For all RC and PT members:

• For the characteristic combination of loads, the compressive stress in the concrete based upon the cracked section is limited to k₁ f_ck in accordance with 7.2(2). The value of k₁ = 0.6 is used for the UK National Annex. Un-tensioned reinforcement is added to keep the concrete stresses within the prescribed limits.

For all RC members and for PT members where crack width design is requested:

• For the characteristic combination of loads, un-tensioned reinforcement is added to ensure that the reinforcement stresses remain below k₃ f_yk in accordance with 7.2(5). The value of k₃ = 0.8 is used for the UK Annex.