Railroad Ties

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Nicole Labbe - One of the best experts on this subject based on the ideXlab platform.

  • optimization of thermal desorption conditions for recovering wood preservative from used Railroad Ties through response surface methodology
    Journal of Cleaner Production, 2018
    Co-Authors: Holly Lauren Haber, Jeff Lloyd, Nourredine Abdoulmoumine, Nicole Labbe
    Abstract:

    Abstract A statistical response surface methodology (RSM) using a central composite design (CCD) model was applied to identify the optimum thermal desorption conditions for maximum recovery of preservative from copper naphthenate (CuNap) treated wood and subsequent production of a high quality pyrolytic vapor from the thermally treated wood. From the designed experiment, 94% of the total preservative present in the Ties was desorbed at temperatures higher than 250 °C and residence times longer than 30 min. Elevating the temperature from 215 °C to 285 °C for 45 min residence time generated a weight loss of 12–36 wt%, an increase in higher heating value (HHV) from 20.1 to 21.9 MJ/kg, and a reduction of energy yield from 90.4 to 71.5% of the resulting thermally treated biomass. Pyrolysis at 450 °C of this material produced a vapor rich in sugars- and lignin-derived compounds. The predicted optimum conditions in terms of a maximum preservative recovery, minimum energy yield loss of the wood, and production of thermally treated biomass that generates a high proportion of sugars- and lignin-derived compounds during pyrolysis were found to be 265 °C and 51 min. Under these optimum conditions, the predicted maximum preservative recovery was 95% while the predicted thermally treated solid retained 77% of the original energy yield and produced high portions of levoglucosan and lignin-derived compounds during subsequent pyrolysis, similar to torrefied wood.

  • environmentally friendly process for recovery of wood preservative from used copper naphthenate treated Railroad Ties
    ACS Sustainable Chemistry & Engineering, 2017
    Co-Authors: Holly Lauren Haber, Jeff Lloyd, Nourredine Abdoulmoumine, Stephen C Chmely, Yagya N Regmi, Nicole Labbe
    Abstract:

    Removal of copper naphthenate (CN) from used wooden Railroad Ties was investigated to improve the commercial viability of this biomass as a fuel source and avoid alternative disposal methods such as landfilling. Bench-scale thermal desorption of organic preservative components from CN-impregnated Ties was followed by extraction of the copper fraction with ethylenediaminetetraacetic acid, 1-hydroxy ethylidene-1,1-diphosphonic acid, or 2,6-pyridine dicarboxylic acid (PDA). Naphthenic acid (NA) and carrier oil were recovered at desorption temperatures between 225 and 300 °C and could potentially be recycled to treat new Ties. The thermal treatment also mimicked torrefaction, improving the biomass properTies for use as a thermochemical conversion feedstock. Chelation with PDA, a biodegradable chelating agent, after desorption had the highest extraction efficiency of copper and other naturally present inorganics, extracting 100% of the copper from both the raw and 225 °C-treated samples. Optimized desorbed mat...

  • two step thermochemical process for adding value to used Railroad wood Ties and reducing environmental impacts
    ACS Sustainable Chemistry & Engineering, 2017
    Co-Authors: Adam Taylor, Jeff Lloyd, Nourredine Abdoulmoumine, Nicole Labbe
    Abstract:

    A two-step thermochemical process combining a thermal desorption at 250–300 °C and a pyrolysis at 500 °C of used creosote-treated wooden Railroad Ties was carried out to recover preservative and produce a high quality bio-oil and biochar. Under optimal temperature between 280 and 300 °C, high preservative removal efficiency (70–74%) was achieved with a high proportion of polycyclic aromatic hydrocarbons (PAHs, 80–82%) and a large portion of the original wood mass (67–70%) was retained. This thermally treated biomass had higher heating value (HHV; 19.9–20 MJ/kg) than the starting material. The physical properTies of the preservative, such as viscosity and density, and its toxic threshold against a common decay basidiomycete fungus were similar to those of commercially available P2-creosote. Pyrolysis of the thermally treated Ties produced bio-oils with lower water content and total acid numbers, and a higher amount of lignin-derived compounds than that of untreated Ties. Biochars derived from the thermally...

  • recovery of creosote from used Railroad Ties by thermal desorption
    Energy, 2016
    Co-Authors: Jeff Lloyd, Nourredine Abdoulmoumine, Nicole Labbe
    Abstract:

    Used creosote-treated wood Ties were thermally treated between 250 and 350 °C to recover preservative and upgrade the wood to provide an improved quality biomass for thermochemical processes. With thermal treatments ranging from 250 to 300 °C, the amounts of creosote, mostly consisting of polycyclic aromatic hydrocarbons (PAHs), recovered were from 47 to 79% of total creosote present in the used Ties. Thermal treatment at 350 °C recovered 97% of total PAH compounds. Larger amounts of PAHs with higher molecular weights (HMWs) and lower vapor pressures (LVP) were recovered at elevated temperatures. Temperature above 300 °C decomposed the wood matrix, with a mass loss ranging between 50 and 63 wt% and produced large amounts of light organics, anhydrosugars, and phenolic compounds that would contaminate the recovered creosote. Our study concluded that thermal treatment ranging between 275 and 300 °C would be preferred to recover preservative for recycling and improve the wood quality, i.e., high carbon content and caloric value, and low hazardous pollutants (creosote residues) for thermochemical processes such as pyrolysis or gasification. These findings suggest that the proposed approach could be a commercially viable and environmentally beneficial alternative to landfill for used Railroad Ties.

