SOLD BY: ASSESSMENT OF CHARACTERISTIC STRENGTH OF PALM KERNEL SHELL CONCRETE
ABSTRACT
Palm kernel shell is a lightweight
aggregate that is gotten from agricultural waste which is environmental
friendly. This research was focused on the assessment of characteristic
strength of palm kernel shell concrete, in view of the fact that the use
of lightweight aggregate is not prominent in the construction industry
in this party of the world. It will also help in reducing construction
cost in areas where they are in abundance. The various changes in
compressive and flexural strength with respect to curing age which has
been evaluated. The aim was achieved by casting the beam and cubes with
total replacement of granite with PKS and also casting an equivalent
control to give a basis for comparison and a water cement ratio of 0.65
at 1:2:4 total beam and cubes of 24 and 24 respectively and were cured
for 7, 14, 21 and 28days crushing 3 each for the PKSC and NWC for each
curing day up to the age of 28 days. The results of crushing values are
as follows for 7, 14, 21 and 28 days; 14.47N/mm2, 18.49N/mm2, 20.33N/mm2 , 23.00N/mm2 and 7.40N/mm2, 9.20N/mm2; 11.30N/mm2 , 13.10 N/mm2,
for NWC and PKSC respectively. The value for the flexural strength is
as follow; 1.87, 0.91, 1.36, 1.81 and 0.34, 0.34, 0.40, 0.34 for NWC and
PKSC respectively. The results showed that the compressive and flexural
strength improved with age of curing, through the compressive and
flexural strength of PKSC is low as compared to that of the NWC. It was
concluded that the compressive and flexural strength of NWC is higher
than that of PKSC. Through PKSC is a LWC, but was designed with the
corresponding design of NWC. It can therefore be concluded that palm
kernel shell is a lightweight aggregate, and can be used to produce
lightweight concrete. Recommendation: The use of PKSC should be design
to the standard design method of lightweight concrete in other to
achieve an optimal output with ranges of water cement ratio of 0.65 to
0.70 in other to get a workable mix without the addition of more water
during mix.
CHAPTER ONE
INTRODUCTION
1.1 BACKGROUND OF THE STUDY
Concrete is formed when fine, cement,
coarse aggregates and water, are mixed in a particular proportion
uniformly to the expected strength. The mix’s method can either be
manual or mechanical. Lightweight Concrete (LC) has been in use since
the time of ancient Roman and that has lead to its famousity due to its
lower density and thermal insulation properties (Chandra and Berntsson,
2002), than when compared to NWC. According to Islam (1999),
paste is formed when there is chemical reaction between the cement and
water, there bye binds the various particles of the aggregate together.
The mixture forms a rock-like solid mass when solidify, there by having a
considerable compressive strength whereas the tension has little
resistance.
When compared with NWC, LC helps in a
great way to reduce the dead load of a structural component, which makes
it considerable in the construction of multi-storey buildings. Whereas,
several studies on LC concern “semilightweight” Concretes can be
achived from lightweight coarse aggregate and natural fine aggregate.
Considering that lightweight fine aggregate has been used in determining
the place of natural sand to manufacture the “total-lightweight” (Berra
and Ferrara, 1990).
PKS are gotten from threshing or
crushing mill to remove the palm seed after the palm kernel oil has been
extracted. During the process of extracting the oil at the mill
industry the solid residues and liquid wastes are obtained
(Olutoge,1995). PKS are known to have stony and hard endocarps that
serve as protective covering for the palm kernel which are usually in
diverse sizes and shapes. They are naturally sized, light in weight and
are appropriate for replacing coarse aggregates in lightweight
construction, since they are known to be hard and of organic origin,
once used to produce concrete, they hardly contaminate or leach to form
toxic substances, since they are attracted together in matrix form. (CEB
– FIP, 1977); This gives PKS produced lightweight concrete an advantage
over aerated concrete, since permeability is low and the chance for
carbonation is reduced. Okafor (1988) described palm kernel shell to
have irregular shape after cracking and therefore its shape cannot be
defined. The shape takes pattern of cracking on the shell and usually
composed of many shapes ranging from semi-circular shapes, parabolic,
other irregular and flaking shapes. After cracking, the edges of the
shells are rough and spiky and the overall shape becomes concave and
convex with a fairly smooth surface. There is no fixed thickness for the
shell, this depends on the species from which it is obtained, ranging
from 1.5 mm to 4 mm and usually between 2 mm and 3 mm.
