Topic
Falling weight deflectometer
About: Falling weight deflectometer is a research topic. Over the lifetime, 2082 publications have been published within this topic receiving 20465 citations. The topic is also known as: FWD.
Papers published on a yearly basis
Papers
Book•
1 Nov 1992
TL;DR: In this paper, the authors present the theory of pavement design and review the methods developed by several organizations, such as the American Association of State Highway and Transportation Officials (AASHTO), the Asphalt Institute (AI), and the Portland Cement Association (PCA).
Abstract: This is a textbook on the structural analysis and design of highway pavements. It presents the theory of pavement design and reviews the methods developed by several organizations, such as the American Association of State Highway and Transportation Officials (AASHTO), the Asphalt Institute (AI), and the Portland Cement Association (PCA). It can be used for an undergraduate course by skipping the appendices or as an advanced graduate course by including them. The book is organized in 13 chapters. Chapter 1 introduces the historical development of pavement design, the major road tests, the various design factors, and the differences in design concepts among highway pavements, airport pavements, and railroad trackbeds. Chapter 2 discusses stresses and strains in flexible pavements. Chapter 3 presents the KENLAYER computer program, based on Burmister's layered theory, including theoretical developments, program description, comparison with available solutions, and sensitivity analysis on the effect of various factors on pavement responses. Chapter 4 discusses stresses and deflections in rigid pavements due to curling, loading, and friction, as well as the design of dowels and joints. Influence charts for determining stresses and deflections are also presented. Chapter 5 presents the KENSLABS computer program, based on the finite element method, including theoretical developments, program description, comparison with available solutions, and sensitivity analysis. Chapter 6 discusses the concept of equivalent single-wheel and single-axle loads and the prediction of traffic. Chapter 7 describes the material characterization for mechanistic-empirical methods of pavement design including the determination of resilient modulus, fatigue and permanent deformation properties, and the modulus of subgrade reaction. Chapter 8 outlines the subdrainage design including general principles, drainage materials, and design procedures. Chapter 9 discusses pavement performance including distress, serviceability, skid resistance, nondestructive testing, and the evaluation of pavement performance. Chapter 10 illustrates the reliability concept of pavement design in which the variabilities of traffic, material, and geometric parameters are all taken into consideration. A probabilistic procedure, developed by Rosenblueth, is described and two probabilistic computer programs including VESYS for flexible pavements and PMRPD for rigid pavements are discussed. Chapter 11 outlines an idealistic mechanistic method of flexible pavement design and presents in detail the AI method and the AASHTO method, as well as the design of flexible pavement shoulders. Chapter 12 outlines an idealistic mechanistic method of rigid pavement design and presents in detail the PCA method and the AASHTO method. The design of continuous reinforced concrete pavements and rigid pavement shoulders is also included. Chapter 13 outlines the design of overlay on both flexible and rigid pavements including the AASHTO, AI, and PCA procedures. An Author Index and a Subject Index are provided.
3,005 citations
TL;DR: In this article, the characteristics and performance of dry and wet recycled concrete aggregate (RCA) as base and subbase materials for concrete pavement were investigated in terms of the moisture-density relationship, particle index, and fine aggregate angularity.
Abstract: This research presents the test results of a laboratory and field study performed to investigate the characteristics and performance of dry and wet recycled concrete aggregate (RCA) as base and subbase materials for concrete pavement. The physical properties of the RCA were investigated in terms of the moisture-density relationship, particle index, and fine aggregate angularity. Performance concerns have focused on compactibility, stability, shear resistance, and particle breakage of the RCA. These were evaluated in the laboratory using the U.S. Army Corps of Engineers Gyratory Testing Machine. The falling weight deflectometer was used to measure the deflection of pavement sections constructed with RCA base and subbase in the subbase material and may be comparable to crushed stone aggregate.
161 citations
TL;DR: The proposed neuro‐fuzzy model showed good generalization capability, and the evaluation of the model performance produced satisfactory results, demonstrating the efficiency and potential of these new mathematical modeling techniques.
Abstract: : Government agencies and consulting companies in charge of pavement management face the challenge of maintaining pavements in serviceable conditions throughout their life from the functional and structural standpoints. For this, the assessment and prediction of the pavement conditions are crucial. This study proposes a neuro-fuzzy model to predict the performance of flexible pavements using the parameters routinely collected by agencies to characterize the condition of an existing pavement. These parameters are generally obtained by performing falling weight deflectometer tests and monitoring the development of distresses on the pavement surface. The proposed hybrid model for predicting pavement performance was characterized by multilayer, feedforward neural networks that led the reasoning process of the IF-THEN fuzzy rules. The results of the neuro-fuzzy model were superior to those of the linear regression model in terms of accuracy in the approximation. The proposed neuro-fuzzy model showed good generalization capability, and the evaluation of the model performance produced satisfactory results, demonstrating the efficiency and potential of these new mathematical modeling techniques.
143 citations
TL;DR: The use of a portable lightweight deflectometer (LWD) for construction quality control or material investigation for earthworks and road construction is increasing around the world as mentioned in this paper, and the use of LWD is reviewed as a field evaluation tool, the test variables and data quality are discussed, and the usefulness and limitations for a variety of earthwork and road assessment scenarios are described.
Abstract: The use of a portable lightweight deflectometer (LWD) for construction quality control or material investigation for earthworks and road construction is increasing around the world LWD is reviewed as a field evaluation tool, the test variables and data quality are discussed, and the usefulness and limitations for a variety of earthwork and road assessment scenarios are described A state-of-the-art reference document is provided for LWD users, consultants, material specifiers, contractors, and clients Data from road foundations (subgrades, granular capping, and subbase) and fully constructed in-service (thinly surfaced) roads were reviewed to demonstrate the flexibility of the LWD and to show that its determination of stiffness modulus may differ from that of the conventional falling weight deflectometer to a varying extent A series of laboratory investigations was undertaken to demonstrate the sensitivity to uniformity of plate-surface contact and the limitations in the interpretation of peak displace
128 citations
TL;DR: The field measurements show a more considerable growth in stiffness than the laboratory tests, with a doubled value two years after construction, neither in the laboratory nor in the field.
108 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2025 | 18 |
| 2024 | 30 |
| 2023 | 54 |
| 2022 | 95 |
| 2021 | 60 |
| 2020 | 66 |