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Tillståndet hos vägöverbyggnader påverkas bland annat av förekomsten av vatten och fukt i vägkonstruktionen. Förekomst av vatten accelererar nedbrytningen av vägen och leder till dyra underhållskostnader. Forskningen har visat att betydande vägandelar behöver tidigarelägga underhållsåtgärder, oavsett trafikvolymen på grund av fuktrelaterade skador. Övervakning av fuktförhållanden i synnerhet med icke-förstörande och kontinuerliga metoder är därför bra att ha vid val av lämplig underhållsåtgärd. Dessutom är det värdefullt att känna till fukttillståndet i vägen för en mer korrekt bedömning av bärighetsmätningar med FWD (fallviktapparat) eller TSD (Traffic Speed Deflectometer), särskild under våren (upptiningsperiod). I denna studie används en flermottagande markradar (GPR) och en fallviktsdeflektometer för bedömning av fuktnivåer och strukturellt tillstånd för en fullskalig vägkonstruktion inomhus. Grundvattennivåer i vägkonstruktionen varierades genom tillförsel av vatten i testkonstruktionen. GPR-mätningarna rapporterar en relativ vattenhalt i testkonstruktionen. Resultaten visade en uppenbar korrelation mellan fallviktsmätningarna och de genomsnittliga GPR-hastighetsmätningarna för de undersökta testerna. Vidare forskning av andra GPR-parametrar, såsom frekvens, magnitud och amplitud för GPR-signalen, rekommenderas., Asphalt pavement performance is affected by the presence of water(moisture). Increased moisture within the road structure can result in substantial cost increase for the for society. Research have showed that significant portion of the road sections need early maintenance measures regardless of traffic volume due to moisture-related damages. Monitoring moisture conditions, preferably using a non-destructive continuous method, offers important information into the decision-making and selecting appropriate maintenance intervention. Furthermore, understanding moisture conditions is critical for accurately interpreting automatic road condition measurements, especially during the spring (thawing) when the roads exhibit the lowest load bearing capacity due to increased levels of moisture. This study employed a multi-receiver ground penetrating radar (GPR) and a falling weight deflectometer (FWD) devices to assess moisture levels and structural condition of field and indoor full-scale test roads. The groundwater level of the test road was varied by introducing water to the system. The results revealed an apparent correlation between the FWD and the average GPR velocity measurements. The GPR measurements provided a relative water content of the test roads. Further exploration of other GPR parameters, such as frequency, magnitude, and amplitude of the GPR signal is recommended., Mätning av fukt/vatten vid FWD mätningar och dess effekter på asfalten/Utilizing GPR and FWD for Pavement Structural Assessment and Moisture Detection

Tillståndet hos vägöverbyggnader påverkas bland annat av förekomsten av vatten och fukt i vägkonstruktionen. Förekomst av vatten accelererar nedbrytningen av vägen och leder till dyra underhållskostnader. Forskningen har visat att betydande vägandelar behöver tidigarelägga underhållsåtgärder, oavsett trafikvolymen på grund av fuktrelaterade skador. Övervakning av fuktförhållanden i synnerhet med icke-förstörande och kontinuerliga metoder är därför bra att ha vid val av lämplig underhållsåtgärd. Dessutom är det värdefullt att känna till fukttillståndet i vägen för en mer korrekt bedömning av bärighetsmätningar med FWD (fallviktapparat) eller TSD (Traffic Speed Deflectometer), särskild under våren (upptiningsperiod). I denna studie används en flermottagande markradar (GPR) och en fallviktsdeflektometer för bedömning av fuktnivåer och strukturellt tillstånd för en fullskalig vägkonstruktion inomhus. Grundvattennivåer i vägkonstruktionen varierades genom tillförsel av vatten i testkonstruktionen. GPR-mätningarna rapporterar en relativ vattenhalt i testkonstruktionen. Resultaten visade en uppenbar korrelation mellan fallviktsmätningarna och de genomsnittliga GPR-hastighetsmätningarna för de undersökta testerna. Vidare forskning av andra GPR-parametrar, såsom frekvens, magnitud och amplitud för GPR-signalen, rekommenderas., Asphalt pavement performance is affected by the presence of water(moisture). Increased moisture within the road structure can result in substantial cost increase for the for society. Research have showed that significant portion of the road sections need early maintenance measures regardless of traffic volume due to moisture-related damages. Monitoring moisture conditions, preferably using a non-destructive continuous method, offers important information into the decision-making and selecting appropriate maintenance intervention. Furthermore, understanding moisture conditions is critical for accurately interpreting automatic road condition measurements, especially during the spring (thawing) when the roads exhibit the lowest load bearing capacity due to increased levels of moisture. This study employed a multi-receiver ground penetrating radar (GPR) and a falling weight deflectometer (FWD) devices to assess moisture levels and structural condition of field and indoor full-scale test roads. The groundwater level of the test road was varied by introducing water to the system. The results revealed an apparent correlation between the FWD and the average GPR velocity measurements. The GPR measurements provided a relative water content of the test roads. Further exploration of other GPR parameters, such as frequency, magnitude, and amplitude of the GPR signal is recommended., Mätning av fukt/vatten vid FWD mätningar och dess effekter på asfalten/Utilizing GPR and FWD for Pavement Structural Assessment and Moisture Detection

To get the best performance of continuously reinforced concrete pavement (CRCP), the good quality of the base, materials used in the concrete mix, and the concrete pavement steel design play essential roles. Long-term performance of PCC pavement depends, to a large extent, on slab support. However, current quality assurance testing on the preparation and construction of subgrade and base layers is quite deficient, does not reflect the importance of slab support, and needs to be improved. In this study, the viability of deflection testing on stabilized base as a quality assurance testing was investigated. Deflection testing was conducted on top of stabilized base in four construction projects, and deflection data were analyzed to back-calculate subgrade k-values and base modulus. To develop a threshold deflection value on top of stabilized base, mechanistic analysis was conducted to estimate maximum deflections on stabilized base with various levels of modulus of subgrade reaction and base modulus. Deflection-based quality assurance testing for support layers in PCC pavement is a significant departure from traditional quality assurance testing. Also, there are some discrepancies between back-calculated (subgrade k-values and base modulus) and forward analysis (deflections) results, implying technical imperfections at this point. However, the advantages of the proposed protocol for quality assurance testing, including the speed of testing and resulting expanded coverage, outweigh the increase in cost. Implementation of the protocol is expected to improve PCC pavement performance. The performance of continuously reinforced concrete pavement (CRCP) in Texas has been quite satisfactory, primarily thanks to the continuous improvements in design and construction. However, severe spalling has been a major problem, and the Texas Department of Transportation (TxDOT) has sponsored several research projects since 1985 to identify solutions for this serious problem. Even though, Embargo status: Restricted until 09/2172. To request the author grant access, click on the PDF link to the left.

