SOLD BY: EFFECT OF ELEVATED TEMPERATURE OF PERFORMANCE STRENGTH OF LATERIZED CONCRETE
ABSTRACT
This research investigated the effect of elevated temperature
on the strength of laterized concrete. This was achieved by partially replacing
sand with 30 percent of laterite to produce concrete cube samples. Samples of
concrete cubes were equally produced which served as control. The specimens were
cured for 28days after which they were subjected to elevated temperature of
0oC, 150oC, 300oc 450oC and 600oC then cooled freely by exposure to the
surrounding air. The average compressive strength obtained were 25.05Nmm2
23.92Nmm2, 22.83Nmm2, 21.79Nmm2 and 17.79Nmm2. The control values were
27.13Nmm2, 25.13Nmm2, 24.14Nmm2, 23.94Nmm2 and 22.12Nmm2. The percentage
reduction in strength of laterized concrete obtained were 7.67%, 4.81%, 5.42%,
8.22%, and 10.9% respectively. This result shows that the residual strength of
laterized concrete decrease with increase in temperature just as being
established with normal concrete.
CHAPTER ONE
INTRODUCTION
1.1 Background of study
The use of laterite as a replacement for sand in concreting works is imperative, most especially in the developing nations in Africa, where the material is cheap and available in large deposits. This is because the cost of procuring sands (fine aggregates) like other traditional construction materials has been increase on daily basis.
The use of laterite as a replacement for sand in concreting works is imperative, most especially in the developing nations in Africa, where the material is cheap and available in large deposits. This is because the cost of procuring sands (fine aggregates) like other traditional construction materials has been increase on daily basis.
However, it was cited in compressive strength of concrete
using lateritic sand and quarry as fine aggregate by Osadebe and Nwakonobi
(2007) that Lateritic soils are usually used as construction material in
Nigeria and other developing and under-developing countries of the world.
According to Lasis and Osunade,(1990) they described the use
of laterite as replace sand component of concrete both totally or partially, is
becoming common among the low income earners for building construction. The
utilization of laterite enables the stipulation of low-cost houses and other
rural infrastructures. Though, laterite has not been widely used in
constructing medium to large-size building structures.
Ayangade, (1990) Reported that about 30% of the world’s
present population still lives in laterite structure. It was observed that the
restriction of laterite building to rural areas is due to lack of accepted
standard design parameters which has and impeded other factors that is
effective structure application of laterized concrete.
The performance of strength of laterized concrete for
stability of structure is essential to improve the resistance to the bumping
heat load. therefore, the recognition of physical and chemical changes in
laterized concrete during heating and cooling is needed in order to determine
the Increase in temperature at definite temperature of the physically and
chemically bounded water discharges which make it becomes stream (Schneider and
Horvath, 2002).
Also when concrete is subjected to high temperatures, it will
distorted, due to reactions which causes progressive collapse of its internal
structure and thus experience loss in its load – bearing capacity (Bazant and
Kaplan, 1996; khoury, 2000; kalifa et al, 2000; Phan et al, 2001). Although
effort data have been made about the behavior of LATCON under high temperature
for structural safety in service and potential of concrete in the event of
elevated temperature. While it is very necessary that the strength properties
of concretes subjected to elevated temperature is to be evaluated. However from
the observation of (Apeh and Ogunbode, 2012). Their tests result showed that
normal concrete cannot resist large load above, while laterized concrete with
25% laterite in the fine aggregate is able to resist higher load with increase
in strength of higher temperatures.
The study of the laterite material shows that the variety of
sand is much sharper than those measured. When it is recognized by the
preliminary assessment of its particle size distribution. Since the investigational
work is to study the effect of elevated temperature on the performance of
strength of laterized concrete.
1.2 STATEMENT OF THE STUDY
In Nigeria the cost of construction of building material has been increase within the last couple of years. This makes it difficult for an average Nigeria people not have capacity to build their houses for themselves. Also human safety in the case of fire is one of the major consideration in the design of building, it’s necessary to have a absolute understanding about the behavior of all construction material before using them in the structural elements. Therefore an exploration of alternative material is to be used as partial replacement of fine aggregate in concrete work, which brings the needs for laterite (soil) for LATCON to solve this problem. And also to look at the performance of LATCON strength when it is subjected to elevated temperature of various degrees.
In Nigeria the cost of construction of building material has been increase within the last couple of years. This makes it difficult for an average Nigeria people not have capacity to build their houses for themselves. Also human safety in the case of fire is one of the major consideration in the design of building, it’s necessary to have a absolute understanding about the behavior of all construction material before using them in the structural elements. Therefore an exploration of alternative material is to be used as partial replacement of fine aggregate in concrete work, which brings the needs for laterite (soil) for LATCON to solve this problem. And also to look at the performance of LATCON strength when it is subjected to elevated temperature of various degrees.
