Torsional Strengthening of RC Beams with Near-Surface Mounted Steel Bars

Table 3

Experimental results of the tested beams.

Beam code	Str. tech.	(MPa)	Tcr (kN·m)	%incr.Tcr	Tu (kN·m)	%incr.Tu	θu (deg./m)	%dec. θu
Control	Un-str.	48	4.50	….	10.75	0.00	4.77	0.00
NSM100	NSM steel bar		8.50	88.89	15.50	44.19	3.97	16.77
NSM150			8.00	77.78	14.75	37.21	3.64	23.69
NSM200			7.00	55.56	14.35	33.49	3.47	27.25
DNSM100			7.50	66.67	13.15	22.33	4.35	8.81
DNSM150			7.00	55.56	12.08	12.33	3.82	19.92
DNSM200			7.00	55.56	11.25	4.65	2.73	42.77

Str. Tech. is strengthening technique; is concrete compressive strength; T_cr is cracking torque; %Incr.T_cr is percentage increase in cracking torque; T_u is ultimate torque; %Incr.T_u is percentage increase in ultimate torque; θ_u is ultimate twist angle; %dec. θ_u is percentage decrease in ultimate twist angle; “Un-str.” is short for “unstrengthened.”