Journal of Emerging Trends in Engineering and Applied Sciences (JETEAS) 6(1): 62- 70
© Scholarlink Research Institute Journals, 2015 (ISSN: 2141-7016)
jeteas.scholarlinkresearch.com
Journal of Emerging Trends in Engineering and Applied Sciences (JETEAS) 6(1):62- 70 (ISSN: 2141-7016)
Determination and Modelling of Effects of Variation in Fine Aggregate Size
on Concrete Properties
S. O. Osuji and I. Inerhunwa
1
Department of Civil Engineering,
Faculty of Engineering, University of Benin,
Benin City, Nigeria.
Corresponding Author: S. O. Osuji
_________________________________________________________________________________________
Abstract
The properties of concrete are likely to change with changes in its composition. This paper examines the effect
of variation in the sizes of fine aggregate on the workability, pulse velocity and compressive strength of
concrete. To do this, fine aggregate (quarry dust) was sieved into three classes: Class 1: 2.00mm < d <
4.75mm, Class 2: 425µm < d < 2.00mm and Class 3: 75µm < d < 425µm. Workability, Ultrasonic Pulse
Velocity (UPV) and compressive strength tests were carried out on concrete cubes made from the three classes
of fine aggregate for two mix ratios (1:2:4 and 1:3:6). Results showed that workability reduces with reduction
in the size of fine aggregate and that concrete made from Class 2 fine aggregate gave the highest value of
strength and pulse velocity while concrete made from Class 1 fine aggregate gave the least values for both mix
ratios. As properties of concrete changes with age, linear models were developed for the prediction of the
strength of concrete from age and pulse velocity and vice versa for each class of fine aggregate and mix ratio.
The linear models showed linear relationships between age, pulse velocity and compressive strength of
concrete with strength and pulse velocity increasing with age and the models were found to be appropriate,
accurate and consistent. The models are useful and can be utilized in obtaining and analyzing the properties of
concrete for the different classes of fine aggregate.
__________________________________________________________________________________________
Keywords: fine aggregate, workability, ultrasonic pulse velocity, compressive strength, linear model
Physical and mineralogical properties of aggregate
must be known before mixing concrete to obtain a
desirable mixture. These properties include shape and
texture, size gradation, moisture content, specific
gravity, reactivity, soundness and bulk unit weight.
These properties along with the water/cementitious
material ratio determine the strength, workability,
and durability of concrete (Mehta and Monteiro,
1993).
INTRODUCTION
Aggregate occupies 70% to 75% of the volume of
conventional normal strength portland cement
concrete and therefore the properties of aggregates
have a dominant effect on the overall performance of
concrete in its fresh and hardened state (Talbot and
Richart, 1923). Among the various characteristics of
aggregates that have significant influence on
properties of concrete, the size distribution of
aggregate particles or otherwise known as aggregate
gradation plays an important role in achieving the
desired properties of concrete.
Aggregates can be divided into several categories
according to different criteria. In accordance with
size, aggregates are divided into coarse and fine
aggregate. Coarse aggregate are aggregates
predominately retained on the No. 4 (4.75 mm) sieve.
Fine aggregate (sand) are aggregates passing No.4
(4.75 mm) sieve and predominately retained on the
No. 200 (75µm) sieve (Shacklock, 1974).
Aggregate gradation determines the void content
within the structure of aggregate and consequently
the amount of cement paste that is required to fill the
void space between the aggregate and ensure a
workable concrete (Mills and Fletcher, 1969). As
cement is the most expensive and high carbon
footprint ingredient in concrete, it is desirable to
optimize the aggregate gradation to minimize the
void content in the aggregate and therefore the
volume of cement paste required to achieve a
workable and economical concrete for a given
application. Concrete containing aggregate with poor
gradation can be particularly vulnerable to problems
such as segregation in plastic state under vibration
(Talbot and Richart, 1923).
