An Investigation of Asphalt Mixtures Using a Naturally Occurring Fibre
DOI:
https://doi.org/10.51699/ajsld.v2i6.1977Keywords:
Bituminous Concrete (BC), Stone Matrix Asphalt, Sisal Fiber, Marshall Properties, Static Indirect Tensile Strength, Static CreepAbstract
In this study, the researchers investigated the effects of using a locally available fiber called Sisal fiber as a stabilizer in Stone Matrix Asphalt (SMA) and as an additive in Bituminous Concrete (BC). The composition of a bituminous mixture typically includes coarse aggregate, fine aggregate, filler, and binder. Hot Mix Asphalt (HMA) refers to a bituminous mixture where all the constituents are mixed, placed, and compacted at high temperatures. SMA is a type of HMA that is gap graded, while BC is a Dense Graded mix (DGM) also known as Bituminous Concrete. SMA requires stabilizing additives such as cellulose fibers, mineral fibers, or polymers to prevent the drainage of the mix. The researchers aimed to study the impact of adding Sisal fiber, a naturally available fiber, as a stabilizer in SMA and as an additive in BC. To prepare the mixes, the researchers followed the aggregate gradation specified by MORTH (Ministry of Road Transport and Highways). The binder content was varied from 4% to 7%, and the fiber content ranged from 0% to a maximum of 0.5% of the total mix. In the preliminary study, fly ash was found to yield satisfactory Marshall Properties, so it was used in subsequent mixes. Using the Marshall Procedure, the Optimum Fiber Content (OFC) for both BC and SMA mixes was determined to be 0.3%. Similarly, the Optimum Binder Content (OBC) for BC and SMA was found to be 5% and 5.2% respectively. The BC and SMA mixes prepared at these optimum levels were then subjected to various performance tests, including Drain Down test, Static Indirect Tensile Strength test, and Static Creep test, to evaluate the effects of fiber addition on mix performance. The study concluded that the addition of Sisal fiber improves the mix properties, such as Marshall Stability, Drain Down characteristics, and indirect tensile strength, for both BC and SMA mixes. It was also observed that SMA performed better than BC in terms of indirect tensile strength and creep characteristics.