  • thermal desorption of creosote remaining in used Railroad Ties investigation by tga thermogravimetric analysis and py gc ms pyrolysis gas chromatography mass spectrometry
    Energy, 2016
    Co-Authors: Jeff Lloyd, Nicole Labbe
    Abstract:

    A two-step thermal process, an initial thermal treatment at mild temperature followed by a fast pyrolysis step, was investigated to recover wood preservatives and produce preservatives-free wood for production of high quality bio-oil from used creosote-treated Railroad Ties. During the initial thermal treatment at temperature of 280 °C for 10–30 min, the treated wood Ties underwent a 20–25% weight loss with energy yield (77–83%). Energy yield at 280 °C was lower than that at 200 and 250 °C (92–97%) but higher than that at the 300 °C (64–74%). Recovery level of creosote at 280 °C was comparable to that at 300 °C. Fast pyrolysis at 450 °C of the 280 °C-treated wood Ties produced high amount of levoglucosan and phenolic compounds with a traceable amount (1.7–1.9% of the total peak area) of creosote compounds.

Chih-hang John Wu - One of the best experts on this subject based on the ideXlab platform.

  • Performance of a Continuously Traversing 2-Camera Non-Contact Optical Strain Sensor for In-Plant Assessment of Prestressed Concrete Railroad Crosstie Transfer Length
    2016 Joint Rail Conference, 2016
    Co-Authors: B. Terry Beck, Aaron A. Robertson, Robert J. Peterman, Chih-hang John Wu
    Abstract:

    Accurate knowledge of transfer length has been shown to be crucial to the goal of maintaining continuous production quality in the modern manufacture of prestressed concrete Railroad Ties. Traditional manual laboratory methods, such as the conventional Whittemore method which requires the use of embedded reference points, are clearly not suitable for production operation or for use in reliable production quality-control.This paper presents the results of another advance in the development of automated transfer length measurement systems for practical in-plant operation. The new device offers a significant improvement over the previously successful automated Laser-Speckle Imaging (LSI) system developed by the authors. The earlier automated LSI strain measurement system has been modified to provide significantly improved optical resolution of longitudinal surface strain, with the ability to resolve longitudinal prestressed concrete crosstie surface strain without time-consuming special surface preparation. More importantly, the new system is also capable of making measurements of strain in a real-time “on-the-fly” manner over the entire distance range of interest on the tie associated with transfer length development. It features both a “jog” mode of operation, similar to its predecessor in which measurements of longitudinal surface strain are automatically captured in arbitrary spatial increments over the entire range of the computer-controlled traverse, and an “on-the-fly” mode in which measurements of longitudinal surface strain are captured without the need for stopping at each measurement location. This latter mode offers the potential of a much faster capture of the strain profile and should prove to be very beneficial for field testing and in-plant diagnostic applications.The performance of this new system is first demonstrated using a new calibrated step-wise uniform strain field setup which has been developed specifically for verification of this and other automated transfer length measurement systems. This verification system produces a calibrated step change in surface deflection, effectively subjecting the automated strain measurement system to an ideal step change in longitudinal strain for a given gauge length. In addition, the new automated system is demonstrated by conducting measurements of longitudinal surface strain on prestressed concrete crossTies in a manufacturing plant. For this latter experimental in-plant testing, strain measurements using the new system are also compared directly with those from the recently introduced 6-camera transfer length measurement system, as well as with the traditional Whittemore gauge measurements. The agreement between these independent measurement systems is remarkable, and it is shown to even be possible to discern differences in strain profile and associated transfer length between adjacent crossTies within a given casting bed. This new automated and high-resolution device should provide a very convenient and fast diagnostic tool for the manufacturer to quickly identify the need to modify production (e.g., concrete mix) if transfer length specifications fall out of desired range.Copyright © 2016 by ASME

  • comparison of transfer lengths in pretensioned concrete Railroad Ties subjected to different magnitudes of rail loads
    2016 Joint Rail Conference, 2016
    Co-Authors: Naga Narendra B. Bodapati, Robert J. Peterman, Terry B Beck, Chih-hang John Wu
    Abstract:

    In order to quantify the effect of different reinforcement types on transfer lengths, an extensive study was conducted with the selected group of twelve different reinforcement types. These reinforcements are extensively used to produce concrete Railroad Ties across the world. These employed twelve (12) different types are of 5.32 mm diameter wires with different surface indent geometries. A research team from Kansas state university visited a PCI certified concrete tie manufacturing plant during January 2013. During the plant visit, four (4) concrete Railroad Ties were cast for each reinforcement type for a total of 48 Ties. Considerable part of the study conducted at the plant was previously published by the authors. However for effective understanding, brief explanation of the tie manufacturing process will be presented in this paper. Strain measuring points were mounted on the bottom surface of a concrete Railroad tie during the casting process. Proper measures were taken to safeguard these strain measuring points during loading. Transfer lengths were calculated using these mounted strain measuring points. Transfer length measurements were calculated at the plant, immediately after the application of prestressing forces to the concrete Ties. After the casting process, two Ties for each reinforcement type were stored at plant location for approximately one year and the remaining two Ties (companion Ties) for the each reinforcement types were shipped and stored at Kansas state university. Transfer length measurements were again calculated at this stage for all 48 Ties. Ties stored at plant location were later subjected to cumulative in-track Railroad loading of 85 million gross tons over six (6) months period of time. Whereas, the companion Ties stored at Kansas state university were not subjected to any loading. Transfer lengths are calculated and compared at this stage and presented [4] in the past.Ties which were already subjected to 85 million gross tons were further loaded to cumulative total of 236.3 million gross tons and the companion Ties stored at Kansas State University were not subjected to any loading. Transfer lengths for the Ties (twenty four) that were subjected 263.3 million gross tons were calculated and presented in this paper with detailed explanation. Transfer length behavior under different magnitudes of loading is also presented along with the discussion.Copyright © 2016 by ASME

  • Suitability and Variability of Non-Destructive Testing Methods for Concrete Railroad Tie Inspection
    2016 Joint Rail Conference, 2016
    Co-Authors: Aref Shafiei, B. Terry Beck, Aaron A. Robertson, Robert J. Peterman, Kyle A Riding, Chris Christensen, Chih-hang John Wu
    Abstract:

    Concrete Railroad Ties have been used in increasing numbers in the U.S., particularly in high-speed rail, heavy-haul freight lines, and new track construction because of their reduced deflections, durability, and competitive cost. In-track assessment of concrete Railroad Ties can be a challenge, however because many exterior tie surfaces are covered by tie pads and rail or ballast. This damage may include concrete section wear from abrasion, cracking, or crumbling, or other types of defects. Damage internal to the concrete can also not be seen visually. The time and cost needed to inspect these tie surfaces means that it is not routinely performed. Non-destructive testing offers promise as a way to assess concrete tie integrity without having to remove ballast, however more information is needed to know how well non-destructive techniques work in detecting damage. Two of the most promising techniques for investigating the integrity of concrete non-destructively are ultrasonic pulse velocity and impact-echo. Ultrasonic pulse velocity (UPV) and Impact-echo (IE) were applied to investigate the uniformity of concrete Railroad tie and its caviTies, cracks and defects for concrete Ties taken from track after service. This paper evaluated the variability of the test results in UPV and IE testing condition in which two concrete Railroad Ties with same manufacture and load history condition were tested in both methods. Two additional concrete Ties with the same manufacture and load history as each other with visible longitudinal cracks were also examined to see how the damage affected the variability measured. For this purpose, wave pulse for every full length tie from full top, half top, longitude and two sides were measured using ultrasonic pulse (ASTM C597). Also, thickness of concrete Ties on both sides, including rail seat location and the middle were assessed by standard tests method for measuring the p-wave speed and the thickness of concrete using the impact-echo method (ASTM C1383). Advice is given on how to interpret ultrasonic pulse velocity and impact-echo measurements and given the variability of the test method how to flag Ties for potential deterioration given that most Ties in service will not have initial measurements taken before damage for comparison.Copyright © 2016 by ASME

  • Experimental Investigation of the Influence of Surface Contaminants on the Transfer Length of Smooth and Indented Prestressing Reinforcements Used in the Manufacture of Concrete Railroad Ties
    2015 Joint Rail Conference, 2015
    Co-Authors: B. Terry Beck, Robert J. Peterman, Chih-hang John Wu, Steve Mattson
    Abstract:

    It has been hypothesized that surface contaminants, such as lubricants on prestressing wires or strands, influence the resulting transfer length. However, until recently, the extent of this possible influence has only been speculation, as has been the relative influence on wire in comparison to strand. With the recent development of the ability to rapidly assess transfer length using new non-contact optical methods, it is now possible to explore hypothetical scenarios such as this with nearly real-time capability in the manufacturing plant.This paper presents a recent attempt to determine the effect of lubricating oil on the transfer length of Ties, by conducting nearly real-time in-plant transfer length measurements using a newly developed prototype multi-camera non-contact transfer length measurement system. The testing was conducted on prismatic concrete turnout Ties manufactured at the Nortrak plant in Cheyenne, Wyoming. Two different types of turnout Ties were investigated, one containing indented 5.32-mm-diameter wire reinforcement and the other containing 3/8-in.-diameter 7-wire strand. These Ties were located near the end of the casting bed. Prior to casting, one end of the form was sprayed with a generic lubricant, literally saturating the prestressing wires or strands. The Ties were then cast and de-tensioned following the normal manufacturing process. This clearly represented a highly worst-case scenario for the influence of surface contaminants.Measurements were made using the new multi-camera system, providing a detailed profile of surface strain over several feet along each end of the last three Ties in the casting beds (one for strand and one for wire) — the last tie being the one subjected to the application of oil prior to casting. Hence, the influence of oil application on adjacent Ties was also revealed by these tests. For the tie end with strand reinforcement subjected to oil soaking, the maximum compressive strain only reached about 400 microstrain, far below the nominal average maximum strain level of approximately 1000 microstrain. In fact, the associated transfer length for the oil-soaked end could not be definitively measured because the strain level never achieved the plateau level of strain. In contrast, the tie end with oil-soaked indented wire exhibited a significant increase in transfer length; however, the transfer length remained well below the distance to the rail seat. From these worst-case tests, one can conclude that smooth strand is potentially highly influenced by lubricating oils, whereas the influence on indented wire is likely small by comparison.Copyright © 2015 by ASME