Our study summarizes findings from a long-term monitoring of pavement on selected road sections with lower traffic intensity. The research involved the comparison of resilient moduli as a design parameter of unbound pavement base layers’ unbound granular materials (UGMs), determined in a laboratory by a test device for a cyclical triaxial test and in situ by impact load test using a falling weight deflectometer (FWD). In particular, the resilient moduli determined in the laboratory by a cyclic triaxial test (Mr,CTT) were compared with the real values of resilient moduli measured by FWD (Mr,FWD). A new, unique, and innovative FWD device was used to determine the Mr,FWD of the UGMs. The innovation lay in the dual-axis deflection measurement—measurement performed not just in the axis parallel to the road, but also in the axis in the transversal direction., Studie shrnuje poznatky z dlouhodobého sledování vozovky na vybraných úsecích komunikací s nižší intenzitou dopravy. Výzkum zahrnoval porovnání modulů pružnosti jako návrhového parametru nestmelených materiálů pro podkladní vrstvy vozovky, stanovených v laboratoři zkušebním zařízením pro cyklickou triaxiální zkoušku a in situ zkouškou rázovým zatěžovacím zařízením (FWD). Konkrétně byly porovnány moduly pružnosti stanovené v laboratoři cyklickým triaxiálním testem se skutečnými hodnotami modulů pružnosti naměřenými FWD. K určení modulů pružnosti bylo použito nové, unikátní a inovativní zařízení FWD. Inovace spočívala ve dvouosém měření průhybu – měření prováděné nejen v ose rovnoběžné s vozovkou, ale také v ose v příčném směru.

Our study summarizes findings from a long-term monitoring of pavement on selected road sections with lower traffic intensity. The research involved the comparison of resilient moduli as a design parameter of unbound pavement base layers’ unbound granular materials (UGMs), determined in a laboratory by a test device for a cyclical triaxial test and in situ by impact load test using a falling weight deflectometer (FWD). In particular, the resilient moduli determined in the laboratory by a cyclic triaxial test (Mr,CTT) were compared with the real values of resilient moduli measured by FWD (Mr,FWD). A new, unique, and innovative FWD device was used to determine the Mr,FWD of the UGMs. The innovation lay in the dual-axis deflection measurement—measurement performed not just in the axis parallel to the road, but also in the axis in the transversal direction., Studie shrnuje poznatky z dlouhodobého sledování vozovky na vybraných úsecích komunikací s nižší intenzitou dopravy. Výzkum zahrnoval porovnání modulů pružnosti jako návrhového parametru nestmelených materiálů pro podkladní vrstvy vozovky, stanovených v laboratoři zkušebním zařízením pro cyklickou triaxiální zkoušku a in situ zkouškou rázovým zatěžovacím zařízením (FWD). Konkrétně byly porovnány moduly pružnosti stanovené v laboratoři cyklickým triaxiálním testem se skutečnými hodnotami modulů pružnosti naměřenými FWD. K určení modulů pružnosti bylo použito nové, unikátní a inovativní zařízení FWD. Inovace spočívala ve dvouosém měření průhybu – měření prováděné nejen v ose rovnoběžné s vozovkou, ale také v ose v příčném směru.

The central theme of this study is to identify strength-stiffness correlations for chemically treated subgrade soils in Indiana. This was done by conducting Unconfined Compression (UC) Tests and Resilient Modulus Tests for soils collected at three different sites—US-31, SR-37, and I-65. At each site, soil samples were obtained from 11 locations at 30 ft spacing. The soils were treated in the laboratory with cement, using the same proportions used for construction, and cured for 7 and 28 days before testing. Results from the UC tests were compared with the resilient modulus results that were available. No direct correlation was found between resilient modulus and UCS parameters for the soils investigated in this study. A brief statistical analysis of the results was conducted, and a simple linear regression model involving the soil characteristics (plasticity index, optimum moisture content and maximum dry density) along with UCS and resilient modulus parameters was proposed.

Resilient modulus (MR) is a key factor in the Mechanistic Empirical Pavement Design Guide (MEPDG) which was adopted by INDOT in January 2009. The resilient modulus can be determined in new pavement projects from subgrade soil samples collected at the site. However, for a pavement rehabilitation project, it becomes difficult to obtain soil information, and coring for samples may not be feasible because of traffic. The literature is rich with correlations between the MR of the subgrade obtained in the laboratory with that estimated from FWD tests in the field. However, the review conducted shows very contradictory and inconsistent findings, thus existing correlations seem to apply only to the cases investigated, i.e., they are ad hoc correlations and cannot be generalized. To improve the interpretation of the FWD data and enhance the reliability of the results in Indiana, FWD and GPR tests were performed at five different road construction projects at the same locations where soil samples were collected and tested in the laboratory for resilient modulus. The selected sites included roads with rigid pavement and treated subgrade and flexible pavement with untreated subgrade. The study showed that (1) FWD backcalculation is greatly affected by pavement thickness; (2) GPR can provide actual thicknesses and can identify discrepancies between as-built and design pavement thickness; (3) for flexible pavements, a one-to-one correlation exists between FWD modulus and laboratory resilient modulus values for untreated subgrade soils; (4) MODTAG or ELMOD codes can both be used to estimate the resilient modulus of the subgrade in flexible pavements; (5) for rigid pavements, results of FWD backcalculation analysis using ELMOD or MODTAG greatly overestimate the resilient modulus of the soil, with backcalculated moduli 1.3 to 6 times higher than laboratory results; (6) ELMOD is recommended for routine analysis of FWD data, while MODTAG is recommended for research or to evaluate the

Our study summarizes findings from a long-term monitoring of pavement on selected road sections with lower traffic intensity. The research involved the comparison of resilient moduli as a design parameter of unbound pavement base layers’ unbound granular materials (UGMs), determined in a laboratory by a test device for a cyclical triaxial test and in situ by impact load test using a falling weight deflectometer (FWD). In particular, the resilient moduli determined in the laboratory by a cyclic triaxial test (Mr,CTT) were compared with the real values of resilient moduli measured by FWD (Mr,FWD). A new, unique, and innovative FWD device was used to determine the Mr,FWD of the UGMs. The innovation lay in the dual-axis deflection measurement—measurement performed not just in the axis parallel to the road, but also in the axis in the transversal direction., Studie shrnuje poznatky z dlouhodobého sledování vozovky na vybraných úsecích komunikací s nižší intenzitou dopravy. Výzkum zahrnoval porovnání modulů pružnosti jako návrhového parametru nestmelených materiálů pro podkladní vrstvy vozovky, stanovených v laboratoři zkušebním zařízením pro cyklickou triaxiální zkoušku a in situ zkouškou rázovým zatěžovacím zařízením (FWD). Konkrétně byly porovnány moduly pružnosti stanovené v laboratoři cyklickým triaxiálním testem se skutečnými hodnotami modulů pružnosti naměřenými FWD. K určení modulů pružnosti bylo použito nové, unikátní a inovativní zařízení FWD. Inovace spočívala ve dvouosém měření průhybu – měření prováděné nejen v ose rovnoběžné s vozovkou, ale také v ose v příčném směru.

