Tension stiffening of rebar‐reinforced coarse aggregate ultra‐high performance concrete (R‐CA/UHPC): Tension capacity prediction and crack width calculation

Coarse aggregate ultra-high performance concrete (CA-UHPC) requires char-acteristic tensile properties for structural design practices both in the service-ability and ultimate limit states. Through uniaxial tension testing, this studyaims to identify the post-cracking performance of rebar-reinforced CA-UHPC(R-CA-UHPC), including cracking, tension stiffening, and tension capacity.Utilizing experimental data derived from average tensile responses, a tension-stiffening model of cracked CA-UHPC was developed, considering scenarioswith and without the shrinkage effect. The findings demonstrate that therestrained shrinkage effect significantly influences the tension stiffening ofcracked CA-UHPC in the pre-yielding phase, while becoming negligible forthe post-yielding behavior. The shrinkage-corrected model exhibits reinforce-ment ratio independence. Furthermore, the non-shrinkage-corrected modeldemonstrates superior predictive accuracy of R-CA-UHPC's global tensileresponse compared to the CA-UHPC tensile constitutive model. Subsequently,a tension-stiffening-based approach was derived and validated to calculatecrack widths in rebar-reinforced UHPC members.