1. ASTM C642. (2006). Test method for specific gravity, absorption, and voids in hardened concrete. West Conshohocken: ASTM International.
2. BS EN 12390-2. (2000). Testing hardened concrete. Making and curing specimens for strength tests. London: British Standards Institution.
3. BS EN 12390-3. (2002). Testing hardened concrete. Compressive strength of test specimens. London: British Standards Institution.
4. BS EN 12390-6. (2009). Testing hardened concrete. Tensile splitting of test specimens. London: British Standards Institution.
5. Bui, D. D., Hu, J., & Stroeven, P. (2005). Particle size effect on the strength of rice husk ash blended gap-graded Portland cement concrete. Cement and Concrete Composites,27(3), 357–366.