses (e.g., lateral support portion  214 ). The concrete of footing  210  may be authenticated by cement taggants  216  in-situ (e.g., data on cement taggants  216 , the presence of cement taggants  216 , the amount of cement taggants  216 , etc.). 
     Referring again to the exemplary embodiment shown in  FIG. 3 , a cement authentication apparatus, shown as scanner  230 , interfaces with cement taggants  216  to determine a characteristic of the concrete in footing  210 . In one embodiment, scanner  230  is used to authenticate the composition, history, grade, or other characteristic of concrete in-situ (i.e. in position within footing  210 ). The authentication of the concrete may be accomplished non-invasively (i.e. without sampling, coring, or otherwise removing the concrete from footing  210 ). Non-invasive testing of footing  210  is intended to collect data without risking damage to building  200  or requiring subsequent concrete repair. 
     In one embodiment, scanner  230  is used to proactively determine buildings  200  that may be at risk for damage (e.g., due to a potential or anticipated storm, due to potential or historical seismic loading, etc.). By way of example, a risk factor may be associated with building  200  based on a feature of cement taggants  216  (e.g., an amount of cement taggants  216 , data in cement taggants  216 , etc.). The risk factor may correspond to a potential for damage due to wind, seismic, or other types of loading. In another embodiment, scanner  230  is used as part of an investigation into potential causes for damage to building  200 . Cement taggants  216  remain within the concrete and remain readable even after an extended period of time. By way of example, cement taggants  216  may identify a manufacturer even after jobsite records have been discarded or as part of an authentication process during initial construction. Cement taggants  216  may include materials (e.g., polymers, etc.) selected to reduce the risk of damage (e.g., during collapse of a building). In other embodiments, cement taggants  216  are disposed within and protected by concrete thereby reducing the risk of damage during collapse of a building. In other embodiments, scanner  230  may be used to inspect footing  210  to verify the quality of the concrete. By way of example, scanner  230  may be used to identify voids in concrete by scanning for taggants. In still other embodiments, scanner  230  may be used to identify a particular portion of building  200  from which a sample of material was taken (e.g., scanner  230  may separate the concrete of upper floors from the concrete of lower floors, etc.). 
     As shown in  FIG. 3 , scanner  230  includes a housing, shown as body  232 , at least partially surrounding a generator  234 . Generator  234  is configured to produce an interrogation signal, according to an embodiment. In some embodiments, generator  234  produces a radio frequency wave (e.g., to interface with cement taggants  216  having RFID devices). In other embodiments, generator  234  is a gamma-ray source (e.g., to interface with cement taggants  216  having particular isotopes, etc.). In still other embodiments, generator  234  is a neutron generator configured to interrogate taggant  216  and trigger a response spectrum. In still other embodiments, the interrogation signal may include an x-ray, an ultraviolet wave, or an acoustic wave. By way of example, cement taggants  216  may respond to the acoustic wave and provide authenticating information (e.g., resonate at a particular frequency, scatter the acoustic wave according to a specified pattern to provide authentication information, store energy from a probe signal and provide a response signal, etc.). 
     In one embodiment, generator  234  is positioned to direct the interrogation signal toward footing  210 . In another embodiment, a waveguide directs the interrogation signal from generator  234  toward footing  210 . Scanner  230  may further include a sensor  236  positioned to receive response signal (e.g., an electromagnetic wave produced by cement taggant  216 , an electromagnetic wave re-radiated or reflected from cement taggant  216 , etc.). A processor  238  is configured to evaluate the interrogation signal produced by generator  234  and the response signal received by sensor  236  to determine a characteristic of the cement within footing  210  (e.g., pour quality, strength, grade, quality, manufacturer, manufacture date, inspection status, approval status, etc.). 
     In another embodiment, scanner  230  does not include generator  234 . Processor  238  of scanner  230  may be configured to evaluate response signals produced by cement taggants  216  (e.g., cement taggants  216  including RFID devices, light waves produced by fluorescent cement taggants  216 , etc.), identify a trace element of cement taggant  216 , or otherwise interact with cement taggants  216 . Such interaction may facilitate the retrieval of data or determine the amount (e.g., quantity, density, presence, etc.) of cement taggants  216  within footing  210 . 
