Effect of Concrete Age and Creep on the Behavior of Concrete-Filled Steel Tube Columns

Table 4

Axially compressed short columns.

Number	(mm)	(MPa)	(MPa)
1	1000 × 12 × 3000	345	40.7	0.050	0.422
2	1000 × 18 × 3000	345	40.7	0.076	0.645
3	1000 × 24 × 3000	345	40.7	0.103	0.876
4	1000 × 30 × 3000	345	40.7	0.132	1.117
5	1000 × 36 × 3000	345	40.7	0.161	1.366

is the area ratio of the steel with respect to that of concrete (), whereas is the hoop effect coefficient ().