Stress-Strain Law for Confined Concrete with Hardening or Softening Behavior

Table 1

Mechanical and geometrical characteristics of specimens considered in Figures 5 and 6 and evaluation of error 𝑃_𝑖(%) of SAm in prediction of curve 𝑓^′_𝑐−𝜀_𝑐 with experimental data.

Code	𝑓𝑓	𝐸𝑓	plies	𝐾𝑙	𝑃1 (%)	𝑃2 (%)
	N/mm * ply	kN/mm * ply
HK-C1	174	15.7	1	3.2	−0.3	0.3
HK-C2	174	15.7	2	6.4	1.7	1.7
HK-G4	75	4.9	2	2.0	0.0	0.0
HK-G5	75	4.9	3	3.0	−0.2	0.2
HK-G6	75	4.9	6	6.0	0.5	0.5
HK-G7	75	4.9	9	9.0	−0.7	0.8
HK-G8	75	4.9	12	12.0	−1.1	1.1
Code	𝑓𝑓	𝐸𝑓	𝑡𝑓	𝐾𝑙	𝑃1 (%)	𝑃2 (%)
	MPa	GPa	mm
SH-C4	2275	82.7	2.5	69.3	−1.8	1.8
SH-C5	2275	82.7	1.0	11.1	2.1	2.1
SH-C6	2275	82.7	1.5	16.6	2.7	2.7
Mean					−0.6	2.1

𝐷=152 mm for HK, 𝐷=152.5 mm for SH. 𝑓^′_𝑐0 = 32.1 MPa for HK, 𝑓^′_𝑐0 = 19.4 MPa for SH-C1/C4, and 𝑓^′_𝑐0=49.0 MPa for SH-C5/C6.