 Open Access
 Total Downloads : 793
 Authors : Mohammed Abas Abdela Salem, R. K. Pandey
 Paper ID : IJERTV4IS020308
 Volume & Issue : Volume 04, Issue 02 (February 2015)
 Published (First Online): 16022015
 ISSN (Online) : 22780181
 Publisher Name : IJERT
 License: This work is licensed under a Creative Commons Attribution 4.0 International License
Effect of CementWater Ratio on Compressive Strengthand Density of Concrete
Mohammed Abas Abdela Salema
1Department of Civil Engineering, Sam Higginbotom Institute of Agriculture Technology & Sciences, Allahabad , India
R. K. Pandeyb
2Department of Civil Engineering, Sam Higginbotom Institute of Agriculture Technology & Sciences , Allahabad, India
Abstract V ariable compressive strength of concrete mixes with cementwater ratios ranging from 1.3 to 1.8, within 7 to 28 days of curing time, were experimentally investigated in this paper. The experiment was carried out to investigate the effect of cementwater ratios on the compressive strength and density of concrete. Compressive strength of concrete mixes were found to increase with both age and cementwater ratio. Any increase in cementwater ratio leads to increase in compressive strength, however, increase in cementwater ratio leads to decrease in aggregates content followed by decrease in density of concrete mix.
From the finding of this research, cementwater ratio plays significant rule and consider the most factor used to increase the strength of concrete mix and to decrease the density of concrete mix. By considering cementwater ratio, light, economical and appropriate strength of concrete structures can be achieved.
Keywords C ementwate ratio ; compressive strength of concrete; concrete density; aggregates content;

INTRODUCTION
Concrete is considered the most used materials in construction work. It has been predicted that concrete will continue to be the most popular industrial material [1]. It is a composite materials resulting from a mixture of cement, water and aggregates, used alone or with steel depending on the design of the structure. It makes any shape when casting in any formwork and form a solid mass when cured by a suitable temperature and humidity.
Compressive strength of concrete is eight times greater than its tensile strength [2]. The tensile strength of concrete is commonly neglected and required addition of steel bars or other materials to use in the design of some structures when tensile strength is taken into consideration. Ordinary concrete should be strong enough to carry its designed loads during all it anticipated life.
Aggregates (fine aggregates, coarse aggregates) are commonly natural crushed or uncrushed materials (artificial materials). Aggregates constitute about onequarter to twothird of the total volume of concrete. Using aggregates in concrete greatly affect all the properties of either plastic or hardened concrete. Selection of suitable aggregates improves the volume stability and the durability of hardened concrete [3].
The compressive strength of concrete is determined by performing compression test on standard sizes of concrete either cubes or cylinders. The proportions of concrete affect partly the strength of concrete, however, watercement ratio consider the most important factor affecting the strength of concrete [3]. There is an optimum amount of water in which maximum strength from a particular mix of proportion of concrete can be achieved [4]. It has observed that compressive strength decreased as watercement ratio decreased [5].
However, the present work aims at experimentally comparing the compressive strength, aggregates, and density of concrete mixes under varied cementwater ratio.

METHODOLOGY

Work Materials and Specimens Preparation
The materials used in this investigation are cement, gavel and water. Allin aggregates size distributions, mixed sand and gravel, were determined by sieve analysis from which grading limit was achieved. The grading limits of allin aggregates confirm a suitable grading distribution which leads to suitable workability and durability.

Experimental Test Procedures
Mix proportions of 1:1.5:3 was determined by using cement, fine aggregates and coarse aggregates respectively. A 4 kg of cement was added to 6 kg and 12 kg of fine and coarse aggregates. Water was added to cement by weight to form cementwater ratios of 1.3, 1.4, 1.5, 1.6, 1.7 and 1.8. The whole was mixed into paste. Meanwhile, the cubic moulds of concrete were oiled to ease the demolding process late.
The concrete was then poured into cubes according to its cementwater ratio and placed for 2 minutes on vibration machine to remove the tapped air from the concrete. The cubes were then covered with polythene to prevent evaporation process.
After 24 hours of sitting time, the cubes were demolded and placed in curing water tank for 7, 14, 28 days respectively. At each specified period of days, the cubes were crushed using crushing machine to determine the compressive strength of concretes.