The size of aggregate plays an important role in the
development of high strength concrete. The strength
of concrete is affected partly by the relative
proportion of cement and of the fine and coarse
aggregates (Alawode and Idowu, 2012). A suitable
gradation of the combined aggregate in a concrete
mix is desired in order to secure workability and to
secure economy in the use of cement. A well-graded
62
Journal of Emerging Trends in Engineering and Applied Sciences (JETEAS) 6(1):62- 70 (ISSN: 2141-7016)
strength development, particularly when concreting
in cold weather, to check serviceability conditions or
compliance criteria, to ensure construction safety
and, generally to estimate the quality of construction
and potential durability (Mills and Fletcher, 1969).
Moreover, prediction of concrete strength at late ages
is significant from both technical and economical
points of view.
mixture produces strong concrete than a harsh or
poorly graded one (Troxell et al., 1968).
Smaller aggregates sizes are considered to produce
high strength concrete because of less concentration
of stress around the particles which are caused by
difference between the elastic modulus of paste and
aggregate (Yaqub and Bukhari, 2006). The grading
and maximum size of aggregates is also an important
parameter in any concrete mix as they affect relative
proportions in mix, workability, economy, porosity
and shrinkage of concrete etc. Experience has shown
that very fine sands or very coarse sands are
objectionable. The former is uneconomical; the latter
gives harsh unworkable mixes (Agrawal et al., 2007).
No clear rules have been presented to describe how
the relationship between UPV and the compressive
strength and other properties of concrete changes
with its mixture proportion. Therefore, there exists a
high uncertainty when one tries to make use of UPV
or any other property of concrete to predict the
strength of concrete in different mixture proportions
(Alawode and Idowu, 2012).
In a concrete member, variations in density can arise
from non-uniform consolidation, and variations in
elastic properties can occur due to variations in
materials, mix proportions, or curing. Thus, by
determining the wave speed at different locations in a
structure, it is possible to make inferences about the
uniformity of the concrete. The compression wave
speed (pulse velocity) is determined by measuring the
travel time of the stress pulse over a known distance
(Khlef, 2012).
The fine aggregate used in concrete construction is
actually composed of particles of different fineness
which gives the concrete a variety of particles to fill
up voids. The question of “which particle size is best
for concrete construction” that will give concrete of
required strength and properties is a major concern in
civil engineering construction.
OBJECTIVE OF THE STUDY
In this paper, the effect of variation of fine aggregate
size on the workability (slump), compressive strength
and pulse velocity for different mix ratios is studied.
The paper also attempts to establish a relationship
between the compressive strength and pulse velocity
with the age of concrete and develop a simple
mathematical model that can help predict the
compressive strength and pulse velocity at any age of
the concrete for different sizes of fine aggregate.
Compressive strength and pulse velocity of concrete
is influenced by many variables, however, including
mixture proportions, aggregate type, age of concrete,
moisture content, and others (Talbot and Richart,
1923). As a result, a strength estimate made with the
pulse velocity method is not reliable if a preestablished calibration curve is not available (Mills
and Fletcher, 1969).
The relationship between Ultrasonic Pulse Velocity
(UPV) and the compressive strength of concrete for a
particular size of aggregate, the effect of sulphate
exposure on the development of UPV and strength of
concrete along with age and the influence of sulphate
exposure and water/cement ratio on the UPV-strength
relationship of concrete have been studied (Khlef,
2012). It was shown that the UPV in the concrete
grew along with the advancement of age and at the
same age, UPV with low w/c are higher than those
with high w/c.
MATERIALS AND METHOD
Materials and methods utilized in this study are
discussed below.
To model the behaviour of concrete under general
loading requires an understanding of the effects of
aggregate type, aggregate size, and aggregate content
(Kozul and Darwin, 1997).
Material Selection
To study the effect of variation of fine aggregate size
on the properties of concrete, materials (aggregate ,
cement and water) were collected and necessary tests
were carried out on the resulting test specimens
(100mm concrete cubes) made from varying the sizes
of fine aggregate in the concrete mix. For this
research, materials used were Ordinary Portland
Cement (OPC), water, granite for coarse aggregate
and quarry dust for fine aggregate.
