the effect of cockleshells on compressive strength of compressed
TRANSCRIPT
THE EFFECT OF COCKLESHELLS ON COMPRESSIVE STRENGTH OF
COMPRESSED SAWDUST CONCRETE CUBE
SYARIFAH AIDA SYAFIQA BINTI SAYED AZMI
AA11039
Report submitted in partial fulfillment of the requirements for the award of the degree
of B. Eng (Hons) Civil Engineering
Faculty Of Civil Engineering & Earth Resources
UNIVERSITI MALAYSIA PAHANG
June 2015
v
ABSTRACT
Due to increasing cost of material in the market nowadays, there is needed to search
another alternative material in order to save the cost in constructing the buildings.
Sawdust had been proven to be the replacement of coarse aggregate in concrete in order
to produce the lightweight concrete. However, there are some problem relate to the uses
of sawdust in concrete making. The production of sawdust requires high water
absorption and affects hardening time of concrete. The objective of this study is to
determine the compressive strength of sawdust lightweight aggregate concrete between
treated and non-treated by using lime as pre-treatment. In this study, sawdust concrete is
casted using the compression method using the cinva ram. The sawdust was treated
using lime before he casting work as for treated sawdust and was soaked in the water
for non-treated sawdust. As to improve the brittleness of the concrete cube, soil is added
to the sawdust concrete with nominal mix 1:1:0.5:2.5; (sand: cement: soil: sawdust).
From the study, its shows that the non-treated sawdust concrete is having the higher
strength compare to the treated sawdust concrete. Based on the result, non-treated
sawdust concrete was added with cockleshell as additive material with nominal mix
1:1:0.5:2.5:0.33, 1:1:0.5:2.5:0.67, 1:1:0.5:2.5:1.00 to achieve the main objective of this
study. The 28 days compressive strength sawdust concrete with nominal mix 1:1:3 were
0.938 Mpa. The treated sawdust concrete with nominal mix 1:1:3 show the lowest
compressive strength 0.063 Mpa. Treated and Non-treated sawdust concrete with the
addition of soil with nominal mix 1:1:0.5:2.5 for 28 days compressive strength are
0.944 Mpa and 1.064 Mpa respectively. The non-treated sawdust gives the higher
compressive strength. Sawdust concrete with the addition cockleshell as an additive
with nominal mix 1:1:0.5:2.5:0.33, 1:1:0.5:2.5:0.67, 1:1:0.5:2.5:1.00 for 28 days
compressive strength ware 1.337 Mpa, 1.053 Mpa and 0.661 Mpa respectively. The
maximum compressive strength of sawdust concrete was 1.064 Mpa for non-treated
sawdust with nominal mix 1:1:0.5:2.5. These values indicate that sawdust cannot be
used in concrete brick production.
vi
ABSTRAK
Kos bahan di pasaran kini makin meningkat. Oleh yang demikian, pelbagai alternatif
dilakukan untuk mengantikan bahan binaan. Habuk kayu terbukti berpotensi untuk
mengantikan batu baur untuk digunakan dalam penghasilan konkrit ringan. Namun
begitu, terdapat beberapa masalah berkaitan dengan penggunaan habuk kayu dalam
pembuatan konkrit ringan. Habuk kayu mempunyai kadar serapan air yang tinggi dan
memberi kesan pada tempoh pengerasan konkrit. Antara objektif dalam kajian ini
adalah menentukan kekuatan konkrit ringan yang menggunakan habuk kayu yang
dirawat menggunakan kapur dengan konkrit ringan yang menggunakan habuk kayu
