High alkali-resistant basalt fiber for reinforcing concrete

摘要

Basalt glasses and fibers with zirconia content in the range from 0 to 7 wt% were obtained using ZrSiO_4 as a zirconium source. Weight loss and tensile strength loss of fibers after refluxing in alkali solution were determined. Basalt fiber with 5.7 wt% ZrO_2 had the best alkali resistance properties. Alkali treatment results in formation of protective surface layer on fibers. Morphology and chemical composition of surface layer were investigated. It was shown that alkali resistance of zirconia doped basalt fibers is caused by insoluble compounds of Zr~(4+), Fe~(3+) and Mg~(2+) in corrosion layer. Mechanical properties of initial and leached fibers were evaluated by a Weibull distribution. The properties of basalt fibers with ZrSiO_4 were compared with AR-glass fibers. The performance of concrete with obtained fibers was investigated.