PSI - Issue 64
Shehroze Ali et al. / Procedia Structural Integrity 64 (2024) 1394–1401 Shehroze Ali et al. / Structural Integrity Procedia 00 (2019) 000 – 000
1399
6
overall increase in the porosity caused by the addition of fibre in the mix. The increased volume of air voids resulted in early cracking which reduced the compressive strength of GF-SFGC. Figure 4a shows a typical failure mode of the specimen tested under compression. 3.3. Flexural strength The flexural strength results of plain SFGC and GF-SFGC are presented in Table 4. Figure 3b shows the effect of the addition of glass fibre on the flexural strength of slag/fly ash geopolymer concrete (SFGC). The flexural strength of SFGC increased due to the addition of glass fibre with respect to the plain SFGC mix. The average flexural strength of GF-SFGC mix was approximately 24% higher compared to SFGC mix. The addition of glass fibre increased the adhesion in the matrix which resulted in good polymeric bonding and optimized the stress transfer mechanism. Hence, an efficient anchoring was achieved in the matrix, which controlled the overall crack development in the mix. The delayed crack propagation ended up in improving the flexural strength of GF-SFGC mix. Figure 4b shows a close-up view of the specimens tested for flexural strength test.
Table 4. Experimental results of SFGC and GF-SFGC mixes.
Compressive strength (MPa)
Flexural strength (MPa)
Mix
7 days
28 days
56 days
28 days
Average
SD
Average
SD
Average
SD
Average
SD
SFGC
34.5 33.7
1.05 1.37
54.4 52.0
1.08 0.85
58.7 57.0
1.07 0.82
5.1 6.3
0.22 0.26
GF-SFGC
*SD = standard deviation.
b
80
8
a
SFGC GF-SFGC
60
6
40
4
20 (MPa)
2
days (MPa)
0
0
Compressive Strength
Flexural Strength @ 28
7 days
28 days
56 days
SFGC
GF-SFGC
Age
Mix
Fig. 3. Average strengths of SFGC and SFGC mixes: (a) compressive strength; and (b) flexural strength.
a
b
Fig. 4. Failure mode: (a) compressive strength test specimens; and (b) close-up view of flexural strength test specimens.
Made with FlippingBook Digital Proposal Maker