Experimental Investigation on Stability and Flow Characteristics of Sustainable Bituminous Concrete Using Recycled Aggregates and Admixtures

Based on the experimental investigation on Marshall Stability, flow characteristics, and Ultrasonic Pulse Velocity of sustainable bituminous concrete prepared from recycled asphaltic pavement aggregates with cement and jaggery admixtures, the following conclusions are drawn:   • The use of recycled aggregates separated from existing bituminous pavement by a combined physical and chemical method is technically feasible for producing sustainable bituminous concrete, reducing dependence on natural aggregate and diverting pavement waste from disposal. • The 11% cement-only admixture combination achieved the highest Marshall Stability of 1070 kg with a flow value of 6 mm, satisfying MoRTH specifications for heavy traffic roads. • The combination of 11% cement and 8% jaggery achieved a Marshall Stability of 1010 kg with a flow of 6.9 mm, also meeting MoRTH heavy traffic requirements while partially replacing cement with an agricultural by-product. • Stability decreases and flow increases with jaggery content beyond 8% at any cement level, indicating that excessive jaggery addition is detrimental to mix stiffness and deformation resistance. • UPV values ranging from 4054 to 5000 m/s across all mixes indicate good to excellent internal quality of the compacted bituminous matrix. The highest UPV (5000 m/s) was recorded for 8% cement + 11% jaggery, suggesting optimal void filling by jaggery at moderate proportions. • The study confirms that sustainable bituminous concrete meeting heavy-traffic pavement specifications can be produced using recycled aggregates with proper admixture selection, offering both economic and environmental benefits through waste valorisation and resource conservation.

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