Pavement Rehabilitation Selection Based on Mechanistic Analysis and Field Diagnosis of Falling Weight Deflectometer Data: Virginia Experience

2000 ◽  
Vol 1730 (1) ◽  
pp. 177-186 ◽  
Author(s):  
Sameh Zaghloul ◽  
Mohamed Elfino
Keyword(s):  
Life Cycle Cost ◽  
Visual Inspection ◽  
Cost Savings ◽  
Cost Effective ◽  
Construction Cost ◽  
Rehabilitation Program ◽  
Falling Weight Deflectometer ◽  
Mechanistic Analysis ◽  
The Difference ◽  
Falling Weight

The effectiveness of using the field diagnosis and falling weight deflectometer (FWD) mechanistic analysis in reducing a 65-km (40-mi) segment of asphalt pavement to project level segments is discussed, along with selecting a cost-effective rehabilitation strategy. A mechanistic-based analysis was performed on the deflection basins measured from I-85 in Virginia to backcalculate the layer moduli. The 65-km segment was divided into structurally homogeneous sections based on the back-calculated layer moduli. The data of each homogeneous section were analyzed further to assess the in situ structural capacity, to identify weak layers, to estimate the remaining structural life, and to determine the current and future rehabilitation needs. It was found that some sections have almost no remaining structural life, and others have remaining structural life of more than 10 years. A comparison was made between the FWD–field diagnosis rehabilitation program and a visual inspection rehabilitation program. Results of the comparison indicated that the visual inspection rehabilitation program resulted in selecting thicker overlays for some of the project sections (overdesigned) and thinner overlays for the other sections (underdesigned). It is estimated that the difference between the FWD–field diagnosis rehabilitation program and the visual inspection rehabilitation program for the overdesigned sections is in the range of 45 percent of the construction cost (savings). Life-cycle cost analysis (LCCA) was performed to quantify the difference between the two rehabilitation programs for the underdesigned sections. Results of the LCCA indicated that the FWD–field diagnosis rehabilitation program would result in 26 percent and 42 percent reduction in the construction cost and user delay cost, respectively.

scholarly journals Optimization of emission reducing energy retrofits in Finnish apartment buildings

2019 ◽  
Vol 111 ◽  
pp. 03002 ◽  
Author(s):  
Janne Hirvonen ◽  
Juha Jokisalo ◽  
Juhani Heljo ◽  
Risto Kosonen
Keyword(s):  
Heat Pump ◽  
Life Cycle Cost ◽  
District Heating ◽  
Cost Savings ◽  
Cost Effective ◽  
Energy Performance ◽  
Heat Pumps ◽  
Apartment Buildings ◽  
Ground Source ◽  
Reduce Emissions

This study examined the cost-optimality of energy renovation on Finnish apartment buildings of different ages, built according to different energy performance requirements. Multi-objective optimization was utilized to minimize both CO2 emissions and life cycle cost (LCC). IDA-ICE simulations were performed to obtain the hourly heating demand of the buildings. Four building age classes and three heating systems (district heating, exhaust air heat pump and ground-source heat pump) were separately optimized. With district heating, it was possible to reduce emissions by 11%, while also reducing LCC. With heat pumps cost-savings could be achieved while reducing emissions by over 49%. With maximal (not cost-effective) investments, emissions could be reduced by more than 70% in all examined cases. In all cases, the cheapest solutions included solar electricity and sewage heat recovery. In old buildings, window upgrades and additional roof insulation were cost-effective. In new buildings, demand-based ventilation was included in all optimal solutions.

