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The Effect Of Partial Replacement Of Conventional Fine Aggregate (sand) With Lateritic Soil In The Production Of Sandcrete Bricks
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1. Weaker tropical weathering give rise to formation of saprolites which are the prevailing weathering product in the tropics and are frequently misinterpreted as laterites
2. Advanced tropical weathering result in the formation of most of the laterites showing a much stronger enrichment of Fe against Al. a higher tropical rainfall end a moderate drainage together with the presence of quartz are generally not sufficient for pronounced incongruent kaolinite dissolution and a pronounced formation of gibsites
3. Strong tropical weathering is prompted by a very pronounced rainfall, a deep ground water level and a high permeability of the weathered rock, allowing an excellent drainage. These factor cause an incongruent dissolution of kaolinites. The composition of the laterites is determined by the imposition of the parent rock
2.8.2 Regional Distribution
Lateritic soil which cover extensive areas in tropical areas or countries with intermittently moist climate. Its occurrence is peculiar to regions having alternating wet and dry period and hot humid conditions (Shally, 2005).
Laterite are widely distributed throughout the world in the region with high rainfall, but especially in the inter-tropical regions of Afica, India, South-east, Asia and South America where they generally occur just below the surface of grassland (Ciria, 1995).
2.8.3 Characteristics of Laterites
The characteristics of laterites include the following
• Extreme form of red soil type
• Leaching of alkalis and silica
• Accumulation of sesquioxides in top layer
• Crust formation near the surface, nodular concentrations, in duration
• When dry, it becomes hard and thus forms a useful building material
• Soil reaction is acidic
• Poor bases saturation (Ashworth, 1996).
2.8.4 Composition of Lateritic Brick
Lateritic is composed of both cohesion and cohesive soil. This form the basis of laterite being referred to as C-Q (C-phi) soil. The cohesionless portion consist of gravel sand and silt which the cohensive portion includes fine particles usually in silt and clay sizes. Laterite soil behave in a unique way with some laterite changing volume when exposed to humidity variation while others are not affected. Hence some components are referred to as unstable. Stability in this sense is based on their ability to withstand variation in term of moisture without a significant change in its properties which is of courses fundamental in material for building construction leasthurba et al (2007)describe the properties of each of these components of lateritics soil as follow
a) Gravel composed of fragment of rock of varying hardness, whose size fall between 2 and 20mm with stable mechanical properties when it comes in contact with water
b) Sand composed of mineral particles with size ranging between 0.06 and 2mm stable, though lack cohesion when dry, it has an appreciable degree of internal friction which means, it offers a great resistance (i.e mechanical) to intraparticle movement. It is normally characterized by apparent cohesion when wet due to the surface tension of water present in the void spaces
c) Silts consist of grains particle ranging from 0.002 to 0.06mm, cohesion is low when dry and it offer resistance intra –particle movement than sands. Silts are characterized by cohesion and therefore cannot be used independently as main material for building
d) Clay the finest of the particle size in lateritic soil, generally smaller than 0.002mm their characteristics differ completely from the larger sized particles in that they consist mainly of microscopic clay mineral which includes kaolinite, illite, and montorillonite. Clay particle are usually located in a thin-film of absorbed water molecules and since they are microscopic, they tend to be very light in comparison to surface tension forces acting on the film of absorbed water clay unlike gravel and sand are not stable and quite sensitive to varying humidity due to strong attraction of clay to water, its volume increases due to increase in moisture content as a result of thick film of absorbed water (Mitchell and soga, 2005). On the other hand as clay dries out, shrinkage cracks may appear in the clay mass with a reduction in strength
Humus or top soil
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ABSRACT - [ Total Page(s): 1 ]ABSTRACT WILL BE HERE SOON ... Continue reading---
CHAPTER ONE - [ Total Page(s): 2 ]CHAPTER ONE1.0 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 ... Continue reading---
CHAPTER THREE - [ Total Page(s): 7 ]ProcedureAbout 200g of soil sample was passed thoroughly with distilled water to form a uniform paste. A portion of the paste was placed in a brass trough bar (linear shrinkage trough device). The surface of sample was leveled and smoothened off to the brass of the trough bar and the trough was then placed in an oven for 24 hours at temperature of about 105°C. The initial length of the trough bar filled with the soil sample was taken. After 24 hours, the trough bar was brought out of the oven ... Continue reading---
CHAPTER FOUR - [ Total Page(s): 15 ]PERCENTAGE OF STABILIZER ... Continue reading---
CHAPTER FIVE - [ Total Page(s): 1 ]CHAPTER FIVE5.0 CONCLUSIONS, REFERENCE AND RECOMMENDATION. 5.1 Conclusion. Tests
have been conducted to evaluate the suitability of lateritic soils
along Asa dam area Ilorin kwara state and its effect on the strength of
sandcrete bricks when used to replace the conventional fine aggregate,
the following conclusions can be drawn from the analysis of the results:
I. The use of lateritic fine as a partial replacement has a significant influence on the engineering pro ... Continue reading---
REFRENCES - [ Total Page(s): 3 ]REFERENCESAdam, E. A. (2001): Compressed Stabilised earth block manufactured in sudan, A. Publication for UNESCO (online) Available from http://unesdoc.unesco.org.Adepegba, D.A. (1975). “Comparative Study of Normal Concrete which contains Laterite Fines instead of Sand†Building Science; 10:135-41.Agbede, I.O. and Manasseh, V. (2008): use of cement sand admixture in lateritic brick production for low cost housing Leonardo electric Journal of practices and technology, 12, pp163-174.Ak ... Continue reading---