yang tidak dirawat. Dalam kajian ini, konkrit di hasulkan menggunakan kaedah
mampatan menggunakan cinva ram. Habuk kayu dirawat dengan menggunakan kapur
sebelum kerja konkrit dijalankan dan untuk habuk kayu yang tidak dirawat ia direndam
menggunakan air sahaja. Untuk mengurangkan kerapuhan konkrit, tanah dicampurkan
dengan nisbah 1:1:0.5:2.5 (pasir: simen: tanah: sebuk kayu). Kajian menunjukkan,
serbuk kayu yang tidak dirawat mempunyai kekuatan mampatan yang lebih tinggi
berbanding dengan serbuk kayu yang di rawat. Berikutan dengan data yang diperolehi,
untuk kajian yang menggunakan debu kulit kerang sebagai bahan tambahan, serbuk
kayu yang tidak dirawat digunakan. Nisbah yang digunakan adalah 1:1:0.5:2.5:0.33,
1:1:0.5:2.5:0.67, dan 1:1:0.5:2.5:1.00. Kekuatan mampatan pada hari yang ke 28 untuk
konkrit yang mempunyai nisbah 1:1:3 adalah 0.938 Mpa. Panggunaan serbuk kayu yang
di rawat untuk konkrit bernisbah 1:1:3 mempunyai bacaan kekuatan mampatan yang
paling rendah iaitu 0.063 Mpa. Untuk konrit yang mempunyai campuran tanah yang
bernisbah 1:1:0.5:2.5 bacaan kekuatan mampatan untuk hari yang ke 28 adalah 0.944
Mpa untuk serbuk kayu yang dirawat dan 1.064 Mpa untuk serbuk kayu yang tidak
dirawat. Untuk kekuatan mampatan, penggunaan sebuk kayu yang tidak dirawat
menggunakan kapur menunjukkan kekuatan mampatan yang tinggi. Untuk kekuatan
mampatan konkrit ringan yang mempunyai campuran debu kulit kerang, untuk nisbah
1:1:0.5:2.5:0.33, kekuatan mampatan adalah 1.337 Mpa, untuk nisbah 1:1:0.5:2.5:0.67
kekuatan mampatan adalah 1.053 Mpa dan 1.064 Mpa untuk konkrit ringan bernisbah
1:1:0.5:2.5:1.00. Data menunjukkan, kekuatan mampatan untuk konkrit ringan yang
menggunakan sebuk kayu tidak boleh diggunakan dalam pengeluaran konkrit bata.
vii
TABLE OF CONTENTS
SUPERVISOR’S DECLARATION i
STUDENT’S DECLARATION ii
DEDICATION iii
ACKNOWLEDGEMENT iv
ABSTRACT v
ABSTRAK vi
TABLE OF CONTENTS vii
LIST OF TABLES ix
LIST OF FIGURES x
LIST OF ABBREVIATIONS xi
CHAPTER 1 INTRODUCTION
1
1.1 Background 1
1.2 Problems Statements 1
1.3 Objectives 2
1.4 Scope of Study 2
1.5 Significant of Study 3
CHAPTER 2 LITERATURE REVIEW 4
2.1 Introduction 4
2.2 Concrete 5
2.2.1 Cement 5
2.2.2 Sawdust 5
2.2.3 Cockleshell 8
2.2.4 Lime 8
2.3 Curing 7
viii
CHAPTER 3 METHODOLOGY 8
3.1 Introduction 8
3.2 Research Phase (Collecting Information and Materials) 8
3.3 Preparation of Samples 8
3.3.1 Preparation the Cockleshells 11
3.3.2 Preparation the Sawdust 11
3.3.3 Producing the Sample 12
3.4 Curing Method 13
3.5 Testing of Samples 14
3.5.1 Compressive Strength Test 14
CHAPTER 4 RESULT AND ANALYSIS 17
4.1 Introduction 17
4.2 Compressive Strength Test 17
4.3 Result Analysis for Compressive Strength Test 20
4.4 Density of Sawdust Concrete 22
CHAPTER 5 CONCLUSION & RECOMMENDATION 25
5.1 Conclusion 25
5.2 Recommendation 27
REFERENCES 28
ix
LIST OF TABLE
Table 3.1 Mix Design for the Samples
10
Table 4.1 Compressive Strength for 7 Days Curing Age
18
Table 4.2 Compressive Strength for 28 Days Curing Age
19
Table 4.3 Density of Sawdust Lightweight Concrete 23
x
LIST OF FIGURES
Figure 3.1 Cinva Ram
9
Figure 3.2 Cockleshell was sun dried
11
Figure 3.3 Collecting Sawdust at Kilang Papan Aman
12
Figure 3.4 Sawdust Cube was left on the Table for A Day
13
Figure 3.5 Curing Method using Saturated Gunny Sack