STATEMENT OF THE PROBLEM
Early age strength prediction in concrete is very
useful in reducing construction cost and ensuring
safety. Furthermore, early age strength prediction has
several practical applications. It can be used to
determine safe stripping time, prestressing
application or post –tensioning time, to monitor
Aggregate
Fine aggregate used for this study is quarry dust. This
was obtained and allowed to dry naturally in the
laboratory for about two weeks for mechanical sieve
analysis for the determination of its particle size
distribution. The quarry dust was then later sieved
into three different sizes using sieves of diameter
63
Journal of Emerging Trends in Engineering and Applied Sciences (JETEAS) 6(1):62- 70 (ISSN: 2141-7016)
2.0mm and 425µm. These gave three classes of fine
aggregate sizes as follows; Class 1: 2.00mm < d <
4.75mm, Class 2: 425µm < d < 2.00mm and Class 3:
75µm < d < 425µm, where d is the size of the fine
aggregate. Coarse aggregate of maximum size 20mm
in diameter was used. The coarse aggregates were
collected and kept at room temperature and pressure
in the laboratory before they were used for the
making of test specimen.
cubes for the whole experiment. Standard cube
moulds of size100mm were used for casting.
Curing
After casting, the concrete was left to set for twentyfour hours and after this period, the concrete was
carefully removed from its mould to ensure that the
edges are not broken off. Then they were taken to the
curing bath where they were cured for seven days,
fourteen days and twenty-eight days.
On reaching the required number of days for testing
(7th, 14th and 28th day), three cubes made from each
class of concrete for each mix ratio were removed
from the curing bath, allowed to dry for a day and
their weight recorded before carrying out pulse
velocity and compressive strength tests on them.
(a) Class 1
Concrete Testing
Workability test (slump test) was conducted on the
fresh concrete for each class of fine aggregate, while
the hardened concrete cube specimens were tested for
ultrasonic pulse velocity in accordance with BS EN
12504-4 and compressive strength test in accordance
with BS EN 12390-3. The specimens were tested at
the end of 7, 14 and 28 days of curing.
(b) Class 2
Regression Analysis of Experimental Results
Regression analysis generates an equation to describe
the statistical relationship between one or more
predictor variables and the response variable.
This equation has the form
Y = b1X1 + b2X2 + ... + C
(1)
where Y is the response (dependent) variable to be
predicted, X1, X2 and so on are the predictor
(independent) variables, b1, b2 and so on are the
coefficients or multipliers that describe the size of the
effect the independent variables are having on the
dependent variable Y, and C (constant term) is the
value Y is predicted to have when all the independent
variables are equal to zero.
(c) Class 3
Fig 1: Picture of the classes of fine aggregate used for
the study
Water
To mix the concrete, clean tap water from a reservoir
was collected. Selecting water from a good source
ensures that the hydration process goes on without
influence from foreign chemical compounds that
might affect the properties of the concrete adversely
or otherwise.
Mix Design, Batching, Mixing and Casting
Concrete mix design was carried out to determine the
mix composition of concrete for two mix ratios (1:2:4
and 1:3:6) with a water-cement ratio (w/c) of 0.55.
Fresh concrete using Class 1 fine aggregate was then
made using mix proportions obtained and mixing was
done using a concrete mixer until a homogenous mix
was obtained.
In this study, the predictor variable is age of concrete
while the response variables are compressive strength
and pulse velocity. The 95% confidence level which
is generally used in most regression analysis was
used.
Models were developed for each class of fine
aggregate and analysed to check their adequacy.
Microsoft Excel package was used in selecting and
analyzing the models that best fit the experimental
data.
After mixing and before casting the concrete cubes,
slump test was carried out in accordance with BS EN
12350-2 to determine the workability of the concrete.
The fresh concrete was then placed in moulds,
vibrated and levelled using a trowel. The same
procedure was followed for the other two classes of
aggregate (Class 2 and 3).
