International Journal of Scientific & Engineering Research, Volume 6, Issue 4, April-2015 204

ISSN 2229-5518

Performance Investigation of Cement Concrete

Under Variation of Curing Time

Shreyash Shah, Ashutosh Patil

Abstract— Today there is a need of speedy construction as the world is growing and developing at a fast rate. Time is as precious as money. Curing each and every element of structure for 28 days sometime becomes a problems due to shortage of time and resources. This work is concerned with finding an experimental research of variation of curing time on concrete compressive strength. For this concrete cubes were cast for a design mix of M-20, 1:1.777:2.826 by weight and 0.47 water cement ratio and M-25, 1:1.432:2.472 by weight and 0.414 water cement ratio using OPC 43 grade, OPC 53 grade and PPC cement as per guidelines for concrete mix proportioning with a slump of 75 mm to 100 mm. The concrete cubes gain about 85%, 94%, 108%, and 124% of target characteristic compressive strength for PPC if cured for first 7, 14, 21 and 28 days respectively.

Keywords—Compressive strength, concrete cubes, curing, OPC 53 grade, OPC 43 grade, PPC, variation.

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1 INTRODUCTION

Concrete is an artificial construction structural material made from the mixture of aggregates (course and fine), water, Portland cement and small amount of air bubbles, incorporated and stabilized into cement mix. Concrete is formed when Portland cement is hydrated and forms cement paste, which when mixed with aggregates hardens and binds into solid mass. Concrete is currently the most widely used construction material as it can be cast to any form and shape at site very easily.Concrete is used in large quantities; almost everywhere mankind has a need of structure. It is very tough to find an option for concrete in construction, which is durable and economic.
Curing can be achieved by keeping the concrete element completely saturated or as much saturated as possible until the water-filled spaces are substantially reduced by hydration products. If the concrete is not cured and is allowed to dry in air, it will gain only 50% of the strength of continuously cured concrete. Improper curing would entail insufficient moisture and this has been found to produce cracks, compromise strength, and reduce long-term durability. The scope of discussion in this study is to investigate the effect of variation of curing time on characteristic compressive strength of concrete.
In the present study, concrete with Pollozona Portland cement (PPC), Ordinary Portland Cement (OPC) 53 grade and Ordinary Portland Cement (OPC) 43 grade, is adopted. Concrete grade of M-25 design mix with a slump in between
75 to 100 mm were considered in the study. We cure the concrete cubes for 7, 14, 21, 28 days and test for characteristic compressive strength.

2 NECESSITY OF PROJECT

It is well known fact that as curing time increases strength of

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• Shreyash Shah is currently pursuing Masters Degree program in Structural Engineering in N.B.N.S.C.O.E; Solapur University, India, PH-9545560016. E-mail: mksshah62@gmail.com

• Ashutosh Patil is currently working as an Assistant Professor in in

N.B.N.S.C.O.E; Solapur University, India, PH-9403688721. E-mail:

er.ashutoshpatil@gmail.com
concrete increases however in practice this curing time varies
due to multiple reasons, shortage of water, inadequate
knowledge, other construction constraints, etc. Hence,
optimum curing period for type of cement grade is not
available in practice.
Now, considering these several reasons, variation in curing
time on compressive strength of concrete needs to be
investigated as time and condition may not allow 28 days of
curing. In this we study the effect of curing time on design mix
of M-25 with different types of cement available in market to
obtain best possible result.

3 LITERATURE REVIEW

Malhotra V.M. (1988) said that cement generally represent 12-

14% of concrete weight. It plays an active part in the mixture
by ensuring cohesion between aggregate grains and it
introduces a decisive contribution to concrete mechanical
strengths. During the hardening process, it generates
shrinkage and heat dissipation phenomena which lead to
material cracking. Ramezanianpour et.al (1995) concluded
that if a concrete is not well cured, particularly at the early
age, it will not gain the required properties at desired level
due to a lower degree of hydration, and would suffer from
irreparable loss. Mamlouk et.al (2006) said if concrete is cured
for only three days, it will reach about 60% of the strength of
continuously cured concrete; if it is cured for seven days, it
will reach 80% of the strength of continuously cured concrete.
If curing stops for some time and then resumes again, the
strength gain will also stop and reactivate. BarisOzer et.al

(2004) said that the curing conditions affect the strengths of

both the OPC concrete and pozzolanic cement concretes.
However, poor curing affects the strength properties of
pozzolanic cement concretes more adversely that those of the
OPC. For pozzolanic cement concretes, at least an initial 7-day
water curing is necessary to expose the pozzolanic activity.
Pozzolanic cement concretes, water-cured for at least 14 days,
can reach the strength level of the OPC concrete cured
continuously in water in periods shorter than 2 months.
Usman et.al (2006) concluded curing plays an important role
in strength of concrete.

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4 MATERIALS AND METHODOLOGY

4.1 Materials

The detail of various materials used in the experimental investigation will be:
• Coarse Aggregate:-Crushed granite stone aggregate of maximum size 20 mm confirming to IS 383-1970 was used. The specific gravity was found to be 2.925.
• Sand (Fine Aggregate):- The fine aggregate used was sand passing through 4.75 mm sieve. The specific gravity was found to be 2.83. The grading zone of fine aggregate was zone I as per IS specification.
• Cement:- OPC 43 grade, OPC 53 grade, PPC (Ultratech Cement) was used.
• Water:- Ordinary clean potable water free from suspended particles and chemicals was used for mixing and curing of concrete.