The rise in the need for concrete in construction industry
using NWA such as granite and gravel has greatly reduces the
availability of natural stone and has lead to the damaged of the
environment leading to imbalance of the ecological system (Short and
Kinniburgh, 1978). Therefore, there is the necessity to explore and find
out good replacement material to replace the natural stone. In the
developed countries, construction industries have researched many
natural and artificial LA that can serve as replacement for conventional
aggregates thereby bringing down the structural sizes of the members.
This has brought incredible changes in the development of LC high rise
structures using LC. However, in Nigeria, the construction industry is yet to fully make
use of LC in the construction of high rise structures. The requirement
of vegetable oil is regularly increasing and commercial cropping of palm
oil is needed in the feature (Ramli,2003).
1.2 STATEMENT OF THE RESEARCH PROBLEM
Continuous increase in
the cost is one of the major challenges the construction industry is
encountering and quality discharge of great number of developmental
project, such projects are dependent on some factors of production that
is the cost of materials (Achuenu, 1991). In line with these Shetty
(1999), the price of concretes primarily depends on; cost of material
and labour. The labour cost can be in the following aspects; formwork,
batching, mixing, transportation, placing and curing.
As a result of the ongoing increase in
the cost of granite and the process of production, epileptic power
supply is another issue of great concern; the above issue tends to
necessitate an alternative means of power supply thereby preventing high
cost overrun and carbon dioxide which has dangerous effect on that
given environment And this has necessitated this research work in other
to look in to alternative method of getting building materials of lower
cost.
Via the field survey carried out by the
researcher before this research work, it was seen that the cost of
coarse aggregate had fluctuated; the fluctuation in cost has been
attributed to great demand and inadequate availability of granite as the
need arises.
Palm kernel shell concrete is a good
replacement for normal weight concrete production in areas in which they
are in abundance as it is a close substitute and an alternative
solution to high cost of granite. And looking at the fact that palm
kernel shell does not poses health risk during the manufacture and the
usage of the palm kernel shell is environmental friendly.
This research seeks to determine the
prospect of PKS as used for the total replacement of coarse aggregate
for concrete production in the Construction Industry of Nigerian,
putting in to consideration the high cost of granite and the low and
abundance of palm kernel shell in the western region, south-south and
middle belt of Nigeria.
Considering the population increase
in Nigeria has led to the demand for housing to shelter the populace.
The cost of construction has also increased sporadically in this nation
as a result of increase in the cost of cement and coarse aggregate day
by day, therefore there is need for an alternative material that could serve as a good substitute for them and still perform the expected function The continuous increase in the cost of materials is a major challenges confronting the construction industry
and the effective and efficient discharge of complex developmental
projects is determined by the factors of production; the cost of construction materials (Achuenu 1991).
Falade (1995), researched on the
suitability of PKS as aggregates in dense and light concrete production
for structural and non-structural usage, many similar efforts in the
direction of managing the waste strategically to enhance the use of PKS
concrete for structural performance. Civil engineering and Building
practice and construction projects in Nigeria depend on concrete to a
great extent. According to (Kirkaldy and Sutatanto,1976), most countries
that produce palm oil, considered palm kernel shell as waste, causing
significant disposal problems.
The process of making and utilization of
PKS, which is of low cost and predominant in most south west areas of
Nigeria, in construction; considering that it improve some properties of
the concrete, it will also save the environment from gaseous pollution,
therefore this work examined the utilization of PKS as course aggregate in view of putting to place its performance by determining the flexural and compressive strength of the concrete produced.
