Influence of SAMI on the performance of reinforcement grids

Abstract

Over the last decades, reinforcement grids have been used to prolong the service life of pavements. Although there is a broad consensus about their overall efficiency, there are still many open questions about the best alternatives regarding the materials to use, the shapes of the grid, their installation method or their position in the pavement among others. One controversial aspect is the use of Stress Absorbing Membranes Interlayers (SAMI) together with the application of a grid. Many manufacturers claim that the SAMI helps sealing any preexisting cracks in the underlying layer, retarding their propagation to the surface. This paper reports about the performance of a reinforcement grid installed with SAMI in a pavement with artificial cracks. One of the parameters analyzed to evaluate the performance, is the propagation of artificial cracks from the base course to the pavement surface. Other important consideration is the rutting development. To that end, the same cracked pavement, reinforced with a fiber grid and SAMI and without any reinforcement is loaded with identical accelerated trafficking, carried out with the traffic simulator MLS10. Results show that, although the grid with SAMI is able to slow down the formation of cracks in the surface, the density of cracks at the end of the tests is as high as if no grid was used. Moreover, resulting rutting in the reinforced pavement is higher than in the pavement without grid, indicating that the use of SAMI has a counterproductive effect on the rutting performance of the reinforcement.