Effect of polypropylene fibre reinforcement on UCS and ductility of cemented sand

A series of unconfined compressive strength (UCS) tests was carried out to evaluate the effect of polypropylene fibre (PPF) reinforcement on the compressive strength and ductility properties of cemented sand. Poorly graded sand was mixed with different cement contents (2%, 4%, 6% and 8%) and reinforced with three different PPF ratios (0, 0.5% and 1%). Specimens were compacted to different relative densities (50% and 70%) and were cured for 3 and 7 days. The results showed that the UCS of the specimens increased with increasing PPF content. The UCS development rate in specimens with 0.5% and 1% PPF and 2% and 4% cement was almost twice as high as that of the specimens with 6% and 8% cement at both relative densities. For a cement content of up to approximately 4%, PPF inclusion yielded positive results. However, PPF inclusion in specimens with more than 4% cement was ineffective. Furthermore, the axial strain at peak strength of the cemented sand specimens increased with increasing PPF content. In cases where the fibre ratio was constant, the peak strains were almost independent of the cement content.