Investigation of tensile cracking characteristics of high strength and toughness ECC(HST-ECC) and CFRP reinforced HST-ECC

To improve the tensile properties of Textile-Reinforced-Engineered-Cementitious-Composites (TR-ECC) and textile utilization efficiency, this study prepared a High-Strength and Toughness-Engineered-Cementitious-Composite (HST-ECC) with excellent compressive and tensile properties through strategic fiber hybridization and cementitious matrix design. Its compressive strength was 160–191 MPa, peak tensile strain was 4.21–9.76 %, tensile strength was 7.61–13.46 MPa, and the maximum crack width corresponding to the peak tensile strain was 70.77–86.16 μm. Building on this foundation, the tensile behavior of Carbon-Fiber-Reinforced-Polymer (CFRP) grid-reinforced HST-ECC (TR-HSTECC) was systematically investigated. Experimental results demonstrate the HST-ECC with textile can be work synergistically. Compared with the HST-ECC without textile, the tensile strength of TR-HSTECC with 3 layers of textile was increased by 194 %, and the peak tensile strain was increased by 118 %, however, the peak tensile strain and the number of cracks were reduced compared with that of the 2 layers of textile. A TR-HSTECC quadrilinear model was proposed, which accurately characterizes the stress-strain curves and strain-hardening at different tensile stages of TR-HSTECC. Additionally, a probability statistical model describing the distribution of cracks width in the tensile process of HST-ECC was established. This model exhibits strong consistency with experimental data and enables an accurate assessment of crack width probability distribution regularity across various tensile loading stages in HST-ECC.