Our study summarizes findings from a long-term monitoring of pavement on selected road sections with lower traffic intensity. The research involved the comparison of resilient moduli as a design parameter of unbound pavement base layers’ unbound granular materials (UGMs), determined in a laboratory by a test device for a cyclical triaxial test and in situ by impact load test using a falling weight deflectometer (FWD). In particular, the resilient moduli determined in the laboratory by a cyclic triaxial test (Mr,CTT) were compared with the real values of resilient moduli measured by FWD (Mr,FWD). A new, unique, and innovative FWD device was used to determine the Mr,FWD of the UGMs. The innovation lay in the dual-axis deflection measurement—measurement performed not just in the axis parallel to the road, but also in the axis in the transversal direction., Studie shrnuje poznatky z dlouhodobého sledování vozovky na vybraných úsecích komunikací s nižší intenzitou dopravy. Výzkum zahrnoval porovnání modulů pružnosti jako návrhového parametru nestmelených materiálů pro podkladní vrstvy vozovky, stanovených v laboratoři zkušebním zařízením pro cyklickou triaxiální zkoušku a in situ zkouškou rázovým zatěžovacím zařízením (FWD). Konkrétně byly porovnány moduly pružnosti stanovené v laboratoři cyklickým triaxiálním testem se skutečnými hodnotami modulů pružnosti naměřenými FWD. K určení modulů pružnosti bylo použito nové, unikátní a inovativní zařízení FWD. Inovace spočívala ve dvouosém měření průhybu – měření prováděné nejen v ose rovnoběžné s vozovkou, ale také v ose v příčném směru.

Resilient modulus (MR) is a key factor in the Mechanistic Empirical Pavement Design Guide (MEPDG) which was adopted by INDOT in January 2009. The resilient modulus can be determined in new pavement projects from subgrade soil samples collected at the site. However, for a pavement rehabilitation project, it becomes difficult to obtain soil information, and coring for samples may not be feasible because of traffic. The literature is rich with correlations between the MR of the subgrade obtained in the laboratory with that estimated from FWD tests in the field. However, the review conducted shows very contradictory and inconsistent findings, thus existing correlations seem to apply only to the cases investigated, i.e., they are ad hoc correlations and cannot be generalized. To improve the interpretation of the FWD data and enhance the reliability of the results in Indiana, FWD and GPR tests were performed at five different road construction projects at the same locations where soil samples were collected and tested in the laboratory for resilient modulus. The selected sites included roads with rigid pavement and treated subgrade and flexible pavement with untreated subgrade. The study showed that (1) FWD backcalculation is greatly affected by pavement thickness; (2) GPR can provide actual thicknesses and can identify discrepancies between as-built and design pavement thickness; (3) for flexible pavements, a one-to-one correlation exists between FWD modulus and laboratory resilient modulus values for untreated subgrade soils; (4) MODTAG or ELMOD codes can both be used to estimate the resilient modulus of the subgrade in flexible pavements; (5) for rigid pavements, results of FWD backcalculation analysis using ELMOD or MODTAG greatly overestimate the resilient modulus of the soil, with backcalculated moduli 1.3 to 6 times higher than laboratory results; (6) ELMOD is recommended for routine analysis of FWD data, while MODTAG is recommended for research or to evaluate the

The central theme of this study is to identify strength-stiffness correlations for chemically treated subgrade soils in Indiana. This was done by conducting Unconfined Compression (UC) Tests and Resilient Modulus Tests for soils collected at three different sites—US-31, SR-37, and I-65. At each site, soil samples were obtained from 11 locations at 30 ft spacing. The soils were treated in the laboratory with cement, using the same proportions used for construction, and cured for 7 and 28 days before testing. Results from the UC tests were compared with the resilient modulus results that were available. No direct correlation was found between resilient modulus and UCS parameters for the soils investigated in this study. A brief statistical analysis of the results was conducted, and a simple linear regression model involving the soil characteristics (plasticity index, optimum moisture content and maximum dry density) along with UCS and resilient modulus parameters was proposed.

Objective of this paper is to discuss the state of art IGBT Gate driver design, which includes the different isolation techniques, compatibility with power device and advanced protections feature. As the industry pushes for higher power and higher switching frequencies power supplies, which use IGBTs for power conversion. Reference to this, IGBT gate drivers is being designed to their ultimate attainable efficiency, smallest footprint, size and weight. Design and development of the Gate driver relates to the expertise on the circuit design and power devices operating characteristics. The subject is vital in order to adopt the modern design for critical operation (i.e., Traction, Healthcare, Energy).

Objective of this paper is to discuss the state of art IGBT Gate driver design, which includes the different isolation techniques, compatibility with power device and advanced protections feature. As the industry pushes for higher power and higher switching frequencies power supplies, which use IGBTs for power conversion. Reference to this, IGBT gate drivers is being designed to their ultimate attainable efficiency, smallest footprint, size and weight. Design and development of the Gate driver relates to the expertise on the circuit design and power devices operating characteristics. The subject is vital in order to adopt the modern design for critical operation (i.e., Traction, Healthcare, Energy).

Objective of this paper is to discuss the state of art IGBT Gate driver design, which includes the different isolation techniques, compatibility with power device and advanced protections feature. As the industry pushes for higher power and higher switching frequencies power supplies, which use IGBTs for power conversion. Reference to this, IGBT gate drivers is being designed to their ultimate attainable efficiency, smallest footprint, size and weight. Design and development of the Gate driver relates to the expertise on the circuit design and power devices operating characteristics. The subject is vital in order to adopt the modern design for critical operation (i.e., Traction, Healthcare, Energy).

Objective of this paper is to discuss the state of art IGBT Gate driver design, which includes the different isolation techniques, compatibility with power device and advanced protections feature. As the industry pushes for higher power and higher switching frequencies power supplies, which use IGBTs for power conversion. Reference to this, IGBT gate drivers is being designed to their ultimate attainable efficiency, smallest footprint, size and weight. Design and development of the Gate driver relates to the expertise on the circuit design and power devices operating characteristics. The subject is vital in order to adopt the modern design for critical operation (i.e., Traction, Healthcare, Energy).

Objective of this paper is to discuss the state of art IGBT Gate driver design, which includes the different isolation techniques, compatibility with power device and advanced protections feature. As the industry pushes for higher power and higher switching frequencies power supplies, which use IGBTs for power conversion. Reference to this, IGBT gate drivers is being designed to their ultimate attainable efficiency, smallest footprint, size and weight. Design and development of the Gate driver relates to the expertise on the circuit design and power devices operating characteristics. The subject is vital in order to adopt the modern design for critical operation (i.e., Traction, Healthcare, Energy).

Penelitian ini bertujuan untuk menguji alat pengukur kelembaban dan pHÂ yang berbasis mikrokontroller menggunakan sensor ultrasonik untuk memudahkan pengeloaan limbah organik rumah tangga.Sistem ini terdiri dari beberapa komponen elektronik seperti LCD, Mikrokontroller, Sensor Ultrasonik yang dibangun menggunakan bahasa pemrograman bahasa C. Adapun metode penelitian yang digunakan dalam eksperimen ini adalah pengujian langsung alat. Hasil penelitian lama pencacahan terhadap 6 jenis limbah sejenis hemat waktu 58,6% dan 99,3% untuk limbah organik campuran dibanding pencacahan secara manual, dengan kecepatan 103 kg/jam. Kelembabab masing jenis limbah tomat memiliki kelembaban tertinggi 81%, sedangkan untuk uji pH tomat, kulit timun, kulit pisang bersifat masam.

