PSI - Issue 66

Ram Lal Riyar et al. / Procedia Structural Integrity 66 (2024) 181–194 Ram Lal Riyar et. al./ Structural Integrity Procedia 00 (2025) 000–000

183

3

corrosion to begin and for chlorides to reach rebar based on Fick's second law was a good match to reality. This paper aims to investigate the influence of reinforcement bars on the fracture behavior of reinforced concrete beams with varying geometric sizes and different percentages of corrosion. The analysis is conducted through a three-point bending test to determine the size effect and fracture parameters at various reinforcement ratios and corrosion percentages.

Nomenclature RC

reinforced concrete

FPZ fracture process zone CMOD crack mouth opening displacement DIC digital image correlation LEFM linear elastic fracture mechanics a crack length OPC ordinary Portland cement

2. Materials and Methods The materials utilised in this investigation consist of OPC 53 grade cement, possessing a specific gravity of 3.15. Additionally, locally sourced river sand of zone II, characterised by a specific gravity of 2.65 and a water absorption rate of 2.17%, was employed. Furthermore, a well-graded 20 mm size of coarse aggregate with a water absorption rate of 1.6% and a specific gravity of 2.71 was used. The reinforcement bars used consist of a 6 mm diameter mild steel bar, as well as HYSD bars having 8 mm and 10 mm in diameter. The concrete mixture has been prepared in compliance with the M30-grade concrete requirements specified in IS-10262. Cement, fine aggregate, and coarse aggregate are all combined at a ratio of 1:1.47:2.82. The water-cement ratio is set at 0.40, and the desired slump range for the concrete is between 50-70 mm. The compressive and tensile strength of concrete were measured at 37.83 MPa and 5.26 MPa, respectively.

Table 1: Geometrical specifications of specimen.

Beam Size

Span (mm)

Depth (mm)

Breadth (mm)

Notch (mm)

Reinforcement (%)

Bar Diameter (mm)

Small

400 800 400 800 400 800 1200 1200 1200

100 200 300 100 200 300 100 200 300

100 100 100 100 100 100 100 100 100

20 40 60 20 40 60 20 40 60

0.27 0.14 0.095

6

Medium Large Small Large Small Medium Medium

0.54 0.27 0.16 0.81 0.4 0.27

8

10

Large

2.1. Geometry of specimen The length-to-depth ratio of each specimen was 4.5, the span was four times the depth, and the proportion of notch to-depth was 0.2; geometrically, they were all the same. The breadth (B) is constant at 100 mm for all specimens. A single longitudinal bar was served without shear reinforcement (stirrups) for the beam specimens. Single bars having diameters of 6 mm, 8 mm, and 10 mm were used for the small, medium, and large sizes, respectively. to cast lightly reinforced concrete beam specimens. Geometrically similar beams are shown in Figure 1 with their specifications