Simplified Design Equation of Minimum Interior Joint Depth for Special Moment Frames with High-Strength Reinforcement

International Journal of Concrete Structures and Materials

Table 3 Key parameters of the joints with Grade 590 MPa (85 ksi) beam bars.

First author	Specimen	Failure mode	Test parameters								Performance evaluation^c
First author	Specimen	Failure mode	\(\varvec{f}_{\varvec{c}}^{\varvec{'}}\) MPa	\(\varvec{f}_{{\varvec{ya}}}\) MPa	\(\varvec{h}_{\varvec{c}}\) mm	\(\frac{{\varvec{h}_{\varvec{c}} }}{{\varvec{d}_{\varvec{b}} }}\)	\(\frac{{A_{s,bot} }}{{A_{s,top} }}\)	\(\frac{\varvec{P}}{{\varvec{A}_{\varvec{g}} \varvec{f}_{\varvec{c}}^{\varvec{'}} }}\)	\(\frac{{\varvec{V}_{{\varvec{jh} \cdot \varvec{m}}} }}{{\varvec{V}_{\varvec{n}} }}\) ^a	\(\varvec{A}_{{\varvec{sh},\varvec{ratio}}}\) ^b	\(\frac{{\varvec{Q}_{\varvec{r}} }}{{\varvec{Q}_{\varvec{m}} }}\)	\(\frac{{\varvec{K}_{\varvec{o}} }}{{\varvec{K}_{\varvec{i}} }}\)	\(\frac{{\varvec{E}_{\varvec{D}} }}{{\varvec{E}_{{\varvec{PP}}} }}\)	Rating
Oka (1992)	J-1	BJ	81	638	300	23.6	0.78	0.11	1.15	0.26	0.70	0.12	0.28	x
Teraoka (2004)	HJ-5	BJ	54	645	400	20.9	1.00	0.18	0.92	0.66	0.76	0.07	0.25	o
	HJ-8	BJ	93	599	400	18.0	1.00	0.20	0.97	0.27	0.91	0.10	0.33	o
	HJ-12	BJ	89	604	400	18.0	1.00	0.17	1.55	0.58	0.71	0.10	0.35	x
Abe (2006)	MJIS	BJ	86	626	475	21.4	1.00	0.15	0.98	0.55	0.80	0.11	0.36	o
Hori (2006)	B15-4	B	152	616	380	19.9	0.67	0.33	0.74	0.70	0.96	0.22	0.40	o
Hori (2006)	B15-5	B	146	616	380	19.9	0.67	03	0.75	0.73	0.93	0.22	0.36	o
Takamori (2007)	HNO. 18	BJ	147	646	700	24.5	1.00	0.10	0.96	0.62	0.96	0.14	0.31	o
	HNO. 19	BJ	165	657	700	24.5	1.00	0.10	1.04	0.57	0.93	0.19	0.34	o
	HNO. 20	BJ	140	640	700	24.5	1.00	0.10	1.10	0.68	0.93	0.18	0.35	o
Hwang (2014)	C2-600	BJa	32	710	550	24.8	0.60	0	0.89	1.70	0.71	0.03	0.15	x
	C3-600	BJa	32	710	450	20.3	0.60	0	1.09	1.46	0.73	0.11	0.19	x
	C4-600	BJa	30	635	550	21.7	0.50	0	0.79	1.81	0.73	0.06	0.17	x

Failure mode: “B”, beam flexural failure; “BJ”, Beam yielding followed by Joint shear failure; “BJa” Beam yielding followed by Joint anchorage failure.
^aExperimental-to-nominal joint strength ratio per ACI 318.
^bProvided-to-required confinement reinforcing ratio per ACI 318 without limiting \(\varvec{f}_{{\varvec{yt}}}\).
^cJoints with hysteresis performance satisfying the three acceptance criteria (Fig. 4) given by ACI 374.1-05 are evaluated to be “Acceptable” and denoted by symbol “o”. The rest joints are evaluated to be “Unacceptable” and denoted by symbol “x”.