National Academies Press: OpenBook

Nondestructive Testing to Identify Delaminations Between HMA Layers, Volume 2 - Theoretical Models (2013)

Chapter: Chapter 4 - Theoretical Models for Mechanical Wave Technology: Deflection-Based Approach

« Previous: Chapter 3 - Theoretical Models for Mechanical Wave Technology: Impact Echo, Impulse Response, and Ultrasonic Surface Waves
Page 38
Suggested Citation:"Chapter 4 - Theoretical Models for Mechanical Wave Technology: Deflection-Based Approach." National Academies of Sciences, Engineering, and Medicine. 2013. Nondestructive Testing to Identify Delaminations Between HMA Layers, Volume 2 - Theoretical Models. Washington, DC: The National Academies Press. doi: 10.17226/22603.
×
Page 38
Page 39
Suggested Citation:"Chapter 4 - Theoretical Models for Mechanical Wave Technology: Deflection-Based Approach." National Academies of Sciences, Engineering, and Medicine. 2013. Nondestructive Testing to Identify Delaminations Between HMA Layers, Volume 2 - Theoretical Models. Washington, DC: The National Academies Press. doi: 10.17226/22603.
×
Page 39
Page 40
Suggested Citation:"Chapter 4 - Theoretical Models for Mechanical Wave Technology: Deflection-Based Approach." National Academies of Sciences, Engineering, and Medicine. 2013. Nondestructive Testing to Identify Delaminations Between HMA Layers, Volume 2 - Theoretical Models. Washington, DC: The National Academies Press. doi: 10.17226/22603.
×
Page 40

Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

38 Theoretical Models for Mechanical Wave Technology: Deflection-Based Approach The research presented in this chapter was carried out by Dr. Halil Ceylan and Dr. Sunghwan Kim at Iowa State University. Seismic waves move in different ways through and around the earth and are of two primary types (Wehausen and Laitone 2002): • Body waves 4 P-waves (primary waves or pressure waves or compres- sion waves); and 4 S-waves (secondary waves or shear waves), • Surface waves 4 Love waves; and 4 Rayleigh waves Seismic pavement nondestructive testing (NDT) uses surface wave propagation to estimate the structural properties (thick- ness and stiffness) of layered pavement systems (Rydén 2004). Dynamic Young’s modulus (E) and Poisson’s ratio (n) are directly calculated from measured seismic velocities by using fundamental relationships. Seismic NDT technology, based on the principle of generation and detection of stress waves, has been shown to produce relatively high-resolution modu- lus profiles compared to most pavement NDT methods. The introduction of the spectral analysis of surface waves (SASW) method (Nazarian 1984) has especially led to wide- spread acceptance of seismic pavement NDT methods and the development of standard field protocols (Nazarian et al. 1995). Two well-known automated seismic pavement NDT devices include the seismic pavement analyzer and the por- table seismic pavement analyzer (Nazarian 1984; Nazarian et al. 1993; Baker et al. 1995). Seismic pavement testing methods involve acquiring raw data on pavement surface, which are simply the time histories of the impact source and the surface deformation. These time records, which describe the pavement structure in terms of P-waves, S-waves, Rayleigh waves, and bending modes, can be analyzed in five different ways. Each of these five methods has its own strengths and limitations as shown in Table 4.1 (Yuan et al. 1999). The arrivals of compression, shear, and Raleigh waves are shown in Figure 4.1 for typical time records from two sensors placed 150 mm apart on a thick asphalt pavement. The dispersive nature of surface waves in a layered medium is used to assess the elastic moduli of pavement layers with the following procedure (see Figure 4.2): 1. Acquire data at the surface of a pavement (measured dis- persion curve). 2. Evaluate the measured experimental dispersion curve. 3. Evaluate shear wave velocity (Vs) with depth profile from the experimental dispersion curve through inverse analysis. Rydén et al. (2004) developed a multimodal approach to seismic pavement testing by using the complete phase veloc- ity spectrum instead of discrete dispersion waves, after con- cluding that the earlier techniques oversimplified the nature of wave propagation along the pavement surface. Rydén and Mooney (2009) conducted an experimental and numerical study to explore low-strain modulus extrac- tion from seismic waves during the lightweight deflectometer (LWD) test and demonstrated the usefulness of the LWD as a source for surface seismic measurements. Figure 4.3 displays the comparison of strain levels from surface waves by using the conventional small hammer source and the LWD source on soft subgrade (Rydén and Mooney 2009). C h a p t e r 4

39 Table 4.1. Pavement Properties Measured with Different Seismic Methodsa Method Primary Use Strength Weakness Time Record Analysis Modulus of top layer Rapid to perform Simple data reduction Results may be affected by underlying layers Sensitive to surface condition Ultrasonic Surface Waves (USW) Modulus of top layer Sensitive to properties of top layer Rapid to perform Layer specific results In manual mode, data reduction is complex Impact Echo (IE) Thickness of top layer or depth to delaminated interface Can determine thickness of the layer Sensitive to delaminated interfaces Substantial contrast between the modulus of two adjacent layers is needed to be effective For multicourse pavements, at least one core is needed for calibration Applies only to pavements with thicker top layer Impulse Response Modulus of subgrade reaction of foundation layers or overall modu- lus of a pavement Powerful tool for rapidly locating weak spots in a pavement May be used to estimate depth to stiff layer (in progress) For flexible pavements, the contributions of differ- ent layers are unknown Results are affected by depth to rigid layer and water table Spectral Analysis of Surface Waves (SASW) Modulus and thickness of each layer Provides the modulus profile in a comprehensive manner More robust than deflection-based methods In manual mode, testing and data reduction are time-consuming and complex Automated analysis applicable only to simple structure a Yuan et al. 1999. Source: Yuan et al. 1999. Figure 4.1. Typical time domain records from seismic test on thick asphalt pavement. Source: Wu et al. 2002. Figure 4.2. SASW procedure flowchart.