  • transfer length measurements in pretensioned concrete Railroad Ties under rail loads
    2015 Joint Rail Conference, 2015
    Co-Authors: Terry B Beck, Naga Narendra B. Bodapati, Robert J. Peterman, Amir Farid Momeni, Chih-hang John Wu
    Abstract:

    During January 2013, concrete Railroad Ties were cast at a tie manufacturing plant with fifteen different reinforcement types that are widely employed in manufacturing of Railroad Ties worldwide. Among these reinforcements; there were 12 different 5.32 mm diameter wires with various surface indent geometries, two different 7-wire strands with 3/8-inch diameter, and one 3-wire strand with 5/16-inch diameter. Four concrete Ties were cast for each reinforcement type for a total of 60 concrete Ties. Among the four Ties for each reinforcement type, two Ties were installed in track and subjected to a cumulative in-track loading of 85 million gross tons (MGT). Before being subjected to this loading, special surface preparation was done on the Ties to protect the strain measuring points on the bottom surface of the Ties from surface abrasion during loading. The other two Ties, which are companion Ties for each reinforcement type, were not subjected to any loading. Surface strains of concrete Railroad Ties were measured at three different stages after prestress transfer: immediately after prestress transfer, one year after prestress before Ties subjected to loading (January 2014), and after half of the Ties were subjected to 85 million gross tons loading (August 2014). Transfer lengths were calculated at all these stages from the measured surface strain values and are presented here. Transfer length results are compared between the Ties subjected to loading and the Ties not subjected to loading, along with detailed explanation of results.Copyright © 2015 by ASME

Robert J. Peterman - One of the best experts on this subject based on the ideXlab platform.

  • Evaluation of Splitting Crack Propagation in Pre-Stressed Concrete Ties Made With Different Types of Coarse Aggregate
    2019 Joint Rail Conference, 2019
    Co-Authors: Aref Shafiei Dastgerdi, Kyle A Riding, Robert J. Peterman, Adrijana Savic, B. Terry Beck
    Abstract:

    Pre-stressed concrete Railroad Ties must meet requirements during service life. Using pre-stressed wires in concrete members enhances load-carrying capacity of concrete Ties. It is important to ensure that pre-stressed forcing is introduced well before rail seat where the high impact load is applied. The required length of wire to fully transfer pretension forcing to concrete member is referred as transfer length. In order to shorten the transfer length, wires with improved indentation are used. As the transfer length is shortened, the high amount of stress concentration at the interface of wire-concrete can lead to longitudinal splitting cracks in concrete Railroad Ties. Splitting crack can occur either right after de-tensioning or during service life. It has been observed that concrete properTies and components can highly affect crack formation and propagation. In this research, the effect of coarse aggregate on the splitting cracks of concrete Railroad Ties was investigated. To assess the impact of coarse aggregate features on splitting crack performance, fracture toughness test was done on three-point bend prisms. The specimens were made of four different coarse aggregate including crushed aggregate and well-rounded aggregate. It was observed that angularity and coarseness of aggregate increases the fracture toughness of concrete by 20%. Then, the same mixes were used in fabrication of pre-stressed prisms with different cover length to evaluate actual performance of splitting cracks after de-tensioning. The wires were tensioned up to 7000 Ib per wire and de-tensioned when concrete strength of 4500 psi is reached. The results of crack area/length of splitting cracks showed that increasing angularity can significantly improve splitting cracks resistance.

