Preliminary Investigation Of Preventive Maintenance Materials Application In Asphalt Pavement

Preventive maintenance can save much cost and is regarded as the most valuable investment in pavement maintenance. The main content in this paper comes from the life extension maintenance project (LVO in Dutch). Three kind of life extension products were applied on the A50highway (the Netherlands) slow lane field trial, respectively named LVO product E, product B and product H. The target of the project is to develop a procedure to test products before application in laboratory for usefulness. As a preliminary research, the objective of this paper is to find out whether these life extension products could be detected in the porous asphalt surface layer; if possible, how is the distribution of the products over the porous asphalt layer, and how is the influence of new binder on the pavement performance.Firstly, a preliminary investigation with the FTIR test was carried out to find out if it was possible to prove the existence of LVO binder at different places over the height of the field surface layer. Firstly, a simple and fast bitumen extraction method was developed under normal temperature; then, all the four sections’recovered bitumen were investigated, and the test results indicate that, comparimg to the reference section, no significant diference can be found about product E and product H, and product B can be detected in top10mm surface layer.Secondly, Nano CT scanning was carried out to find the image differences between the reference section and the treated sections. The test results indicate: product E cannot be detected obviously at present by the images; product B is visible in top8-10mm depth of the porous asphalt, while product H is visible in the top0-20mm, and the estimated quantity of the product B and H are approximately0.18Kg/m2and0.29Kg/m2respectively. For asphalt constitution research over the whole depth, all sections treated with the LVO products show higher mortar contents and less voids over the3-8mm depth in the pavement surface layer.Finally, three point bending test was carried out successfully. The stiffness test results suggest that the stiffness increases with increased frequencies for all the specimens. The Surface-Down stiffness is always lower than the Surface-Up for all the tested sections. Sections treated with three products all show a higher stiffness mean value than the reference sections in the Surface-Down test, which shows the LVO products improve the stiffness of the asphalt to some extent. Failure test indicates an average failure stress of all sections above4MPa, and almost no difference between reference sections and the treated sections. Failure energy until max load and until1.5mm displacement is also more or less the same. The failure test results indicate that the pavement is still under good condtionis and performs well, and the advantage of the LVO products can not be observed currently.