14
Figure 3.6 Compression Test
15
Figure 4.1 Compressive Strength versus Curing Age Graph
20
Figure 4.2 The Compressive Strength for 7 and 28 Days Bar Chart
21
Figure 4.3 Density of Concrete Cube for 7 and 28 Days Bar Chart 24
xi
LIST OF ABBREVIATIONS
NT – Control Non-Treated Control Sample with ratio of 1:1:3 (sand:
cement: sawdust)
T –Control Treated Control Sample with ratio of 1:1:3 (sand:
cement: sawdust)
NT – Soil Non-Treated Sample with ratio of 1:1:0.5:2.5 (sand:
cement: soil: sawdust)
T – Soil Treated Sample with ratio of 1:1:0.5:2.5 (sand:
cement: soil: sawdust)
CS – 0.33 Non-Treated Sample with ratio of 1:1:0.5:2.5:0.33
(sand: cement: soil: sawdust: cockleshells)
CS – 0.67 Non-Treated Sample with ratio of 1:1:0.5:2.5:0.67
(sand: cement: soil: sawdust: cockleshells)
CS – 1.00 Non-Treated Sample with ratio of 1:1:0.5:2.5:1.00
(sand: cement: soil: sawdust: cockleshells)
1
CHAPTER 1
INTRODUCTION
1.1 Background
Lightweight concrete is the current trend in construction to make the concrete
lighter than the regular concrete. By using the lightweight concrete in construction, it
may reduce the construction cost in term of transporting the goods and also reduce the
duration of the construction work. Concrete is the mixture of cement, fine aggregate,
course aggregate and water. A lot of additional material had been identified to produce
the lighter concrete mix. Sawdust is one of the additional materials that can be substitute
with coarse aggregate to produce a lighter concrete. By using sawdust as the substitute
for coarse aggregate, the concrete can be utilized to promote the green and sustainable
environment.
1.2 Problem Statement
The mixing of sawdust concrete requires a lot of water and affects the
hardening time because it has high rate of water absorption. The addition of cockleshell
as concrete material will affect the increasing the strength of concrete. By adding
cockleshell powder can also improve mechanical strength of concrete due to the
existence of calcium carbonate in cockleshell ( Muthusammy and Sabri, 2012). By
adding the lime to the sawdust concrete, it should neutralize the acid constituents of the
wood and prevent a possible effect that might have on the hydration process of the
cement. (Johnson et al. , 1930). From the previous study, water curing method shown
that it is not suitable for the sawdust concrete. The method of casting also gives the
impact for the compressive strength of sawdust concrete. Moreover, by using manual
2
casting, the compaction that carried out by hand rodding or tamping sometimes does not
completely remove the air bubbles during the casting method. Nevertheless it is
important to do a pretreatment process to the sawdust.
1.3 Objectives
The important point of this study is to determine the compressive strength of
the sawdust concrete sample and the mixing of additive material in sawdust concrete
mixtures. The objectives of this study are:
i. To determine the compressive strength of sawdust lightweight concrete between
the treated and non-treated by using lime as the pretreatment.
ii. To determine whether soil can improve the brittleness of sawdust concrete or
not.
iii. To study the effect of adding cockleshell as an additive on the strength of
sawdust lightweight concrete.
