PSI - Issue 60

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Swathy S et al. / Procedia Structural Integrity 60 (2024) 591–603 Swathy S et al./ Structural Integrity Procedia 00 (2019) 000 – 000

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Fig 4 Polypropylene fibre The slab designated as SP2-SBF were strengthened using BFRP fan in following steps: Holes were drilled through the thickness of slab at 16 designated locations which were marked after the curing period of 28 days. The loose materials were removed and cleaned using air compressor further fan shaped slits were formed on both faces of slab using concrete cutter. Epoxy resin (Nitobond) was mixed at the time of impregnating the slits, and cables were used to tie together the fibers which were impregnated with the resin and the end of the cable tie was chopped off. After the above process, slits were coated with epoxy resin and BFRP rope like string were inserted into the holes filled with adhesive (Sika dure 330). Finally, the prepared fibers were impregnated into the slits using a brush and holes were levelled with plastering cement hardener (white cement). Fig.5 shows the distribution of BFRP string over the critical sections for slabs which are reinforced with 16 BFRP fans.

Fig 5 Preparation of slab

Slab SP3-SBL was provided for strengthening using basalt laminate in which basalt strips are obtained from basalt fabrics and the dimension of basalt strip is 1000 x100 mm. Four strips of the dimension is laminated using epoxy resin ( Nitibond) in a radial pattern like a star shaped pattern on both the top and bottom surface for preparing the specimen following steps are followed: the slab was air compressed and cleaned then the section is marked which is to be laminated, the resin is applied over the marked section over the slab dimension, the basalt strip is pasted over the slab and an another coat of epoxy resin is applied over the specimen on both top and bottom surface of the specimen. 1000x 100 mm basalt strip is laminated in radial pattern on both top and bottom surface of the slab to be strengthened.