1.4 AIM AND OBJECTIVES
The project was aim at assess the
suitability of PKS for use, as coarse aggregate in lightweight
production concrete. The aim shall be carried out through the following
objectives:
The specific objectives are:
- To determine the properties of the aggregates.
- To determine the workability test of the concrete.
- To carry out flexural and compressive strengths of the concrete.
- To compare the results in I, II and III above in order to establish any difference in the concrete.
1.5 METHODOLOGY
The methodology employed for this
research work was essentially laboratory experimentation and entails the
use of laboratory experiments on the cubes that was cast from the
concrete gotten from the PKS as coarse aggregate. All the samples ware
tested based on laboratory test to determine the compressive and
flexural strength of the cast palm kernel shell concrete cubes.
Information was obtained from the relevant standard and codes of
practice (BS 812 PT2, ASTM etc), text books, articles, journals, lecture
notes and past researches which provide information on the study area.
Sieve analysis and other relevant tests which will help determine the
quality of the PKS that was used which was carried out according to the
stipulated standards. The concrete produced from the palm kernel shell
was tested for water/cement ratio, workability, bulk density, specific
gravity, water absorption capacity, abrasion and resistance moisture
content. Dangote cement was used as the ordinary Portland cement.
Mechanical and Physical properties of
PKS was determined via the means of the following tests: bulk density,
specific gravity test, aggregate impact value tests and slump. Cube
crushing tests were carried out to determine the flexural and
compressive strengths of palm kernel shell concrete. The sieve analysis
was carried out using the sieves arranged in decreasing size of opening
and shaker in order to distinguish the samples of the aggregate to
fractions. The curvature, coefficients of uniformity and gradation were
determined. The mixing of the concrete was carried out mainly by hand
mix with the aid of a shovel. The fine aggregate (fine aggregate) was
poured on the mixing try, on a spot where it was been mixed uniformly
with cement. The total numbers of concrete cubes that was cast was 48
numbers of (100 x 100 x 100mm) and (100 x 100 x 450mm) sizes for the
compressive and flexural strengths test of the normal weight and palm
kernel shell aggregate respectively. The concrete cubes specimens was
cured for 7, 14, 21 and 28, curing ages respectively. The samples ware
crushed in order to determine the flexural and compressive strength.
Table 1: Details of laboratory tests that was carried out on the materials.
| Fine Aggregate | Cement | Coarse Aggregate | Concrete |
| Sieve analysis | Soundness test | Sieve analysis | Slump test |
| Specific gravity | Constituency test Setting time(initial and final) | Specific gravity | Compressive and flexural strength |
| Moisture content | Co-efficient of uniformity | ||
| Bulk density | Bulk density |
Source; lab work, 2013
Three (3) numbers of Cubes was crushed
for flexural and compressive strength each crushing day, for the NWC and
PKSC respectively.
Total numbers of Cubes for compressive strength test (100 x 100×100mm) = 24 cubes.
Total numbers of Cubes for flexural strength test (100 x 100×450mm) = 24 cubes.
Total numbers of cubes for compressive and flexural strength test = 48 cubes.
1.6 SCOPE AND LIMITATION TO THE STUDY
The scope of the study is focused on the
actual use of PKS as a total replacement of granite in concrete
production. This project also compared the compressive and flexural
strength of granite and palm kernel shell with a mix’s of 1:2:4 and 0.65
water/cement ratio at maximum mean flexural and compressive strength
for the various curing days. This research carried out the following
laboratory test:
- Bulking and bulk density test
- Consistency test
- Moisture content test
- Specific gravity test
- Workability test
- Slump test
- Co-efficient of uniformity
- Setting time test
- Soundness test
- Sieve analysis test
- Compressive and flexural strengths
The Results obtained was subjected to
statistical, graphical and mathematical analysis to generate reasonable,
logical and scientific conclusion from which recommendations were
drawn. However the aggregate impact value was not carried out, as the
equipment required for the test is not available in the laboratory.
Fluctuation in electrical power supply has also limited some
experimental works cause delays and the time frame for the research work
has also been a limitation to the extent to which the research was been
carried out.
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