Effect of chemical exposure on the interfacial bond characteristics of novel bio-fiber reinforced engineered cementitious composites

The present study focuses on understanding the influence of chemical immersion on the bond performance of the bio-fiber-reinforced Engineered Cementitious Composites (ECC) matrix. Standard concrete cylinders of size 150 mm × 300 mm, corresponding to M30 grade, were cast. After 28 days of curing, the cylinders were cut at different interface anglesrecast using bio-fiber-reinforced ECC. These bond samples were subjected to two different chemical immersions, namely (a) 3.5% HCl solution and (b) 10% MgSO4 solution. The parameters evaluated include (i) type of bio-fiber used, (ii) type of chemical solution, (iii) duration of exposure, and (iv) angle of interface. The bond specimens were tested through the slant shear test (compression) and the split-tensile test (tension). From the experiments, it can be observed that the interfacial bond strength decreases with increasing interface angle and exposure duration. From the split-tensile bond test, it was noticed that the tensile bond strength reduced by about 51.11% for flax and 25.30% for hemp ECC when exposed to MgSO4 solution for 180 days. From the Mohr–Coulomb failure analysis, it is evident that all the specimens underwent adhesive failure irrespective of the type of chemical exposure and angle of interface.