PSI - Issue 70

C. Manoj Prabhu et al. / Procedia Structural Integrity 70 (2025) 207–214

210

2 3 4 5 6 7 8 9

10M-5 10M-10 10M-15 10M-20 10M-25 12M-0 12M-5 12M-10 12M-15 12M-20 12M-25

65 60 55 50 45 70 65 60 55 50 45

5

30 30 30 30 30 30 30 30 30 30 30

1:2.5 1:2.5 1:2.5 1:2.5 1:2.5 1:2.5 1:2.5 1:2.5 1:2.5 1:2.5 1:2.5

0.35 0.35 0.35 0.35 0.35 0.35 0.35 0.35 0.35 0.35 0.35

10 15 20 25 10 15 20 25 0 5

10M

12M

10 11 12

(c)

(a)

(b)

Fig.2. Test setup; (a) oven drying samples; (b) water absorption; (c) RCPT

4. Durability studies on GPC specimens Durability is a significant parameter for evaluating the long-term efficiency of GPC. Various tests, which includes as water absorption, sorptivity, RCPT, and sulphate attack, were performed to evaluate the durability of GPC against environmental deterioration. The findings of the test are summarized in Table 2.

Table.2. Durability test findings for GPC specimens S.No Mix ID Water Absorption (%)

Sorptivity (mm/min⁰·⁵)

RCPT (Coulombs)

Sulphate attack

Weight loss (%)

Strength loss (%)

30 d 1.25 1.18 1.12 1.08 1.05 1.02 1.00 1.15 1.10 1.06 1.03 1.00 0.98

90 d 1.90 1.75 1.65 1.58 1.50 1.45 1.38 1.70 1.60 1.52 1.45 1.40 1.35

30 d

90 d

1 2 3 4 5 6 7 8 9

CM

3.78 3.02 2.90 2.85 2.72 2.60 2.54 3.00 2.88 2.80 2.68 2.55 2.42

0.090 0.085 0.080 0.078 0.075 0.073 0.070 0.085 0.080 0.078 0.075 0.073 0.070

2350 2045 1920 1845 1800 1675 1510 1995 1850 1720 1600 1540 1480

6.5 4.5

10.25 7.75 7.52 7.35 7.10 6.82 6.56 7.53 7.37 7.14 6.65 6.40 5.96

10M-0 10M-5 10M-10 10M-15 10M-20 10M-25 12M-0 12M-5 12M-10 12M-15 12M-20 12M-25

4.12 4.00 3.75 3.42 3.20 4.0 3.56 3.30 3.10 2.85 3.8

10 11 12 13

4.1. Water absorption test Water absorption is a significant factor of the permeability and durability of GPC. Fig 3 illustrates variations in water absorption corresponding to various RHA replacement amounts and molarities. WB values varied from 2.54% to 3.02% at 10M and from 2.42% to 3.0% at 12M. As the percentage of RHA increased, WB values decreased. This reduction can be due to RHA's smaller particle size and pozzolanic nature, which increase matrix densification and lower geopolymer concrete permeability. The increased packing and extra gel formation help to reduce WB (Wong et al 2020.,). The findings indicate a consistent decline in water absorption with the increasing percentage of RHA.