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

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water and superplasticizer were added in the mixer and mixed for 3 min. The total mixing time for SFGC and GF SFGC were 7 mins and 8 mins, respectively. After mixing, the mixer was stopped, and the slump test was conducted to measure the workability of fresh mixes of SFGC and GF-SFGC. A standard polyvinyl chloride (PVC) mould of 100 mm diameter × 200 mm height was used to cast the specimen for the compressive strength test. A total of nine specimens were prepared to determine 7, 28 and 56-day compressive strength for each of the mix (SFGC and GF-SFGC). The densities of the mixes were determined using three specimens for each of the mix cast in PVC moulds of 150 mm diameter × 300 mm height. To determine the flexural strength, three specimens for each type of the mix were cast using plywood prism moulds of 100 mm square cross section and 500 mm length. The fresh mixes of SFGC and GF-SFGC were poured into the moulds using scoops. The moulds were filled in three equal layers, each layer was compacted using an electric vibrator (approximately 10-12 seconds/per layer) to allow air bubbles/voids to break-through the top surface and achieve a relatively smooth surface of concrete. The top surfaces were finished using a trowel and the specimens were kept under an ambient curing condition for 7 days. Figure 1 shows the mixing and preparation of SFGC and GF-SFGC specimens. After 7 days, the specimens were taken out of the moulds and left in the laboratory under ambient curing condition (average temperature 22 °C) until the day of testing.

Fig. 1. Mixing and preparation of SFGC and GF-SFGC specimens.

2.4. Testing All the testing of SFGC and GF-SFGC mixes were conducted at the laboratories of the University of Wollongong, Australia. The workability of the fresh mixes was determined using a slump test in accordance with AS 1012.3.1-14 (AS 2014). The density of SFGC and GF-SFGC mixes were determined using the weight of the hardened specimens measured on the day of testing in accordance with AS 1012.1-14 (AS 2014). Since, the samples were cured at ambient-cured laboratory conditions, no significant volume shrinkage was observed. The compressive strength of the SFGC and GF-SGGC mixes were determined in accordance with AS 1012.9-14 (AS 2014). All the specimens tested for compressive strength were capped with high strength plaster to achieve a uniform loading face. A compression machine (MATEST) with a loading capacity of 3000 kN was used to conduct the compression strength test. The flexural strength of the mixes was determined in accordance with AS 1012.11-14 (AS 2014). All the specimens tested for flexural strength were checked and ensured that none of the test specimens had surface cracking prior to loading. A universal machine (Instron) with a loading capacity of 500 kN was used to conduct the flexural strength test. All the specimens for flexural strength were tested to failure, under a force-