Description
ACI 302.1R-15:
The quality of a concrete floor or slab is highly dependent on achieving a hard and durable surface that is flat, relatively free of cracks, and at the proper grade and elevation. Properties of the surface are determined by the mixture proportions and the quality of the concreting and jointing operations. The timing of concreting operations—especially finishing, jointing, and curing—is critical. Failure to address this issue can contribute to undesirable characteristics in the wearing surface such as cracking, low resistance to wear, dusting, scaling, high or low spots, poor drainage, and increasing the potential for curling.
Concrete floor slabs employing portland cement, regardless of slump, will start to experience a reduction in volume as soon as they are placed. This phenomenon will continue as long as any water, heat, or both, is being released to the surroundings. Moreover, because the drying and cooling rates at the top and bottom of the slab are not the same, the shrinkage will vary throughout the depth, causing the as-cast shape to be distorted and reduced in volume.
This guide contains recommendations for controlling random cracking and edge curling caused by the concrete’s normal volume change. Application of present technology permits only a reduction in cracking and curling, not elimination. Even with the best floor designs and proper construction, it is unrealistic to expect completely crack- and curl-free floors. Consequently, every owner should be advised by both the designer and contractor that it is completely normal to expect some amount of cracking and curling on every project, and that such an occurrence does not necessarily reflect adversely on either the adequacy of the floor’s design or the quality of its construction (Ytterberg 1987).
This guide describes how to produce high-quality concrete slabs-on-ground and suspended floors for various classes of service. It emphasizes such aspects of construction as site preparation, concrete materials, concrete mixture proportions, concrete workmanship, joint construction, load transfer across joints, form stripping procedures, finishing methods, and curing. Flatness/levelness requirements and measurements are outlined. A thorough preconstruction meeting is critical to facilitate communication among key participants and to clearly establish expectations and procedures that will be employed during construction to achieve the floor qualities required by the project specifications. Adequate supervision and inspection are required for job operations, particularly those of finishing.
ACI 302.2R-06
This guide contains materials, design, and construction recommendations for concrete slabs-on-ground and suspended slabs that are to receive moisture-sensitive flooring materials. These flooring materials include sheet rubber, epoxy coatings, vinyl composition tile, sheet vinyl, carpet, athletic flooring, laminates, and hardwood. Chapters 1 through 8 provide an understanding of concrete moisture behavior and drying, and show how recommended construction practices can contribute to successful performance of floor covering materials. This background provides a basis for the recommendations in Chapter 9 to improve performance of floor covering materials in contact with concrete moisture and alkalinity.
Because this guide is specific to floor moisture problems and solutions, refer to the most current editions of both ACI 302.1R, “Guide for Concrete Floor and Slab Construction,” and ACI 360R, “Design of Slabs-on-Ground,” for general information. These two documents contain guidance on floor design and construction that is needed to achieve successful floor covering performance.
ACI 360R-10
This guide presents information on the design of slabs-on-ground, primarily industrial floors. It addresses the planning, design, and detailing of slabs. Background information on design theories is followed by discussion of the types of slabs, soil-support systems, loadings, and jointing. Design methods are given for unreinforced concrete, reinforced concrete, shrinkage-compensating concrete, post-tensioned concrete, fiber-reinforced concrete slabs-on-ground, and slabs-on-ground in refrigerated buildings, followed by information on shrinkage and curling.
Advantages and disadvantages of these slab design methods are provided, including the ability of some slab designs to minimize cracking and curling more than others. Even with the best slab designs and proper construction, it is unrealistic to expect crack-free and curl-free floors. Every owner should be advised by the designer and contractor that it is normal to expect some cracking and curling on every project. This does not necessarily reflect adversely on the adequacy of the floor’s design or quality of construction. Design examples are given.
