Open Journal Systems

Effective thermal conductivity of foamcrete of different densities

Md Azree Othuman Mydin

Abstract


The main purpose of this study is to investigate the thermal conductivity of foamed concrete. Various densities of foamed concrete samples ranging from 650, 700, 800, 900, 1000, 1100 and 1200 kg/m3 with constant cement-sand ratio of 2:1 and water-cement ratio of 0.5 were produced. This study was limited to the effect of density, porosity and pore size on thermal conductivity of foamed concrete. Hot-guarded Plate method was used to obtain the thermal conductivity of foamed concrete at different densities. The porosity value of foamed concrete was determined through the Vacuum Saturation Apparatus. In turn to examine the effect of pore size on thermal conductivity of foamed concrete, pore size measurements were made under a microscope with a magnification of 60x. Lower density foamed concrete translates to lower thermal conductivity. The density of foamed concrete is controlled by the porosity where lower density foamed concrete indicates greater porosity. Therefore, thermal conductivity changes considerably with the porosity of foamed concrete because air is the poorest conductor compared to solid and liquid due to its molecular structure.

Keywords


foamed concrete; thermal conductivity; hot-guarded plate; thermal properties; lightweight concrete; porous material

Full Text:

PDF

References


Huang, C. L. Pore Structure Properties of Materials, Fu-Han, Tainan, Taiwan, 1980.

Yunsheng, X., Chung, D.D.L. Effect of sand addition on the specific heat and thermal conductivity of cement. Cem. Concr. Res. 2000. 30(1): p. 59-61

Budaiwi, I., Abdou, A., Al-Homoud, M. Variations of thermal conductivity of insulation materials under different operating temperatures: Impact on envelope-induced cooling load. J. of Archaeological Engineering 2002. 8(4): p 125-132.

BCA. Foamed concrete: Composition and properties. Report Ref. 46.042, Slough: BCA, 1994.

Jones, M. R., McCarthy, A. Preliminary views on the potential of foamed concrete as a structural material. Mag. Concr. Res. 2005. 57(1): p 21-31.

Kessler, H. G. Cellular lightweight concrete, Concrete Engineering International, 1998. p 56-60.

Aldridge, D., Ansell, T. Foamed concrete: production and equipment design, properties, applications and potential. In: Proceedings of one day seminar on foamed concrete: Properties, applications and latest technological developments, Loughborough University, 2001.

Weigler, H., Karl, S. Structural lightweight aggregate concrete with reduced density - Lightweight aggregate foamed concrete. Int. J. Lightweight Concr. 1980. 2(2): p 101-104.

Md Azree, O. M. Effect of using additives to the compressive strength of lightweight foamed concrete. Master Dissertation, School of Housing, Building and Planning, University of Science Malaysia, Penang, 2004.

ASTM. C 150-02a. Standard Specification for Portland Cement. ASTM, West Conshohocken, PA, 2002.

BS EN 12. Specification for Portland Cement. British Standards Institution, London, 1991.

BS EN 12620. Aggregates for Concrete. British Standards Institution, London, 2002.

Website: www.portafoam.com

ASTM C 177-97. Standard test method for steady-state heat flux measurements and thermal transmission properties by means of the guarded-hot-plate apparatus. American Society for Testing and Materials, 1997.

Cabrera, J. G., and Lynsdale, C. J. A new gas permeameter for measuring the permeability of mortar and concrete. Mag. Concr. Res., 1998. 40(144): p. 177-182.

Demirboga, R., Gul, R. The effects of expanded perlite aggregate, silica fume and fly ash on the thermal conductivity of lightweight concrete.Cem. Concr. Res. 2003. 33(10): p 723-727.

Narayanan, N., Ramamurthy, K. Structure and properties of aerated concrete: a review. Cement Concrete Composites 2000. 22(5): p 321–329.


Refbacks

  • There are currently no refbacks.