Flexural behavior of precast concrete-filled steel tubes connected with high-performance concrete joints

Figures & Tables

Group	Specimen’s ID	Concrete type	Connection length (L)	Objective
G1	B0	NC	—	Control beam
	N-L1		15 cm	Impact of NC connection with varied lengths in connected beams under sagging moment
	N-L2		20 cm
	N-L3		30 cm
G2	B0	NC	—	Control beam
	E-L1	ECC	15 cm	Impact of ECC connection with varied lengths in connected beams under sagging moment
	E-L2		20 cm
	E-L3		30 cm
G3	B0	NC	—	Control beam
	H-L1	UHFRC	15 cm	Impact of UHFRC connection with varied lengths in connected beams under sagging moment
	H-L2		20 cm
	H-L3		30 cm

	Specimen’s ID	Cracking stage			Ultimate stage			Elastic stiffness index (K)	K _B/K _B0	Absorbed energy (E)	E _B/E _B0
	Specimen’s ID	P _cr (kN)	P _crB/P _crB0	Δ_cr (mm)	P _u (kN)	P _uB/P _uB0	Δ_Pu (mm)	Elastic stiffness index (K)	K _B/K _B0	Absorbed energy (E)	E _B/E _B0
G1	B0	12.95	1.00	0.66	44.01	1.00	3.92	19.62	1.00	148.35	1.00
	N-L1	10.21	0.79	0.99	38.27	0.87	3.82	10.31	0.53	98.81	0.67
	N-L2	10.96	0.85	0.83	40.16	0.91	3.90	13.20	0.67	137.76	0.93
	N-L3	11.32	0.87	0.78	42.43	0.96	3.74	14.51	0.74	135.54	0.91
G2	B0	12.95	1.00	0.66	44.01	1.00	3.92	19.62	1.00	148.35	1.00
	E-L1	11.56	0.89	0.95	42.54	0.97	4.43	12.17	0.62	152.93	1.03
	E-L2	12.32	0.95	0.77	46.08	1.05	4.11	16.00	0.82	208.01	1.40
	E-L3	13.91	1.07	0.49	48.97	1.11	4.62	28.39	1.45	251.11	1.69
G3	B0	12.95	1.00	0.66	44.01	1.00	3.92	19.62	1.00	148.35	1.00
	H-L1	13.84	1.07	0.61	46.85	1.06	3.21	22.69	1.16	130.14	0.88
	H-L2	14.52	1.12	0.43	49.24	1.12	3.50	33.77	1.72	205.44	1.38
	H-L3	15.26	1.18	0.37	51.37	1.17	3.89	41.24	2.10	252.77	1.70

Concrete	Cement (kg/m³)	Fine aggregate (kg/m³)	Coarse aggregate (kg/m³)	Fly ash (kg/m³)	Water/binder	PVA/steel fiber (%) in volume	HRWR (kg/m³)	f c ′ {f}_{\text{c}}^{^{\prime} } (MPa)
NC	350	700	1,150	—	0.43	—	—	32.56
ECC	580	450	—	610	0.22	2.10	35.3	63.67
UHFRC	500	600	990	35	0.24	2.00	15.6	126.75