1.4 Scope of Study
The foremost thing of this study is to determine the compressive strength of the
sawdust lightweight concrete. The pretreatment process and adding the soil to improve
the brittleness of the sawdust lightweight concrete is tested. Concrete that having the
higher strength will be tested by adding the cockleshell as an additive into the concrete
mix. In this study, the sawdust will be used as the concrete mixture instead of course
aggregate.
i. Prepare the control mix specimen of 1:1:3 (by volume) of cement, sand, sawdust
to determine the compression strength of specimen sample.
ii. The ratio of cockleshell amounts of cockleshell that will be add are 0.33, 0.67
and 1.00
iii. 42 cube samples will be produced. Six sample of each as three for seven days
and three for 28 days which are listed below will be produce:
3
a) 1:1:3 control sample ( cement: sand: non-treated sawdust )
b) 1:1:3 treated sample ( cement: sand: treatment sawdust )
c) 1:1:0.5:2.5 (cement: sand: soil: non-treated sawdust )
d) 1:1:0.5:2.5 (cement: sand: soil: treated sawdust )
e) 1:1:0.5:2.5:0.33 ( cement: sand: soil: non-treated sawdust: cockleshell )
f) 1:1:0.5:2.5:0.67 ( cement: sand: soil: non-treated sawdust: cockleshell )
g) 1:1:0.5:2.5:0.10 ( cement: sand: soil: non-treated sawdust: cockleshell )
iv. Pre-treat the sawdust with lime solution before the casting process.
v. The cube will undergo cube production by compaction.
vi. For the curing process, it will be the saturated wet covering method (covering
with wet gunny sack)
vii. The compressive strength value will be taken at day 7 and day 28.
1.5 Significance of Study
The expected outcome of this study is the potential of sawdust as the
replacement of coarse aggregate to produce brick concrete for structural construction.
The additional of cockleshell in the sawdust concrete mixture will give the positive
result of the concrete strength of the concrete.
4
CHAPTER 2
LITERATURE REVIEW
2.1 Introduction
Lightweight structural concrete will be about 25% lighter compare to the
ordinary concretes (Faridah and Nurul, 2010). It also can be define as the type of
concrete which is includes an expanding agent that is increases the volume of the
mixture while giving additional qualities like lessened the dead weight.
Nevertheless, structural lightweight concrete can be economical especially in
the combination of high load bearing capacity and low density, but also by low density
alone ( Bomhard, 1980 ). In this study the brick concrete for the construction will be
produce. So that, the dead weight can be lessen and can give the impact in shorten the
construction period.
Dr. Clarke, J.L (1993) told that the lightweight aggregate concrete have more
density. So that, by replace the sawdust as the replacement of the coarse aggregate is the
better choice in the making of lightweight brick concrete. Clean sawdust without
any large amount of bark has proved to be sat isfactory. This does not introduce a high
content of organic material that may upset the reaction of hydration (Neville, 2000). In
addition, sawdust concrete has received some attention as lightweight
concrete in building construction for number of years. It has been invest igated in many
countries (Paramasivem and Loke, 1980).
5
2.2 Concrete
Concrete is the most common construction material used in the constructions.
The range of specification is suitable to all application. Moreover it can be
manufactured to an inexhaustible range of specifications to suit all applications.
Lightweight concrete is considered as having a density not exceeding 1920 kg/m3, while
normal density concrete is considered to have the usual density ranging from 2240 to
2480 kg/m3 (Al-Bayati, 2013)
2.2.1 Cement
The cement that will use is Ordinary Portland Cement. The cement will be
mixed with water to form a paste. This cement paste will holds and bonds the aggregate
together. For the sawdust concrete, cement and sawdust are mixed thoroughly because
of the difference in unit weights. The mixing needed a little longer period than the
ordinary concrete (Paramasivem and Loke, 1980).
2.2.2 Sawdust
Sawdust can be defined as loose particles or wood chippings obtained as by
products from sawing of timber into standard useable size. Timber is one of the oldest
structural materials used by man. Temples and monuments build several years ago
which still remain in good condition show the durability and usefulness of timber
(Kullkarni, 2005). Sawdust has been used in concrete for at least 40 years, but not
widely. Although it’s seriously limited by its low compressive strength, sawdust
concrete can be made to perform will in certain floor and wall applications. (Haitham,
2013). Haitham (2013) also said that with proper cement to sawdust ratios, it is not
flammable. Therefore, it can be used for manufacturing precast units for use in certain
floor and wall application.