Estimation of tensile strains at the bottom of asphalt concrete layers under wheel loading using deflection basins from falling weight deflectometer tests

2012 ◽  
Vol 39 (7) ◽  
pp. 771-778 ◽  
Author(s):  
Jean-Pascal Bilodeau ◽  
Guy Doré
Keyword(s):  
Asphalt Concrete ◽  
Tensile Strain ◽  
Analysis Tool ◽  
Falling Weight Deflectometer ◽  
Proposed Model ◽  
Mechanistic Analysis ◽  
Pavement Engineering ◽  
Wheel Loading ◽  
Using Data ◽  
Falling Weight

The falling weight deflectometer is a pavement analysis tool that is now widely used in the pavement engineering field. Using the backcalculation process and the measured deflection basin, the layers moduli can be determined and a mechanistic analysis of the pavement can be made. A new approach is proposed to bypass the necessity of the backcalculation by allowing a direct estimation of the tensile strain at the bottom of asphalt concrete using the deflection basin. A model based on a finite element theoretical pavement analysis is proposed for this purpose. Complementary models have been developed to use the proposed models without having to determine the layers moduli. The proposed model to estimate the tensile strain at the bottom of the asphalt concrete layers is validated and calibrated using data obtained on an instrumented experimental site.

scholarly journals Fast Falling Weight Deflectometer Method for Condition Assessment of RC Bridges

2021 ◽  
Vol 11 (4) ◽  
pp. 1743
Author(s):  
Mauro Coni ◽  
Fausto Mistretta ◽  
Flavio Stochino ◽  
James Rombi ◽  
Mauro Sassu ◽  
...  
Keyword(s):  
Test Procedure ◽  
Cost Effective ◽  
Dynamic Force ◽  
Falling Weight Deflectometer ◽  
Annual Average Daily Traffic ◽  
Short Period ◽  
Cost Efficient ◽  
Action Measures ◽  
Falling Weight ◽  
The Impact

In this paper, the use of Fast Falling Weight Deflectometer (Fast-FWD) is analyzed as a non-destructive and quick test procedure to evaluate the efficiency of short-span bridges. The Fast-FWD is an instrument that can produce a broadband dynamic force up to an impact value of 120 KN: The impact is constant and replicable, providing accurate action measures of bridge stiffness in a truly short period (30 ms). In this paper, a single-span reinforced concrete bridge is investigated, using the Fast-FWD. The considered bridge, approximately 12.0 m long and 15.5 m wide, was in critical condition. The bridge is in a suburban principal road near to the City of Cagliari in Sardinia (Italy), with an Annual Average Daily Traffic of 13,500 vehicles/day, and was suddenly closed, creating serious problems for urban mobility. In these conditions, the investigation through other standard techniques is time-consuming and labor intensive. For this reason, it is important to introduce methods that can be rapid, accurate and cost-efficient. In this paper, bridge stiffness values obtained during the in situ experimental campaign were compared with finite element models values. The Fast-FWD has the potential to provide engineering information that can help us to better understand bridge condition, in a rapid and cost-effective procedure.

Static and Dynamic Backcalculation Analyses of an Inverted Pavement Structure

2013 ◽  
Vol 723 ◽  
pp. 196-203 ◽  
Author(s):  
James Maina ◽  
Wynand JvdM Steyn ◽  
Emile B. van Wyk ◽  
Frans le Roux
Keyword(s):  
South African ◽  
Maintenance Strategy ◽  
Falling Weight Deflectometer ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Back Calculation ◽  
The Difference ◽  
Falling Weight ◽  
Non Destructive ◽  
Crucial Part

A crucial part of any maintenance strategy is an intricate understanding of the material characteristics of the pavement, so that the current level of damage may be accurately assessed and an appropriate plan implemented. Advances in the precision to which these parameters can be determined, as well as improvements in how these results are interpreted under varying conditions of measurement and analysis, are essential in the effective execution of a maintenance strategy. Results from Falling Weight Deflectometer (FWD), which is a Non-Destructive Testing (NDT) device, can be used to predict elastic modulus of any layer by comparing measured deflection data to calculated values through an iterative process referred to as back-calculation. This paper presents a comparison between static and dynamic back-calculation procedures, specifically with regard to typical South African inverted pavements. The analysis indicates a dynamic analysis provides results of greater accuracy than a static analysis, although the effect of the difference requires further investigation.

