Performance evaluation of Recron fibre and glass wool fibre reinforced self-compacting mortar at elevated temperature: A comparative study

The reinforcements of Recron fibre (RF) (0.2 %, 0.4 % and 0.6 %) and glass wool fibre (GWF) (0.5 %, 1 % and 1.5 %) have been evaluated for rheology, durability, compressive strength (CS) and flexural strength (FS) of selfcompacting mortar (SCM) at different levels (0.43, 0.55 and 0.7) of effective water-to-cement ratio (w/c). The reinforcement of RF and GWF has resulted in negative impact on workability of SCM, and the highest yield stress of 232 MPa was obtained with reinforcement of RF of 0.6 %, followed by yield stress of 162 MPa with reinforcement of GWF of 1.5 % in SCM with w/c of 0.43. At 28 days of curing, the highest value of CS; 49.3 MPa was obtained for specimens having control mix with w/c of 0.43. The addition of fibres has decreased the CS but FS has increased with reinforcement of optimum fibre dosage. The lowest value of CS;15.7 MPa was obtained for SCM mix having w/c of 0.7 and RF of 0.6 %, whereas the highest values of FS; 8.7 MPa was obtained for SCM (w/ c of 0.43) with individual reinforcement of RF of 0.4 % and GWF of 1.0 %. The water permeability of SCMs was adversely affected by the increasing dosage of fibre reinforcements and w/c, but increasing dosage of RF and GWF has decreased the charge transfer rate through the SCM. The addition of RF and GWF has avoided the explosive spalling in SCM up to the heating temperature of 800 degrees C, however, the explosive spalling has occurred at 600 degrees C in control mix specimens. Compared to control mix design, the reinforcement of GWF has effectively controlled the strength loss in SCM, whereas, the addition of RF has improved the CS and FS with heating up to the temperature of 400 degrees C. A steep decrement in CS and FS was observed with heating at 600 degrees C and 800 degrees C. Considering the rheology and properties of SCM at ambient and elevated temperatures, the optimal dosage of fibre reinforcement in SCM is recommended as; RF of 0.2-0.4 % and GWF of 0.5 %.