Minimum Flexural Reinforcement Steel Ratios of High-Strength Concrete Beams

Table 3

Summary of the literature empirical studies on minimum flexural reinforcement limit beams.

Source	No. of beams	Reinforcement ratio (%)	Beam size (mm)	Concrete cube strength (MPa)	Steel yield strength (MPa)	Notes
Mohammed et al. [16]	6	0.165–0.29	150 × (255–340)	30, 60, 90	659
Fantilli et al. [9]	36	0.1–0.4	100 × 200	30, 45, 60	450
			200 × 400
Appa Rao et al. [21]	12	0.15–1.0	50 × 100	30	389–637	The minimum reinforcement decreases as the beam depth increases. The optimum ductility number was observed to be 0.20 in RC beams with a compressive strength of 30 MPa.
			100 × 200
			200 × 400
Rashid and Mansur [24]	16	1.25–5.31	250 × 400	42-126	460–537	The stresses generated by shrinkage of concrete and the creep associated with it can significantly affect the cracking moment.
				Cylinder
Ashour [25]	9	1.18, 1.77, 2.37	200 × 250	48, 78, 102	530	Cracking moment obtained by over estimates actual cracking moment by 1.5–2.0 times.
				Cylinder
Ozcebe et al. [26]	6	0.32–0.7	180 × 270	60–90	387, 486	Recommend the ratio of yield load to cracking load to be taken as 1.5.
			T-beams	Cylinder
Carpinteri et al. [27]	45	0.12–2	100 × 100	48.2	518–643	Minimum reinforcement ratio is inversely proportional to the beam depth.
			100 × 200
			200 × 400
Bruckner and Eligehausen [28]	6	0.15	300 × 125	31.8, 33.6	580	Minimum reinforcement ratio is directly proportional to the beam depth.
			300 × 250
			300 × 500
Bosco et al. [29]	30	0.043–1.0	150 × 100	91.2	441–637	Minimum reinforcement ratio is inversely proportional to the beam depth.
			150 × 200
			150 × 400