1. 1) Berntsson, L. and Chandra, S., (1982). “Damage of concrete sleepers by calcium chloride.” Cement and Concrete Research, 12(1), 87-92.
2. 2) Broch, J. T., (1984). “Mechanical vibration and shock measurements.” Denmark: Brüel & Kjær.
3. 3) BS EN 12390-3, (2009). “Testing hardened concrete: Part 3: Compressive strength of test specimens.” London, UK: British Standards Institution.
4. 4) BS EN 12620, (2013). “Aggregates for Concrete.” London, UK: British Standards Institution.
5. 5) BS EN 13230-1, (2009). “Railway applications-track-concrete sleepers and bearers-part 1: General requirements.” London, UK: British Standard Institution.