Effects of short fiber and pre-tension on the tensile behavior of basalt textile reinforced concrete

Abstract

Tensile behaviors of basalt textile-reinforced concrete (BTRC) with five layers of textile and different volume contents of short carbon, glass, and steel fibers (0.5 vol%, 1.0 vol%, and 1.5 vol% for carbon and steel fibers and 0.5 vol% for glass fiber) are investigated under uniaxial tensile loading by using an MTS load frame. Pre-tensioned BTRC with 0.5 vol% of short carbon and steel fibers is also tested. The reinforcing mechanisms of different short fibers and pre-tension conditions are illustrated, and digital image correlation analysis is performed to obtain full-field strain and crack distribution. First crack stress, ultimate load, and toughness are significantly improved by short fibers and pre-tension. The improving trend differs with the increase in volume fractions of various short fibers. Short glass, steel fibers, and pre-tension can increase crack numbers with reduced crack spacing and width, whereas short carbon fiber exerts no obvious effect. In addition, the shape of cracks changes from linear pattern to curved form due to the addition of short fibers. The critical crack widens quickly, whereas other non-critical cracks diminish when the strain level goes beyond the ultimate strain. On the basis of the Aveton–Cooper–Kelly model, the relationship of the normalized effective factor and interfacial frictional shear stress is derived.