An analytical study on the complete strain hardening process of ultra high toughness cementitious composites under direct tension load

The ideal tensile stress–strain curve of ultra high toughness cementitious composites (UHTCC) shows trilinear stress–strain relationship. And its strain hardening process can be divided into multiple cracking zone and post multiple cracking zone. In this paper, the general expression of the fiber bridging stress laws in the crack plane is presented, and the stress–strain models are established for both zones based on the law. Furthermore, the critical fiber length between fiber pull-out and fiber rupture in the post multiple cracking zone are deduced. And the precondition to guarantee the post multiple cracking zone is deduced.

► The stress–strain models are established for multiple cracking zone and post multiple cracking zone. ► The fiber bridging stress laws in the crack plane is presented. ► The effects of micro-parameters on the strain and crack width are analyzed for multiple cracking zone. ► The critical length of fiber pull-out and rupture is deduced for post multiple cracking zone. ► The precondition for post multiple cracking zone is proposed.