PSI - Issue 70

R. Karthikeyan et al. / Procedia Structural Integrity 70 (2025) 89–96

92

Fig.4 Test Configuration

3. Results and Discussion 3.1 Strength and Deformation The strength and deformation of control beam as well as rubberized concrete beams containing fibre reinforcement are presented through Tables 2 to 5 Table 2. Test Results for Rubberised Concrete Beam (SC)

SI.No

Identification of beams

First crack (k N)

Deflection at FCL (mm)

Yield Load (k N)

Def @YL Ultimate Load (k N)

Deflection at Ultimate

1.

SC

18.50

1.95

32.0

5.50

60.00

12.0

Table 3. Test Results of Rubberised Concrete Beam (SR11 &SR12)

SI.No

Identification of beams

First crack (k N)

Deflection at FCL (mm)

Yield Load (k N)

Def @YL

Ultimate Load (k N)

Deflection at Ultimate

1.

SR11

20.00

2.75

34.50

6.00

62.50

14.40

2.

SR12

22.50

3.10

37.50

6.50

65.00

15.60

The ultimate load of the sand-coated rubberized concrete beams reinforced with steel fibres were evaluated and are presented in Table 2. The experimental results demonstrated that the beams SR11 and SR12 exhibited significant improvement in their load-bearing capacities when compared to the control specimen. Specifically, beam SR11, which incorporated 2.5% rubber and 0.5% steel fibre, showed an increase of 4.16% in ultimate load capacity, while beam SR12, containing 2.5% rubber and 1.0% steel fibre, exhibited an 8.33% increase compared to SC as shown in Fig.5. These improvements were attributed to the synergistic effect of sand-coated rubber aggregates and steel fibre reinforcement. The application of a sand coating to the rubber particles significantly improved the interfacial bond between the rubber and the surrounding cementations matrix. This enhancement effectively addressed the typical issue of weak adhesion commonly observed with untreated rubber particles. As a result, the sand-coated rubber aggregates contributed to better stress transfer and overall matrix integrity. Additionally, the inclusion of steel fibres enhanced the mechanical performance of the beams by improving their crack-bridging ability. The fibres restrained crack propagation, contributed to the distribution of stresses after cracking, and improved the post-cracking behaviour of the concrete. The combined effect of improved bonding from the sand coating and the mechanical reinforcement provided