Analyses on Prestress Loss and Flexural Performance of the Laminated Bamboo Beam Applied with Prestressed BFRP Sheet

Table 7

Positions of neutral axis under different loads.

Load (kN)	B-1		B-2		B-3
	hl (mm)	hl/h	hl (mm)	hl/h	hl (mm)	hl/h
5	72.97	0.49	73.90	0.49	75.26	0.50
10	72.15	0.48	73.82	0.49	75.37	0.50
15	69.99	0.47	73.67	0.49	75.02	0.50
20	65.82	0.44	72.05	0.48	73.62	0.49
25	61.89	0.41	68.82	0.46	69.86	0.47
Pu	57.93	0.39	65.49	0.44	63.86	0.43

Note. h_l is the distance between the neutral axis and the bottom surface of the laminated bamboo beam; P_u is the ultimate load.