EFFECT OF MUNICIPAL HEATING SYSTEM COAL ASH ON THE INSULATION PROPERTIES OF LIGHT WEIGHT CONCRETE

Abstract

Large quantities of coals have been used as fuel use for central heating system in Turkey. It has been causing a considerable waste that has been dumped into landfills. On the other hand enhanced construction activities, shortage of conventional building materials and abundantly available industrial wastes have promoted the development of new building materials. In this study, usage of coal ash as supplementary building material in light weight concrete was investigated. For this purpose, chemical analyses of the coal ash, perlite, and silica fume samples were determined. Lime was added to the coal ash as a binder. The binder (slaked lime) ratio was kept constant at 45% throughout this study. In order to get comparable results samples were prepared with five different compositions. Expanded perlite and silica fume added some mixtures. After certain time of curing, physical and mechanical tests were conducted. It was concluded that, coal ash can be used economically for the production of lightweight building blocks (LWBB). Optimal strength-thermal conductivity combination was obtained by the usage of silica fume and expanded perlite together. Improved strength properties were obtained by using hydrothermal curing conditions and super plasticizer addition

Keywords

• Coal ash, silica fume, expanded perlite, lime, lightweight concrete blocks

References

1. ASTM C 109. Standard test method for compressive strength of hydraulic cement mortars. ASTM; 1993.
2. ASTM C 494. Standard specification for chemical admixtures for concrete. ASTM 1994.
3. ASTM C 618. Standard specification for coal fly ash and raw or calcined natural pozzolan for use a mineral admixture in concrete. ASTM; 2003.
4. ASTM C 1113-90. Test method for thermal conductivity of refractories by hot wire (Platinum resistance thermometer technique).
5. Demirboga R, Orung I˙, Gul R. Effects of expanded perlite aggregate and mineral admixtures on the compressive strength of low-density concretes. Cement and Concrete Research 2001;31:1627–32.
6. Kayali O., Fly ash lightweight aggregates in high performance concrete, Construction and Building Materials 22 (2008) 2393–2399
7. Karakoc M.B. Effects of expanded perlite aggregate on physical and mechanics properties of high strength concrete. A Master‟s thesis, Department of Civil Engineering, Ataturk University, Erzurum, Turkey; 2004.
8. Neville AM, Brooks JJ. Concrete Technology. Longman Scientific and Technical; 1987. p. 188, 349.

9. Mulenga DM, Stark J, Nobst P. Thaumasite formation in concrete and mortars containing fly ash. Cement Concrete Compos 2003;25:907–12.
10. TS EN 678. Determination of the dry density of autoclaved aerated concrete, this standard specifies the procedure for the determination of dry density of autoclaved aerated concrete. Turkish Standards Institution (TSE); 1995.
11. TS EN 679. Determination of the compressive strength of autoclaved aerated concrete, This standard specifies the procedure for the determination of the compressive strength of autoclaved-aerated concrete, 1995.
12. TS EN 992. Determination of the dry density of lightweight aggregate concrete with open structure, this standard, specifies a method of determining the dry density of light weight aggregate concrete with open structure. Turkish Standards Institution (TSE) 1998.
13. TS 3624. Test method for determination the specific gravity the absorption water and the void ratio in hardened concrete, this standard specifies the test method for determination the specific gravity, the absorption water and void ratio in hardened concrete. Turkish Standards Institution (TSE); 1981.
14. TS EN 12350-2. Testing fresh concrete- Part 2: slump test, this standard specifies two procedures for sampling fresh concrete bycomposite sampling and by spot sampling. Turkish Standards Institution (TSE); 2002.
15. Yasar E, Atis CD, Kilic A, Gulsen H. Strength properties of lightweight concrete made with basaltic pumice and fly ash. Materials Letters 2003;57:2267–70