Ctf is a white adhesive and expensive as well....bal rapid set is fine for asphalt floors as it is polymodified to start with..but if you want that extra added flex then go for bal rapid set flexi.....bal ptb flexi is good for large format tiles but needs practice to work with it......
her's some info on those adhesives for you mat.........
BAL Rapidset
A cement-based, polymer modified, non-slip, rapid setting, water-resistant and frost-resistant adhesive suitable for fixing ceramic wall and floor tiles including fully vitrified and porcelain, ceramic mosaics, quarry tiles, dark natural stone, terrazzo and brick slips. Suitable for a variety of backgrounds/bases including concrete/brick/block walling, cement:sand rendering, gypsum plaster, plasterboard, fibre cement sheets, cement:sand screeds, ceramic/quarry tile/terrazzo/hard natural stone, vinyl tiles/sheet, mastic asphalt. BS EN 12004 C2FT Adhesive.
BAL Rapidset Flexible
A flexible, rapid-setting, non-slip, water-resistant and frost-resistant wall and floor tile adhesive especially suitable for fixing tiles, including fully vitrified and porcelain tiles to low porosity backgrounds and bases. Suitable for use on concrete/brick/block walling, cement:sand rendering, plaster, plasterboard, cement sheets, tile backer boards, concrete bases, cement:sand screeds, plywood overlay, ceramic/quarry tile/terrazzo/hard natural stone, vinyl tiles/sheet, mastic asphalt. BAL Rapidset Flexible white is especially ideal for fixing natural stone, slate, marble (including translucent marble) and travertine. Conforms to BS EN 12004, Type C, Class 2FT.
BAL PTB (Pourable Thick Bed) Flexible
A highly polymer modified, flexible, rapid-setting, water-resistant, frost-resistant floor tile adhesive, especially suitable for fixing tiles, including fully vitrified and porcelain tiles to low porosity backgrounds and bases. Sulphate-resistant, cement-based, pourable, thick-bed solid-bed floor tile adhesive suitable for fixing ceramic tiles, quarries, natural stone and terrazzo in interior and exterior situations. Its consistency makes it particularly suitable for fixing large tiles and those with profiled backs. Back-buttering is not necessary. Suitable for use on concrete, cement:sand screeds, ceramic/quarry tile/terrazzo/hard natural stone, plywood overlay, vinyl tiles/sheet, mastic asphalt. BS EN 12004 C2F Adhesive
BAL CTF 3
White, cement-based, polymer modified, non-slip, water-resistant and frost-resistant adhesive suitable for fixing ceramic wall and floor tiles, ceramic mosaics, quarry tiles, natural stone, terrazzo and brick slips. Suitable for a variety of backgrounds/bases including concrete/brick/block walling, cement:sand rendering, gypsum plaster, plasterboard, fibre cement sheets, cement:sand screeds, ceramic/quarry tile/terrazzo/hard natural stone, vinyl tiles/sheet, mastic asphalt.