Calculation of Axial Compression Capacity for Square Columns Strengthened with HPFL and BSP

Table 2

Main test results.

Specimen number	Column	(MPa)	(MPa)	Sectional dimension (mm × mm)	Volume stirrup ratio (%)	Strand ratio (%)	Rebar ratio (%)	Angle ratio (%)	Maximum load (kN)	Increase of ultimate bearing capacity (%)		Ultimate displacement (mm)
										To Z01	To Z02
Z01	Concrete column	—		202 × 204	0	0	0	0	1080	—	—	1.82
Z02	RC column	—		202 × 203	0.521	0	1.131	0	1220	12.96	—	6.33
Z1	RC columns strengthened with HPFL and BSP	13.80	34.10	253 × 261	0.521	0.305	1.131	0.916	1490	37.96	22.13	7.43
Z2		32.61		257 × 260	0.521	0.305	1.131	0.916	1720	59.26	40.98	5.76
Z3		32.61		243 × 261	0.521	0.305	1.131	0.916	1770	63.89	45.08	5.86
Z4		32.61		251 × 257	0.521	0.305	1.131	0.916	1656	53.33	35.74	6.87
Z5	Concrete columns strengthened with HPFL and BSP	32.61		251 × 252	0	0.305	0	0.916	1640	51.85	34.43	6.58
Z6		32.61		248 × 261	0	0.305	0	0.916	1608	48.89	31.80	6.21

Note: the maximum displacements in the table were the displacements of specimens when their loads dropped to 85% of the maximum load.