     Referring next to the embodiment shown in  FIG. 4 , a structure, shown as bridge  250 , includes a base, shown as footing  260 , and a supported portion, shown as roadway  270 . Footing  260  may include concrete having specified characteristics (e.g., strength, grade, quality, manufacturer, manufacture date, inspection status, approval status, etc.). Roadway  270  may include concrete or may include another material (e.g., asphalt, gravel, etc.). As shown in  FIG. 4 , a cement authentication apparatus, shown as scanner  280 , is used to authenticate the concrete of footing  260 . Scanner  280  may direct interrogation signals  282  toward footing  260 . In other embodiments, scanner  280  otherwise interfaces with footing  260  to retrieve data or determine the amount (e.g., quantity, density, presence, etc.) of taggants within footing  260 . Scanner  280  facilitates post-pour inspection of bridge  250  and reduces subsequent reliance on jobsite records to determine characteristics of the cement. In one embodiment, taggants within footing  260  have properties that facilitate post-pour interrogation thereof. By way of example, the taggants may have a RFID device or may be a gamma-ray-sensitive device such that data encoded therein may be retrieved even if the surface of footing  260  is covered (e.g., covered with soil or gravel, etc.). In other embodiments, the taggants are infra-red sensitive or fluoresce and are configured to facilitate examination thereof when the surface of footing  260  is visible or accessible. 
     Referring next to  FIGS. 5-7 , a cement authentication apparatus may be used to determine a characteristic of cement. As shown in  FIGS. 5-6 , a cement authentication apparatus, shown as authentication assembly  300 , includes a housing, shown as chute  310 . Chute  310  is configured to contain a volume of cementitious material, shown as concrete  320 , that includes a taggant, shown as cement taggant  322 . In some embodiments, chute  310  is a concrete chute for a concrete mixer truck. The other components of authentication assembly  300  may be fixed or removably coupled to chute  310 . By way of example, an inspector may couple chute  310  to the concrete mixer truck at a jobsite to authenticate concrete  320 . Such authentication may occur for each concrete mixer truck or with a sample of concrete mixer trucks (e.g., one truck within a group of trucks, etc.). Concrete  320  may include a mixture of cement and additional materials or may include only cementitious material and cement taggants  322 . Concrete  320  may be dry (e.g., cement powder and other materials, etc.) or may be wet (e.g., a mixture of cement powder, other materials, and water, etc.). 
     In one embodiment, concrete  320  flows within chute  310  along flow direction  312 . As shown in  FIGS. 5-6 , a sensor  330  is positioned to interface with cement taggant  322 . Sensor  330  may detect response signals (e.g., light waves, radio waves, gamma rays, etc.) produced by cement taggant  322  within concrete  320 . In other embodiments, sensor  330  otherwise interfaces with cement taggants  322  to detect data or the amount of cement taggants  322  within concrete  320 . According to one embodiment, sensor  330  is configured to provide a sensor signal relating to a characteristic of concrete  320 . In some embodiments, sensor  330  provides a plurality of sensor signals at a sampling rate. Authentication assembly  300  may include a processor configured to determine the characteristic of concrete  320  by evaluating the sensor signal, according to an exemplary embodiment. The processor may be configured to evaluate the plurality of sensor signals to authenticate an entire batch of concrete  320 , average data from the plurality of sensors signals, or evaluate the amount of cement taggants  322  within different portions of concrete  320  (e.g., an amount of cement taggants  322  during the initial pour relative to a mid-pour amount of cement taggants  322 ), among other alternatives. 
     In some embodiments, authentication assembly  300  includes a flow rate sensor configured to provide flow rate signals relating to the flow rate of concrete  320  along chute  310 . The processor may be configured to determine the characteristic of cement within concrete  320  by evaluating the flow rate signals. By way of example, the processor may divide the amount of cement taggants  322  detected by sensor  330  in a period of time by the flow rate of concrete  320  to estimate the total number of cement taggants  322  within a batch of concrete  320 . 
