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
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Map of Part of Ilorin Showing the Sampling Location
1.2 Relief and Drainage
The study area is well drained but some parts of the city close to the flood plain of the Asa river valley have drainage problems caused by the high ground water table during the raining season (Oyegun, 1982).
The topography of Ilorin is a well dissected land scape with a plateaus like surface covered by lateritic crust. The elevation of the study is 310m and it is considerably revolved from the harvest river valley.
1.3 Climate and Vegetation
The climate of Ilorin is the humid tropical type, characterized by both the wet and dry season with a mean annual temperature of 25 to 28.9 0C, also the mean rainfall 1,150mm, exhibiting the double maximum pattern between April and October every year. Days are very hot during the dry season from November to February, temperature typically ranges from 33 to 34 0C while from February to April, values are frequently between 34.6 and 370C (Jimoh, 1997).
Essentially, Ilorin is located in the transition zone between the deciduous (rain forest) of the south west ad savannah grass lands of the north (Oyegun, 1982).
The vegetation of Ilorin is composed of species of plant such as locust bean trees, shear butter trees, acacia trees, elephant grasses, shrubs and herbaceous plant among others are common in this area (Oyegun, 1982).
Further, from research of Jimoh (1997), Ilorin is underlain by basement complex rocks which composed largely of metamorphic especially Gneiss are resistance quartzites. The soil of Ilorin from the precambbian basement rocks and it is under the grass land savannah forest cover and belongs to the soil ferrugenious soil
1.4 Aim and Objectives
The aim of this study is to investigate the effect of partial replacement of conventional fine aggregate (sand) with lateritic soil in the production of sandcrete bricks.
1.5 Objectivesof the Study
The objectives of this project are;
i. to determine the compressive strength of each of the brick units when they have completely cured.
ii. to determine the maximum permissible percentage replacement with lateritic soil that satisfied this standard requirements.
1.6 Statement of the Problem
A major factor affecting the construction industry in developing countries is the cost of building materials some of which have to be imported. As prices increase sharply, there is a growing awareness to relate research to local materials as alternatives for the construction of functional but low-cost dwelling both in the urban and rural area of Nigeria.
This work seeks to study the possibility of using laterite as replacement for conventional fine aggregate (sand) in sandcrete brick production with the view of reducing the cost of building construction.
1.7 Justification
This research work will be carried out in order to replace conventional fine aggregate used
for sandcrete bricks production with lateritic soils in order to reduce the cost of production. This will be made possible due to the availability of laterite everywhere.
1.8 Scope and Limitation of the Study
The scope of this study will cover the determination of the strength of laterite replaced sandcrete brick. The investigation will be done for 10%, 20% and 30% replacement of sand with laterite available in the location of the study. The soil sample will be collected from three (3) different location in the study area. At a depth ranging from 1 meter to 2 meter of the soil profile. However, the lateritic soil firstly be characterized. The tests that will be conducted in the laboratory are Atterberg Limits Tests, Grain Size Analysis, Specific Gravity Test, Soil Compaction Test, Compression Test and the Determination of Moisture Content.
Theapplication of the result of this study will however, be limited to the locations of sample collection. Nonetheless, it can serve as guide in the evaluation of laterite from other location as replacement for fine aggregates in sandcrete bricks production.
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