  • material characteristics evaluation of existing pre stressed concrete Railroad Ties after service period
    2018 Joint Rail Conference, 2018
    Co-Authors: Aref Shafiei Dastgerdi, Robert J. Peterman, Kyle A Riding, Terry B Beck
    Abstract:

    As an important element in track, pre-stressed concrete Railroad Ties in the high-speed rail industry must meet the safety and performance specifications of high-speed trains. Systematic destructive and non-destructive evaluation of existing concrete Ties can lead to a better understanding of the effect of prestressed concrete tie material design on performance and failure within their service life. It has been evident that environmental and climate conditions also have a significant impact on concrete Railroad Ties, causing various forms of deterioration such as abrasion and freeze-thaw damage. Understanding of the material characteristics that cause failure in different types of existing concrete Railroad Ties taken from different places is the main focus of this paper. Observing the current status and damages of Railroad Ties taken from track might give a correlation between the material characteristic and type of distress and cracking seen. Although it has been seen by previous works that effective factors such as air void system and material composition directly affect the performance of concrete Ties such as freeze-thaw, material evaluation of existing Ties after service life has not been addressed in previous publications. In this research, the authors have investigated the material characteristic such as aggregate and air-void system of existing pre-stressed concrete Railroad Ties taken from track. However, compressive and splitting tensile strength and fractured surface of samples cored from the Ties were acquired. In order to obtain the strength of concrete materials of existing Ties, six samples were cored from six different types of Ties taken from tracks across the U.S., according to ASTM C42-16, and tested using ASTM C39 and ASTM C496 methods. However, the concrete air-void system (ASTM C457) was measured on saw-cut samples extracted from the Ties to evaluate the influence air content and distribution on mechanical properTies of the Ties. Regarding the history and service life condition of the Ties, it seems that material properTies of the Ties effectively alter the performance of the Ties. Aggregate sources used at each location may have different properTies such as texture, angularity, and mineralogy, contributing either propagation or resistance in splitting cracking in concrete. Furthermore, the polished surface of samples extracted from the Ties show the uniformity and air void system in some Ties which demonstrate their superiority in terms of resistance to freeze-thaw damage. Considering the results of this research, comprehensive evaluation of material characteristics might give a better view of existing concrete Railroad Ties situation, providing a worthwhile background for future tie design considerations.Copyright © 2018 by ASME

  • Determining the Remaining Prestress Force in a Prestressed Concrete Crosstie
    2017 Joint Rail Conference, 2017
    Co-Authors: James D. Scott, B. Terry Beck, Aaron A. Robertson, Robert J. Peterman, Kyle A Riding, John Wu
    Abstract:

    The research presented herein focuses on determining the amount of internal prestressing force and bending resistance that is necessary to provide a durable long-term concrete Railroad tie. In order to accomplish this, the researchers conducted a systematic evaluation of existing concrete Ties that successfully withstood over 25 years of service in track. An experimental method for determining the remaining prestress force in these existing prestressed concrete Railroad Ties is currently under development.The Ties are first loaded in the upside-down orientation, with supports located at the rail seats, and two point loads applied at the center of the tie. A loading rate of 1,000 lb/min was used to initiate flexural cracking in the center of the tie. Once cracking was observed, the Ties underwent 200 cycles of loading to reduce the friction between the prestressing tendons and the concrete. When the cycling was completed, the existing crack was instrumented with an extensometer to measure the Crack Opening Displacement (COD). The Ties were loaded once more at 1,000 lb/min to develop a Load vs. COD relation.A systematic method of determining the load required to reopen the crack from the Load vs. COD relation is being developed using Ties cast at a manufacturing plant that were instrumented with internal vibrating-wire strain gages. Using the load required to reopen the crack, along with the known cross-sectional properTies at the center of the tie, the remaining prestress force is calculated through equilibrium of forces. This method allows for the determination of the remaining prestress force in a member with known section properTies to be obtained through load testing.Copyright © 2017 by ASME

  • comparison of transfer lengths in pretensioned concrete Railroad Ties subjected to different magnitudes of rail loads
    2016 Joint Rail Conference, 2016
    Co-Authors: Naga Narendra B. Bodapati, Robert J. Peterman, Terry B Beck, Chih-hang John Wu
    Abstract:

    In order to quantify the effect of different reinforcement types on transfer lengths, an extensive study was conducted with the selected group of twelve different reinforcement types. These reinforcements are extensively used to produce concrete Railroad Ties across the world. These employed twelve (12) different types are of 5.32 mm diameter wires with different surface indent geometries. A research team from Kansas state university visited a PCI certified concrete tie manufacturing plant during January 2013. During the plant visit, four (4) concrete Railroad Ties were cast for each reinforcement type for a total of 48 Ties. Considerable part of the study conducted at the plant was previously published by the authors. However for effective understanding, brief explanation of the tie manufacturing process will be presented in this paper. Strain measuring points were mounted on the bottom surface of a concrete Railroad tie during the casting process. Proper measures were taken to safeguard these strain measuring points during loading. Transfer lengths were calculated using these mounted strain measuring points. Transfer length measurements were calculated at the plant, immediately after the application of prestressing forces to the concrete Ties. After the casting process, two Ties for each reinforcement type were stored at plant location for approximately one year and the remaining two Ties (companion Ties) for the each reinforcement types were shipped and stored at Kansas state university. Transfer length measurements were again calculated at this stage for all 48 Ties. Ties stored at plant location were later subjected to cumulative in-track Railroad loading of 85 million gross tons over six (6) months period of time. Whereas, the companion Ties stored at Kansas state university were not subjected to any loading. Transfer lengths are calculated and compared at this stage and presented [4] in the past.Ties which were already subjected to 85 million gross tons were further loaded to cumulative total of 236.3 million gross tons and the companion Ties stored at Kansas State University were not subjected to any loading. Transfer lengths for the Ties (twenty four) that were subjected 263.3 million gross tons were calculated and presented in this paper with detailed explanation. Transfer length behavior under different magnitudes of loading is also presented along with the discussion.Copyright © 2016 by ASME