Clean sawdust without any large amount of bark has proved to be satisfactory.
This does not introduce a high content of organic material that may upset the reaction of
hydration ( Neville, 2000 ). In addition, sawdust concrete has received some attention
6
as a lightweight concrete in building construction for number of years. It has been
investigated in many countries (Paramasivem and Loke, 1980). In Akram’s studies in
2013, he used sawdust as the substitute to coarse aggregate. It is due to its lightweight
properties, in addition to its excellent absorbing characteristic. In Zaharin study in 2014,
he said that, sawdust concrete with different additives in having different mix ratio has a
potential in the lightweight concrete industry.
2.2.3 Cockleshell
Cockles or anadara granosa is the type of bivalve shellfish that grows well in
muddy coastal area. It is cheap protein source which is quite common to be prepared as
local dishes (Mustakimah, et al., 2012). Effort towards preserving natural coarse
aggregate for future generation and reducing cockle shell waste originating from the
fisheries industry has initiated studies on possibility of integrating this waste in concrete
production. Replacement of appropriate cockleshell content is able to produce workable
concrete with satisfactory strength. According to Aniza Mijan, Faridah Suhari and
Saiful Bahari Yusuf (2011) stated that concrete with cockleshell mixture showed the
improvement in mechanical strength. The size of particles influenced the density,
strength and water absorption. In this study the cockleshell is grinded to become dust
before it is added into the concrete mix.
2.2.4 Lime
Various materials have been mixed to the concrete in construction work with
the view of increasing the hydration of the cement and thus increasing the strength. The
properties of sawdust concrete were highly improved using pretreated sawdust. The
increase of compressive strength was up to 50% for moderate sawdust ratio.
(Haitham,2013). The addition of lime to the sawdust concrete should neutralize the acid
constituent of the wood and prevent a possible effect they might have on the hydration
of the cement. The pretreatment of sawdust using lime can stimulate extraction of
harmful substance in sawdust and improved its properties as an aggregate,
(Haitham,2013).
7
Sawdust needs the pretreatment process. Pretreatment of sawdust is necessary
to make sure that extractable materials in the sawdust do not upset the hardening
qualities of the cement. Addition of lime 1/6 to 1/3 volume per volume of cement to the
sawdust before mixing has been recommended by Portland Cement Association
(Paramasivem and Loke, 1980). The amount of lime used for treatment of sawdust is
1/3 from the weight of water that used for soaking the sawdust and the sawdust was
soaked the sawdust with lime solution ( Mohd Zaharin, 2014 )
2.3 Curing
Curing process is the best known early work on the effects of cement
hydration. Curing is the name given to the procedures used for promoting the hydration
of the cement, and consists of a control temperature and of moisture from and into the
concrete. Curing allows continuous hydration of cement and consequently continuous
gain in the strength, once curing stops strength gain of the concrete also stops. Proper
moisture condition are critical because the hydration of the cement virtually ceases
when the relative humidity within the capillaries drops below 80% (Neville, 2000 ). The
most important is need to be paying attention is cured of the specimen because curing
function as to keep concrete moist the bond between the paste to make the aggregates
gets stronger. Concrete basically does not harden properly if it is left to dry out. (Mohd
Zaharin, 2014) Saturated wet covering method is used in this study. This method is most
often used curing method in the construction industry. In this method moisture retaining
fabrics such as burlap cotton mats, gunny bag and rugs are used as wet covering to keep
the concrete in a wet condition during the curing period. Gunny bag is selected to cover
the cube and tested at 28 days after curing (Nahata et al., 2014). Since wet saturated
covering method is the best alternative for sawdust concrete, this curing method is used
in this study. The gunny sack should be watered daily to prevent it to dry.
8
CHAPTER 3
METHODOLOGY
3.1 Introduction
This chapter will review the technique and method that used to this study to
achieve the study’s objective successfully. This will be consist three phase which are
collecting information and materials, sawdust lightweight concrete production and the
testing of samples.
