Study of indirect tensile strength and cyclic indirect tensile modulus of fiber reinforced cement stabilized fly ash, stone dust and aggregate mixture for pavement application

Owing to the huge quantity of fly ash (FA) generated in the thermal power plants, the researchers and road authorities across the globe are exploring the use of bulk amount of FA in road construction. The presence of high volume of fine particles in fly ash, makes it of lower strength and brittle when stabilized with cement. Hence, a mixture of stone dust (SD), aggregates (AG), and FA was prepared to enhance the gradation of fly ash prior to cement stabilization. In order to enhance the strength and brittle behavior of stabilized mix, randomly oriented polypropylene fiber (FI) has been used for reinforcement. Therefore, a laboratory study was carried out to observe the unconfined compressive strength (UCS), indirect tensile strength (IDT) and cyclic indirect tensile modulus of fiber reinforced cement stabilized FA, stone dust, aggregate mixture with fiber reinforcement. Cement dosage was varied from 4to 8% in 2% intervals and fiber percentage was varied as 0%, 0.25%, 0.35%, and 0.5%. Results shows that inclusion of fiber upto 0.25% enhances the compressive strength, however, any further addition of fiber have minimal effect on strength. However, IDT increases with increment in fiber dosage from 0 to 0.5%. Inclusion of fiber also results in ductile behavior of stabilized FA. An optimum fiber dosage of 0.25-0.35% was observed for the stabilized fly ash and fly ash-stone dust-aggregate mixture. A strong regression equation was developed between IDT and cyclic IDT modulus.