Evaluation of In Situ Moisture Content at Long-Term Pavement Performance Seasonal Monitoring Program Sites

1999 ◽  
Vol 1655 (1) ◽  
pp. 118-126 ◽  
Author(s):  
Y. Jane Jiang ◽  
Shiraz D. Tayabji
Keyword(s):  
Moisture Content ◽  
Monitoring Program ◽  
Pavement Performance ◽  
Seasonal Monitoring

Use of Long Term Pavement Performance-Seasonal Monitoring Program Data to Develop and Validate a Generalized Regression Model to Predict the In-Situ Resilient Modulus of Subgrade Soils for Pavement Design and Evaluation

2020 ◽  
Vol 2674 (5) ◽  
pp. 673-684
Author(s):  
Mohamed Elshaer ◽  
Christopher DeCarlo ◽  
Wade Lein ◽  
Harshdutta Pandya ◽  
Ayman Ali ◽  
...  
Keyword(s):  
Prediction Model ◽  
Resilient Modulus ◽  
Monitoring Program ◽  
Pavement Design ◽  
Pavement Performance ◽  
Regression Approach ◽  
Seasonal Monitoring ◽  
Generalized Regression

Resilient modulus (Mr) is a critical input for pavement design as it is the main property used to evaluate the contribution of subgrade to the overall pavement structure. Considering this, practitioners need simple and accurate ways to determine the Mr of in-situ subgrade without the need for expensive and time-consuming testing. The objective of this study is to develop a generalized regression prediction model for in-situ Mr of subgrades, compare it with established prediction models, and assess the model’s predictions on pavement performance using the Mechanistic-Empirical Pavement Design Guide (Pavement ME). The prediction model was built using field data from 30 pavement sections studied in the Long Term Pavement Performance (LTPP) Seasonal Monitoring Program where backcalculated modulus from falling weight deflectometer testing, in-situ moisture contents, and subgrade material properties were considered in the model. Based on the results, it was found that liquid limit, plasticity index, WPI (the product of percent passing #200 and plasticity index), percent coarse sand, percent fine sand, percent silt, percent clay, moisture content, and their respective interactions were significant predictors of in-situ Mr values. The findings showed that the generalized regression approach was able to predict Mr more accurately than predictions from the Witczak model. To assess the application of the predictive model on pavement performance, three LTPP sections located in New York, South Dakota, and Texas were analyzed to predict the rutting performance based on Mr values obtained from the developed generalized prediction model and those obtained from the current Pavement ME model and then compared with rut depths measured in the field. The findings showed that, for coarse-grained subgrades that have a low degree of plasticity, the generalized regression model predicted rutting performance similar to the embedded Pavement ME model. For fine-grained subgrades, the developed model tends to predict lower rut depths which were closer to the field measured rut depths. Overall, the generalized regression approach was successfully applied to create a simple, practical, cost-effective and accurate Mr prediction model that can be used to estimate the stiffness of subgrades when designing and evaluating pavements.

Remote sensing of cyanobacterial blooms in Lake Champlain, USA

2013 ◽  
Vol 13 (5) ◽  
pp. 1402-1409
Author(s):  
Adam Trescott ◽  
Elizabeth Isenstein ◽  
Mi-Hyun Park
Keyword(s):  
Remote Sensing ◽  
Satellite Images ◽  
Monitoring Program ◽  
In Situ Monitoring ◽  
Cyanobacterial Blooms ◽  
Lake Champlain ◽  
Initiation And Propagation ◽  
Landsat 7

The objective of this study was to develop cyanobacteria remote sensing models using Landsat 7 Enhanced Thematic Mapper Plus (ETM+) as an alternative to shipboard monitoring efforts in Lake Champlain. The approach allowed for estimation of cyanobacteria directly from satellite images, calibrated and validated with 4 years of in situ monitoring data from Lake Champlain's Long-Term Water Quality and Biological Monitoring Program (LTMP). The resulting stepwise regression model was applied to entire satellite images to provide distribution of cyanobacteria throughout the surface waters of Lake Champlain. The results demonstrate the utility of remote sensing for estimating the distribution of cyanobacteria in inland waters, which can be further used for presenting the initiation and propagation of cyanobacterial blooms in Lake Champlain.