FWD testing was completed on three urban arterial sections and six residential streets prior to and after rehabilitation to select the appropriate layout for FWD testing, establish joint performance threshold values, optimize FWD testing time and cost, and evaluate the effect of asphalt overlays on joint performance parameters. Moreover, the performance of full-depth repairs (FDR) and the incorporation of joint performance at the design stage were studied. Residential streets joint and basin FWD testing was completed to evaluate the structural capacity of residential streets and compare their performance to arterial regional roads. Comparisons between two widely used FWD geophones layouts allowed for the selection of a layout that represents the more critical loading condition on joints. Peak deflections and differential deflections were correlated with load transfer efficiencies to select threshold values for LTEs, peak deflections and differential deflections to trigger rehabilitation at the appropriate time. Statistical testing was used to optimize FWD testing to two load levels instead of four. The study found that asphalt overlays reduce recorded deflections and overestimate computed joints performance parameters. The effect of asphalt overlays was evaluated to establish correction factors, Fasphalt, for each load level to estimate deflections on the concrete surface using deflections obtained from testing on the overlay surface of Pembina Highway. The correction was found to improve the reliability of joint condition evaluation for that site. The study also found that FDRs generally restore the load transfer capacity of joints with good support and mechanical load transfer achieved. Moreover, it was demonstrated that joint performance information can be used at the design stage in the decision-making process to select the location and type of joint repairs. Lastly, residential streets were found to have less load transfer capacity than arterial regional roads

FWD testing was completed on three urban arterial sections and six residential streets prior to and after rehabilitation to select the appropriate layout for FWD testing, establish joint performance threshold values, optimize FWD testing time and cost, and evaluate the effect of asphalt overlays on joint performance parameters. Moreover, the performance of full-depth repairs (FDR) and the incorporation of joint performance at the design stage were studied. Residential streets joint and basin FWD testing was completed to evaluate the structural capacity of residential streets and compare their performance to arterial regional roads. Comparisons between two widely used FWD geophones layouts allowed for the selection of a layout that represents the more critical loading condition on joints. Peak deflections and differential deflections were correlated with load transfer efficiencies to select threshold values for LTEs, peak deflections and differential deflections to trigger rehabilitation at the appropriate time. Statistical testing was used to optimize FWD testing to two load levels instead of four. The study found that asphalt overlays reduce recorded deflections and overestimate computed joints performance parameters. The effect of asphalt overlays was evaluated to establish correction factors, Fasphalt, for each load level to estimate deflections on the concrete surface using deflections obtained from testing on the overlay surface of Pembina Highway. The correction was found to improve the reliability of joint condition evaluation for that site. The study also found that FDRs generally restore the load transfer capacity of joints with good support and mechanical load transfer achieved. Moreover, it was demonstrated that joint performance information can be used at the design stage in the decision-making process to select the location and type of joint repairs. Lastly, residential streets were found to have less load transfer capacity than arterial regional roads

Currently, Scania is not offering full air suspended AWD trucks, which it seems to be a demand for. This study acts as a first step to fulfill this demand. Including, a benchmarking of what competitors offer as well as an investigation and an evaluation of Scania’s current suspension system. Moreover, a requirement specification and a concept generation for a front air suspension system on AWD trucks have been presented. Eight concept were generated, where two were chosen for further study of design, force analysis and roll gradient analysis. It was concluded that there is a market for this configuration, however, implementing it would require extensive design work., I nuläget erbjuder inte Scania luftfjädring för samtliga hjulaxlar på AWD lastbilar, vilket det tycks finnas ett kundbehov av. Denna studie agerar som ett initialt steg till att uppfylla detta kundbehov. Studien inkluderar inledningsvis en analys av vad konkurrenter erbjuder samt en undersökning och utvärdering av Scanias nuvarande fjädringssystem. Utöver det, har en kravspecifikation och en konceptgenerering för främre luftfjädring på AWD lastbilar presenterats. Åtta stycken koncept genererades, varav två stycken valdes för vidare studie av design, kraftanalys samt krängstyvhetsanalys. Slutsatserna var att det finns en marknad för denna typ av konfiguration, dock skulle det behövas omfattande designarbete för att implementera det.

Currently, Scania is not offering full air suspended AWD trucks, which it seems to be a demand for. This study acts as a first step to fulfill this demand. Including, a benchmarking of what competitors offer as well as an investigation and an evaluation of Scania’s current suspension system. Moreover, a requirement specification and a concept generation for a front air suspension system on AWD trucks have been presented. Eight concept were generated, where two were chosen for further study of design, force analysis and roll gradient analysis. It was concluded that there is a market for this configuration, however, implementing it would require extensive design work., I nuläget erbjuder inte Scania luftfjädring för samtliga hjulaxlar på AWD lastbilar, vilket det tycks finnas ett kundbehov av. Denna studie agerar som ett initialt steg till att uppfylla detta kundbehov. Studien inkluderar inledningsvis en analys av vad konkurrenter erbjuder samt en undersökning och utvärdering av Scanias nuvarande fjädringssystem. Utöver det, har en kravspecifikation och en konceptgenerering för främre luftfjädring på AWD lastbilar presenterats. Åtta stycken koncept genererades, varav två stycken valdes för vidare studie av design, kraftanalys samt krängstyvhetsanalys. Slutsatserna var att det finns en marknad för denna typ av konfiguration, dock skulle det behövas omfattande designarbete för att implementera det.

Ground penetrating radar (GPR) has been one of the most potent nondestructive techniques used in the diagnosis of roads over the years. Nowadays GPR is mostly used for determining layer thicknesses. The falling weight deflectometer (FWD) technique, which is used for elastic moduli determination, is time-consuming, discontinuous, and requires traffic restrictions. Layer thickness information should be obtained through coring or project documentation. Recently, GPR and FWD techniques have been used in combination where layer thicknesses from GPR scans are used as an input for FWD measurements in order to back-calculate the elastic moduli of the layers. However, inferring mechanical properties from dielectric properties are seldom targeted for the combined use of these two nondestructive techniques. The specific objective of this paper is to determine the possible relationship of FWD pavement deflections and GPR data based on road test field surveys. The relationship between GPR and FWD data in compliance with mentioned assumptions and conditions is quantified. The authors believe that the described relationship confirms the usefulness and eligibility of using GPR in connection with FWD as a tool for predicting the mechanical properties of materials, hence facilitating road diagnostics and minimizing the demands for traffic restrictions., Ground penetrating radar (GPR) has been one of the most potent nondestructive techniques used in the diagnosis of roads over the years. Nowadays GPR is mostly used for determining layer thicknesses. The falling weight deflectometer (FWD) technique, which is used for elastic moduli determination, is time-consuming, discontinuous, and requires traffic restrictions. Layer thickness information should be obtained through coring or project documentation. Recently, GPR and FWD techniques have been used in combination where layer thicknesses from GPR scans are used as an input for FWD measurements in order to back-calculate the elastic moduli of the layers. However, inferring mechanical properties from dielectric properties are seldom targeted for the combined use of these two nondestructive techniques. The specific objective of this paper is to determine the possible relationship of FWD pavement deflections and GPR data based on road test field surveys. The relationship between GPR and FWD data in compliance with mentioned assumptions and conditions is quantified. The authors believe that the described relationship confirms the usefulness and eligibility of using GPR in connection with FWD as a tool for predicting the mechanical properties of materials, hence facilitating road diagnostics and minimizing the demands for traffic restrictions.

