Modeling of Bond Stress–Slip Relationships of a Strand in Concrete during Steam Curing

International Journal of Concrete Structures and Materials

Table 1 Test specimens and test results.

Nos.	Names	Curing time, t (h)	Equivalent age, t _e (h)	Measured parameters							Calibrated parameters
				Concrete strength, S (MPa)	Characteristic points (Fig. 7)						Calibrated parameters
					(1)		(2)		(3)		Shape parameter, α _b	Bond condition, η	Frictional bond resistance, ν
					s ₁	τ _max	s ₂	τ _max	s ₃	τ _f	Shape parameter, α _b	Bond condition, η	Frictional bond resistance, ν
1	P4A	4	7.8	1.8	5.96	0.33	12.28	0.33	14.80	0.22	0.70	0.25	0.67
2	P4B	4	7.8	2.9	8.68	0.78	15.27	0.78	23.00	0.56	0.60	0.46	0.72
3	P6A	6	23.5	7.6	7.13	1.67	11.45	1.67	15.84	1.22	0.23	0.61	0.73
4	P6B	6	23.5	8.7	6.20	1.95	13.52	1.95	18.21	1.01	0.24	0.66	0.52
5	P6C	6	23.5	9.3	4.37	2.00	12.46	2.00	13.81	1.78	0.25	0.66	0.89
6	P6D	6	23.5	8.5	7.29	2.11	11.67	2.11	16.38	1.65	0.26	0.72	0.78
7	P8A	8	53.8	14.2	4.60	4.34	11.82	4.34	19.56	3.13	0.18	1.15	0.72
8	P8B	8	53.8	15.9	4.79	3.94	11.19	3.91	15.21	3.04	0.15	0.99	0.77
9	P10A	10	85.2	22.3	7.08	7.57	9.37	7.57	16.59	6.01	0.12	1.60	0.79
10	P10B	10	85.2	23.8	7.69	8.02	13.84	8.02	17.70	6.42	0.18	1.64	0.80
11	P10C	10	85.2	24.4	6.75	7.87	12.19	7.87	16.48	6.08	0.22	1.59	0.77
12	P10D	10	85.2	25.0	8.69	8.13	12.94	8.13	15.65	6.68	0.23	1.63	0.82