| 1. |
- Said, Safwat, 1951-, et al.
(author)
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Evaluation of pavement structure reinforced with steel fabrics
- 2002
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In: Bearing Capacity Of Roads Railways and Airfields. - London : CRC Press. - 9781000108101 - 9789058093967 - 9781003078814 ; , s. 497-504
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Book chapter (other academic/artistic)abstract
- This paper describes the rehabilitation procedure of an old cracked asphalt pavement located at E6 motorway in the West of Sweden. A trial has been made to design the road structure with steel fabric reinforcement in the asphalt concrete. Three full-scale, 100-meter test sections were built. Two test sections were reinforced with steel fabrics and one section without reinforcement as a reference road section. These sections are instrumented with strain gauges. The sections have been tested by deflection measurements with Falling Weight Deflectometer, strain measurements at the bottom surface of the overlays, strain on the steel bars, unevenness and rut depth measurements and manual distress surveys. This work is a part of a co-operation project, called REFLEX, partly financed by the European Commission. The objective is to evaluate the performance of new and rehabilitated road structures reinforced with steel fabric.
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| 2. |
- Gustafson, Kent, 1951-, et al.
(author)
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Bearing capacity of flexible road structures reinforced with steel fabrics
- 2002
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In: Bearing Capacity Of Roads, Railways and Airfields. - London : CRC Press. - 9781000108101 - 9789058093967 ; , s. 423-432
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Book chapter (other academic/artistic)abstract
- The EU-project REFLEX, "Reinforcement of Flexible Road Structures with Steel Fabrics to Prolong Service Life" is a three-year study (1999-2002) with the main objective to develop a new methodology of road construction and rehabilitation with the use of steel reinforcement fabrics. The result will be gained through a mix of work comprising experimental as well as theoretical work. Of great importance is accelerated pavement testing and test roads to verify the results of the laboratory work and to validate and calibrate theoretical models. Accelerated tests were carried out with the Heavy Vehicle Simulator HVS-NORDIC. Further within the frame of the project a number of test roads, some already existing and some built during the project, were investigated. This paper presents the performance and results from some of the full-scale tests.
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| 3. |
- Lenngren, C. A., et al.
(author)
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Airfield pavement structural analyses and design in Sweden
- 2002
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In: Bearing Capacity Of Roads Railways and Airfields. - London : CRC Press. - 9781000108101 - 9789058093967 ; , s. 325-334
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Book chapter (other academic/artistic)abstract
- The present paper discusses how a mechanistic design process evolved for airfields in Sweden and how it is being used. Also, a sensitivity study is presented showing parameter influence on the bearing capacity expressed in Pavement Classification Number (PCN). For example, how do revised asphalt strain criteria affect the resulting PCN-value? Other parameters included the stiffness of the asphalt layer, the base layer, and subgrade during the spring thaw period. An equivalent number of standard wheel load (ESWL) was calculated for some commonly used aircrafts on selected Swedish airfield pavements. These calculations were based on the tensile strain at bottom of the asphalt layer. Thus, the Aircraft Classification Number (ACN) derived in this manner could be compared to the existing status. The paper also discusses some future applications using high-speed rolling deflectometers.
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| 4. |
- Ryden, N., et al.
(author)
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Multichannel analysis of seismic waves for layer moduli evaluation of pavements
- 2022
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In: Bearing Capacity Of Roads Railways and Airfields. - London : CRC Press. - 9789058093967 - 9781000108101 ; , s. 705-714
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Book chapter (peer-reviewed)abstract
- Results from the application of a new seismic technique for non-destructive testing of pavement layer moduli are presented. The method is based on the multichannel analysis of surface waves (MASW) method and multichannel simulation with one receiver (MSOR). The MSOR method uses one accelerometer (receiver), a light hammer (source), and a single-channel recording device to generate a simulated multichannel record in a fast and simple manner. In the case study presented, the dispersion curve of surface waves shows different branches associated with the layers of different stiffness. From an objective observation of branches, seismic velocities, and resonant frequencies we evaluate the total number of layers with different stiffness properties, the dynamic E-modulus, Poisson's ratio, and thickness of the top asphalt layers. We propose using this information in the back-calculation of Falling Weight Deflectometer (FWD) data.
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| 5. |
- Wågberg, Lars-Göran
(author)
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Pavement deterioration : Crack initiation and crack propagation models
- 2002. - 1
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In: Bearing Capacity Of Roads Railways and Airfields. - London : CRC Press. - 9781000108101 - 9789058093967 ; , s. 549-560
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Book chapter (other academic/artistic)abstract
- The objective of the study presented here was to develop models for predicting the cumulative number of load applications to the initiation of cracking for flexible pavements and to develop models for predicting crack propagation in flexible pavements. Crack initiation is defined as the first appearance of cracking in the wheel paths. The models are aimed for use in Pavement Management Systems. Data used in the study consists of data from a Swedish LTPP (Long-Term Pavement Performance) study where over 600 test sections have been monitored during more than ten years. Every year a detailed distress survey and measurements of rut depth and the longitudinal profile has been carried out at each test section. The database contains information about traffic, climate, pavement structure, surface condition and structural strength. Pavement response based explanatory factors included, among other things, tensile strain at the bottom of the asphalt layer and other deflection based factors (i.e. surface curvature index, curvature basin factor, bearing capacity). The modelling of crack initiation models was carried out using a survival analysis approach. The results showed that data came from a Weibull distribution with an increasing risk of failure as pavement age increases. The modelling of crack propagation models was carried out using linear regression analysis. From the data, describing the yearly development of cracks, a Cracking Index was calculated. The same approach of developing crack models was used in the PARIS (Performance analysis of road infrastructure) project carried out within the 4th European Framework Programme Road Transport 1996-1998. Models were successfully developed to predict the cumulative number of traffic loadings to the initiation of cracking in the wheel paths. The models included two independent variables to pavement response and ageing (a relationship between a response variable and the annual cumulative number of traffic loadings). As response variables Surface Curvature Index 300 or Tensile Strain at the bottom of the asphalt layer can be used in the crack initiation models. Models were also developed to predict crack propagation in the wheel paths. For any given section of road, the slope of the linear model can be estimated from the level of distress at the last distress survey and the age of the pavement surface or the number of ESALs carried by the pavement at that time. All models have been validated against independent data, not used in the development phase.
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