1.3 AIM AND OBJECTIVE
The aim of the research is to access the performance of strength laterized concrete at elevated temperature with the view to determining it durability properities.
The aim of the research is to access the performance of strength laterized concrete at elevated temperature with the view to determining it durability properities.
The objective of this study work is
1. To determine the physical properties of laterized aggregate that is, if it’s suitable for production of strength laterized concrete.
2. To determine the compressive strength of concrete produced with laterite as fine aggregate (sand) at 28days of ages in ordinary water.
3. To examine the strength of laterized concrete at different temperature.
4. To cast laterized concrete cube, cured, and test for the durability.
1. To determine the physical properties of laterized aggregate that is, if it’s suitable for production of strength laterized concrete.
2. To determine the compressive strength of concrete produced with laterite as fine aggregate (sand) at 28days of ages in ordinary water.
3. To examine the strength of laterized concrete at different temperature.
4. To cast laterized concrete cube, cured, and test for the durability.
1.4 IMPORTANT OF THE STUDY
Laterite soil is a material which has abundant and cheap soil in Nigeria and in West Africa. It has potential which could be used as construction material, but most laterite soils are composed predominantly of kaolinite and quartz and have swelling clay minerals (montmorillon). The most predominant and significant quality engineering application is swelling properties which reduce the bearing strength of the soil. The proportion of aluminimum oxides found in laterite soil tends to form a weakly bonded particulate.
Laterite soil is a material which has abundant and cheap soil in Nigeria and in West Africa. It has potential which could be used as construction material, but most laterite soils are composed predominantly of kaolinite and quartz and have swelling clay minerals (montmorillon). The most predominant and significant quality engineering application is swelling properties which reduce the bearing strength of the soil. The proportion of aluminimum oxides found in laterite soil tends to form a weakly bonded particulate.
Also the tensile strength is small and occasionally, a slight
cohesion reflects an increase in the surface change as a result of finer
fundamental particles introduced by leaching. Therefore the significant of this
research is to improve the production of alternative material for quality
concrete in construction industries, and also understanding the performance
characteristics of strength of laterized concrete when exposed to temperature that
is, if it can reduce the like hood of structural collapse in the event of fire,
and to reduce the cost of producing concrete.
1.5 SCOPE AND LIMITATION OF THE STUDY
The research is restricted to effect of elevated temperature on laterized concrete. Therefore it will cover the experimental and preliminary laboratory tests, in order to determine the strength durability. The study will be limited to sand at 0% (control) and 30% replacement of laterite weight will be prepared. And the heating of cubes to elevated temperature will be 0oc, 150oc, 300oc, 450oc and 600oc of cooling method.
The research is restricted to effect of elevated temperature on laterized concrete. Therefore it will cover the experimental and preliminary laboratory tests, in order to determine the strength durability. The study will be limited to sand at 0% (control) and 30% replacement of laterite weight will be prepared. And the heating of cubes to elevated temperature will be 0oc, 150oc, 300oc, 450oc and 600oc of cooling method.
1.6 RESEARCH METHODOLOGY
The methodology that will be employed for this research work is basically on laboratory experiment and entails the preparation and testing of fresh concrete of latcon specimen. Lateritic soil, sharp sand, granite, and portable water will be collected. The experiment will involve 30% laterite as partially replacing sand by weight for fine aggregate. The laboratory preliminary test will be carried on sample to be use for this research, such as sieve analysis, specific gravity test, bulk density, moisture content test on aggregate both fine and coarse aggregate, compaction test on laterite and sand, Atterberg test such as liquid limit, plastic limit and plastic index on laterite, slump test, heating of cubes to different temperature such as 0℃,150℃,300℃,450℃,600℃. And comprehensive test in other to determine the properities durability. The total numbers of concrete cubes to be cast are thirty numbers of size mould (100×100×100mm) sizes and the cubes concrete specimen will be cured for just only 28days of age hydration.”
The methodology that will be employed for this research work is basically on laboratory experiment and entails the preparation and testing of fresh concrete of latcon specimen. Lateritic soil, sharp sand, granite, and portable water will be collected. The experiment will involve 30% laterite as partially replacing sand by weight for fine aggregate. The laboratory preliminary test will be carried on sample to be use for this research, such as sieve analysis, specific gravity test, bulk density, moisture content test on aggregate both fine and coarse aggregate, compaction test on laterite and sand, Atterberg test such as liquid limit, plastic limit and plastic index on laterite, slump test, heating of cubes to different temperature such as 0℃,150℃,300℃,450℃,600℃. And comprehensive test in other to determine the properities durability. The total numbers of concrete cubes to be cast are thirty numbers of size mould (100×100×100mm) sizes and the cubes concrete specimen will be cured for just only 28days of age hydration.”
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