PSI - Issue 68

Eyad Shahin et al. / Procedia Structural Integrity 68 (2025) 238–244 E. Shahin et al. / Structural Integrity Procedia 00 (2025) 000–000

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2.3. Uniaxial tensile test The uniaxial tensile test was conducted to evaluate the tensile strain-hardening behavior of ECC with 30% to 90% GGBS replacement. Dogbone specimens, as shown in Figure 1(a), were used for the tensile tests, with three specimens tested for each mixture. The gauge length for the measurement setup was established at 72.5 mm and including half the width of the top holder (7.5 mm), resulted in a total gauge length of 80 mm, as shown in Figure 1(b). The tensile test was performed using a 100 kN Instron testing machine, with a controlled loading rate of 1 mm/min. The force was automatically recorded using a data acquisition system. Tensile displacement was measured using two external linear variable displacement transducers (LVDTs) placed on either side of the dogbones, as shown in Figure 1(b). The strain for each specimen was determined from the elongation measured by these LVDTs. 2.4. Quasi-static compressive test The compressive test was performed in accordance with ASTM C109/C109M-21, ASTM (2020). Three cube specimens from each ECC mixture, each 50 mm in size, were prepared to assess the residual compressive strength following exposure to elevated temperatures. After these specimens cooled, compression tests were conducted on the 50 mm cubes, including control specimens that were not subjected to high temperatures. These tests utilized a closed-loop controlled servo valve concrete compression machine with a capacity of 5000 kN, as shown in Figure 1(c), and a stress control rate of 0.20 MPa/sec. Load values during the tests were captured using a computerized data recording system. For each test phase, three specimens were tested, and the average values were recorded.

Fig. 1. (a) dogbone dimensions; (b) Tensile test setup of dogbone; (c) 5000 kN servo valve controlled concrete compression machine.

2.5. Rapid chloride permeability test (RCPT) Chloride-induced corrosion of reinforcing steel is a significant cause of concrete deterioration, leading to expensive repairs in structures like bridges and marine installations. The Rapid Chloride Permeability Test (RCPT), a widely used method for assessing concrete's resistance to chloride ion penetration, measures the electrical charge passed through a concrete sample over six hours, ASTM (2012). In this study, PE-ECC cylinder specimens with 100 mm diameter and 200 mm in height from G30, G60, and G90 mixtures were tested using RCPT, as shown in Figure 2(b). The specimens were fully saturated, sealed, and subjected to a 60V DC voltage, as shown Figure 2(a).