Engineering Properties of Normal Concrete Grade 40 Containing Rice Husk Ash at Different Grinding Times

The effect of rice husk ash produced at different grinding times on the engineering properties of concrete was studied. Eight rice husk ashes representing different grinding times were used in this investigation. Rice husk ash (RHA) was used to partially replace Portland cement Type I at 15% by weight of cementitious material. The compressive strength of concrete was designed to achieve grade 40 N/mm2 at 28 days. A super plasticizer was added to all mixes to provide workability in the range of 110-120 mm. However, the water to cement ratio (w/c) of the concrete was maintained at 0.49. Based on the results, the morphology of the rice husk ashes was changed by grinding. Optimum grinding time appeared to be approximately 90 minutes, during which time the compressive strength increased significantly. Generally, incorporation of RHA at various grinding times can dramatically decrease or increase the engineering properties of concrete.

Grinding, Compressive strength, Superplasticizer, Concrete, Rice husk ash

ASTM C204-07, Standard Test Methods for Fineness of Hydraulic Cement by Air-Permeability Apparatus. American Society for Testing and Materials.

ASTM C618-08, Standard Specification for Coal Fly Ash and Raw or Calcined Natural Pozzolan for Use as a Mineral Admixture in Concrete. American Society for Testing and Materials.

Bouzoubaâ, N., & Fournier, B., 2001. Concrete Incorporating Rice-husk Ash: Compressive Strength and Chloride-ion Penetrability. Materials Technology Laboratory. Mtl 2001-5 (tr).

BS 882:1992, Specification for Aggregates from Natural Sources for Concrete. British Standards Institution.

BS EN 12390-3:2002, Testing Hardened Concrete, Compressive Strength of Test Specimens. British European Standards Specifications.

BS EN 12504-2:2001, Determination of Rebound Number. British European Standards Specifications.

BS EN 12504-4:2004, Determination of Ultrasonic Pulse Velocity. British European Standards Specifications.

Coutinho, JS., 2003. The Combined Benefits of CPF and RHA in Improving the Durability of Concrete Structures, Cement and Concrete Composites, Volume 25, Number 1, pp.51-59.

Fowell, RJ., & Johnson, ST., 1982. Rock Classification and Assessment for Rapid Excavation. Proceedings of the Symposium on Strata Mechanics, Newcastle upon Tyne; 1982. pp. 241-249.

Gaydecki, P., Burdekin, F., Damaj, W., John, D., Payne, P., 1992. The Propagation and Attenuation of Medium-frequency Ultrasonic Waves in Concrete: a Signal Analytical Approach. Measurement Science and Technology, Volume 3, Number 1, pp. 126.

Hewlett, P C., 1998. Lea’s Chemistry of Cement and Concrete, Fourth Edition, Oxford: Elsevier.

Isaia, GC., Gastaldini, ALG., Moraes, R., 2003. Physical and Pozzolanic Action of Mineral Additions on the Mechanical Strength of High-performance Concrete, Cement & Concrete Composites, Volume 25, Number 1, pp. 69-76.

Kim, JK., Kim, CY., Yi, ST., Lee, Y., 2009. Effect of Carbonation on the Rebound Number and Compressive Strength of Concrete, Cement & Concrete Composites, Volume 31, Number 2, pp. 139–144.

Mehta, PK., 1987. Supplementary Cementing Materials for Concrete, Canada Centre for Mineral and Energy Technology (CANMET), Energy, Mines and Resources, Canada, pp. 3-33.

Mehta, PK., & Folliard, KJ., 1994. Rice Husk Ash - a Unique Supplementary Cementing Material, CANMET/ACI Symposium in Advance Concrete Technology, Michigan, USA, ACI SP-154, pp. 419-444.

Paya, J., Monzo, J., Borrachero, MV., Peris-Mora, E., 1995. Mechanical Treatment of Fly Ashes: Part I. Physico-chemical Characterization of Ground Fly Ashes, Cement and Concrete Research, Volume 25, Number 7, pp. 1469-1479.

Qudais, SAA., 2005. Effect of Concrete Mixing Parameters on Propagation of Ultrasonic Waves, Construction and Building Materials, Volume 19, Number 4, pp. 257–263.

RILEM TC116-PCD., 1999. Permeability of Concrete as a Criterion of its Durability, Materials and Structures, Volume 32, Number 217, pp. 163-173.