     In one embodiment, cement taggants  322  are positioned within a hollow shell (e.g., a polymeric shell, etc.) or include a material having a density that is less than the density of concrete  320 . As shown in  FIG. 5 , sensor  330  is coupled to a rod  332  with a fin  334 . In some embodiments, rod  332  is rotatably coupled to brackets  314  of chute  310  and defines an axis of rotation. Concrete  320  flowing along chute  310  contacts fin  334  and rotates rod  332  about the axis of rotation and relative to brackets  314 . As shown in  FIG. 5 , sensor  330  is positioned at an end of fin  334  such that rotation of fin  334  and rod  332  positions sensor  330  along an upper surface of concrete  320  (e.g., to interface with a greater amount of cement taggants  322  floating along an upper surface of concrete  320 , etc.). 
     In another embodiment, rod  332  is fixed to brackets  314  such that fin  334  remains stationary relative to chute  310 . Cement taggants  322  interface with sensor  330  as concrete  320  flows within chute  310 . Authentication assembly  300  having a stationary fin  334  positions sensor  330  within the volume of concrete  320  (e.g., thereby interfacing with cement taggants  322  having a density equal to or greater than the density of concrete  320 ). In some embodiments, authentication assembly  300  includes a fixed or rotating fin  334  to selectively interface with cement taggants  322  having particular data. By way of example, concrete  320  may include a first set of cement taggants  322  having a first density and a second set of cement taggants  322  having a second density. Authentication assembly  300  may include a rotating fin  334  to position sensor  330  for interfacing with either the first set of cement taggants  322  or the second set of cement taggants  322 . In still other embodiments, fin  334  is fixed (e.g., within a plane orthogonal to flow direction  312 ), and a plurality of sensors  330  interface with cement taggants  322 . A first sensor  330  may be positioned to interface with the first set of cement taggants  322  (e.g., along the surface of concrete  320 , etc.), and a second sensor  330  may be positioned to interface with the second set of cement taggants  322  (e.g., at an end of fin  334 , etc.). 
     Referring to the embodiment shown in  FIG. 6 , authentication assembly  300  includes a plurality of sensors  330  coupled to rod  332  with a plurality of fins  334 . In one embodiment, the plurality of sensors  330  provide a plurality of sensor signals. A processor may evaluate the plurality of sensor signals to determine the characteristic of concrete  320 . Concrete  320  flowing along flow direction  312  rotates fins  334  thereby sequentially exposing sensors  330  to concrete  320 . According to one embodiment, sensors  330  are identical and the processor is configured to average or otherwise manipulate signals from sensors  330  (e.g., to reduce the risk of false negative readings from one sensor  330 ). According to another embodiment, sensors  330  detect different cement taggants  322  (e.g., a first sensor  330  is a photo sensor to detect the fluorescence of cement taggants  322  and a second sensor is a radiofrequency antenna configured to receive radio waves from cement taggants  322 , etc.). 
     Referring next to the embodiment shown in  FIG. 7 , concrete  320  is positioned within a housing, shown as container  316 . In one embodiment, an inspector authenticates concrete  320  by positioning a sample in container  316  and operating authentication assembly  300 . As shown in  FIG. 7 , concrete  320  includes cement taggants  322 , a volume of cementitious material, shown as cement particles  324 , and additional material, shown as aggregate  326 . Sensors  330  are coupled to a driver, shown as drill  340 , with rod  332  and fin  334 . Drill  340  moves (e.g., rotates, etc.) rod  332  and fin  334  within concrete  320 . A processor is configured to evaluate sensor signals provided by sensors  330  to determine a characteristic of concrete  320 . As shown in  FIG. 7 , authentication assembly  300  may authenticate wet or dry concrete  320 . In some embodiments, concrete  320  does not flow through container  316  thereby reducing the need to couple authentication assembly  300  along the flow path between the batch of concrete (e.g., within a drum of a concrete mixer truck, etc.) and work area (e.g., a concrete form). Authentication assembly  300  as shown in  FIG. 7  is intended to facilitate the remote authentication of concrete  320  (e.g., within a dedicated test area on a jobsite, etc.). In other embodiments, sensor  330  is positioned outside the volume of concrete  320 . Sensor  330  may authenticate concrete  320  by interfacing with cement taggants  322  therein (e.g., by sensing response signals generated by cement taggants  322 , by identifying the trace elements of cement taggants  322 , etc.). 
