Introduction. In the world-wide practice on construction of rigid road pavements significant attention has been given to jointed plain concrete pavements (JPCP) with transverse joints strengthened by dowel bars. Performance of JPCP is sufficiently affected by right alignment and location of dowel bars thereby the methods of non-destructive testing of dowel bar positioning have been gain in great importance. This paper represents analytical review of methods of non-destructive testing of dowel bar alignment and location emphasizing an attention on standard method using magnetic pulse induction which is applicable to testing of metallic bar position in concrete pavements.
General Part. In the general part of this paper, several main aspects of reviewed test method were analyzed:
- the classification of dowel bars misalignment and their impact on pavement performance;
- the comparison of implemented methods of non-destructive testing of dowel bar positioning;
- possibilities of method of magnetic impulse induction and an approach to analytical evaluation of transverse joints dowel bar misalignment using magnetic image tomography;
- the usage of results of testing of transverse joints dowel bar position to eliminate dowel bars misalignment;
- examples of predictive estimation of results of testing of transverse joints dowel bar position and their impact on performance of JPCP.
The reviewed method of testing and test results estimation concerns practice on application of two levels of performance (e.g. acceptable level and rejectable level) to evaluate the performance of each individual dowel bar or each doweled transverse joint and also a section of rigid road pavement with several consecutive transverse joints with restricted performance.
Conclusions.
1. World-wide implemented standard method of non-destructive testing of dowel bar alignment and location allows to detect and to eliminate dowel bars misalignment thus ensuring required load transfer efficiency and international roughness index of rigid road pavements. The estimation of road pavement sections with several consecutive joints considering each joint performance allows to ensure the designed service life of road pavement.
2. Standard method of non-destructive testing of dowel bar alignment and location for transverse joints of rigid road pavement using magnetic pulse induction developed by American Society for Testing and Materials assures high precision of measurement of metallic bar position in doweled bar of concrete pavement joints and enables to detect five types of dowel bar misalignment.
3. In connection with the intensification of issues on construction of rigid road pavements in Ukraine as well as the high importance of the considering test method, an important task should be the development and implementation of an appropriate national standard.
