Investigation of seashells as additive in stone mastic asphalt mixtures in terms of gradation and adding method

In this thesis study, the usability of waste seashell aggregates instead of basalt aggregate in stone mastic asphalt mixtures was investigated. The seashells obtained as waste were crushed and added by 5% in proportion to the same gradation instead of natural basalt aggregate. Different options were created by changing the maximum size of the seashell aggregate as 0.425 mm, 0.180 mm and 0.075 mm. In addition, the effects of the methods of adding seashell fillers to basalt aggregate by dry aggregate method, moist aggregate method and slurry method were investigated. Stone mastic asphalt mixtures are designed according to the Marshall method. Modified Lottman, indirect tensile strength, Marshall stability, Hamburg wheel track and repeated creep tests were performed on the mixtures. The use of seashell aggregates has been found to increase the stability, low temperature cracking resistance, water damage resistance and deformation resistance of stone mastic asphalt mixtures. It was found that with the reduction of the seashell aggregate size, the improvement in the mechanical properties of the mixture increased, and the best properties were achieved by adding fillers in size. When evaluated in terms of filler addition methods, the moist aggregate method gives better results than the slurry method and dry aggregate method.