Balanced Ratio of Concrete Beams Internally Prestressed with Unbonded CFRP Tendons

International Journal of Concrete Structures and Materials

Table 5 Balanced ratio with each parameter.

No.	Effects	Initial prestress		Compressive concrete strength		Bonded FRP tendon		Effective depth		Distance between loading points		Balanced ratio
No.	Effects	\( f_{pfi} \) (MPa)	\( f_{pfi} /f_{pfm} \)	\( f_{c}^{'} \) (MPa)	\( f_{c}^{'} /f_{c,std}^{'} \)	A _bf (mm²)	A _bf/A _bf,min	d _pf (mm)	L/d _pf	L _p (mm)	L _p/L	\( \rho_{pfb}^{U} \)	\( \rho_{pfb}^{B} \)	\( \rho_{pfb}^{U} /\rho_{pfb}^{B} \)
1	Standard	845	0.5	40	1.0	745	1.0	560	26.8	4667	0.33	0.0027	0.0039	0.68
2	\( f_{pfi} \)	676	0.4	40	1.0	745	1.0	560	26.8	4667	0.33	0.0021	0.0033	0.63
3	\( f_{pfi} \)	1014	0.6	40	1.0	745	1.0	560	26.8	4667	0.33	0.0037	0.0051	0.73
4	f ^’_c	845	0.5	30	0.75	745	1.0	560	26.8	4667	0.33	0.0021	0.0032	0.65
5	f ^’_c	845	0.5	50	1.25	745	1.0	560	26.8	4667	0.33	0.0032	0.0046	0.70
8	d _pf	845	0.5	40	1.0	745	1.0	600	25	4667	0.33	0.0029	0.0042	0.71
9	d _pf	845	0.5	40	1.0	745	1.0	520	28.8	4667	0.33	0.0025	0.0039	0.65
10	A _bf	845	0.5	40	1.0	372.5	0.5	560	26.8	4667	0.33	0.0030	0.0043	0.70
11	A _bf	845	0.5	40	1.0	1118	1.4	560	26.8	4667	0.33	0.0024	0.0037	0.65
12	L _p	845	0.5	40	1.0	745	1.0	560	26.8	0	0	0.0015	0.0035	0.43
13										2333	0.17	0.0020	0.0036	0.55
14										7000	0.50	0.0032	0.0039	0.83