3.2 Research Phase (Collecting Information and Materials )
Literature reviews from the previous study was done to find out more related
information and to understand more about the sawdust concrete. The material like
cement, sand and lime is prepared by the university laboratory. In this study, sawdust is
completely replacing the coarse aggregate with the ratio 1:1:3 and 1:1:0.5:2.5. Sawdust
is obtained from Kilang Papan Aman at Gambang, Kuantan, Pahang. Then, the
cockleshell is collected at Warung Nasi Lemak Kerang at Taman Tas, Kuantan.
3.3 Preparation of Samples
Firstly, sawdust will undergo pre-treatment by using lime solution. Prepare the
material and equipment for the laboratory testing before the work done. For the
equipment, check with the lab assistance about the condition of the machine. For this
study, compression test machine, sieve set, mechanical sieve shaker, weight scale and
CCA Cube Press (Cinva Ram) will be used.
9
Figure 3.1 Cinva Ram
For the materials, the mix ratio 1:1:3 (cement:sand:sawdust). Cube size that
will be used is 100mm x 100mm x 100mm. Cube production are by compaction by
using the Cinva Ram. The curing stage is at 7days and 28 days. All samples will be
cured by the saturated wet covering method. In this method moisture retaining fabrics;
gunny sacks are used as wet covering to keep the concrete in a wet condition during the
curing period. This water dissolves the extractive materials that retard the hardening
process. All samples are prepared using the ratio of:
a) 1:1:3 control sample ( cement: sand: non-treated sawdust )
b) 1:1:3 treated sample ( cement: sand: treatment sawdust )
c) 1:1:0.5:2.5 (cement: sand: soil: non-treated sawdust )
d) 1:1:0.5:2.5 (cement: sand: soil: treated sawdust )
e) 1:1:0.5:2.5:0.33 ( cement: sand: soil: non-treated sawdust: cockleshell )
f) 1:1:0.5:2.5:0.67 ( cement: sand: soil: non-treated sawdust: cockleshell )
g) 1:1:0.5:2.5:0.10 ( cement: sand: soil: non-treated sawdust: cockleshell )
10
Table 3.1 Mix Design for the Samples
Cement Sand Soil Sawdust Cockleshell
NT-Control
1 1 3
1041.70 1380.25 - 1351.80 -
1042.50 1402.10 - 1362.72 -
1022.00 1370.21 - 1521.02 -
T-Control
1 1 3
1076.83 1331.79 - 1545.34 -
1056.84 1332.24 - 1569.74 -
1032.47 1355.72 - 1611.14 -
NT-Soil
1 1 0.5 2.5
1018.40 1339.06 461.32 1278.25 -
1042.21 1346.62 460.04 1238.53 -
1031.63 1326.89 461.28 1287.91 -
T-Soil
1 1 0.5 2.5
1045.98 1344.46 479.75 1297.57 -
1015.58 1316.27 449.24 1279.31 -
1073.07 1337.14 454.12 1269.92 -
CS – 0.33
1 1 0.5 2.5 0.33
1040.00 1450.99 479.48 1356.31 467.10
1073.70 1467.61 486.20 1390.75 464.10
1076.44 1483.32 474.12 1378.19 461.60
CS - 0.67
1 1 0.5 2.5 0.67
1075.92 1486.14 483.56 1333.44 953.90
1019.50 1487.64 456.87 1328.04 929.38
1018.89 1435.18 455.26 1347.95 957.25
CS – 1.00
1 1 0.5 2.5 1.00
1033.61 1327.97 446.04 1281.16 1414.01
1053.52 1316.55 466.93 1341.26 1409.29
1080.28 1309.33 470.18 1334.72 1443.41
11
3.3.1 Preparing the Cockleshells
Cockleshells were collected from at Warung Nasi Lemak Kerang at Taman Tas
Kuantan. The cockleshells had been washed to remove the dirt and sundried for a day.
Then, the cockleshells had been grinded into powder using mechanical jaw crusher.
