امين اميرچقماقي

Semi-flexible pavement is commonly used as a surface layer in roadways subjected to heavy and intense traffic. This pavement structure consists of a porous asphalt skeleton into which a cementitious grout is injected. Enhancing the performance of the cementitious grout can significantly influence the behavior and functionality of the pavement. Numerous studies have investigated the effects of various additives and pozzolanic materials on the properties of cementitious slurries and semi-flexible pavements. Sewage sludge ash (SSA), a byproduct of incinerated sewage sludge from wastewater treatment plants, has also been considered a potential additive. Previous research on its application in concrete for other industries has demonstrated promising results. Given its latent cementitious properties, SSA can be used in limited proportions as a partial cement substitution, meeting or improving the required performance criteria for cementitious slurries and semi-flexible pavement layers. Moreover, considering the high pollution levels and substantial economic and environmental costs associated with landfilling sewage sludge, utilizing it as a raw material in other industries holds significant importance. This study investigates the effects of incorporating SSA into the cementitious grout in semi-flexible pavements. After incinerating the sewage sludge and grinding the resulting ash, tests such as XRD, XRF, BET, SEM, and LPSA were conducted to eva‎luate and compare SSA's pozzolanic and cementitious characteristics. Performance tests were subsequently carried out on slurries where cement was partially substituted with SSA in proportions ranging from 0% to 20%. The results of SSA analysis indicated that, despite its higher porosity, specific surface area, and water demand compared to cement, SSA possesses latent cementitious properties, making it a viable partial cement substitute. Furthermore, the performance tests on the slurries demonstrated that incorporating up to 10% SSA could satisfy the required flowability and compressive and flexural strength criteria. Tests on resilient modulus, moisture sensitivity, and semi-circular bending revealed that substituting cement with up to 10% SSA can meet the performance requirements for semi-flexible pavements. Specifically, replacing 5% of cement with SSA improved the semi-flexible pavement layer's indirect tensile strength and fracture energy at intermediate service temperatures.

روسازي نيمه انعطاف پذير , دوغاب سيماني , مخلوط آسفالتي متخلخل , خاكستر لجن فاضلاب , مكانيك شكست

Semi flexible pavement , Cementitious Grouts , Porous asphalt mixture , Sewage sludge ash , Fracture mechanics

amin amirchaghmaghi

mahmoud ameri - pooyan ayar