4.2Methodology

Experimental Procedure: To investigate the effect of variation of curing time on compressive strength of concrete, half of the concrete cubes were cast and cured with normally and were tested for the age of curing and half of the concrete cubes were cured for 7, 14, 21 and 28 days and were tested for characteristic strength. The concrete cube size measuring

150×150×150 mm in dimension will be used. The batching of the concrete was carried out by weight for strength of 25
N/mm^2. The mould were filled in three layers tamping each layer 25 times.

Workability: Workability of cubes mixed was measured before casting of cubes. The workability maintained was medium i.e. slump was maintained between 75 mm to 100 mm for mass concrete.

Experimental Procedure: The compressive strength is taken as maximum compressive load resisted by per unit area.

Test Results: The concrete cubes were tested in “Compression Testing Machine of Technical and Scientific Sales Instruments” which has a capacity 200 tones. The tests were carried out at “Vidya Vikas Pratishthan Polytechnic, Solapur ”.

Results indicate that, the percentage of strength obtained for
PPC are greater than OPC 53 grade and OPC 43 grade.

TABLE 1

QUANTITIES FOR 12 CUBES, M-20

TABLE 2

QUANTITIES FOR 12 CUBES, M-25

TABLE 3

TEST RESULTS FOR M-20 (OPC 43 GRADE)

(Laboratory: VVP Polytechnic, Solapur)

TABLE 4

TEST RESULTS FOR M-20 (OPC 53 GRADE)

(Laboratory: VVP Polytechnic, Solapur)

TABLE 5

TEST RESULTS FOR M-20 (PPC)

(Laboratory: VVP Polytechnic, Solapur)

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TABLE 6

TEST RESULTS FOR M-25 (OPC 43 GRADE)

(Laboratory: VVP Polytechnic, Solapur)

TABLE 7

TEST RESULTS FOR M-25 (OPC 53 GRADE)

(Laboratory: VVP Polytechnic, Solapur)

TABLE 5

TEST RESULTS FOR M-25 (PPC)

(Laboratory: VVP Polytechnic, Solapur)

Fig. 1. Average Compressive Strength of M-20 Concrete

Fig. 1. Average Compressive Strength of M-25 Concrete

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Fig. 3. Graphical Representation of Average Compressive Strength of

M-20 and M-25 Concrete Using OPC 43 Grade

Fig. 5. Graphical Representation of Average Compressive Strength of

M-20 and M-25 Concrete Using PPC

Fig. 4. Graphical Representation of Average Compressive Strength of

M-20 and M-25 Concrete Using OPC 53 Grade

5 CONCLUSIONS

1. Series of experiments were conducted on M-20 concrete. From the results it can be said that, compressive strength attained by 21 days curing is almost equal or more than target strength.
2. Concrete cubes cast with PPC cement gives better results thanOPC 43 gradeand OPC 53 grade.
3. 7 days, 14 days, 21 days and 28 days curing give 81-
82%, 91-93%, 99-101%, 117-119% of the target
characteristic strength which is 26.6 N/mm^2 and 31.6
N/mm^2 for M-20 and M-25 grade of concrete
respectively if OPC 43 grade cement is used.
4. 7 days, 14 days, 21 days and 28 days curing give 82-
84%, 92-93%, 100-103%, 122-125% of the target
characteristic strength which is 26.6 N/mm^2 and 31.6
N/mm^2 for M-20 and M-25 grade of concrete
respectively if OPC 53 grade cement is used.
5. 7 days, 14 days, 21 days and 28 days curing give 85-
86%, 95-96%, 103-109%, 120-127% of the target
characteristic strength which is 26.6 N/mm^2 and 31.6
N/mm^2 for M-20 and M-25 grade of concrete
respectively if OPC 43 grade cement is used.
6. Studies may be carried out for other types of

cements, other types of admixtures and ground

granulated blast furnace slag cements etc.

From the above finding we can conclude that 21 days
curing can be enough as concrete cubes gain about 99-
109%.

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6 REFERENCES

[1] Shreyash Shah, Ashutosh Patil, “An Experimental Investigation of Effect of Variation of Curing Time on Compressive Strength of Concrete”, International Journal of Emerging Technology and Advance Engineering (IJETAE), Vol. 5, Issue 3, pp 151-154.
[2] IS 10262-2009, “Concrete Mix Proportioning”
[3] Mamlouk, M.S. and Zaniewski, J.P (2006). “Materials
for Civil and Construction Engineers”, 2nd ed., New
Jersey: Pearson Prentice Hall.
[4] Malhotra V.M. A Global Review with Emphasis on
Durability and Innovative Concrete. Journal of
American Concrete Institute, Vol. 30, 1988.
[5] Price, W. H. (1991). “Factors influencing Concrete
Strength”, J. Am. Concrete Institute
[6] Ramezanianpour, A.A. and V.M. Malhotra (1995).
“Effect of Curing on the Compressive Strength,
Resistance to Chloride-Ion Penetration and Porosity of Concretes Incorporating Slag, Fly Ash or Silica Fume”, Cement and Concrete Composites”. 17(2).
[7] BarisOzer, M. HulusiOzkul (2004). “The influence of initial water curing on the strength development of ordinary portland and pozzolanic cement concretes”, Cement and Concrete Research.
[8] Fernando Lopez Gayarre, Carlos Lopez-Colina Perez, Miguel A. Serrano Lopez, Alberto Domingo Cabo (2014), “The effect of curing conditions on the compressive strength of recycled aggregate concrete”, Construction and Building Materials.
[9] Usman Ghani, Faisal Shabbir and Kamran Muzaffar Khan (2006). “Change in Concrete Properties Due to Lack of Curing”, 31st conference on Our World in Concrete & Structures: 16 - 17 August 2006, Singapore.

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