  • Performance of a Continuously Traversing 2-Camera Non-Contact Optical Strain Sensor for In-Plant Assessment of Prestressed Concrete Railroad Crosstie Transfer Length
    2016 Joint Rail Conference, 2016
    Co-Authors: B. Terry Beck, Aaron A. Robertson, Robert J. Peterman, Chih-hang John Wu
    Abstract:

    Accurate knowledge of transfer length has been shown to be crucial to the goal of maintaining continuous production quality in the modern manufacture of prestressed concrete Railroad Ties. Traditional manual laboratory methods, such as the conventional Whittemore method which requires the use of embedded reference points, are clearly not suitable for production operation or for use in reliable production quality-control.This paper presents the results of another advance in the development of automated transfer length measurement systems for practical in-plant operation. The new device offers a significant improvement over the previously successful automated Laser-Speckle Imaging (LSI) system developed by the authors. The earlier automated LSI strain measurement system has been modified to provide significantly improved optical resolution of longitudinal surface strain, with the ability to resolve longitudinal prestressed concrete crosstie surface strain without time-consuming special surface preparation. More importantly, the new system is also capable of making measurements of strain in a real-time “on-the-fly” manner over the entire distance range of interest on the tie associated with transfer length development. It features both a “jog” mode of operation, similar to its predecessor in which measurements of longitudinal surface strain are automatically captured in arbitrary spatial increments over the entire range of the computer-controlled traverse, and an “on-the-fly” mode in which measurements of longitudinal surface strain are captured without the need for stopping at each measurement location. This latter mode offers the potential of a much faster capture of the strain profile and should prove to be very beneficial for field testing and in-plant diagnostic applications.The performance of this new system is first demonstrated using a new calibrated step-wise uniform strain field setup which has been developed specifically for verification of this and other automated transfer length measurement systems. This verification system produces a calibrated step change in surface deflection, effectively subjecting the automated strain measurement system to an ideal step change in longitudinal strain for a given gauge length. In addition, the new automated system is demonstrated by conducting measurements of longitudinal surface strain on prestressed concrete crossTies in a manufacturing plant. For this latter experimental in-plant testing, strain measurements using the new system are also compared directly with those from the recently introduced 6-camera transfer length measurement system, as well as with the traditional Whittemore gauge measurements. The agreement between these independent measurement systems is remarkable, and it is shown to even be possible to discern differences in strain profile and associated transfer length between adjacent crossTies within a given casting bed. This new automated and high-resolution device should provide a very convenient and fast diagnostic tool for the manufacturer to quickly identify the need to modify production (e.g., concrete mix) if transfer length specifications fall out of desired range.Copyright © 2016 by ASME

Jeff Lloyd - One of the best experts on this subject based on the ideXlab platform.

  • optimization of thermal desorption conditions for recovering wood preservative from used Railroad Ties through response surface methodology
    Journal of Cleaner Production, 2018
    Co-Authors: Holly Lauren Haber, Jeff Lloyd, Nourredine Abdoulmoumine, Nicole Labbe
    Abstract:

    Abstract A statistical response surface methodology (RSM) using a central composite design (CCD) model was applied to identify the optimum thermal desorption conditions for maximum recovery of preservative from copper naphthenate (CuNap) treated wood and subsequent production of a high quality pyrolytic vapor from the thermally treated wood. From the designed experiment, 94% of the total preservative present in the Ties was desorbed at temperatures higher than 250 °C and residence times longer than 30 min. Elevating the temperature from 215 °C to 285 °C for 45 min residence time generated a weight loss of 12–36 wt%, an increase in higher heating value (HHV) from 20.1 to 21.9 MJ/kg, and a reduction of energy yield from 90.4 to 71.5% of the resulting thermally treated biomass. Pyrolysis at 450 °C of this material produced a vapor rich in sugars- and lignin-derived compounds. The predicted optimum conditions in terms of a maximum preservative recovery, minimum energy yield loss of the wood, and production of thermally treated biomass that generates a high proportion of sugars- and lignin-derived compounds during pyrolysis were found to be 265 °C and 51 min. Under these optimum conditions, the predicted maximum preservative recovery was 95% while the predicted thermally treated solid retained 77% of the original energy yield and produced high portions of levoglucosan and lignin-derived compounds during subsequent pyrolysis, similar to torrefied wood.