RESULTS AND DISCUSSIONS
Grading of Fine Aggregate
Figure 2 shows result of particle size distribution of
fine aggregate used for the study in the form of a
particle size distribution curve. From the curve, the
range of size of fine aggregate is between 4.75mm
and 75µm and is distributed among coarse sand,
For every class of fine aggregate, 9 cubes were each
cast for a mix ratio 1:2:4 and another 9 cubes for a
mix ratio of 1:3:6. This gave a total number of 54
64
Journal of Emerging Trends in Engineering and Applied Sciences (JETEAS) 6(1):62- 70 (ISSN: 2141-7016)
medium sand and fine sand portions of the graph
which represent the three classes of fine aggregates
used for this study (Class 1, Class 2 and Class 3
respectively).
aggregate. The results represent the average of three
cubes tested each for a particular class, mix ratio and
age.
Table 1: Pulse Velocity Test Results
Mix Ratio
Fine
Aggregate
Class
Class 1:
2.00mm < d
< 4.75mm
Class 2:
425µm < d
< 2.00mm
Class 3:
75µm < d <
425µm
Pulse Velocity (1 x 101km/s)
1:2:4
1:3:6
7
days
14
days
28
days
7
days
14
days
28
days
0.273
0.284
0.304
0.257
0.260
0.263
0.286
0.297
0.317
0.266
0.273
0.280
0.262
0.274
0.295
0.246
0.251
0.260
Table 2: Compressive Strength Test Results for the
different classes of fine Aggregates
Mix Ratio
Fine
Aggregate
Class
Class 1:
2.00mm <
d<
4.75mm
Class 2:
425µm <
d<
2.00mm
Class 3:
75µm < d
< 425µm
Fig. 2: Particle Size Distribution of Fine Aggergate
(Quarry Dust)
Slump Test Results
Slump test results of the fresh concrete is presented in
Fig. 3. The Figure shows slump for concrete made
from Class 2 and Class 3 fine aggregates for mix
ratios of 1:2:4 and 1:3:6. Concrete made form Class 1
fine aggregate gave a collapse slump for both mix
ratios and hence of high workability. The slump of
fresh concrete made from Class 2 concrete is about
twice that of Class of 3 for 1:2:4 mix ratio and about
three times of class 3 for 1:3:6 mix ratio.
Compressive Strength (N/mm2)
1:2:4
1:3:6
7
days
14
days
28
days
7
days
14
days
28
days
16.80
19.50
21.50
12.20
15.20
19.20
19.33
25.00
34.00
16.17
22.00
26.50
13.80
15.33
19.00
11.00
12.00
15.00
Figures 4 and 5 show the graph of Ultrasonic Pulse
Velocity (UPV) against age of concrete for mix ratios
1:2:4 and 1:3:6 respectively. The graphs show almost
a linear relationship between pulse velocity and age
of concrete made from the three different classes of
fine aggregate with pulse velocity increasing with age
of concrete. Concrete made from Class 2 fine
aggregate gave the highest pulse velocity with a 28
days UPV of 0.317x101km/s and 0.280x101km/s for
mix ratios 1:2:4 and 1:3:6 respectively, while the
concrete made from Class 3 fine aggregate gave the
lowest pulse velocity with a 28 days UPV of
0.295x101km/s and 0.260x101km/s respectively for
mix ratios 1:2:4 and 1:3:6. Generally, UPV values for
mix ratio 1:2:4 were higher than respective UPV
values for mix ratio 1:3:6.
Fig. 3: Slump Test Results
Pulse Velocity and Compressive Strength Results
Tables 1 and 2 show the results for the concrete pulse
velocity as well as the compressive strength of the
concrete made from the different classes of fine
65
Journal of Emerging Trends in Engineering and Applied Sciences (JETEAS) 6(1):62- 70 (ISSN: 2141-7016)
Fig.4: Graph of pulse velocity against age of concrete
for mix ratio of 1:2:4
Fig.6: Graph of compressive strength against age of
concrete for mix ratio of 1:2:4
Fig. 7: Graph of compressive strength (F) against age
of concrete (t) for mix ratio of 1:3:6
Fig. 5: Graph of pulse velocity against age of
concrete for mix ratio of 1:3:6
To check whether variation in fine aggregate size will
affect relationship between compressive strength of
concrete and UPV, graphs of compressive strength
against UPV were plotted. Figures 8 and 9 show the
graph of compressive strength and UPV of concrete
for the different classes of fine aggregate for mix
ratios 1:2:4 and 1:3:6. From the graphs plotted, a
linear relationship is observed between compressive
strength and UPV of concrete, with strength
increasing as UPV increases for concrete made from
the three classes of fine aggregate (Class 1, 2 and 3)
and for both mix ratios (1:2:4 and 1:3:6).
