Early-age stress relaxation and cracking potential of High-strength concrete reinforced with Barchip fiber

Abstract High-strength concrete (HSC) is vulnerable to early-age cracking due to the low water-to-cement (w/c) ratio. The polypropylene fiber, Barchip fiber, is utilized to improve the early-age behavior of HSC. Investigations on the influence of the proportion of Barchip fiber on early-age stress relaxation and cracking potential of HSC were conducted utilizing restrained ring test in this research. Experimental investigations and related analysis demonstrated that: (1) the free shrinkage of HSC decreased with increasing proportion of Barchip fiber; (2) the strain in steel ring decreased with increasing proportion of Barchip fiber; (3) the residual stress decreased with increasing proportion of Barchip fiber; (4) the relaxed stress of HSC decreased with increasing proportion of Barchip fiber; (5) the stress rate of HSC decreased with increasing proportion of Barchip fiber; (6) the cracking potential of HSC decreased with increasing proportion of Barchip fiber. The cracking potential parameter at the age of 10.58 d decreased by 15.2%, 31.9%, and 44.3% when the proportion of Barchip fiber increased from 0% to 0.3%, 0.6%, and 0.9%, respectively.