Relationship between Backcalculated and Estimated Asphalt Concrete Dynamic Modulus with Respect to Falling Weight Deflectometer Load and Temperature

2020 ◽  
Vol 2674 (9) ◽  
pp. 887-897
Author(s):  
Nathan D. Bech ◽  
Julie M. Vandenbossche
Keyword(s):  
Asphalt Concrete ◽  
Dynamic Modulus ◽  
Falling Weight Deflectometer ◽  
Multiple Methods ◽  
Primary Methods ◽  
Overlay Design ◽  
The Difference ◽  
Binder Aging ◽  
Aging Models ◽  
Falling Weight

There are several methods for determining the stiffness of asphalt concrete in an existing pavement. The three primary methods are: dynamic modulus testing in the laboratory, predictive equations, and falling weight deflectometer (FWD) testing. Asphalt over asphalt (AC/AC) overlay design procedures allow the use of multiple methods to characterize fatigue damage in the existing asphalt concrete. Therefore, understanding the difference between these methods is critical for AC/AC overlay design. The differences between the methods for determining asphalt concrete stiffness and how these differences are related to FWD load magnitude and asphalt temperature are examined. Data from the Federal Highway Administration’s Long-Term Pavement Performance Program (LTPP) are used in this investigation. It is found that the stiffness determined through FWD testing and backcalculation is generally less than that estimated using the Witczak predictive equation and binder aging models. Furthermore, it is found that both FWD load magnitude and asphalt temperature have a significant effect on the difference between backcalculated and estimated stiffness of asphalt concrete. Backcalculated stiffness increases relative to estimated stiffness as FWD load and temperature increase. These effects must be considered when multiple methods of determining asphalt concrete stiffness are used interchangeably for overlay design.

Mineral/microfibrillated cellulose composite materials: High performance products, applications, and product forms

TAPPI Journal ◽  
2018 ◽  
Vol 17 (09) ◽  
pp. 507-515 ◽  
Author(s):  
David Skuse ◽  
Mark Windebank ◽  
Tafadzwa Motsi ◽  
Guillaume Tellier
Keyword(s):  
Composite Materials ◽  
High Performance ◽  
Aqueous Suspension ◽  
Production Capacity ◽  
Cost Savings ◽  
Cost Effective ◽  
New Materials ◽  
Wet Strength ◽  
Product Forms ◽  
Cellulose Composite

When pulp and minerals are co-processed in aqueous suspension, the mineral acts as a grinding aid, facilitating the cost-effective production of fibrils. Furthermore, this processing allows the utilization of robust industrial milling equipment. There are 40000 dry metric tons of mineral/microfbrillated (MFC) cellulose composite production capacity in operation across three continents. These mineral/MFC products have been cleared by the FDA for use as a dry and wet strength agent in coated and uncoated food contact paper and paperboard applications. We have previously reported that use of these mineral/MFC composite materials in fiber-based applications allows generally improved wet and dry mechanical properties with concomitant opportunities for cost savings, property improvements, or grade developments and that the materials can be prepared using a range of fibers and minerals. Here, we: (1) report the development of new products that offer improved performance, (2) compare the performance of these new materials with that of a range of other nanocellulosic material types, (3) illustrate the performance of these new materials in reinforcement (paper and board) and viscosification applications, and (4) discuss product form requirements for different applications.

Pound Wise and Penny Foolish? Weight Loss and The Dynamics of Health Care Spending

2011 ◽  
Vol 14 (2) ◽  
Author(s):  
Thomas G Koch
Keyword(s):  
Weight Loss ◽  
Cost Savings ◽  
Cost Effective ◽  
Economic Consequences ◽  
Health Care Spending ◽  
Order Of Magnitude ◽  
Dynamic Measures ◽  
The Cost ◽  
The Impact ◽  
The Relationship

Current estimates of obesity costs ignore the impact of future weight loss and gain, and may either over or underestimate economic consequences of weight loss. In light of this, I construct static and dynamic measures of medical costs associated with body mass index (BMI), to be balanced against the cost of one-time interventions. This study finds that ignoring the implications of weight loss and gain over time overstates the medical-cost savings of such interventions by an order of magnitude. When the relationship between spending and age is allowed to vary, weight-loss attempts appear to be cost-effective starting and ending with middle age. Some interventions recently proven to decrease weight may also be cost-effective.

