PSI - Issue 30

A.K. Kychkin et al. / Procedia Structural Integrity 30 (2020) 173–178 Kychkin A.K., Struchkov N.F., Vinokurov G.G. et al. / Structural Integrity Procedia 00 (2019) 000–000

175

3

Fractographic studies of basalt fiber reinforced polymers were carried out using an Olympus SZX-10 optical stereomicroscope. The structure of longitudinal sections of basalt fiber reinforced polymers was studied using a JEOL JSM-7800F scanning electron microscope. 3. Results and Discussion To assess the effect of exposure to climatic tests on the structure of basalt fiber reinforced polymers, thin sections of cross-sections of basalt fiber reinforced polymer rebars with diameters of 6, 8 and 20 mm were studied. The areas where the samples of basalt fiber reinforced polymers were cut were carefully polished. Figure 1 shows fragments of the obtained thin sections with a magnification of 25×, before and after exposure. Analytical studies have established that in the initial state the structure of basalt fiber reinforced polymers is rather homogeneous and monolithic (Fig. 1 a). Revealed the dense content of reinforcing basalt fibers; only individual pores up to 10–20 microns in size are observed.

Fig. 1. Images of polished transverse sections of basalt fiber reinforced polymers of rods with a diameter of 20 mm: (a) in the initial state and (b) after exposure (magnification ×25).

It was found that after climatic tests, the homogeneity and solidity of basalt fiber reinforced polymers are noticeably disturbed (see Fig. 1 b). Significant porosity appears, the number of pores in the cross section of basalt fiber reinforced polymers increases by almost ~ 1.5 times. On Fig. 2 shown a fragment of a longitudinal section of the basalt fiber reinforced polymer of the rod after exposure. As can be seen from the images, the formation of pores at the micro level between the basalt continuous fibers is clearly observed. It should be assumed that with more prolonged climatic, the pores at the microlevel will significantly increase and coagulate, forming the porosity of the basalt fiber reinforced polymer at the macrolevel.

a

b

Fig. 2. Longitudinal section of a basalt fiber reinforced polymer rod with a diameter of 20 mm after exposure; magnification: a) ×1000, b) ×5000