INDOT adopted the Mechanistic-Empirical Pavement Design Guide (MEPDG) beginning January 1, 2009, which is based on the FHWA Long Term Pavement Performance (LTTP) field study. The resilient modulus of the soil, MR, is required to implement the new design guide, as well as the pavement input parameters. The soil resilient modulus test requires special, expensive, equipment, significant time investment and effort, which has led researchers to develop MR prediction models and alternative methods to estimate the resilient modulus using non-destructive tests such as Falling Weight Deflectometer, FWD, Light Weight Deflectometer, LWD, and Dynamic Cone Penetrometer, DCP. The objectives of the project are geared toward a practical approach for pavement design procedures to effectively determine the soil resilient modulus for rehabilitation projects, targeting specifically untreated subgrade soils type A-6 and A-7-6. A total of four sites in Indiana were selected to conduct FWD, LWD, and DCP tests, as well as resilient modulus tests in the laboratory. In addition to the output from the four sites, additional data were collected from the data repository of INDOT which has geotechnical and pavement information. Extensive analysis and comparisons were done in an attempt at establishing relationships between the field tests and the laboratory results. The study showed the following: (1) high quality FWD tests conducted on top of the pavement can be used to estimate the subgrade MR, as long as site conditions and pavement layers thickness are well known; (2) the results of FWD tests on top of the subgrade are not reliable, as they are affected by the low confinement of the soils; and (3) LWD and DCP tests can be used to provide and assessment of the quality and uniformity of the subgrade, but do not provide reliable estimates of the stiffness of the subgrade.

INDOT adopted the Mechanistic-Empirical Pavement Design Guide (MEPDG) beginning January 1, 2009, which is based on the FHWA Long Term Pavement Performance (LTTP) field study. The resilient modulus of the soil, MR, is required to implement the new design guide, as well as the pavement input parameters. The soil resilient modulus test requires special, expensive, equipment, significant time investment and effort, which has led researchers to develop MR prediction models and alternative methods to estimate the resilient modulus using non-destructive tests such as Falling Weight Deflectometer, FWD, Light Weight Deflectometer, LWD, and Dynamic Cone Penetrometer, DCP. The objectives of the project are geared toward a practical approach for pavement design procedures to effectively determine the soil resilient modulus for rehabilitation projects, targeting specifically untreated subgrade soils type A-6 and A-7-6. A total of four sites in Indiana were selected to conduct FWD, LWD, and DCP tests, as well as resilient modulus tests in the laboratory. In addition to the output from the four sites, additional data were collected from the data repository of INDOT which has geotechnical and pavement information. Extensive analysis and comparisons were done in an attempt at establishing relationships between the field tests and the laboratory results. The study showed the following: (1) high quality FWD tests conducted on top of the pavement can be used to estimate the subgrade MR, as long as site conditions and pavement layers thickness are well known; (2) the results of FWD tests on top of the subgrade are not reliable, as they are affected by the low confinement of the soils; and (3) LWD and DCP tests can be used to provide and assessment of the quality and uniformity of the subgrade, but do not provide reliable estimates of the stiffness of the subgrade.

Most studies of stream wood have focused on pieces a parts per thousand yen0.1 m diameter. However, this approach may overlook an important feature of small streams, where wood < 0.1 m can constitute the majority of wood pieces. We examined the effect of fine wood (FW) on local drift of stream macroinvertebrates. The study was carried out at seven sites in four boreal forest streams, from early June to mid-August 2011. This was done by anchoring bundles of FW at each site and measuring drift upstream and downstream of each bundle. We hypothesized that FW would increase drift density, biomass and diversity of aquatic invertebrates. Ten weeks after FW addition, aquatic drift density was higher downstream than upstream of FW bundles, while drift biomass and drift diversity did not differ significantly downstream and upstream of FW.

The use of geogrids in granular pavement layers could increase the modulus and the stiffness of granular layer and hence the required layer thickness can be reduced. Though, geogrids are being used in granular pavements to provide lateral restraint, bearing capacity, and membrane tension support, very limited studies have been carried out to investigate the effects of geogrids on modulus and stiffness of granular layer. In this study, two sections of a granular pavement were constructed: one with a geogrid at the bottom of the base layer and the other without a geogrid. Two sections were then tested using Falling Weight Deflectometer (FWD) and FWD results were analysed to determine the effect of geogrid on the overall modulus and stiffness of the granular pavement. The results suggested that the pavement section with geogrid has higher overall modulus and deflection ratio compared to the pavement section without geogrid.

Falling weight deflectometer (FWD) and ground penetrating radar (GPR) are nondestructive test devices widely used by transportation agencies to assess pavement conditions. The two papers in this thesis evaluated the uncertainties associated with interpreting data from these devices and assessed potential applications. In the first paper, FWD tests were conducted on asphalt pavements with varying supporting conditions, and individual layer modulus values were estimated using forward-and back-calculation methods. Dynamic cone penetrometer (DCP) test device was used to independently measure individual layer penetration resistance (PR) values to compare with the estimate moduli values. Results indicated that the predicted subgrade moduli values from forward- and back-calculations are strongly correlated but produce slightly different values. The predicted asphalt and base layer moduli values from forward- and back-calculations, however, showed significant scatter. Comparison between DCP-PR and the predicted base and subgrade layer modulus yielded non-linear relationships. The relationships produced lower standard errors when only data from subgrade layer is considered. The relationships developed in this study fell within the upper and lower bounds of relationships documented in the literature. In the second paper, the efficacy of using a ground-coupled GPR system and a hand-held dielectric property measurement device to determine the asphalt and pavement foundation layer thicknesses is assessed. The actual pavement thicknesses were measured from pavement cores and foundation layer thicknesses were obtained using dynamic cone penetrometer (DCP) tests. Further, the viability of using GPR to detect moisture variations in the base layers is assessed. Tests were conducted on various asphalt pavement test sections built at a test site in Iowa with different foundation support and drainage conditions, and layer thicknesses. A comparative analysis of core measurements and asph

