The Effect Of Partial Replacement Of Conventional Fine Aggregate (sand) With Lateritic Soil In The Production Of Sandcrete Bricks

CHAPTER ONE
1.0     Introduction   
Lateritic soils are formed in hot, wet tropical regions with an annual rainfall between 750 to 300mm, (usually in areas with a significant dry season) on a variety of different types of rock with high iron content. The location on the earth, that characterize these conditions fall between latitude 35oS and 35oN (Person, 1970).
Laterisation is the removal of silicon through hydrolysis and oxidation that result in the formation of laterite and lateritic soil. The degree of laterization is estimated by the silica-sesquioxide (S-S) ratio (SiO2) (Fe2O3+Al2O3). The silica-sesquioxide (S-S) ratio less than 1.33 are indicative of laterites, those between 1.33 and 2.00 are lateritic soil and those greater than2.00 are no laterite types. (Lasisi and Ogunjimi, 1984).
High cost of building materials has been the bane of construction industry in the developing countries of the world. This is as a result of importation of some of the material. As price increases sharply, there is a growing awareness to relate research to local materials as alternative for the construction of functional, but low cost dwelling both in this urban and rural areas. One of such local materials that is being researched is lateritic soil.
Lateritic soils has been one of the major building materials in Nigeria for a long time. The main reason lies on the fact that it is readily available and the cost of procuring it is relatively low.
According to Akintorinwa et.al, (2012),lateritic soil abounds locally and its use mainly limited to civil engineering work like road construction and land fill operation.It is less utilized in the building industry except in filling work. In lieu of abundance of lateritic soil and its availability, its optimum use in building production could positively affect the cost of buildings leading to the production of more affordable housing units.(Joshua and Lawal, 2011). It’s use in the building production is not yet generally accepted because there are no sufficient technical data in it, house limited it’s wider applicable in building construction work (Udoeyoet.al, 2006).
Studies are currently going on in the use of lateritic soil in concrete production where laterite is made to partly or wholly replace conventional fine aggregate in the production of concrete know as laterized concrete and in the production of bricks units such as Compressed Laterized Brick (CLB), usually stabilized with cement. Presently these application are mostly limited to building in rural areas and low income housing project which are mostly situated at satellite areas (out skirts) of Central Business Areas (CBA’s).
This study seeks to contribute to the potential use of laterite as replacement for fine aggregate in the production of bricks.
1.1    Location and Accessibility
    The sample is along the Asa-dam Ilorin, Kwara state. The location is defined by longitude E0040 321 52.61 and the latitude N080 27102.41. The location is an open space and thus easily accessible. It is essentially a road cut