Regarding the probably flexural strength of C5 - Technical Issues

RE: Regarding the probably flexural strength of C5

Nan Li — Wed, 06 May 2026 08:35:03 +0000

@brooke yes Nick, figure 5.16. which means there will be a chance to lead to 20% + or - in %NBS?. while you are here Nick I might ask one more thing regarding C2 table.C2A.1. is the column sway Vb formula correct? is it suppose to be Hi ( story Hight of the soft story) instead of Heff? Thank you

RE: Regarding the probably flexural strength of C5

Nic Brooke — Wed, 06 May 2026 07:56:08 +0000

Are you referring to the drop of the "actual relationship" line compared to the "assumed relationship" in Figure 5.16 of C5-2025?

That decrease is generally not considered in assessments, though might be in some instances where non-linear analysis is used.

Regarding the probably flexural strength of C5

Nan Li — Wed, 06 May 2026 06:05:18 +0000

in 5.5.5.2.1. the Mprob is corresponding to the moment when the extreme concrete fibre reaches strain = 0.003. Also, as per section C5.5.3.4.1 the bilinear approximation rules and C5.5.5.3.4.3, the curvature cap rules. the moment at curvature cap can be 20% approx less than the moment at 0.003 due to losing the lever arm of steel and concrete as the result of the spalling concrete cover. I am just wondering how this 20% moment difference is considered in the C5 framework. Thank you