Influence of Rate of Temperature Rise during Firing process on Compressive Strength of Mukono Ntawo Ball Clay

Byekwaso Ronald, Enjiku Ben D. D


This study was focused on the effect of varying the rate of temperature rise during firing process on the compressive strength of ball clay slab from Ntawo clay deposit from Mukono District, in central Uganda. The rectangular clay slabs of dimensions of 16cm by 4cm by 1cm were produced of clay particles of  45μm size. They were dried under open shade and fired at varied rate of temperature rise of 20C min-1,30C min-1,40C min-1,50C min-1 and 60C min-1to  firing temperatures of 5000C, 6000C, 7000C. 8000C, 9000C and 1000C and held at the temperatures for one hour. The fired slabs were then cooled to room temperature in the electric  furnace. The chemical composition by percentage weight of the unfired clay sample was determined by x-ray diffraction using RIX 3000 spectrometer. The compressive force of the samples were measured using 500SN-1299417 compressive machine. It was observed  that Ntawo ball clay to contained 67.20% of silica, 18.20% of alumina,2.83% of iron oxide,1.38% of titanium, 0.06% of phosphorous penta-oxide, 0.31% of calcium oxide, 0.98% of potassium oxide and 0.19% of sodium oxide. The compressive strength of the samples decreased with increase in the rate of temperature rise. The null hypothesis that the compressive strength of the fired samples did not depend on the rate of temperature rise during the firing process was rejected at α=0.05 and α=0.01 levels of significance. The decrease of compressive strength  with increase of  the rate of temperature rise between 20C min-1 to 30C min-1 was negligible for all the  firing temperatures. The percentage decrease f compressive strength with the rate f temperature rise was appreciable for firing temperatures 0f 5000C and 10000C of 11%.


Rate of temperature rise; Compressive strength; Firing temperature and Fired clay.

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. Ankara, B. (1986). Influence of firing temperature and firing times on mechanical and physical properties of clay. Istanbul:

. Aragus, & Phillipe. (2003). Brique et architecture. Paris: Madrid.

. Bowman, G. M., & Hutka, J. (2002). Particle size analysis, In soil Physical measurement and interpretation for land evaluation. New York.

. Campbell, & James. (2003). Brick; A world History. LondonThames and hudson. New York : Thames and hudson.

. Cater, Barry, C., Norton, & Grant, M. (2007). Ceramic materials: Science and engineering, Illustrated . Johannesberg: Springer, Amazon.

. Dondi, F., Kokear, M., Vaesri, B., & Kyeaser, M. (1999). Rate of temperature rise;Heating rates and rise in temperature. New York.

. Goffer, Z. (2007). Archeological chemistry analysis. Vol 170 of chemical analysis: a series of monographs on analytical chemistry and its applications. 2nd edition, illustrated. Willey – inter science . Texas, United States.

. Hall, C., & Hoff, W. (2002). Water transport in brick, stone and concrete. London and New York: Spon press.

. Highley, D., & Bloodworth, A. (2006). Ball-Clay Mineral Planning Factsheet, British Geological Survey. London: MP Factsheet.

. Hydraform. (2010-2013). History of Books. London:

. Kang, S., & Joong, L. (2005). Sintering, densification, grain growth and microstructure illustrated. Material science and engineering. Johannesberg: Reflex engineering.

. Keaves, N. (2015). Sedimentary Environment Mineral Identification. London: London Times.

. Kenoya, & Jonathan. (2005). Uncovering the keys to the Lost Indus cities. . London: Scientific Americans .

. Kerry, D. (2014). History of Bricks and Brick making. (2014, May 28). London : Designer Brick Tiles , pp. 1-2.

. Khalaf, Devenny, A. S., & Mater, J. (2002). Porosity of clay bricks, factors behind this. London.

. Kornmann. ( 2007). Clay Bricks and Roof Tiles, manufacturing and properties. London: Lasim.

. Lin, K. L. (2006). Feasibility study of using brick made from municipal solid waste Incinerator fly ash slag. New York.

. M, M. M. (1965). Clays in Uganda. Internal report MGI, Geological surveys and mines Entebbe, Uganda. Entebbe: 100pp.

. Mayone, & Mike. (2014). Brickmaking in the UK/USA: A BRIEF HISTORY. Washington DC:

. Mazen, F. (2009). Vitrification and Porosity of materials. New York: New York Times.

. McGeary, R. K. ( 1961). Mechanical packing of spherical particles . London: Amer. Ceram. Soc.

. Meland, N., & Norrman, J. O. (2010). Movement of Sediment by Water flows, Transport velocities of single particles in bed-load. New York.

. Mureramanzi, G. S. (2010). Comparative study of compressive strength Characteristics between specific burnt mud bricks and ordinary burnt clay bricks. London: London Times.

. New Delhi. (2000). Functions of mineral ingredients in clay soils and materials. New York: Science Experimental Laboratory.

. Nishikawa, A. (1984). Technology of Monolithic Refractories. London: Plibrico Japan Co.

. Nortion, F. H. (1970). Fine ceramics, Technology and Applications. New York: McGraw-Hill book .

. Nyakairu, S., Maszey, F., & Boerey, H. (2001). Analysis of Mineralogical composition of Kaolin. Kampala: SERD.

. Ogunye, F., & Boussabaine, H. (2002). Diagnosis of assessment methods for weather ability of stabilized compressed soil blocks. Construction and building materials . London.

. Peter. ( 2001). Random House. London : . London the Bioraphy , 2.

. Plumbridge. (2013). History of Local Brick Making. Paris: NAHB.

. Punmia, B. C., & Kumar. (2003). Basuc Civil engneering. Cairo: Firewall media.

. Rilem, C. P. (1984). Absorption of water by immersion under Vacuum. Materials and structures. London.

. Stoessell, L., & Hay, V. (1978). Examples of Kaolin content deposits, a look at areas around mountain Kilimanjaro. Dodoma.

. Swanage. (2008). History of Ball clay, Swanage Railway, the purbeck Mineral Mining Museum. Purbeck.

. The widespread use of Ball Clays. (2008). Introduction to Ball Clays. new York: The Ball Clay Heritage Society.

. Tigue, M. C. (2001). Mixture theory for suspended sediment transport: American Society of Civil Engineers, Proceedings. New York: Journal of the Hydraulics Division.

. Ultrone, C., Sebastian, E., Elert, K., Torre, M. J., Cazalla, O., & Vavarro, C. R. (2004). Influence of mineralogy, rate of firing and firing temperature on the porosity of bricks. New York: J Euro Ceramic soc.

. Ultrone, G. C., Sebastian, E., & Dela, M. J. (2005). Torre,Constr. Build Mater. London.

. Urbanek, T., & Lee, J. (2010). Compressive Strength of Concrete & Concrete Cubes . Washington DC: Journal of Testing and Evaluation.

. Veast, D., & Nyakairu, B. (1998). Mineralogical nature of soil and the properties therein. Johanesberg.

. Wilson, I. R. (2008). The constitution, evaluation and ceramic properties of ball clays. London: Overseas Geological services.

. World Encyclopedia. (1976). Clay Bricks, tracing its origins.


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