PSI - Issue 64

Sareh Akbarpoor et al. / Procedia Structural Integrity 64 (2024) 822–832 Sareh Akbarpoor/ Structural Integrity Procedia 00 (2019) 000 – 000

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2.1. Materials

2.1.1. Concrete The compressive strength of the concrete specimens was evaluated after a 28-day curing period using concrete cubes, in accordance with BS EN 12390-3 (2019). Testing was conducted with a loading rate set at 0.6 ± 0.2MPa/s. The mean values from three specimens are detailed in Table 2. 2.1.2. CFRP composites A CFRP laminate (Sika CarboDur S NSM 1030, width 10 mm, thickness 3 mm) was used.. The mechanical properties provided by manufactures are detailed in Table 2. 2.1.3. Epoxy Adhesive (EA) The epoxy adhesive (Sikadur®-330) was utilised in the study and its mechanical properties provided by the manufacturer are listed in Table 2. 2.1.4. Developed Cement-based Adhesive (CBA) A new cement-based adhesive was developed by using cement, water, micro-cement, filler, silica fume, super plasticizer, and primer, as presented in Table 3. The materials used for developing this adhesive are as follows: • Portland cement 52.5 • Micro-cement(Sika® InjectoCem-190) was used which is a two-part, mineral injection grout (d95 < 9.5 μm). • Filler: Oven-dried sand with the maximum size of 1.18 mm was used. • Silica Fume (SikaFume-50 S) was used in order to increase the bond (Al-Abdwais, and Al-Mahaidi, 2016a). • Super-plasticizer: (ViscoCrete-25 MP, supplied by Sika) was utilised. • Primer: Sikadur®-52 Injection Type N, was used which is a two-part epoxy with low viscosity and a normal pot life. After 28 days, mechanical properties were obtained in accordance with the standard BS EN 1015 – 11 (2019), utilising a beam specimen measuring 40 mm x 40 mm x 160 mm, as detailed in Table 2 and shown in Fig. 2. By adjusting the amount of super-plasticizer, the appropriate viscosity was achieved to maintain stability of the adhesive in the groove, preventing any unintended flowing. Therefore, the flow table test, conducted in accordance with BS EN 1015-3 (1999), was used to determine a suitable value for the desired viscosity, as detailed in Table 2.

Table 3. Mix ratio of CBA

Water / Cement

Water / (Cement+Micro-Cement (powder part))

Water / Binder1*

Water / Binder2**

Filler / Binder 1*

mix

CBA

0.20

0.16

0.15

0.13

0.79

*Binder1 = Cement + Micro-Cement (powder part) + Silica Fume **Binder2 = Cement + Micro-Cement (powder part) + Silica Fume +Primer