308R-01
Guide to Curing Concrete
2001, 31 pp.
$58.50

The term "curing" is frequently used to describe the process by which hydraulic-cement concrete matures and develops hardened properties over time as a result of the continued hydration of the cement in the presence of sufficient water and heat. While all concrete cures to varying levels of
maturity with time, the rate at which this development takes place depends on the natural environment surrounding the concrete, and the measures taken to modify this environment by limiting the loss of water, heat, or both, from the concrete, or by externally providing moisture and heat. The word
"curing" is also used to describe the action taken to maintain moisture and temperature conditions in a freshly placed cementitious mixture to allow hydraulic-cement hydration and, if applicable, pozzolanic reactions to occur so that the potential properties of the mixture may develop. Current curing techniques are presented; commonly accepted methods, procedures, and materials are described. Methods are given for curing pavements and other slabs on ground, for structures and buildings, and for mass concrete. Curing methods for several specific categories of cement-based products
are discussed in this document. Curing measures, in general, are specified in ACI 308.1. Curing measures directed toward the maintenance of satisfactory concrete temperature under specific environmental conditions are addressed in greater detail by Committees 305 and 306 on Hot and Cold Weather Concreting, respectively, and by ACI Committees 301 and 318.

Contents:

Chapter 1 Introduction, p. 308R-2

1.1 Introduction
1.2 Definition of curing
1.3 Curing and the hydration of portland cement
1.3.1 Hydration of portland cement
1.3.2 The need for curing
1.3.3 Moisture control and temperature control
1.4 When deliberate curing procedures are required
1.4.1 Natural conditions
1.4.2 Sequence and timing of curing steps for unformed surfaces
1.4.3 When curing is required for formed surfaces
1.4.4 When curing is required: cold and hot weather
1.4.5 Duration of curing
1.5 The curing-affected zone
1.6 Concrete properties influenced by curing

Chapter 2 Curing methods and materials, p. 308R-12

2.1 Scope
2.2 Use of water for curing concrete
2.3 Initial curing methods
2.3.1 Fogging
2.3.2 Liquid-applied evaporation reducers
2.4 Final curing measures
2.4.1 Final curing measures based on the application of water
2.4.2 Final curing methods based on moisture retention
2.5 Termination of curing measures
2.6 Cold-weather protection and curing
2.6.1 Protection against rapid drying in cold weather
2.6.2 Protection against frost damage
2.6.3 Rate of concrete strength development in cold weather
2.6.4 Removal of cold-weather protection
2.7 Hot-weather protection and curing
2.8 Accelerated curing
2.9 Minimum curing requirements
2.9.1 General
2.9.2 Factors influencing required duration of curing

Chapter 3 Curing for different types of construction, p. 308R-19

3.1 Pavements and other slabs on ground
3.1.1 General
3.1.2 Curing procedures
3.1.3 Duration of curing
3.2 Buildings, bridges, and other structures
3.2.1 General
3.2.2 Curing procedures
3.2.3 Duration of curing
3.3 Mass concrete
3.3.1 General
3.3.2 Methods and duration of curing
3.3.3 Form removal and curing formed surfaces
3.4 Curing colored concrete floors and slabs
3.5 Other constructions

Chapter 4 Monitoring curing and curing effectiveness, p. 308R-22

4.1 General
4.2 Evaluating the environmental conditions in which the concrete is placed
4.2.1 Estimating evaporation rate
4.3 Means to verify the application of curing
4.4 Quantitative measures of the impact of curing procedures on the immediate environment
4.5 Quantitative measures of the impact of curing procedures on moisture and temperature
4.6 Maturity method
4.7 Measuring physical properties of concrete affected by temperature and moisture control to assess curing effectiveness

Chapter 5 References, p. 308R-26

5.1 Referenced standards and reports
5.2 Cited references