  • environmentally friendly process for recovery of wood preservative from used copper naphthenate treated Railroad Ties
    ACS Sustainable Chemistry & Engineering, 2017
    Co-Authors: Holly Lauren Haber, Jeff Lloyd, Nourredine Abdoulmoumine, Stephen C Chmely, Yagya N Regmi, Nicole Labbe
    Abstract:

    Removal of copper naphthenate (CN) from used wooden Railroad Ties was investigated to improve the commercial viability of this biomass as a fuel source and avoid alternative disposal methods such as landfilling. Bench-scale thermal desorption of organic preservative components from CN-impregnated Ties was followed by extraction of the copper fraction with ethylenediaminetetraacetic acid, 1-hydroxy ethylidene-1,1-diphosphonic acid, or 2,6-pyridine dicarboxylic acid (PDA). Naphthenic acid (NA) and carrier oil were recovered at desorption temperatures between 225 and 300 °C and could potentially be recycled to treat new Ties. The thermal treatment also mimicked torrefaction, improving the biomass properTies for use as a thermochemical conversion feedstock. Chelation with PDA, a biodegradable chelating agent, after desorption had the highest extraction efficiency of copper and other naturally present inorganics, extracting 100% of the copper from both the raw and 225 °C-treated samples. Optimized desorbed mat...

  • two step thermochemical process for adding value to used Railroad wood Ties and reducing environmental impacts
    ACS Sustainable Chemistry & Engineering, 2017
    Co-Authors: Adam Taylor, Jeff Lloyd, Nourredine Abdoulmoumine, Nicole Labbe
    Abstract:

    A two-step thermochemical process combining a thermal desorption at 250–300 °C and a pyrolysis at 500 °C of used creosote-treated wooden Railroad Ties was carried out to recover preservative and produce a high quality bio-oil and biochar. Under optimal temperature between 280 and 300 °C, high preservative removal efficiency (70–74%) was achieved with a high proportion of polycyclic aromatic hydrocarbons (PAHs, 80–82%) and a large portion of the original wood mass (67–70%) was retained. This thermally treated biomass had higher heating value (HHV; 19.9–20 MJ/kg) than the starting material. The physical properTies of the preservative, such as viscosity and density, and its toxic threshold against a common decay basidiomycete fungus were similar to those of commercially available P2-creosote. Pyrolysis of the thermally treated Ties produced bio-oils with lower water content and total acid numbers, and a higher amount of lignin-derived compounds than that of untreated Ties. Biochars derived from the thermally...

  • recovery of creosote from used Railroad Ties by thermal desorption
    Energy, 2016
    Co-Authors: Jeff Lloyd, Nourredine Abdoulmoumine, Nicole Labbe
    Abstract:

    Used creosote-treated wood Ties were thermally treated between 250 and 350 °C to recover preservative and upgrade the wood to provide an improved quality biomass for thermochemical processes. With thermal treatments ranging from 250 to 300 °C, the amounts of creosote, mostly consisting of polycyclic aromatic hydrocarbons (PAHs), recovered were from 47 to 79% of total creosote present in the used Ties. Thermal treatment at 350 °C recovered 97% of total PAH compounds. Larger amounts of PAHs with higher molecular weights (HMWs) and lower vapor pressures (LVP) were recovered at elevated temperatures. Temperature above 300 °C decomposed the wood matrix, with a mass loss ranging between 50 and 63 wt% and produced large amounts of light organics, anhydrosugars, and phenolic compounds that would contaminate the recovered creosote. Our study concluded that thermal treatment ranging between 275 and 300 °C would be preferred to recover preservative for recycling and improve the wood quality, i.e., high carbon content and caloric value, and low hazardous pollutants (creosote residues) for thermochemical processes such as pyrolysis or gasification. These findings suggest that the proposed approach could be a commercially viable and environmentally beneficial alternative to landfill for used Railroad Ties.

  • thermal desorption of creosote remaining in used Railroad Ties investigation by tga thermogravimetric analysis and py gc ms pyrolysis gas chromatography mass spectrometry
    Energy, 2016
    Co-Authors: Jeff Lloyd, Nicole Labbe
    Abstract:

    A two-step thermal process, an initial thermal treatment at mild temperature followed by a fast pyrolysis step, was investigated to recover wood preservatives and produce preservatives-free wood for production of high quality bio-oil from used creosote-treated Railroad Ties. During the initial thermal treatment at temperature of 280 °C for 10–30 min, the treated wood Ties underwent a 20–25% weight loss with energy yield (77–83%). Energy yield at 280 °C was lower than that at 200 and 250 °C (92–97%) but higher than that at the 300 °C (64–74%). Recovery level of creosote at 280 °C was comparable to that at 300 °C. Fast pyrolysis at 450 °C of the 280 °C-treated wood Ties produced high amount of levoglucosan and phenolic compounds with a traceable amount (1.7–1.9% of the total peak area) of creosote compounds.

