EFFECT OF HYBRID MICRO STEEL-POLYPROPYLENE FIBERS ON HIGH STRENGTH CONCRETE WITH MICRO SILICA FUME
MUTHANNA JOURNAL OF ENGINEERING AND TECHNOLOGY (MJET)
Volume 3, Issue 1, December, Pages90-102
Othman Hameed Zinkaah
Assistant Lecturer, Department of civil Engineering, College of Engineering, Almuthana University
E-mail address: Al_azawy2001@yahoo.com
The present investigations consider the effect of hybrid micro steel- polypropylene fibers on high strength concrete. The fractions of steel and polypropylene fibers are 1% and 0.5% by volume respectively. Many mixes have been investigation by combination between steel fibers and polypropylene fibers with different percentages it is (0%S.F-100%P.P.F), (100%S.F- 0%P.P.F), (25%S.F, 75%P.P.F), (50%S.F-50%P.P.F), (75%S.F-25%P.P.F) in addition to reference mix. Properties of high strength concrete such as compressive strength, splitting strength, flexural strength, static modulus of elasticity, and absorption have been studied. The results showed that, the compressive strength decrease by about 28% when adding (0%S.F- 100%P.P.F), and there are a small increasing with adding (100%S.F-0%P.P.F). However the results showed that there are an inverse relationship between compressive strength and theamount of polypropylene fibers. Experimental work also showed that adding (0%S.F-
100%P.P.F)decrease the splitting strength by about 16%, while using hybrid fibers increase the splitting strength but less than its increasing when adding (100%S.F-0%P.P.F). It can beconcluded that, the maximum effect of hybrid fibers is on the flexural strength, it is reach to 128% more than reference mix. Furthermore absorption increases by using polypropylene fibers.