Figures 6 and 7 show the graph of compressive
strength against age of concrete for mix ratios 1:2:4
and 1:3:6 respectively. The graph showed
compressive strength increasing with age of concrete.
Concrete made from Class 2 fine aggregate gave the
highest compressive strength
with a 28 days
strength of 34.00N/mm2 and 26.5N/mm2 for mix
ratios 1:2:4 and 1:3:6 respectively, while the concrete
made from Class 3 fine aggregate gave the lowest
compressive strength with a 28 days strength of
19.00N/mm2 and 15.00N/mm2 respectively for mix
ratios 1:2:4 and 1:3:6. As for pulse velocity,
compressive strength values for mix ratio 1:2:4 were
higher than respective compressive strength values
for mix ratio 1:3:6.
66
Journal of Emerging Trends in Engineering and Applied Sciences (JETEAS) 6(1):62- 70 (ISSN: 2141-7016)
(a) Class 1
(b) Class 2
(c) Class 3
Fig. 8: Graph of compressive strength against UPV (1x101km/s) for mix ratio of 1:2:4
(a) Class 1
(b) Class 2
(c) Class 3
Fig. 9: Graph of compressive strength against UPV for mix ratio of 1:3:6
properties of concrete (compressive strength and
UPV) when the age of the concrete is known for
concrete made from the different classes of fine
aggregates and for both mix ratios 1:2:4 and 1:3:6 .
Additionally, models were also developed for the
Model Development and Validation (Regression
Analysis on Experimental Data)
As properties of concrete change with age, models
were developed for the prediction of the different
67
Journal of Emerging Trends in Engineering and Applied Sciences (JETEAS) 6(1):62- 70 (ISSN: 2141-7016)
variables are well explained by the independent
variables and that the linear models (regression line)
fit the data and can be used for obtaining values
outside the experimental range.
prediction of concrete’s compressive strength from its
UPV value.
These models (Figures 4 - 9) were developed by
carrying out a linear regression analysis on
experimental results (Tables 2 and 3) using a
confidence level of 95% with MS Excel spreadsheet
application. Table 4 (a and b) shows a summary of
the models with their coefficient of determination
(R2) which is an indication of how the dependent
variables can be explained by the independent
variables as well as the pattern of residual plot
obtained for all models developed.
Furthermore, residual plots for all models developed
gave a fairly random plot centered on zero through
the range of fitted values. This indicates that: (1) a
linear model produced a decent fit to the data (2) that
the models are correct on the average for all fitted
values and (3) that the models are appropriate for the
data. Sample residual plots for the models developed
for concrete made from the different classes of fine
aggregate used in this research are presented in
Figure 10 (a-f).