40 Source: Rydén and Mooney 2009. Figure 4.3. Comparison of strain levels from surface waves using conventional small hammer source and LWD source on soft subgrade. References Baker, M. R., K. Crain, and S. Nazarian. 1995. Determination of Pavement Thickness with a New Ultrasonic Device. Research Report 1966-1, Center for Geotechnical and Highway Materials Research, Univer- sity of Texas at El Paso. Nazarian, S. 1984. In situ determination of soil deposits and pavement sys- tems by spectral analysis of surface waves method. PhD dissertation. University of Texas at Austin. Nazarian, S., M. R. Baker, and K. Crain. 1993. SHRP-H-375: Fabrication and Testing of a Seismic Pavement Analyzer. Transportation Research Board of the National Academies, Washington, D.C. Nazarian, S., D. Yuan, and M. Baker. 1995. Rapid Determination of Pavement Moduli with Spectral-Analysis-of-Surface-Waves Method. Research Report 1243-1, The University of Texas at El Paso. Rydén, N., C. B. Park, P. Ulriksen, and R. D. Miller. 2004. Multimodal Approach to Seismic Pavement Testing. Journal of Geotechnical and Geoenvironmental Engineering, 130, No. 6, pp. 636–645. Rydén, N. 2004. Surface Wave Testing of Pavements. PhD dissertation. Lund Institute of Technology, Lund, Sweden. Rydén, N., and M. A. Mooney. 2009. Analysis of surface waves from the light weight deflectometer. Soil Dynamics and Earthquake Engineer- ing, 29, No. 7, pp. 1134–1142. Wehausen, J. V., and E. V. Laitone. 2002. Surface waves. Springer, Berlin. Wu, H., I. Wang, I. Abdallah, and S. Nazarian. 2002. A rapid approach to interpretation of SASW results. Proc., 6th BCRA Conference 2002, Lisbon, Portugal. Yuan, D., S. Nazarian, D.-H. Chen, and M. McDaniel. 1999. Use of Seismic Methods in Monitoring Pavement Deterioration During Accelerated Pavement Testing with TxMLS. Proc., First International Conference on Accelerated Pavement Testing (APT), Reno, Nevada.

Next: Renewal Technical Coordinating Committee »
Nondestructive Testing to Identify Delaminations Between HMA Layers, Volume 2 - Theoretical Models Get This Book
×
 Nondestructive Testing to Identify Delaminations Between HMA Layers, Volume 2 - Theoretical Models
MyNAP members save 10% online.
Login or Register to save!
Download Free PDF

TRB’s second Strategic Highway Research Program (SHRP 2) Report S2-R06D-RW-2: Nondestructive Testing to Identify Delaminations Between HMA Layers, Volume 2 describes the theoretical models used in the development of nondestructive testing (NDT) techniques capable of detecting and quantifying delaminations in HMA pavements.

SHRP 2 Report S2-R06D-RW-2 was developed as part of SHRP 2 Renewal Project R06D, which generated a sizable amount of documentation regarding the findings of evaluations and equipment development. The report for SHRP 2 Renewal Project R06D is therefore divided into five volumes. Volume 1 is a comprehensive summary of the study. Volumes 2 through 5 provide more detailed technical information and are web-only. The topics covered in other volumes are listed below.

Volume 3: Controlled Evaluation Reports

Volume 4: Uncontrolled Evaluation Reports

Volume 5: Field Core Verification

Renewal Project R06D also produced a Phase 3 Report to document guidelines for use of ground penetrating radar and mechanical wave nondestructive technologies to detect delamination between asphalt pavement layers.

READ FREE ONLINE

  1. ×

    Welcome to OpenBook!

    You're looking at OpenBook, NAP.edu's online reading room since 1999. Based on feedback from you, our users, we've made some improvements that make it easier than ever to read thousands of publications on our website.

    Do you want to take a quick tour of the OpenBook's features?

    No Thanks Take a Tour »
  2. ×

    Show this book's table of contents, where you can jump to any chapter by name.

    « Back Next »
  3. ×

    ...or use these buttons to go back to the previous chapter or skip to the next one.

    « Back Next »
  4. ×

    Jump up to the previous page or down to the next one. Also, you can type in a page number and press Enter to go directly to that page in the book.

    « Back Next »
  5. ×

    To search the entire text of this book, type in your search term here and press Enter.

    « Back Next »
  6. ×

    Share a link to this book page on your preferred social network or via email.

    « Back Next »
  7. ×

    View our suggested citation for this chapter.

    « Back Next »
  8. ×

    Ready to take your reading offline? Click here to buy this book in print or download it as a free PDF, if available.

    « Back Next »
Stay Connected!