RESULTS AND DISCUSSION
Table I shows the variation of the strength of concrete mixes with cementwater ratios. It was observed that the higher cementwater the higher the strength of concrete. However, the higher cementwater ratio leads to the less density and weight of concrete. In addition, the compressive strength was observed to increase with age of curing days. As a result, the cementwater ratio is considered the main factor of determination the compressive and weight of concrete.
The plot of compressive strength of concrete mixes with variations of cementwater ratio is shown in Figure (1). Figure
(2) shows the plot of compressive strength with variations of ages. It was observed that the optimum compressive strength
at 28 days after casting. Figure (3) and Figure (4) show the
275
250
Compressive Strength (kg/cm2)
225
200
175
150
125
100
75
28 days after casting
plots of density and aggregates of concrete versus cement water ratios.
TABLE I. VARIATIONS OF WEIGHT, DENSITY, AND COMPRESSIVE STRENGTH OF CONCRETRE MIXES WITH CEMENTWATER RATIO
157
S
/
N
Cement Water
Ratio
Age (days
)
weight of cube
(g)
Density of cube
(g/cm3)
Crushing load (kg)
Compressive Strength
(kg/cm2)
a
1.3
7
8232
2.439
20250
90
b
1.4
7
8215
2.434
23400
104
c
1.5
7
8184
2.425
24570
110
d
1.6
7
8168
2.42
27000
120
e
1.7
7
8151
2.415
29025
129
f
1.8
7
8130
2.409
30375
135
g
1.3
14
8434
2.499
31500
140
h
1.4
14
8427
2.497
32400
144
i
1.5
14
8394
2.487
33750
150
j
1.6
14
8387
2.485
35325
k
1.7
14
8387
2.485
36450
162
l
1.8
14
8360
2.477
37800
168
m
1.3
28
8529
2.527
39600
176
n
1.4
28
8512
2.522
41625
185
o
1.5
28
8492
2.516
42750
190
p
1.6
28
8478
2.512
44550
198
q
1.7
28
8461
2.507
48600
216
r
1.8
28
8441
2.501
52650
234
7 days after casting 14 days after casting
1.3 1.35 1.4 1.45 1.5 1.55 1.6 1.65 1.7 1.75 1.8
CementWater Ratio
Fig. 1. Plot of Compressive Strength of Concrete vs. CemenWater Ratio
250
Compressive Strength (kg/cm2)
1.8
1.7
225
1.6
200
1.7
1.5
1.4
175
1.6
1.3
150
1.5
1.4
125
1.3
100
9 12 15 18 21 24 27
Age (days)
Fig. 2. Plot of Compressive Strength of Concrete vs. Age
2530
2525
Concrete Density (kg/m3)
2520
2515
2510
2505
2500
1.3 1.35 1.4 1.45 1.5 1.55 1.6 1.65 1.7 1.75 1.8
CementWater Ratio
Fig. 3. Effect of CementWater Ratio on Density of Concrete
2075
2050
2025
Aggregates (kg/m3)
2000
1975
1950
1925
1900
1875
1850
1.3 1.35 1.4 1.45 1.5 1.55 1.6 1.65 1.7 1.75 1.8
CementWater Ratio
Fig. 4. Effect of CementWater Ratio on Aggregates of Concrete

RECOMMENDATION
The use of suitable cementwater ratio in concrete mix can determine the expected weight and strength of concrete mix. By this concept, more economical concrete mix is related to cementwater ratio.
REFERENCES

R.J .Detwiler, B.J. Dalgheish, R.B. Williamson (1989),Assessing the durability of concrete in freezing and thawing, . ACI Mater, J. 1989, 42, 2935.

W.H. Mosley, J.H. Bungey (2000), Reinforced Concrete Design, 5rd ed., Macmillan Publisher Limited, London, UK, 2000.

L.K.A Sear, J. Dews, B. Kite, F.C. Harris, J. F. Troy (1996),Abrams rule, air and high watertocement ratios, Construction and Building Materials, Vol. 10, No 3, 1996, PP 221226.

O. Lafe (1986), Elements of Reinforced Concrete Design, Macmillan Publisher , London, UK

P.G. Omotola, O.I. Idowu (2011),Effect of watercement Ratios on the Compressive Strength and Workability of Concrete and Lateritic Concrete Mixes, The Pacific Journal of Science and Technology, Vol 12, No 2, November 2011, pp 99105.M.