Performance Of Basalt Fibre Modified Bitumen In Dense Bitumen Macadam

Abstract

Among the various techniques available for improving the properties of asphalt wearing courses, the addition of fibers has been taking on an increasingly prominent role.  Today, the magnitude of what has been produced using these techniques along with the available information collected by monitoring in place behavior has enabled developing a thorough and significant assessment.

Sometime due to a specific reason such as exceeding wheel load or extreme climatic condition by being too hot or cold, the bitumen fails to prevail to certain required attributes such as grade, Dynamic Shear Rheometer (DSR), Indirect Tensile Strength Test, Fatigue Test, Resilient Modulus Test, Moisture Damage Performance Test, Rutting Test etc. Modifiers of asphalt cement are used to overcome this problem and improve the rheological properties of the asphalt cement. There are many modifiers available in the market now a days, but only four are going to be used in this research. Polypropylene, Basalt fibre, cellulose are added to asphalt cement with different percentages and conduct different physical tests. It has been observed that the behaviour of asphalt cement after adding the modifiers differ from percentage to another. Ideal improvement to the rheological properties of asphalt cement. Exponential increase in traffic, overloading of commercial vehicles and significant variations in daily and seasonal temperatures have shown some limitations of conventional bitumen performance. It is thought that with the help of additives is one of the approaches to improve performance of flexible pavements. Here fibres have been used to improve the performance of asphalt mixtures against permanent deformation and fatigue cracking, Because of their inherent compatibility with asphalt cement and excellent mechanical properties.

 In the present study, an attempt has been made to study the effects of use of a mineral fibre called Basalt fibre is used as an additive in Dense Bituminous Macadam (DBM). An experimental study is carried out on conventional bitumen and fibre modified binder. Using Marshall Procedure, Optimum fibre Content (OFC) and Optimum Binder Content (OBC) for DBM are found respectively. The modified bitumen at different percentages are subjected to different performance tests like Dynamic Shear Rheometer (DSR) and Creep Properties to evaluate the effects of fibre addition on mix performance.