Bond characteristics of carbon fabric-reinforced cementitious matrix in double shear tests

• Double shear tests were conducted to study the bond between textiles and concrete.
• Fabric delamination from the matrix governed the failure of mortar-based specimens.
• Fabric rupture at free length governed the failure of epoxy-based specimens.
• Bond stress at failure was 28% less in mortar-based than in epoxy-based specimens.
• For the same bonded area, bond stress at failure decreased when bonded length increased.

This study examined the bond characteristics between fabric-reinforced cementitious matrix (FRCM) systems and concrete. Twenty-seven double-shear specimens were tested under direct shear loading. Two types of cementitious mortars (FRCM specimens) and one type of epoxy (FRE specimens) were used as a matrix. Fabric delamination governed the failure of the FRCM specimens without debonding at the concrete/matrix interface. The FRCM specimens experienced cracking prior to failure whereas the FRE specimens failed suddenly by fabric rupture without cracking. The bond stress of the FRCM specimens at failure was on average 28% lower than that of the FRE specimens. For the same width of the bonded area, the bond stress at failure typically decreased with an increase in the bonded length of the fabric. Similarly, for the same bonded area, the bond stress at failure tended to decrease by increasing the bonded length. This reduction in the bond stress at failure was more pronounced in the FRE specimens than in the FRCM specimens.