Using Time Series to Incorporate Seasonal Variations in Pavement Design

1996 ◽  
Vol 1539 (1) ◽  
pp. 33-43 ◽  
Author(s):  
Hesham A. Ali ◽  
Neville A. Parker
Keyword(s):  
Time Series ◽  
Structural Properties ◽  
Seasonal Variations ◽  
Monitoring Program ◽  
Statistical Technique ◽  
Pavement Design ◽  
Seasonal Monitoring ◽  
Program Data ◽  
Series Technique

Analysis of the seasonal monitoring program data of the long term pavement performance program indicated that some pavement structural properties often follow predictable seasonal patterns. Time series is a statistical technique that may be used to develop periodic functions to predict the values of such properties as a function of time. The application of time series technique in characterizing the seasonal variations of pavement structural properties as simulated functions is presented. In addition, the incorporation of such variations in both empirical and mechanistic-empirical methods of flexible pavement design is demonstrated. To this end, a computer program, seasonal variation in pavement design, was written to carry out the required calculations and to facilitate the comparison between empirical and mechanistic-empirical design methods.

scholarly journals In situ DNA fragmentation during the re-establishment of desiccation tolerance in germinated seeds of Cedrela fissilis Vell.

2019 ◽  
Vol 41 (2) ◽  
pp. 244-249
Author(s):  
Tathiana Elisa Masetto ◽  
José Marcio Rocha Faria
Keyword(s):  
Cell Death ◽  
Moisture Content ◽  
Dna Fragmentation ◽  
Desiccation Tolerance ◽  
Cell Injury ◽  
Tunel Staining ◽  
Long Term Storage ◽  
Germinated Seeds

Abstract: Dehydration is a necessary procedure prior to exposing seeds to long term storage, but this is associated with metabolism-linked injury mediated by cell injury. In order to assess cellular alterations during re-establishment of desiccation tolerance (DT) in C. fissilis germinated seeds and their relation to DNA damage, we verified the occurrence of DNA fragmentation through the TUNEL test and its evidence through the cytological analyses. To re-establish DT, germinated seeds were incubated for 72 h in polyethylene glycol (PEG, -2.04 MPa) before dehydration in silica gel (at 10% moisture content) followed by rehydration. The moisture content changes during the reestablishment of the desiccation tolerance was accomplished. (DT)TdT-dUPT terminal nick-end labeling (TUNEL) was used to assess rates of cell death. TUNEL staining was performed using Click-iT-TUNEL Alexa Flour imaging assay. The TUNEL test showed a consistent DNA fragmentation in the 2 and 5 mm long radicles. Moreover, nuclear and chromosomal alterations were observed in the 5 mm meristematic root cell cycle, contributing to the identification of diagnostic markers of cell death.

Calibration of Flexible Pavement Performance Equations for Minnesota Road Research Project

2003 ◽  
Vol 1853 (1) ◽  
pp. 134-142 ◽  
Author(s):  
David H. Timm ◽  
David E. Newcomb
Keyword(s):  
Field Performance ◽  
Calibration Procedure ◽  
Asphalt Pavements ◽  
Pavement Performance ◽  
Design System ◽  
Research Project ◽  
Pavement Distress ◽  
Performance Project

As mechanistic-empirical (M-E) pavement design gains wider acceptance as a viable design methodology, there is a critical need for a well-calibrated design system. Calibration of the pavement performance equations is essential to link pavement responses under load to observed field performance. A field calibration procedure for asphalt pavements that incorporates live traffic, environmental effects, observed performance, and in situ material characterization was developed. The procedure follows the M-E design process, iterating the transfer function coefficients until the performance equation accurately predicts pavement distress. Test sections from the Minnesota Road Research Project were used to demonstrate the calibration process, and fatigue and rutting performance equations were developed. It is recommended that further calibration studies be undertaken with this methodology, possibly by using sections from the Long-Term Pavement Performance project.

scholarly journals RELATING FLEXIBLE PAVEMENT ACCEPTANCE CRITERIA TO PERFORMANCE USING MEPDG SIMULATIONS AND PIECEWISE CUBIC SPLINE INTERPOLATION / LANKSČIŲJŲ DANGŲ ATRANKOS KRITERIJŲ SUSIEJIMAS NAUDOJANT MEPDG MODELIUS IR DALINĘ KUBINĘ SPLAININĘ INTERPOLIACIJĄ

2012 ◽  
Vol 18 (1) ◽  
pp. 125-132 ◽  
Author(s):  
Anshu Manik ◽  
Karim Chatti ◽  
Kasthurirangan Gopalakrishnan
Keyword(s):  
Spline Interpolation ◽  
Fatigue Cracking ◽  
Flexible Pavement ◽  
Pavement Performance ◽  
Air Voids ◽  
Field Investigations ◽  
The Relationship

