Assessing the Seismic Performance of Exterior Precast Concrete Joints with Ultra-High-Performance Fiber-Reinforced Concrete

International Journal of Concrete Structures and Materials

Table 5 Comparisons between test results and ACI 374.1–05 acceptance criteria (1)

		Acceptance criteria	PJ-MR ( +)	PJ-MR (–)	PJ-CR ( +)	PJ-CR (–)	PJ-MU ( +)	PJ-MU (–)	PJ-CU ( +)	PJ-CU (–)
	\(\frac{{M}_{peak}}{{M}_{n}}\)	≤ 1.25	0.89	0.83	0.91	0.89	0.91	0.89	0.99	0.90
During third cycle of 4% drift cycles	\(\frac{{M}_{3rd}}{{M}_{peak}}\)	≥ 0.75	0.92	0.98	0.97	0.98	0.89	0.97	0.89	0.91
	\(\beta\)	≥ 1.25	1.304		1.395		1.351		1.299
	\(\frac{{K}_{s}}{K}\)	≥ 0.05	0.17	0.24	0.43	0.39	0.29	0.22	0.17	0.13

M_n: nominal beam moment strength (calculated based on measured material properties)
M_peak: peak beam moment (measured)
M_3rd: peak beam moment during 3rd cycle of 4.0% drift ratio (measured)
β: relative energy dissipation ratio (ACI 374.1–05)
K_s ( +): secant stiffness for positive loading* from a drift ratio of − 0.35% to a drift ratio of + 0.35% (ACI 374.1–05)
K_s (–): secant stiffness for negative loading** from a drift ratio of − 0.35% to a drift ratio of + 0.35% (ACI 374.1–05)
K ( +): initial stiffness for positive loading* for first cycle (ACI 374.1–05)
K (–): initial stiffness for negative loading** for first cycle (ACI 374.1–05)
^*Positive loading, defined as loading from right to left (see Fig. 5)
^**Negative loading, defined as loading from left to right (see Fig. 5)