Nybyggnation och underhåll av skogsbilvägar medför stora kostnader för skogsbruket. Georadar (GPR) är en teknik som kan användas för att läsa av en vägs struktur vilket ger ett möjligt tillvägagångssätt för att reducera kostnader vid upprustning av vägar. Detta genom att endast partier med sämre bärighet rustas upp och därmed läggs rätt mängd material på rätt ställe längs vägen. Alternativet är dagens subjektiva bedömning av åtgärdsbehov och godtycklig placering av grusmängd. Syftet med denna studie var att kvantifiera skillnader i spårbildning mellan 100 %, 75 % samt 50 % påförd materialmängd i överbyggnaden av total rekommenderad materialmängd för att uppnå bärighet motsvarande vägklass 3B, samt hur spårbildning i vägkroppen påverkas av vältning. Grusmängden för överbyggnaden dimensionerades med ledning från data insamlade med GPR och fallviktsmätare. Analysen grundade sig på inventering av sex block med vardera tre sträckor (50 meter långa) samt en referenssträcka (30 meter lång), för vilka materielmängd samt behandling skiljde sig åt. Vägytan mättes dagligen inom blocken under en fem-dagarsperiod då vägen belastades av virkestransporter. Den skogsbilväg studien genomfördes på hade en undergrund av normalmorän. Ingen signifikant skillnad mellan vältade eller ovältade sträckor uppvisades. Inga signifikanta skillnader uppvisades heller mellan sträckorna med olika materialnivåer. Det maximala spårdjupet som registrerades uppgick till 87 mm, medelvärdet för spårbildningen var 23 mm. Dessa resultat tyder på att den materialmängd som påförs överbyggnaden vid upprustning av en väg kan reduceras, om vägen har en undergrund av normalmorän, utan att spårbildning vid trafikering blir besvärande vid förhållanden liknande de för denna studie. Detta innebär en stor teoretisk besparingspotential för SCA Skog, då den rådande rekommendationen för materialmängd för att uppnå B-bärighet är 1630 ton/km, vilket innebär en materialkostnad om ca 100 000 kr/km. Ytterligare studier krävs, Construction and maintenance of forest roads are costly for the forest industry. Ground Penetrating Radar (GPR) is a technique for reading the road structure, which is a possible approach to reduce the cost of road upgrades. This by simply placing gravel on stretches with lower bearing capacity, and thereby adding the right amount of material in the right place along the way. The alternative is today's subjective assessment of the need for action and arbitrary placement of gravel lot. The purpose of this study was to quantify differences in rutting between 100 %, 75 % and 50 % applied gravel amount on the superstructure. These amounts were based on the total recommended amount of material to achieve buoyancy corresponding to road bearing class 3B, and how rutting in the road structure is affected by overturning. Gravel amount for the superstructure was designed with guidance from the data collected with the GPR and a falling weight deflect meter. The analysis was based on the inventory of six blocks, each with three sections (50 meters long) and a reference section (30 meters long), where the road surface was measured daily for five days of timber load transport. The study was conducted on a subgrade of normal moraine No significant difference between overturned or not overturned distances where exhibited. Neither was significant differences demonstrated between sections with different material amounts. The maximum rut depth recorded was 87 mm; the mean of rutting was 23 mm. These results suggest that the amount of material applied to the superstructure at the improvement of a road can be reduced if the road has a subgrade of normal moraine, rutting was not troublesome for traffic on any section. This is a significant theoretical savings potential for SCA Skog, since the current recommendation for the amount of material to achieve the B-bearing capacity is 1630 tons / km, which means a material cost of approximately 100.000 SEK / km. Further studies are required to

The Oregon Department of Transportation (ODOT) is in the process of implementing the recently introduced AASHTO Mechanistic-Empirical Pavement Design Guide (MEPDG) for new pavement sections. However, the vast majority of pavement work conducted by ODOT involves rehabilitation of existing pavements. Hot mix asphalt (HMA) overlays are the preferred rehabilitation treatment for both flexible and rigid pavements in Oregon. However, like new work sections, HMA overlays are also susceptible to fatigue cracking (alligator cracking and longitudinal cracking), rutting, and thermal cracking. Additional work was therefore needed to calibrate the design process for rehabilitation of existing pavement structures. 38 pavement sections throughout Oregon were included in this calibration study. A detailed comparison of predictive and measured distresses was made using the MEPDG released software Darwin M-E (Version 1.1). It was found that Darwin M-E predictive distresses did not accurately reflect measured distresses, calling for a local calibration of performance prediction models was warranted. Four distress prediction models (rutting, alligator cracking, longitudinal cracking, and thermal cracking) of the HMA overlays were calibrated for Oregon conditions. A comparison was made between the results before and after the calibration to assess the improvement in accuracy of the distress prediction models provided by the local calibration. While the thermal cracking model could not be calibrated, the locally calibrated models of rutting, alligator cracking, and longitudinal cracking provided better predictions with lower bias and standard error than the nationally (default) calibrated models. However, there was a high degree of variability between the predicted and measured distresses, especially for longitudinal cracking, even after the calibration. It is believed that there is a significant lack-of-fit modeling error for the occurrence of thermal cracks. The Darwin M-E calibrated m

Today a newly built road has high standards on the bearing capacity; it should withstand the rigors of heavy traffic. To test the roads ability to cope with the oversized strain we use heavy and light weight case, static plate load or YPK (Wide area compaction control) as a control for bearing capacity. The method is used to measure the roads E-module, which is a measurement of the bearing capacity. To understand the term ”bearing capacity”, knowledge from other fields must be gathered. Fields such as geotechnology, road construction, packing, checking and deformation. In the current situation the roads are not optimized for its purpose along the entire route. This because the bearing capacity may be varied, which means that certain parts of the road can break before others. With an active design the road is constructed in places according to the bearing capacity. This results in a more even life expectancy of the entire route. A field trial was made during April of 2012 in Gislaved on the reconstruction of one existing road and a new development outside of Gislaved. Heavy weight case and plate loading tests was made on the sub base. The most emphasis was made on checking the bearing capacity and the degree of compaction in the roads construction to see if there is any connection between static plate load and heavy weight case. The test results was also used to conduct an active design of the road using a specialized computer program to calculate the thicknesses required for the bound material. Comparisons with the normal sections have shown that the road will cope with the set traffic load and that the active design contributes to a more even life expectancy along the entire route. An evaluation of old and new results have shown benefits with heavy weight case compared to using a plate load. Heavy fall weight is a fast and informative method of controlling bearing capacity and packing. Keywords: Bearing capacity, FWD, PLT, packing, checking and active design.

This report presents a mechanistic approach and procedures for determining layer coefficients to characterize the in-situ behaviors of rubblized pavements. This procedure was developed based on the 1993 AASHTO Pavement Design Guide utilizing Falling Weight Deflectometer (FWD) testing and in-place simulation using back-calculation layer modulus. In order to evaluate the rubblized pavement systematically, twelve constructed pavement sections were extensively tested by FWD annually after construction. The FWD data was processed using the proposed mechanistic procedure. In addition, statistical analysis was conducted to compare the pavement structure parameters each year, including layer coefficient and in-situ resilient modulus using Analysis of Variance (ANOVA) and Z-tests. In the ANOVA, the comparison of the structure capacities derived from the field FWD tests with those from the mechanistic procedure supports the null hypothesis, which concluded there is no difference between the structural numbers from these two methods. Also, statistically, the layer coefficients in each year are significantly different. The in-situ resilient moduli for each year varied significantly. The results from Z-test show that for Hot Mixed Asphalt (HMA) layers, the layer coefficient confidence interval could be as high as 0.70 and also as low as 0.38. For the base layers, the layer coefficient confidence interval could be as high as 0.25 and also as low as 0.16. A layer coefficient of 0.42 is recommended for HMA and 0.22 for rubblized layer for the design of HMA overlay on rubblized PCC pavement.