     Referring next to the embodiment shown in  FIG. 8 , concrete is produced and distributed according to a process  400 . As shown in  FIG. 8 , raw cementitious material is mined ( 410 ) and processed (e.g., milled, ground, etc.) at  420 . The processed cementitious material may be provided to a concrete plant at  430 . In some embodiments, additional materials (e.g., aggregates, reinforcement fibers, chemical admixtures, fly ash, sand, etc.) are mixed into the processed cementitious material by the concrete plant at  430 . The mixed concrete is thereafter distributed to a jobsite ( 440 ). The mixed concrete may be distributed with concrete trucks to a remote jobsite or transported to an internal manufacturing facility (e.g., to produce pre-form concrete products). The distributed concrete is thereafter poured into a concrete form ( 450 ). 
     As shown in  FIG. 8 , taggants may be introduced into the cementitious material at a plurality of points within process  400 . Taggants may be introduced after the raw cementitious material is processed between  420  and  430 . Such taggants may include data relating to a characteristic of the cementitious material (e.g., processor&#39;s identity, processing date, etc.). The processed cementitious material is provided to a concrete plant at  430  where it may be authenticated before or after being mixed with additional materials (i.e. the cementitious material may be authenticated between  430  and  440 ). By way of example, a concrete plant may authenticate the processor, the processing date, the moisture content, or still another characteristic of the cementitious material to ensure that the concrete produced therefrom conforms with predetermined specifications (e.g., standards, customer requests, etc.). A processor may monitor a mix status of the concrete by evaluating a homogeneity of the taggants in the concrete mixture. The mix status may include whether the concrete has been mixed to a specified degree. 
     In some embodiments, taggants are introduced between  430  and  440  (e.g., to identify a production time, etc.) by the concrete plant or an inspector. The concrete is thereafter delivered to the jobsite at  440 . The concrete may be authenticated by an inspector upon arrival or at another point before entering the concrete form (e.g., as the concrete flows down the concrete chute, etc.). Taggants may be added to the concrete between  440  and  450  (e.g., taggants specifying the area of the building where the concrete is intended to be placed). After the concrete is poured into the form at  450 , the concrete may be authenticated (i.e. in-situ authentication) either before or after the concrete sets. In some embodiments, inspectors introduce taggants at various points throughout process  400  after the authentication process and before the following process (e.g., taggants relating to an authentication status of the cementitious material). 
     While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. For example, elements shown as integrally formed may be constructed of multiple parts or elements. It should be noted that the elements and/or assemblies of the enclosure may be constructed from any of a wide variety of materials that provide sufficient strength or durability, in any of a wide variety of colors, textures, and combinations. Accordingly, all such modifications are intended to be included within the scope of the present inventions. The order or sequence of any process or method steps may be varied or re-sequenced according to other embodiments. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims. 
     The present disclosure contemplates methods, systems, and program products on any machine-readable media for accomplishing various operations. The embodiments of the present disclosure may be implemented using existing computer processors, or by a special purpose computer processor for an appropriate system, incorporated for this or another purpose, or by a hardwired system. Embodiments within the scope of the present disclosure include program products comprising machine-readable media for carrying or having machine-executable instructions or data structures stored thereon. Such machine-readable media can be any available media that can be accessed by a general purpose or special purpose computer or other machine with a processor. By way of example, such machine-readable media can comprise RAM, ROM, EPROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to carry or store desired program code in the form of machine-executable instructions or data structures and which can be accessed by a general purpose or special purpose computer or other machine with a processor. When information is transferred or provided over a network or another communications connection (either hardwired, wireless, or a combination of hardwired or wireless) to a machine, the machine properly views the connection as a machine-readable medium. Thus, any such connection is properly termed a machine-readable medium. Combinations of the above are also included within the scope of machine-readable media. Machine-executable instructions include, for example, instructions and data, which cause a general-purpose computer, special purpose computer, or special purpose processing machines to perform a certain function or group of functions. 
     Although the figures may show a specific order of method steps, the order of the steps may differ from what is depicted. Also two or more steps may be performed concurrently or with partial concurrence. Such variation will depend on the software and hardware systems chosen and on designer choice. All such variations are within the scope of the disclosure. Likewise, software implementations could be accomplished with standard programming techniques with rule-based logic and other logic to accomplish the various connection steps, processing steps, comparison steps, and decision steps.