Enhancing Stone Mastic Asphalt through the Integration of Waste Paper and Cement Kiln Dust

Abstract

In the realm of civil engineering and industrial construction, the infusion of waste materials into road pavements has emerged as a pivotal strategy for augmenting the attributes of asphalt mixtures while concurrently mitigating the environmental repercussions associated with waste. This investigation delineates a dry method for the preliminary treatment of waste paper, preceding its amalgamation into asphalt mixtures. The focal point is the incorporation of waste paper and Cement Kiln Dust (CKD) as modifiers in Stone Mastic Asphalt (SMA). It is posited that the inclusion of waste paper fibers can substantially elevate the SMA's flexibility and crack resistance. Simultaneously, CKD is purported to bolster the asphalt's strength and durability through its cementitious characteristics. A series of SMA blends were formulated, integrating waste paper and CKD in varied proportions ranging from 0.2% to 1% by weight. Subsequent evaluations encompassed analyses of air voids, density, drain-down characteristics, Indirect Tensile Strength (ITS), and Marshall Stability. The outcomes revealed that the drain-down test exhibited enhancements in volumetric parameters, notably density and air voids. Concomitantly, there was a 33% increase in Marshall Stability and a 37% improvement in ITS. Additional advancements were observed in Marshall Flow, Tensile Strength Ratio (TSR), and skid resistance. In summation, this study establishes that waste paper, when appropriately treated and amalgamated with CKD, can be efficaciously utilized in SMA mixes, yielding mixtures with superior volumetric and mechanical properties. This methodology not only augments the stiffness and minimizes binder drainage but also enhances rutting resistance. Most crucially, it paves the way for sustainable and ethical practices in the reuse and recycling of waste materials.