This report presents a mechanistic approach and procedures for determining layer coefficients to characterize the in-situ behaviors of rubblized pavements. This procedure was developed based on the 1993 AASHTO Pavement Design Guide utilizing Falling Weight Deflectometer (FWD) testing and in-place simulation using back-calculation layer modulus. In order to evaluate the rubblized pavement systematically, twelve constructed pavement sections were extensively tested by FWD annually after construction. The FWD data was processed using the proposed mechanistic procedure. In addition, statistical analysis was conducted to compare the pavement structure parameters each year, including layer coefficient and in-situ resilient modulus using Analysis of Variance (ANOVA) and Z-tests. In the ANOVA, the comparison of the structure capacities derived from the field FWD tests with those from the mechanistic procedure supports the null hypothesis, which concluded there is no difference between the structural numbers from these two methods. Also, statistically, the layer coefficients in each year are significantly different. The in-situ resilient moduli for each year varied significantly. The results from Z-test show that for Hot Mixed Asphalt (HMA) layers, the layer coefficient confidence interval could be as high as 0.70 and also as low as 0.38. For the base layers, the layer coefficient confidence interval could be as high as 0.25 and also as low as 0.16. A layer coefficient of 0.42 is recommended for HMA and 0.22 for rubblized layer for the design of HMA overlay on rubblized PCC pavement.

Nondestructive testing has become an integral part for evaluation and rehabilitation strategies of pavements in recent years. Pavement evaluation employing the Falling Weight Deflectometer (FWD) and the Ground Penetrating Radar (GPR) can provide valuable information about pavement performance characteristics and be a very useful tool for project prioritization purposes and estimation of construction budget at the network level. FWD deflection testing is an accurate tool for determining pavement structural capacity and estimating the required thickness of overlays and hence is an accurate tool for planning for or estimating required current and future construction budgets. GPR is the only tool that a highway agency may use to develop an inventory of pavement layers thicknesses in the most efficient manner possible. By estimating pavement layer thicknesses and stiffness properties more reliable projections of network rehabilitation strategies and needs can be established, thus resulting in cost effective use of available funds. Traditional obstacles for the use of FWD and GPR in pavement evaluation at the network level used to be expenses involved in data collection, limited resources and lack of simplified analysis procedures. This report presents Indiana experience in pavement evaluation with the FWD and GPR at the network level. A network level FWD and GPR testing program is implemented as a part of a study to overcome those traditional obstacles. This testing program included Interstate Highways I – 64, I – 65, I – 69, I – 70 and I – 74 and a number of U.S. Roads and State Routes. It is concluded that network level testing employing the FWD and GPR is a worthwhile, technically sound program that will provide a baseline of structural capacities of in–service pavements in Indiana. Periodical generation of necessary data will be useful for determining how best to quantify structural capacity and estimate annual construction budget. FWD data on 2200 lane miles of the

This study evaluated 18 pavement sections located in high-traffic highways in Virginia to find a premium pavement design with a life span of 40 years or more using current and past field experience. The selected pavement sections were thought to perform well. Eight flexible pavements, six composite pavements, two continuously reinforced concrete pavements, and two jointed plain concrete pavements were investigated. Field testing consisted of (1) falling weight deflectometer (FWD) testing to assess the structural capacity of the different pavements and to backcalculate the pavement layer materials' moduli, (2) ground-penetrating radar (GPR) scanning to determine layer thicknesses and to locate any abnormalities inside the pavements, (3) digital imaging to determine condition indices, (4) longitudinal profile measurements to calculate International Roughness Index, and (5) coring and boring to perform material characterization of pavement layers. Hot mix asphalt tests included resilient modulus and creep compliance. Concrete was tested for compressive strength. The analysis of the collected data suggests that premium pavement designs can be obtained. The field investigations suggest that all the tested sites are performing satisfactorily and show very low structural distress. Limited material-related problems were found at some sites, which induced non-load related distresses. It was also confirmed that FWD, GPR, and digital imaging are very useful tools to assess the condition of existing pavements. Since the three categories of pavements (flexible, composite, and rigid) were found to perform well, the study recommends that evaluation of other pavement sections, which are thought to perform in a less than optimal state, be conducted to define the causes of the less than desired performance. The selection of the most appropriate premium pavement design should be based on a detailed life-cycle cost analysis; hence, such analysis should be performed. Mechanistic empiric

This study evaluated 18 pavement sections located in high-traffic highways in Virginia to find a premium pavement design with a life span of 40 years or more using current and past field experience. The selected pavement sections were thought to perform well. Eight flexible pavements, six composite pavements, two continuously reinforced concrete pavements, and two jointed plain concrete pavements were investigated. Field testing consisted of (1) falling weight deflectometer (FWD) testing to assess the structural capacity of the different pavements and to backcalculate the pavement layer materials' moduli, (2) ground-penetrating radar (GPR) scanning to determine layer thicknesses and to locate any abnormalities inside the pavements, (3) digital imaging to determine condition indices, (4) longitudinal profile measurements to calculate International Roughness Index, and (5) coring and boring to perform material characterization of pavement layers. Hot mix asphalt tests included resilient modulus and creep compliance. Concrete was tested for compressive strength. The analysis of the collected data suggests that premium pavement designs can be obtained. The field investigations suggest that all the tested sites are performing satisfactorily and show very low structural distress. Limited material-related problems were found at some sites, which induced non-load related distresses. It was also confirmed that FWD, GPR, and digital imaging are very useful tools to assess the condition of existing pavements. Since the three categories of pavements (flexible, composite, and rigid) were found to perform well, the study recommends that evaluation of other pavement sections, which are thought to perform in a less than optimal state, be conducted to define the causes of the less than desired performance. The selection of the most appropriate premium pavement design should be based on a detailed life-cycle cost analysis; hence, such analysis should be performed. Mechanistic empiric

This study evaluated 18 pavement sections located in high-traffic highways in Virginia to find a premium pavement design with a life span of 40 years or more using current and past field experience. The selected pavement sections were thought to perform well. Eight flexible pavements, six composite pavements, two continuously reinforced concrete pavements, and two jointed plain concrete pavements were investigated. Field testing consisted of (1) falling weight deflectometer (FWD) testing to assess the structural capacity of the different pavements and to backcalculate the pavement layer materials' moduli, (2) ground-penetrating radar (GPR) scanning to determine layer thicknesses and to locate any abnormalities inside the pavements, (3) digital imaging to determine condition indices, (4) longitudinal profile measurements to calculate International Roughness Index, and (5) coring and boring to perform material characterization of pavement layers. Hot mix asphalt tests included resilient modulus and creep compliance. Concrete was tested for compressive strength. The analysis of the collected data suggests that premium pavement designs can be obtained. The field investigations suggest that all the tested sites are performing satisfactorily and show very low structural distress. Limited material-related problems were found at some sites, which induced non-load related distresses. It was also confirmed that FWD, GPR, and digital imaging are very useful tools to assess the condition of existing pavements. Since the three categories of pavements (flexible, composite, and rigid) were found to perform well, the study recommends that evaluation of other pavement sections, which are thought to perform in a less than optimal state, be conducted to define the causes of the less than desired performance. The selection of the most appropriate premium pavement design should be based on a detailed life-cycle cost analysis; hence, such analysis should be performed. Mechanistic empiric

