PSI - Issue 70

R. Ashwathi et al. / Procedia Structural Integrity 70 (2025) 424–431

426

SCM Supplementary Cementitious Materials BCC Blended Cement Concrete ML Machine Learning D Days

2. Experimental work and results The experimental setup of tests on the mechanical properties of concrete incorporated with the cementitious supplementary materials at varying ages of curing is shown in Fig.1. The setup includes specimen preparation, controlled curing condition and testing.

Fig. 1. Tests on the mechanical properties of concrete

2.1. Compressive strength of concrete

The compressive strength is enhanced due to the pozzolanic reaction and the filler ability of the cementitious materials. It also contributes towards the denser structure, with reduced porosity (Zerihun Mitiku Damtie; Vo, Duy Hai, 2022). The corresponding strength results of different cementitious materials are given in Table. 1.

Table 1. Compressive strength of concrete Specimen 7 D (N/mm²) 14D (N/mm²)

28 D (N/mm²)

7 D (N/mm²)

14D (N/mm²)

28 D (N/mm²)

Specimen

Controlled

32.24

37.64 30.32 32.01 31.07 27.84 32.48 31.12 29.16 23.68

41.2

SF - 10% 27.12 SF - 20% 28.26 SF - 30% 25.46 SF - 40% 25.12 FA - 10% 22.16 FA - 20% 20.18 FA - 30% 18.16 FA - 40% 16.34

40.42 42.68 41.42 37.12 41.62 40.28 37.34 32.18

MK -10% 13.12 MK -20% 13.78 MK -30% 14.68 MK -40% 14.12 RHA - 10% 14.28 RHA - 20% 15.64 RHA - 30% 14.26 RHA - 40% 12.38

27.84 29.37 31.16 30.29 30.24 32.78 28.96 28.34

37.12 39.16 41.54 40.38 40.24 42.36 38.62

36.48 The strength gain is attributed to the chemical reaction of calcium hydroxide with the hydration products where it produces additional Calcium Silicate Hydrate gel and improved packing density (Velumani et al., 2023). As the pozzolanic reaction continues to progress, the maximum strength gain is observed 28 days of curing compared to the early ages of curing(Singh P.K.; Kumar, Rakesh, 2023).

2.2. Split Tensile strength

The improvement in the tensile strength is due to the improvement in the bond within the matrix particularly at the Interfacial Transition Zone (ITZ) which is weak and porous (Shanmugasundaram et al., 2022). The incorporated materials make the matrix more durable and uniform and enhance the zone by refining the bond between aggregate and cement paste (Saand T.; Keerio, Manthar Ali; Bangwar, D. K., 2019). The corresponding strength results of different cementitious materials are given in Table. 2