Author (s) : DOI : 10.32692/IJDI-ERET/15.2.2026.2601

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1). S. I. Sarsam, Sarsam and Associates Consult Bureau (SACB), Baghdad, Baghdad, IRAQ

Abstract :

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Rutting resistance of AC mixture under dynamic flexural stresses was evaluated in this work with the aid of the (FN). Influence of eight microstrain levels, three binder percentages, and three testing environments on the changes in the FN were evaluated and modeled. Beam specimens of AC mixture were extruded from roller compacted slab samples and practiced the fatigue process under dynamic flexural stresses. It was noticed that the FN increases by (25, 50, 137.5, and 225) % when the strain level rises from (100 to 200, 500, 700, and 1000) microstrain respectively. The increase in the testing temperature from (5 to 20) º C and from (5 to 30) º C exhibited a decline in the FN of AC specimens by (20, 20, and 16.6) % and (33.3, 56, and 66) % when the test was conducted under (250, 400, and 750) microstrain levels respectively. The FN increased by (1.2, and 2.3) folds when the asphalt binder content rises from (4.3 to 4.8 and 5.3) % respectively. The obtained mathematical models may be implemented to describe the behavior of FN of AC under the assessed testing variables. The obtained linear and polynomial mathematical regression models with high coefficient of determination (R^2) can only provide a rough guide, exhibits empirical nature and limited domain, and may be implemented for fast and preliminary estimation of flexural strength within the investigated material ranges of properties and instant detection of AC quality in terms of FN and permanent deformation. It is concluded that the FN is sensitive to the changes in BC, testing environment, and flexural strain levels and could be implemented to verify the initiation of rutting in AC.

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