Cost Avoidance and Clinical Benefits Derived from a Pharmacy-Managed Anemia Program

2000 ◽  
Vol 35 (2) ◽  
pp. 169-175 ◽  
Author(s):  
Robert A. Quercia ◽  
Ronald Abrahams ◽  
C. Michael White ◽  
John D'Avella ◽  
Mary Campbell
Keyword(s):  
Cost Savings ◽  
Cost Effective ◽  
Hemodialysis Patients ◽  
Cost Avoidance ◽  
Number Of Patients ◽  
Epoetin Alpha ◽  
Clinical Benefits ◽  
Unit Dose ◽  
One Year ◽  
Alpha Therapy

A pharmacy-managed anemia program included distribution and clinical components, with the goal of making epoetin alpha therapy for hemodialysis patients more cost-effective. The Pharmacy Department prepared epoetin alpha doses for patients in unit-dose syringes, utilizing and documenting vial overfill. Pharmacists dosed epoetin alpha and iron (oral and intravenous) per protocol for new and established patients. Baseline data were obtained in 1994, one year prior to implementation of the program, and were re-evaluated in 1995 and 1998. Cost avoidance from utilization of epoetin alpha vial overfill in 1995 and 1998 was $83,560 and $91,148 respectively. In 1995 and 1998, cost avoidance from pharmacy management of anemia was $191,159 and $203,985 respectively. The total cost avoidance from 1995 through 1998 was estimated at $1,018,638. The number of patients with hematocrits under 31% decreased from 32% in 1994 to 21% and 14% in 1995 and 1998 respectively. We conclude that a pharmacy-managed anemia program for hemodialysis patients results in significant cost savings and better achievement of target hematocrits.

The Future of Plasma-Based Surface Engineering Techniques in Tribology (Keynote)

2005 ◽  
Author(s):  
Allan Matthews ◽  
Adrian Leyland
Keyword(s):  
Surface Engineering ◽  
Performance Enhancement ◽  
Bulk Material ◽  
Cost Savings ◽  
Cost Effective ◽  
Ceramic Coatings ◽  
Performance Improvements ◽  
Treatment Techniques ◽  
Wide Range ◽  
Macro Scale

Over the past twenty years or so, there have been major steps forward both in the understanding of tribological mechanisms and in the development of new coating and treatment techniques to better “engineer” surfaces to achieve reductions in wear and friction. Particularly in the coatings tribology field, improved techniques and theories which enable us to study and understand the mechanisms occurring at the “nano”, “micro” and “macro” scale have allowed considerable progress to be made in (for example) understanding contact mechanisms and the influence of “third bodies” [1–5]. Over the same period, we have seen the emergence of the discipline which we now call “Surface Engineering”, by which, ideally, a bulk material (the ‘substrate’) and a coating are combined in a way that provides a cost-effective performance enhancement of which neither would be capable without the presence of the other. It is probably fair to say that the emergence and recognition of Surface Engineering as a field in its own right has been driven largely by the availability of “plasma”-based coating and treatment processes, which can provide surface properties which were previously unachievable. In particular, plasma-assisted (PA) physical vapour deposition (PVD) techniques, allowing wear-resistant ceramic thin films such as titanium nitride (TiN) to be deposited on a wide range of industrial tooling, gave a step-change in industrial productivity and manufactured product quality, and caught the attention of engineers due to the remarkable cost savings and performance improvements obtained. Subsequently, so-called 2nd- and 3rd-generation ceramic coatings (with multilayered or nanocomposite structures) have recently been developed [6–9], to further extend tool performance — the objective typically being to increase coating hardness further, or extend hardness capabilities to higher temperatures.

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