2nd International Conference on Civil, Structural and Transportation Engineering (ICCSTE’xx16), Ottawa, Kanada, 5 - 06 Mayıs 2016, ss.1-8
This study examines the effect of
polypropylene fibers with different characteristics on the flexural strength
and deflection value of concrete. Hyperplasticizer was used in all mixtures. As
the amount of fiber in the mixtures increased, the amount of hyperplasticizer
was increased as well. Slump value of the fresh concrete ranged from 150 to 190
mm. No lump or segregation was observed in the fresh concrete. The effect of
the amount of plasticizer on the flexural behavior and amount of deflection was
investigated. Beam specimens (150x150x550 mm) were used to test flexural
strength. Four point flexural test was conducted on the specimens. Deflection
values at the moment of exerting the largest load and breaking were measured.
The changes in the flexural strength in 7 and 28 days were recorded. Flexural
strength of some specimens in a period of 7 days were found to be higher than
their flexural strength in a period of 28 days. Flexural strengths ranged from
4.43 MPa to 6.29 MPa. Increases and decreases were observed in the flexural
behavior compared to the control sample. The highest decrease was 15.46% and
the highest increase was 21.98%. Increases and decreases were observed in the
deflection values under the largest load compared to the control sample. The highest
decrease was 21.47% and the highest increase was 43.42%. Increases and
decreases were observed in the deflection values at the moment of breaking
compared to the control sample. The highest decrease was 23.24% and the highest
increase was 47.21%. Furthermore, the compressive strength of the specimens
were examined. The effect of the change in compressive strength on flexural
strength and deflection values was investigated.