International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395 -0056
Volume: 04 Issue: 03 | Mar -2017
p-ISSN: 2395-0072
www.irjet.net
Curing of Concret Shaikh A.S.1, Lahare P.S.2, Nagpure V.B.3 Ghorpde S.S4 Department of Civil Engineering, Ashok Polytechnic, Maharashtra ---------------------------------------------------------------------***--------------------------------------------------------------------1,2,3,4
ABSTRACT - Efficient uninterrupted curing is the key to quality concrete. Proper curing of concrete is crucial to obtain design strength and maximum durability. The curing period depends on the required properties of concrete, the purpose for which it is to be used, and the surrounding atmosphere namely temperature and relative humidity. Curing is designed mainly to keep the concrete moist, by preventing the loss of moisture from the concrete during the period in which it is gaining strength. Curing may be applied in a number of ways and the most appropriate means of curing may be dictated by the site or the construction method. The present paper is directed to elaborate effectiveness of different curing methods and study the influence of climate on the strength properties of concrete. KeyWords: Temperature
Curing,
Concrete,
prevent adequate hydration. The surface is particularly susceptible to insufficient hydration because it dries first. If temperatures are favorable, hydration is relatively fast the first few days after concrete is placed; however, it is important for water to be retained in the concrete during this period, that is, for evaporation to be prevented or substantially reduced. 1.1 CURING PERIOD AND TEMPRUTURE The curing period depends upon the type of cement used, mixture proportions, required strength, size and shape of member, ambient weather, future exposure conditions, and method of curing. Since all desirable properties are improved with curing, the period should be as long as practical. For most concrete structures, the curing period at temperatures above 5º C (40º F) should be a minimum of 7 days or until 70% of the specified compressive or flexural strength is attained. The period can be reduced to 3 days if high early strength concrete is used and the temperature is above 10º C (50º F).
Efficient,
1. INTRODUCTION Curing is the maintenance of a satisfactory moisture content and temperature in concrete for a period of time immediately following placing and finishing so that the desired properties may develop. The need for adequate curing of concrete cannot be overemphasized. Curing has a strong influence on the properties of hardened concrete; proper curing will increase durability, strength, water tightness, abrasion resistance, volume stability, and resistance to freezing and thawing and deicers. Exposed slab surfaces are especially sensitive to curing as strength development and freeze-thaw resistance of the top surface of a slab can be reduced significantly when curing is defective. When Portland cement is mixed with water, a chemical reaction called hydration takes place. The extent to which this reaction is completed influences the strength and durability of the concrete. Freshly mixed concrete normally contains more water than is required for hydration of the cement; however, excessive loss of water by evaporation can delay or © 2017, IRJET
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1.2 SEVERAL FACTORS AFFECT TO COUNTERACT SELF- DESICCATION 1. Aggregate pore size: If it is very fine, water may not migrate readily into the surrounding paste. 2. The spacing between the aggregate particles: if it is too large, the paste surrounding the aggregates may not be accessible to the water in the aggregate within a reasonable time. These influences may be expressed in a simplified engineering approach in terms of an efficiency term, η, which is a factor in the range of 0 to, describing the portion of water in the aggregates that can become available for internal curing. Accordingly, whether any improvement in water retention was matched by an increase in degree of the cement hydration. Initial surface absorption tests and compressive strength measurements were made to assess whether any improvement in water retention was matched by an increase in degree of cement |
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