Table of Contents
ACI 302.1R-04:
Chapter 1—Introduction
1.1—Purpose and scope
1.2—Terminology
1.3—Related work of other committees
Chapter 2—Classes of floors
2.1—Classification of floors
2.2—Single-course monolithic floors: Classes 1, 2, 4, 5,and 6
2.3—Two-course floors: Classes 3, 7, and 8
2.4—Class 9 floors
2.5—Special finish floors
Chapter 3—Design considerations
3.1—Scope
3.2—Slabs-on-ground
3.3—Suspended slabs
3.4—Miscellaneous details
Chapter 4—Site preparation and placing environment
4.1—Soil-support system preparation
4.2—Suspended slabs
4.3—Bulkheads
4.4—Setting screed guides
4.5—Installation of auxiliary materials
4.6—Concrete placement conditions
Chapter 5—Materials
5.1—Introduction
5.2—Concrete
5.3—Portland cement
5.4—Aggregates
5.5—Water
5.6—Curing materials
5.7—Admixtures
5.8—Liquid surface treatments
5.9—Reinforcement
5.10—Evaporation reducers
5.11—Gloss-imparting waxes
5.12—Joint materials
5.13—Volatile organic compounds (VOC)
Chapter 6—Concrete properties and consistency
6.1—Concrete properties
6.2—Recommended concrete mixture
6.3—Concrete mixture analysis
Chapter 7—Batching, mixing, and transporting
7.1—Batching
7.2—Mixing
7.3—Transporting
Chapter 8—Placing, consolidating, and finishing
8.1—Placing operations
8.2—Tools for spreading, consolidating, and finishing
8.3—Spreading, consolidating, and finishing operations
8.4—Finishing Class 1, 2, and 3 floors
8.5—Finishing Class 4 and 5 floors
8.6—Finishing Class 6 floors and monolithic-surface treatments for wear resistance
8.7—Finishing Class 7 floors
8.8—Finishing Class 8 floors (two-course unbonded)
8.9—Finishing Class 9 floors
8.10—Toppings for precast floors
8.11—Finishing lightweight concrete
8.12—Nonslip floors
8.13—Decorative and nonslip treatments
8.14—Grinding as a repair procedure
8.15—Floor flatness and levelness
8.16—Treatment when bleeding is a problem
8.17—Delays in cold-weather finishing
Chapter 9—Curing, protection, and joint filling
9.1—Purpose of curing
9.2—Methods of curing
9.3—Curing at joints
9.4—Curing special concrete
9.5—Length of curing
9.6—Preventing plastic-shrinkage cracking
9.7—Curing after grinding
9.8—Protection of slab during construction
9.9—Temperature drawdown in cold storage and freezer rooms
9.10—Joint filling and sealing
Chapter 10—Quality control checklist
10.1—Introduction
10.2—Partial list of important items to be observed
Chapter 11—Causes of floor and slab surface imperfections
11.1—Introduction
11.2—Cracking
11.3—Low wear resistance
11.4—Dusting
11.5—Scaling
11.6—Popouts
11.7—Blisters and delamination
11.8—Spalling
11.9—Discoloration
11.10—Low spots and poor drainage
11.11—Curling
11.12—Analysis of surface imperfections
Chapter 12—References
12.1—Referenced standards and reports
12.2—Cited references
12.3—Other references
ACI 302.2R-06
CONTENTS
Chapter 1—Introduction and background
1.1—Introduction
1.2—Flooring moisture issues
1.3—Concrete slabs that receive flooring materials
1.4—Changes in construction methods and materials that affect floor systems
1.5—Floor flatness changes with time
1.6—Other considerations
Chapter 2—Concrete moisture basics
2.1—Introduction
2.2—Moisture movement
2.3—Concrete drying profiles
2.4—Effects of moisture movement
2.5—Equilibrium moisture content
2.6—Drying and wetting of concrete
2.7—Moisture loss during drying
Chapter 3—Concrete moisture testing
3.1—Introduction
3.2—Standard guides and test methods
3.3—Qualitative and quantitative tests
3.4—Test parameters
3.5—Underlayment testing
3.6—Comments on moisture vapor emission rate tests
Chapter 4—Concrete pH testing
4.1—Introduction
4.2—Test methods
4.3—ASTM test differences
4.4—Factors affecting pH test results
Chapter 5—Floor covering and adhesive manufacturer’s recommendations
5.1—Introduction
5.2—Manufacturer’s recommendations
5.3—Dealing with multiple floor covering requirements
Chapter 6—Drying of concrete
6.1—Introduction
6.2—Concrete drying with no external source of moisture
6.3—Concrete drying: exposed to moisture from below
6.4—Concrete drying: exposed to moisture from above
6.5—Concrete drying from both sides
6.6—Effect of concrete-making materials
6.7—Effect of fresh and hardened concrete properties
6.8—Effect of thickness
6.9—Effect of curing
6.10—Drying of mature concrete
6.11—Effect of drying environment
6.12—Drying at exposed edge
6.13—Drying of lightweight concrete
Chapter 7—Vapor retarder/barrier
7.1—Introduction
7.2—Vapor retarder/barrier location
7.3—Vapor transmission through retarder/barrier
Chapter 8—Floor covering materials
8.1—Introduction
8.2—Communication between architect and engineer
8.3—Floor covering technical resources
8.4—Floor adhesives and coverings
8.5—Effect of moisture in flooring adhesives
8.6—Effect of concrete moisture on adhesive performance
