Table 6: Specimen specification of double skin concrete-filled uPVC tube.

Label Concrete Class D (mm) d (mm) Height, h (mm) Number of Specimens
C3D1H1 C25 110 57 220 3
C3D2H1 C25 140 69 280 3
C3D3H1 C25 140 57 280 3
C3D1H2 C25 110 57 440 3
C3D3H2 C25 140 57 560 3
C3D1H3 C25 110 57 660 3
C3D3H3 C25 140 57 840 3