Nondestructive testing has become an integral part for evaluation and rehabilitation strategies of pavements in recent years. Pavement evaluation employing the Falling Weight Deflectometer (FWD) and the Ground Penetrating Radar (GPR) can provide valuable information about pavement performance characteristics and be a very useful tool for project prioritization purposes and estimation of construction budget at the network level. FWD deflection testing is an accurate tool for determining pavement structural capacity and estimating the required thickness of overlays and hence is an accurate tool for planning for or estimating required current and future construction budgets. GPR is the only tool that a highway agency may use to develop an inventory of pavement layers thicknesses in the most efficient manner possible. By estimating pavement layer thicknesses and stiffness properties more reliable projections of network rehabilitation strategies and needs can be established, thus resulting in cost effective use of available funds. Traditional obstacles for the use of FWD and GPR in pavement evaluation at the network level used to be expenses involved in data collection, limited resources and lack of simplified analysis procedures. This report presents Indiana experience in pavement evaluation with the FWD and GPR at the network level. A network level FWD and GPR testing program is implemented as a part of a study to overcome those traditional obstacles. This testing program included Interstate Highways I – 64, I – 65, I – 69, I – 70 and I – 74 and a number of U.S. Roads and State Routes. It is concluded that network level testing employing the FWD and GPR is a worthwhile, technically sound program that will provide a baseline of structural capacities of in–service pavements in Indiana. Periodical generation of necessary data will be useful for determining how best to quantify structural capacity and estimate annual construction budget. FWD data on 2200 lane miles of the

The sealing and resealing of joints and cracks in PCC, HMA, and composite pavements is assumed to be an important component of pavement maintenance. Recently this practice has been challenged by research indicating that sealing may not be cost-effective. The Indiana Department of Transportation currently spends approximately four million dollars annually to perform joint/crack sealing. The primary objective of the research presented in this report is to investigate the costeffectiveness of joint/crack sealing in relation to pavement performance. The results of a mail survey showed that most states, including Indiana, do not have quantitative justification for sealing policies, nor do they know the cost-effectiveness of the operations. Based on the experimental design for this research, nineteen test sites were selected in Indiana, each site having one sealed section and one unsealed section. Collected data including falling weight deflectometer measurements, pavement roughness, visual condition surveys, and core samples were used to evaluate the pavement performance between sealed and unsealed sections. A three-dimensional finite element pavement model was developed to evaluate the test location effect on the load transfer measurements. The temperature effect was evaluated by statistical analyses and a temperature correction factor for deflections on asphalt pavement is provided. A statistical model was developed to compare the pavement performance between sealed and unsealed sections for three pavement types, PCC, HMA and composite. The results indicated that there appears to be no significant differences between the performance of sealed and unsealed sections regardless of pavement type, drainage condition and road classification.

The study has concentrated on residues in unbound road layers. The materials selected were processed municipal solid waste incinerator (MSWI) bottom ash, crushed concrete and air-cooled blast furnace slag (AcBFS). The deformation on loading the possible strength development over time and the resistance to mechanical and climatic action were studied in the laboratory and in the field The results were compared with those of the conventional aggregates they could possibly replace, such as sand, gravel and crushed rock. The methods used in the laboratory were cyclic load triaxial tests, Los Angeles tests, micro-Deval tests and freeze-thaw tests. In the field, test sections with residues and reference sections with conventional aggregates in the unbound layers were monitored by means of falling weight deflectometer (FWD) measurements.

The study has concentrated on residues in unbound road layers. The materials selected were processed municipal solid waste incinerator (MSWI) bottom ash, crushed concrete and air-cooled blast furnace slag (AcBFS). The deformation on loading the possible strength development over time and the resistance to mechanical and climatic action were studied in the laboratory and in the field The results were compared with those of the conventional aggregates they could possibly replace, such as sand, gravel and crushed rock. The methods used in the laboratory were cyclic load triaxial tests, Los Angeles tests, micro-Deval tests and freeze-thaw tests. In the field, test sections with residues and reference sections with conventional aggregates in the unbound layers were monitored by means of falling weight deflectometer (FWD) measurements.

Falling weight deflectometer (FWD) is currently used by most highway agencies to determine the structural condition of the highway network. Utilizing the deflections measured by the FWD, the resilient moduli of layers in the flexible pavement is determined using backcalculation software packages. The moduli can be input into semi-empirical mechanistic equations to estimate the remaining life of the pavement system and aid in informing pavement engineers about timing of maintenance and rehabilitation needs. There have been concerns among practitioners and the research community about the adequacy of the resilient moduli determined by the backcalculation software. Some of the backcalculation models have been simplified and field verification may be needed. Field-measured stresses and strains may be used to quantify the reliability of the backcalculated moduli. The Virginia Smart Road, which has 12 different flexible pavement designs and was built and instrumented with pressure cells, strain gages, thermocouples, frost probes and moisture sensors. To validate the backcalculated moduli theoretically and through instrument response, this research was conducted with following objectives: 1) to determine the resilient moduli of the unbound granular materials on the Virginia Smart Road using small and large plates of the FWD; 2) to investigate the extent of spatial and temporal variability of the FWD deflections among pavement sections; 3) to develop a temperature correction model for the backcalculated HMA resilient moduli; 4) to define an appropriate backcalculation approach and compare the four widely used software approaches; and 5) to correlate backcalculated and laboratory measured moduli. In addition, the FWD measurements were used to establish a comparison between in-situ measured and computed stresses and strains in the pavement. The analytical approaches used are linear elastic, viscoelastic, and viscoelastic combined with nonlinearity. Results show that estimatio

The sealing and resealing of joints and cracks in PCC, HMA, and composite pavements is assumed to be an important component of pavement maintenance. Recently this practice has been challenged by research indicating that sealing may not be cost-effective. The Indiana Department of Transportation currently spends approximately four million dollars annually to perform joint/crack sealing. The primary objective of the research presented in this report is to investigate the costeffectiveness of joint/crack sealing in relation to pavement performance. The results of a mail survey showed that most states, including Indiana, do not have quantitative justification for sealing policies, nor do they know the cost-effectiveness of the operations. Based on the experimental design for this research, nineteen test sites were selected in Indiana, each site having one sealed section and one unsealed section. Collected data including falling weight deflectometer measurements, pavement roughness, visual condition surveys, and core samples were used to evaluate the pavement performance between sealed and unsealed sections. A three-dimensional finite element pavement model was developed to evaluate the test location effect on the load transfer measurements. The temperature effect was evaluated by statistical analyses and a temperature correction factor for deflections on asphalt pavement is provided. A statistical model was developed to compare the pavement performance between sealed and unsealed sections for three pavement types, PCC, HMA and composite. The results indicated that there appears to be no significant differences between the performance of sealed and unsealed sections regardless of pavement type, drainage condition and road classification.