Issue 58

M. Emara et al, Frattura ed Integrità Strutturale, 58 (2021) 86-104; DOI: 10.3221/IGF-ESIS.58.07

(a) partial confinement

(b) Full confinement

(a) The column in 3D view

(b) Cross section

Figure 8: Dimensions of the tested column specimens and their reinforcement details (dimensions in mm).

Figure 9: The lengths of SM wraps (dimensions in mm).

SM schemes ∗

Volumetric ratio of lateral reinforcement %

Height of the wraps (mm)

Longitudinal reinforcement (mm)

Transverse reinforcement (mm)

Number of SM wraps

Specimen NO

Specimen label

C CONTROL 6∅12 ∅8@180 6∅12 ∅8@180 CS1OC

െ

െ

െ

1

0.513

PC around upper & lower portion of OC of the column sample PC around upper & lower portion of OC of the column sample FC around the full height of OC of the column sample FC around the full height of OC of the column sample FC around the full height of ED of the column sample

2

One

0.578

325

6∅12 ∅8@180 6∅12 ∅8@180 6∅12 െ 6∅12 ∅8@180

Two

0.645

325

3

CS2OC

One

0.609

950

4

CFOC

One

0.24

950

5

CWFOC

One

0.621

950

6

CFED

Note: (*) ‘‘PC” denotes the partial confinement, ‘‘OC” denotes the outer core of the column, ‘‘FC” denotes the full confinement, and ‘‘ED” denotes the external diameter of the column. Table 1: Full details of the specimens and their confinement specifications. Material properties Crushed stone with 14 mm maximum size and 2.78 specific gravity was used as coarse aggregate. The medium-sized sand, with 2.53 specific gravity and 2.91 fineness modulus, was utilized as fine aggregate. Both coarse and fine aggregates (crushed stone and sand) are compatible with the Egyptian Standards [33]. The Portland Cement, which has a strength grade of 42.5 MPa and identical to cement type 1 in the Egyptian Standards [34] and British Standards [35], was utilized in the preparation of the concrete admixture.

91