The major constituent material in block production which is river sand, is costly, scarce and unavailable in some places. This has serious effect on the production cost of blocks used in construction. Flexural strength which is an important mechanical property has been ignored to an extent with regards to block moulding technology. This work presents the flexural strength of soilcrete blocks made with readily available and affordable late rite and the optimization of the flexural strength using Scheffe�s simplex lattice design method. Statistical tools were used to verify the proposed optimization technique. The optimum value of the flexural strength is 1.452N/mm2.

Optimisation, Flexural Strength, Soilcrete Blocks, Scheffe�s Simplex Method

[1] I.O. Agbede, and J. Manasseh, �Use of cement-sand admixture in lateritic brick production for low cost housing� Leornado Electronic Journal of Practices and Technology, 12, 2008, pp163-174.
[2] L. Boeck, K.P.R. Chaudhuri, H.R. Aggarwal, �Sandcrete blocks for buildings: A detailed study on mix compositions, strengths and their costs� The Nigerian Engineer, 38 (1), 2000.
[3] J.I. Aguwa, �Performance of laterite-cement blocks as walling units in relation to sandcrete blocks,�. Leornado Electronic Journal of Practices and Technologies, 9(16), 2010, pp 189-200.
[4] O.S. Komolafe, �A study of the alternative use of laterite-sand-cement�, Proc. Conference on Materials Testing and Control, University of Science and Technology, Owerri, Imo State, Feb. 27-28, 1986.
[5] A.M. Neville, �Properties of concrete,� 3rd ed. London, Pitman, 1981
[6] J.C. Ezeh, O.M. Ibearugbulem, U.C. Anya, �Optimisation of aggregate composition of laterite/sand hollow block using Scheffe�s simplex method,� International Journal of Engineering, 4(4), 2010, pp471-478.
[7] B.O. Mama, and N.N. Osadebe, �Comparative analysis of two mathematical models for prediction of compressive strength of sandcrete blocks using alluvial deposits�, Nigerian Journal of Technology, Vol.30 (3), 2011
[8] O.U. Orie, �Five-component-concrete mix optimisation using Scheffe�s theory � A case study of mound soil as a mix component�, Thesis (PhD). Civil Engineering department, University of Benin, 2008.
[9] C.E. Okere, D.O. Onwuka, S.U, Onwuka, J.I. Arimanwa, �Simplex-based Concrete mix design,� International Organisation of Scientific Research Journal of Mechanical and Civil Engineering. Vol. 5, Issue 2, 2013, pp 46-55.
[10] S.O. Obam, �A model for optimisation of strength of palm kernel shell aggregate concrete�, Unpublished thesis. Civil Engineering department, University of Nigeria, Nsukka, 1998.
[11] British Standard Institution, BS 882: 1992, �Specification for aggregates from natural sources for concrete�, 1992.
[12] British Standards Institution, BS EN 1008:2002. �Mixing water for concrete � Specification for sampling, testing and assessing the suitability of water, including water recovered from processes in the concrete industry, as mixing water for concrete� 2002.
[13] H. Scheffe, �Experiments with mixtures,� Royal Statistical Society Journal, Series B. 20, 1958, 344-360.