Early life freeze/thaw tests on concrete with varying types of fibre content

In normal circumstances, concrete should never be allowed to freeze in its early life. This article examines how the use of fibres can improve performance under these unacceptable circumstances. Concrete is very vulnerable to damage by freezing in its early life. This article describes an investigation of the performance of monofilament, crimped/structural polypropylene and steel-fibre types, compared with plain and air-entrained concrete, with particular regard to resistance to damage by freezing in the very early life of the concrete. Trials by Squibbs(1) and Sermram(2) at the University of Newcastle indicated monofilament fibres in concrete provided a degree of protection against early-age freezing of concrete. Squibbs carried out 50 cycles while Sermram carried out 100 cycles. These preliminary tests showed that concrete subjected to freeze/thaw cycles that commenced 24 hours after casting survived visually intact when monofilament fibres were included in the mix. These tests were a precursor to the early life tests as detailed in this article.