Influence of Different Fibers on Cracking Resistance of Shaft Wall Mass Concrete

Abstract

Early-age cracks in shaft concrete has become a serious problem in 1000m-plus deep mine due to the high internal temperature and thermal stresses. For the purpose of improve the cracking resistance of concrete, we report a novel experimental design by Temperature Stress Test Machine (TSTM) to study the influence of three fibers including basalt fiber, polyvinyl alcohol fiber and steel fiber on early-age cracking resistance of shaft wall mass concrete. Results of the experimental research indicated that (1) Three fibers can restrain expansion and shrinkage deformation finitely, and the shrinkage resistance effect of different fibers was steel fiber>polyvinyl alcohol fiber>basalt fiber; (2) Three fibers can finitely reduce the tensile stress increasing speed which was basalt fiber>polyvinyl alcohol fiber>steel fiber during; (3) The main function of fibers is restrain crack expansion and brittle failure rather than reduce cracking potential, and the rank of function is steel fiber>basalt fiber>polyvinyl alcohol fiber.