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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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(i) Egg layingmachine. The egg laying machines are usually of the Rosa Commetta type that can lay up to ten blocks at a time. This is usually used for mass production and the process can be automated, leading to great hourly output of about 300 -500 blocks. Both pressure and vibration are applied and bricks of high quality can be produced with these machines. The bricks are usually laid n bare surfaces without pallets and are removed for storage after 2-3 days of production.
(ii) Vibrating machines: These machines are commonly used by medium scale producers. They are electrically operated or diesel powered. The majority of the machines are designed to produce one bricks at a time with the bricks vibrated for about 10 to 15 seconds. Few, however, can produce up to three blocks at a time. The bricks are produced on pallets and carried to the place of temporary storage. They can provide adequate compaction. Care must be taken while moving the green bricks on the pallet to the place of temporary storage so as to prevent cracks resulting from vibration while moving the bricks.
(iii) Hand press machine. The hand press machine is manually operated. Demoulding is achieved through a series of levers. The hand press machine does not compact as well as the egg laying and vibrating machines and hence produces bricks of lower quality. One bricks is moulded at a time.
2.6.3 Curing.
Curing of sandcrete bricks is necessary to enable the bricks develop adequate or optimum strength by allowing for proper hydration of the cement. Green bricks that are exposed to high temperatures loose water rapidly by evaporation, resulting in weak bricks. Thus it is recommended that newly produced bricks be placed in covered shades and protected from the adverse effect of the elements. Works by Uzomaka (1977) and Rahman (1968) suggest curing by sprinkling with water as the best method of curing, from strength and convenience point of view. This is the most common method employed by commercial brick producers. Sprinkling should be done at least twice in a day. NIS 87 (2004) requires that the bricks be left on the pallets for at least 24 hours and be cured for at least 3 days. Adequate care must be taken when removing the pallets for another production so that cracks are not induced in the bricks.
2.6.3.1 Storage of cured bricks
Cured bricks are removed to storage to provide space for new productions. The bricks need adequate care at this stage. Many bricks are normally damaged at this stage due to poor handling. NIS 87: (2004) requires that the bricks be stacked not more than 5 courses high. The bricks are now ready for use.
2.6.3.2 Factors affecting the strength of sandcrete bricks
The factors that affect the quality and strength of sandcrete bricks can be divided into three namely (i) those related to the quality and relative proportions of the constituents (ii) those related to the manufacturing process and (iii) age of the bricks.
2.7 Advantages of sandcrete Bricks
1. Economically raw material is available
2. Hard and durable
3. Compressive strength is good enough for ordinary construction
4. Different orientation and sizes gives different surfaces
5. Very low maintenance cost is required
6. Reusable and recyclable
7. High fire resistance
8. Produce less environmental pollution during manufacturing
2.7.1 Disadvantages of Sandcrete Bricks
1. Time consuming construction
2. Cannot be used in high seismic zone
3. Since bricks absorb water easily, therefore it causes fluorescence when not exposed to air
4. Rough surface of brick may cause mold growth of not properly cleaned
5. Cleaning brick surface is a hard job
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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---