The coefficient of determination (R2) obtained for the
various models ranged from 0.9258 to as high as
0.9994. The high values showed that the dependent
Table 4a: Models and their Regression Parameters for 1:2:4 Mix Ratio
Class 1
Class 2
Class 3
Model
Developed
Linear Model
R
Pattern
of
Residual
Plot
F vs Age
F= 0.2122t +
15.8
0.9258
Fairly
Random
F = 0.6906t +
14.83
0.9964
Fairly
Random
F = 0.2497t +
11.965
0.9981
UPV vs
Age
v = 0.0015t +
0.263
0.9994
Fairly
Random
v = 0.0015t +
0.276
0.9994
Fairly
Random
v = 0.0016t +
0.2515
0.9988
Fairly
Random
F vs
UPV
F = 145.34v 22.447
0.9379
Fairly
Random
0.9987
Fairly
Random
0.9941
Fairly
Random
2
Model
R
Pattern
of
Residual
Plot
Model
R
Pattern
of
Residual
Plot
Fairly
Random
2
F = 470.4v 115.01
Table 4b: Models and their Regression Parameters for 1:3:6 Mix Ratio
Class 1
Class 2
Patter
Patter
Linear
n of
n of
2
2
Model
R
Model
R
Model
Residu
Residu
al Plot
al Plot
Fairly
Fairly
F vs
F = 0.3265t
0.988
F = 0.4676t
0.931
Rando
Rando
+ 13.92
7
Age
+ 10.2
4
m
m
UPV
vs Age
v = 0.0003t +
0.2555
0.964
3
Fairly
Rando
m
v = 0.0006t
+ 0.2625
0.964
3
Fairly
Rando
m
F = 159.52v 28.143
2
Class 3
Model
F=
0.1939t +
9.5
v=
0.0007t +
0.2415
2
R
0.991
8
0.999
3
Patter
n of
Residu
al Plot
Fairly
Rando
m
Fairly
Rando
m
Fairly
F = 470.4v Fairly
F=
Fairly
0.994
Rando
115.01
0.998 Rando
159.52v Rando
1
m
m
28.143
m
2
1
Where F = compressive strength in N/mm , v = Ultrasonic Pulse Velocity (UPV) in 1 x 10 km/s and t = Age of
concrete in days.
F vs
UPV
F = 145.34v
- 22.447
0.937
9
68
Journal of Emerging Trends in Engineering and Applied Sciences (JETEAS) 6(1):62- 70 (ISSN: 2141-7016)
Figure 10a: Residual plot of Compressive Strength vs
age for 1:2:4 mix ratio using Class 1 fine aggregate
Figure 10b: Residual plot of Compressive Strength vs
age for 1:3:6 mix ratio using Class 1 fine aggregate
Figure 10c: Residual plot of UPV vs age for 1:2:4 mix
ratio using Class 2 fine aggregate
Figure 10d: Residual plot of UPV vs age for 1:3:6 mix
ratio using Class 2 fine aggregate
Figure 10e: Residual plot of compressive strength
UPV vs age for 1:2:4 mix ratio using Class 3 fine
aggregate
Figure 10f: Residual plot of compressive strength
UPV vs age for 1:3:6 mix ratio using Class 3 fine
aggregate
obtained. This value of UPV was then applied to the
compressive strength/UPV model (F = 470.4v –
115.01) and a compressive strength of 34.6N/mm2
was obtained which agrees with the value earlier
obtained from the compressive strength/Age model
and hence consistent. This value was also close to the
experimental value of 34.00N/mm2 obtained.
From the residual plot it is shown that predicted
values obtained using models developed were close
to actual data obtained from experiments. This also
further validates the accuracy of the models for use in
predicting and obtaining values outside experimental
range.
All models developed for a particular class and mix
ratio were found to be consistent as values of
compressive strength obtained using the compressive
strength/Age model at a particular age were very
close to values of compressive strength obtained
using the compressive strength/UPV model with the
UPV value obtained from the UPV/Age model at the
same age. For example, at 28 days for class 2 fine
aggregate concrete and 1:2:4 mix ratio, a value of
compressive strength of 34.2N/mm2 was obtained
using the compressive strength/Age model (F =
0.6906t + 14.83). From the UPV/Age model (v =
0.0015t + 0.276), a UPV of 0.318 x 101km/s was
CONCLUSION
The effect of variation in the sizes of fine aggregate
used in the manufacture of concrete for different mix
ratios have been studied. From experimental results
and analysis of same, it was revealed that the size of
fine aggregate used affects the workability of
concrete and the finer the aggregate, the lower the
workability for all mix ratios.