Chapter 9—Design and construction recommendations
9.1—Introduction
9.2—Testing
9.3—Vapor retarder/barrier
9.4—Concrete materials
9.5—Concrete properties
9.6—Surface finish
9.7—Curing
9.8—Surface preparation
9.9—Repairs
9.10—Protection
9.11—Moisture mitigation
Chapter 10—References
10.1—Referenced standards and reports
10.2—Cited references
Appendix—Two case studies of moisture-related flooring problems
A.1—Value engineering results in flooring failure
A.2—Postconstruction trench drains results in flooring failure
ACI 360R-10
Contents:
Chapter 1—Introduction
1.1—Purpose and scope
1.2—Work of ACI Committee 360 and other relevant committees
1.3—Work of non-ACI organizations
1.4—Design theories for slabs-on-ground
1.5—Construction document information
1.6—Further research
Chapter 2—Definitions
2.1—Definitions
Chapter 3—Slab types
3.1—Introduction
3.2—Slab types
3.3—General comparison of slab types
3.4—Design and construction variables
3.5—Conclusion
Chapter 4—Soil support systems for slabs-on-ground
4.1—Introduction
4.2—Geotechnical engineering reports
4.3—Subgrade classification
4.4—Modulus of subgrade reaction
4.5—Design of slab-support system
4.6—Site preparation
4.7—Inspection and site testing of slab support
4.8—Special slab-on-ground support problems
Chapter 5—Loads
5.1—Introduction
5.2—Vehicular loads
5.3—Concentrated loads
5.4—Distributed loads
5.5—Line and strip loads
5.6—Unusual loads
5.7—Construction loads
5.8—Environmental factors
5.9—Factors of safety
Chapter 6—Joints
6.1—Introduction
6.2—Load-transfer mechanisms
6.3—Sawcut contraction joints
6.4—Joint protection
6.5—Joint filling and sealing
Chapter 7—Design of unreinforced concrete slabs
7.1—Introduction
7.2—Thickness design methods
7.3—Shear transfer at joints
7.4—Maximum joint spacing
Chapter 8—Design of slabs reinforced for crack-width control
8.1—Introduction
8.2—Thickness design methods
8.3—Reinforcement for crack-width control only
Chapter 9—Design of shrinkage-compensating concrete slabs
9.1—Introduction
9.2—Thickness determination
9.3—Reinforcement
9.4—Other considerations
Chapter 10—Design of post-tensioned slabs-on-ground
10.1—Introduction
10.2—Applicable design procedures
10.3—Slabs post-tensioned for crack control
10.4—Industrial slabs with post-tensioned reinforcement for structural support
Chapter 11—Fiber-reinforced concrete slabs-on-ground
11.1—Introduction
11.2—Synthetic fiber reinforcement
11.3—Steel fiber reinforcement
Chapter 12—Structural slabs-on-ground supporting building code loads
12.1—Introduction
12.2—Design considerations
Chapter 13—Design of slabs for refrigerated facilities
13.1—Introduction
13.2—Design and specification considerations
13.3—Temperature drawdown
Chapter 14—Reducing effects of slab shrinkage and curling
14.1—Introduction
14.2—Drying and thermal shrinkage
14.3—Curling and warping
14.4—Factors that affect shrinkage and curling
14.5—Compressive strength and shrinkage
14.6—Compressive strength and abrasion resistance
14.7—Removing restraints to shrinkage
14.8—Base and vapor retarders/barriers
14.9—Distributed reinforcement to reduce curling and number of joints
14.10—Thickened edges to reduce curling
14.11—Relation between curing and curling
14.12—Warping stresses in relation to joint spacing
14.13—Warping stresses and deformation
14.14—Effect of eliminating sawcut contraction joints with post-tensioning or shrinkage-compensating concrete
14.15—Summary and conclusions
Chapter 15—References
15.1—Referenced standards and reports
15.2—Cited references
Appendix 1—Design examples using Portland Cement Association method
A1.1—Introduction
A1.2—The PCA thickness design for single-axle load
A1.3—The PCA thickness design for slab with post loading
A1.4—Other PCA design information
Appendix 2—Slab thickness design by Wire Reinforcement Institute method
A2.1—Introduction
A2.2—The WRI thickness selection for single-axle wheel load
A2.3—The WRI thickness selection for aisle moment due to uniform loading
Appendix 3—Design examples using Corps of Engineers’ charts
A3.1—Introduction
A3.2—Vehicle wheel loading
A3.3—Heavy lift truck loading
Appendix 4—Slab design using post-tensioning
A4.1—Design example: Post-tensioning to minimize cracking
A4.2—Design example: Equivalent tensile stress design
Appendix 5—Design example using shrinkagecompensating concrete
A5.1—Introduction
A5.2—Example selecting the optimum amount of reinforcement to maximize the compressive stress in the
concrete where the slab thickness, the joint spacing, and prism expansion are known
Appendix 6—Design examples for steel FRC slabs-on- ground using yield line method
A6.1—Introduction
A6.2—Assumptions and design criteria
Appendix 7—Construction document information
A7.1—Introduction
A7.2—Example design criteria
A7.3—Typical details
Conversion factors