The performance of the highway system is inevitably linked to its quality of design and construction. To control the quality of construction, elaborate Quality Assurance (QA) programs have been developed by highway agencies based on statistical sampling and acceptance procedures to ensure that the work is in accordance with the plans and specifications. The QA procedure is intended to ensure that the constructed pavement would perform well during its design life. However, numerous field investigations and research studies over the years have identified a gap in our understanding of the relationship between the QA test results and pavement performance (fatigue cracking, rutting, etc.). This paper is intended to present the framework for developing an understanding of the relationship between QA tests and flexible pavement performance, which is essential for developing Performance Related Specifications (PRS). In the first part of the paper, the Michigan Department of Transportation's (MDOT) QA program and Long-Term Pavement Performance (LTPP) databases were used to empirically investigate any relationship between key QA variables and various pavement performance measures. In the second part of the paper, the Mechanistic-Empirical Pavement Design Guide (MEPDG) software was used together with an accurate and efficient interpolation technique to develop many simulations for the purpose of showing the effect of variability in QA parameters including plant air voids, in-situ density and asphalt content on flexible pavement performance. Santrauka Greitkelių sistemos darbas (funkcionavimas) yra neišvengiamai susijęs su jo projektavimo ir statybų kokybe. Greitkelių agentūros, remdamosi statistinėmis atrankos ir ėmimo procedūromis, parengė kokybės užtikrinimo (KU arba QA) programas, kad būtų kontroliuojama statybų kokybė ir užtikrinamas darbas pagal planus ir specifikacijas. KU (QA) procedūra siekiama užtikrinti, kad pagaminta danga gerai funkcionuotų projekte nurodytą laiką. Tačiau metams einant, atlikus daugybę natūrinių ir mokslinių tyrimų, buvo nustatytas didelis santykio tarp KU (QA) bandymų rezultatų ir dangos darbo (funkcionavimo) (plyšių atsiradimo dėl nuovargio, provėžų ir kt.) vertinimo skirtumas. Šiame darbe skatinama plėtoti supratimą apie ryšius tarp KU (QA) bandymų ir lanksčiųjų dangų funkcionavimo, kuris yra nepaprastai svarbus kuriant su darbu (funkcionavimu) susijusias specifikacijas (PRS). Pirmoje darbo dalyje buvo naudojamos Mičigano transporto departamento (MDOT) KU (QA) programos ir ilgalaikės dangos darbo (funkcionavimo) (LTPP) duomenų bazės, siekiant empiriškai ištirti bet kuriuos santykius tarp pagrindinių KU (QA) kintamųjų ir įvairių dangų darbo matavimų. Antroje darbo dalyje buvo naudojama mechanistinio ir empirinio dangų projektavimo vadovo (MEPDG) programinė įranga kartu su tikslia ir efektyvia interpoliacijos technika, siekiant sukurti modelius, kuriuose perteiktas KU (QA) parametrų kintamumo poveikis lanksčiųjų dangų funkcionavimui, įskaitant augalų oro ertmes, vietinį tankį ir asfalto sandarą.

Examination of moisture content variation within an operational wet deck

TAPPI Journal ◽  
2013 ◽  
Vol 12 (1) ◽  
pp. 45-50 ◽  
Author(s):  
LAURENCE SCHIMLECK ◽  
KIM LOVE-MYERS ◽  
JOE SANDERS ◽  
HEATH RAYBON ◽  
RICHARD DANIELS ◽  
...  
Keyword(s):  
Moisture Content ◽  
Southeastern United States ◽  
Forest Products ◽  
Time Domain Reflectometry ◽  
Water Application ◽  
Wood Moisture ◽  
International Paper ◽  
Content Variation ◽  
Moisture Variation

Many forest products companies in the southeastern United States store large volumes of roundwood under wet storage. Log quality depends on maintaining a high and constant wood moisture content; however, limited knowledge exists regarding moisture variation within individual logs, and within wet decks as a whole, making it impossible to recommend appropriate water application strategies. To better understand moisture variation within a wet deck, time domain reflectometry (TDR) was used to monitor the moisture variation of 30 southern pine logs over an 11-week period for a wet deck at the International Paper McBean woodyard. Three 125 mm long TDR probes were inserted into each log (before the deck was built) at 3, 4.5, and 7.5 m from the butt. The position of each log within the stack was also recorded. Mixed-effects analysis of variance (ANOVA) was used to examine moisture variation over the study period. Moisture content varied within the log, while position within the stack was generally not significant. The performance of the TDR probes was consistent throughout the study, indicating that they would be suitable for long term (e.g., 12 months) monitoring.

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