The Effect of Freeze and Thaw Cycles on Durability of Steel Fibers Concrete

Abstract

The new concrete types like steel fibers concrete have intensively investigated during the last decades. Although, many researches had focused on the mechanical properties of steel fibers concrete, few researches had concern with its durability with regards to freezing and thawing cycles. This research is aimed to study the behavior of steel fibers concrete under repeated cycles of freezing and thawing. Four different mixes has been investigated, three with steel fiber content of 0%, 0.5%, 1% and 1.25% as volume fraction of total mix in addition to reference mix without fiber. 60 specimens were tested according to ASTM-C666-97. 90 cycles of freezing and thawing were preformed after 28 days of curing. The compressive strength, flexural strength, Pulls velocity and durability factor, weight change and total absorption were tested after 0, 30, 60 & 90 cycles.The results show that steel fibers concrete possess an acceptable freezing and thawing resistance. However, a considerable redetection in compressive strength and flexural strength was recorded with the increment of exposure to freezing and thawing cycles. The results also indicate a slight decrease in the specimens’ weight with the increase in number of freezing & thawing cycles without any deterioration in the apparent look of specimens. All mixes show close results for total absorption at all stage of the test.