Particles sizes for cockleshells are sieve through 1.186 mm.
Figure 3.2 Cockleshell was Sun Dried
3.3.2 Preparing the Sawdust
Sawdust was collected at Kilang Papan Aman, Gambang, Kuantan. Before
mixes the sawdust with the cement and sand, sawdust that use as the treated sawdust
must be undergo pretreatment process first. The amount of lime that used for the
treatment process is 1/3 from the weight of water that used for soaking the sawdust. The
sawdust need to be soaking for a night. After that, wring the sawdust to remove the
excessive water. For the non-treatment sawdust, sawdust just only needs to be soaks in
the water, and then wring it to remove the excessive water.
12
Figure 3.3 Collecting Sawdust at Kilang Papan Aman
3.3.3 Producing the Sample
Procedures for preparing sawdust lightweight concrete samples are:
i. Prepare all the material that will be used for the mixture.
ii. Treat the sawdust before undergo the mixing process except for the sawdust that
will be used for the sample of non-treatment sawdust.
iii. A control sample that uses the ratio 1:1:3 is prepared which is cement, sand,
sawdust.
iv. Mix sand and sawdust together and blend it until both of the materials is truly
mix and uniform. After that add cement to the mixture and blend it.
v. The concrete mixture is casting into cube by using the method of cube
production by compaction. The CCA cube press (Cinva Ram) is used in this
process.
vi. Then, leaves the concrete cube on the table for a day before put the concrete
cubes under the gunny sack for the curing process.
vii. For the samples that contain soil, spray the water on the surface of the concrete
cube.
viii. Using the same step iv-vii to prepare the non-treatment control sample
ix. Using the same step iv-vii, add the cockleshells to the sawdust concrete using
the different ratio of cockleshell.
13
Figure 3.4 Sawdust Cube was left on the Table for A Day
3.4 Curing Method
In this study, saturated wet covering is used. This is the most suitable curing
method for the sawdust concrete that is having problems with concrete hardening. This
method is most often used curing method in the construction industry. In this method,
moisture retaining fabrics, gunny sacks was selected to cover the cube and tested after
28 days after curing. Gunny bag are used as wet covering to keep the concrete in wet
condition during the curing period.
Curing Procedures:
i. Pre-soaked gunny sacks are applied to the concrete surface.
ii. Water is reapplied as necessary to prevent the material from drying out.
iii. Gunny sacks should be rinsed prior to its first use to avoid possible staining.
14
Figure 3.5 Curing Method using Saturated Gunny Sack
3.5 Testing of Samples
All the samples of cube concrete are prepared for compressive strength test.
This test is to determine the concrete strength. From this test we will able to determine
which sample that have a higher compressive strength. Compression test is done by
taking readings on the force applied to the cube at the maximum reading. The maximum
value of this strength test sample is taken as the extents of the samples begin to destroy
and devastate. All specimens for this test are in cube with size 100 mm x 100 mm x 100
mm. All readings for each sample were recorded and the data.
3.5.1 Compressive Strength Test
The main objective of the study is to determine the compressive strength of the
lightweight concrete. In this phase the compressive strength will be determine. Before
the compressive strength can be determined, the specimens needed to undergo curing
process for about 7 and 28 days. After curing process, the testing for the compression
strength was carried out.
15
Compressive strength test (BS 1881: Part 16: 1983)
i. Prepare the concrete cube accordance to the standard.
ii. Measure the weight of each specimen.
iii. Use at least three concrete specimens for testing.
iv. Place the concrete specimen between the compression plates with the
appropriate cushioning material.
v. Slowly apply the load without a shock. Observe and record the highest load
reached.
vi. When the load begins to decrease, remove the load and sketch the type of the
failure in the specimen.
vii. Repeat the process for each of the specimens
viii. Calculate the ultimate compressive strength for each specimen.
Figure 3.6 Compression Test
16
All the data that obtained from the compression test will be analysed. From
that, mechanical properties of compression strength of the sawdust concrete with
different admixtures will be determined.