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  • optimization of thermal desorption conditions for recovering wood preservative from used Railroad Ties through response surface methodology
    Journal of Cleaner Production, 2018
    Co-Authors: Holly Lauren Haber, Jeff Lloyd, Nourredine Abdoulmoumine, Nicole Labbe
    Abstract:

    Abstract A statistical response surface methodology (RSM) using a central composite design (CCD) model was applied to identify the optimum thermal desorption conditions for maximum recovery of preservative from copper naphthenate (CuNap) treated wood and subsequent production of a high quality pyrolytic vapor from the thermally treated wood. From the designed experiment, 94% of the total preservative present in the Ties was desorbed at temperatures higher than 250 °C and residence times longer than 30 min. Elevating the temperature from 215 °C to 285 °C for 45 min residence time generated a weight loss of 12–36 wt%, an increase in higher heating value (HHV) from 20.1 to 21.9 MJ/kg, and a reduction of energy yield from 90.4 to 71.5% of the resulting thermally treated biomass. Pyrolysis at 450 °C of this material produced a vapor rich in sugars- and lignin-derived compounds. The predicted optimum conditions in terms of a maximum preservative recovery, minimum energy yield loss of the wood, and production of thermally treated biomass that generates a high proportion of sugars- and lignin-derived compounds during pyrolysis were found to be 265 °C and 51 min. Under these optimum conditions, the predicted maximum preservative recovery was 95% while the predicted thermally treated solid retained 77% of the original energy yield and produced high portions of levoglucosan and lignin-derived compounds during subsequent pyrolysis, similar to torrefied wood.

  • environmentally friendly process for recovery of wood preservative from used copper naphthenate treated Railroad Ties
    ACS Sustainable Chemistry & Engineering, 2017
    Co-Authors: Holly Lauren Haber, Jeff Lloyd, Nourredine Abdoulmoumine, Stephen C Chmely, Yagya N Regmi, Nicole Labbe
    Abstract:

    Removal of copper naphthenate (CN) from used wooden Railroad Ties was investigated to improve the commercial viability of this biomass as a fuel source and avoid alternative disposal methods such as landfilling. Bench-scale thermal desorption of organic preservative components from CN-impregnated Ties was followed by extraction of the copper fraction with ethylenediaminetetraacetic acid, 1-hydroxy ethylidene-1,1-diphosphonic acid, or 2,6-pyridine dicarboxylic acid (PDA). Naphthenic acid (NA) and carrier oil were recovered at desorption temperatures between 225 and 300 °C and could potentially be recycled to treat new Ties. The thermal treatment also mimicked torrefaction, improving the biomass properTies for use as a thermochemical conversion feedstock. Chelation with PDA, a biodegradable chelating agent, after desorption had the highest extraction efficiency of copper and other naturally present inorganics, extracting 100% of the copper from both the raw and 225 °C-treated samples. Optimized desorbed mat...

  • two step thermochemical process for adding value to used Railroad wood Ties and reducing environmental impacts
    ACS Sustainable Chemistry & Engineering, 2017
    Co-Authors: Adam Taylor, Jeff Lloyd, Nourredine Abdoulmoumine, Nicole Labbe
    Abstract:

    A two-step thermochemical process combining a thermal desorption at 250–300 °C and a pyrolysis at 500 °C of used creosote-treated wooden Railroad Ties was carried out to recover preservative and produce a high quality bio-oil and biochar. Under optimal temperature between 280 and 300 °C, high preservative removal efficiency (70–74%) was achieved with a high proportion of polycyclic aromatic hydrocarbons (PAHs, 80–82%) and a large portion of the original wood mass (67–70%) was retained. This thermally treated biomass had higher heating value (HHV; 19.9–20 MJ/kg) than the starting material. The physical properTies of the preservative, such as viscosity and density, and its toxic threshold against a common decay basidiomycete fungus were similar to those of commercially available P2-creosote. Pyrolysis of the thermally treated Ties produced bio-oils with lower water content and total acid numbers, and a higher amount of lignin-derived compounds than that of untreated Ties. Biochars derived from the thermally...

  • recovery of creosote from used Railroad Ties by thermal desorption
    Energy, 2016
    Co-Authors: Jeff Lloyd, Nourredine Abdoulmoumine, Nicole Labbe
    Abstract:

    Used creosote-treated wood Ties were thermally treated between 250 and 350 °C to recover preservative and upgrade the wood to provide an improved quality biomass for thermochemical processes. With thermal treatments ranging from 250 to 300 °C, the amounts of creosote, mostly consisting of polycyclic aromatic hydrocarbons (PAHs), recovered were from 47 to 79% of total creosote present in the used Ties. Thermal treatment at 350 °C recovered 97% of total PAH compounds. Larger amounts of PAHs with higher molecular weights (HMWs) and lower vapor pressures (LVP) were recovered at elevated temperatures. Temperature above 300 °C decomposed the wood matrix, with a mass loss ranging between 50 and 63 wt% and produced large amounts of light organics, anhydrosugars, and phenolic compounds that would contaminate the recovered creosote. Our study concluded that thermal treatment ranging between 275 and 300 °C would be preferred to recover preservative for recycling and improve the wood quality, i.e., high carbon content and caloric value, and low hazardous pollutants (creosote residues) for thermochemical processes such as pyrolysis or gasification. These findings suggest that the proposed approach could be a commercially viable and environmentally beneficial alternative to landfill for used Railroad Ties.