Variation in fine aggregate size affects the
compressive strength in the same manner as it affects
the pulse velocity of concrete, with the concrete made
69
Journal of Emerging Trends in Engineering and Applied Sciences (JETEAS) 6(1):62- 70 (ISSN: 2141-7016)
BS EN 12390-3, 2009. Testing Hardened Concrete:
Compressive Strength of Test Specimens, British
Standards Institution, UK.
from the medium sized fine aggregate i.e. class 2
(425µm < d < 2.00mm) giving the highest value of
compressive strength and pulse velocity for all mix
ratios. Concrete made from Class 1 fine aggregate
gave the lowest values of strength for all mix ratios.
BS EN 12504-4, 2004. Testing Concrete:
Determination of Ultrasonic Pulse Velocity, British
Standards Institution, UK.
For all types of concrete, the relationships between
age, pulse velocity and compressive strength were
linear with strength and pulse velocity increasing
with age. Values of compressive strength and pulse
velocity for mix ratio 1:2:4 were higher than
respective values for mix ratio of 1:3:6.
Khlef, F.L., 2012. Proposed UPV-Strength
Relationship for Concrete Subjected to Sulfate
Attack, Anbar Journal for Engineering Sciences, Iraq,
p. 114 – 122
Kozul,R. and Darwin, D., 1997. Effects of Aggregate
Type, Size, and Content on Concrete Strength and
Fracture Energy, University Of Kansas Center For
Research, Inc., Kansas.
Models were developed for the prediction of
compressive strength from age, pulse velocity from
age and compressive strength from pulse velocity for
concrete made from each of the three classes of fine
aggregate and for mix ratios 1:2:4 and 1:3:6 making a
total of 18 models. The models which are linear
models were found to be appropriate, accurate, and
consistent with predicted values from other models
and experimental values with each model unique
from the others. The benefit of this is that a concrete
property can be obtained and analysed from another
property (such as age which is usually known) and
vice versa.
Mehta, P. K. and Monteiro, P. J. M., 1993. Concrete
Structure, Properties, and Materials, Prentice-Hall,
Inc., Englewood Cliffs, NJ
Mills, W. H. and Fletcher, O. S., 1969. Control and
Acceptance of Aggregate Gradation by Statistical
Methods, Highway Research Board, Bulletin 290, pp.
35-49.
Shacklock, B. W., 1974. Concrete Constituents and
Mix Proportions, Cement and Concrete Association,
London
For general construction purposes, it is recommended
that Class 2 fine aggregate as defined in this paper be
used in the manufacture of concrete as it gave the
highest strength with acceptable workability.
Talbot, A.N., and Richart, F.E., 1923. The Strength
of Concrete and its Relation to the Cement,
Aggregate and Water, Bulletin No. 137: 1-116
This paper was limited to the study of the variation of
concrete properties with variation of fine aggregate
size so as to determine and model the behavior of
concrete for the different sizes (classes) of fine
aggregate used. In order to fully understand this
variation,
further
studies
should
include
determination of the effects on and variation of
concrete properties when a combination of two
classes of fine aggregates are used and also when all
three classes of fine aggregates are used, and the
results compared with values obtained in this study.
Troxell G. L, Davis H. S, and Kelly J.W, 1968.
Composition and Properties of Concrete, 2nd Ed.,
Mc. Graw –Hill Book Company
Yaqub, M. and Bukhari, I., 2006. Effect Of Size of
Coarse Aggregate on Compressive Strength of High
Strength Concerts” 31st Conference on OUR
WORLD IN CONCRETE & STRUCTURES,
Singapore.
REFERENCES
Agrawal, P., Gupta, Y. P. and Bal, S., 2007. Effect of
Fineness of Sand on the Cost and Properties of
Concrete, New Building Materials and Construction
World (NMM&CW), India
Alawode O. and Idowu O.I., 2012. Effects of WaterCement Ratios on the Compressive Strength and
Workability of Concrete and Lateritic Concrete
Mixes, The Pacific Journal of Science and
Technology, Volume 12. Number 2, Hawaii
BS EN 12350-2, 2009. Testing Fresh Concrete:
Slump Test, British Standards Institution, UK.
70