Guide for the use of low-density concrete in civil works projects
Preface
1—Introduction
1.1 Background and Purpose
1.2 Engineering Responsibilities and Requirements
1.3 Delays in Contract Awards
2—Materials
2.1 Low-Density Concrete Classifications
2.1.1 Structural-grade low-density aggregate concrete
2.1.2 High-strength, low-density concrete
2.1.3 Specified-density concrete
2.2 Cementitious Materials
2.2.1 Selection of cementitious materials
2.2.2 Specification details
2.2.3 Other requirements
2.2.4 Pozzolans
2.2.5 Availability investigation of cementitious materials
2.3 Aggregates
2.3.1 Particle density
2.3.2 Particle shape and surface texture
2.3.3 Absorption characteristics
2.3.4 Gradations
2.3.5 Maximum strength ceiling
2.3.6 Sources of aggregate
2.3.7 Availability investigation
2.4 Water for Mixing and Curing
2.5 Chemical Admixtures
3—Mixture Proportioning Considerations
3.1 Selecting Concrete Mixture Proportions
3.2 Basis for Selection of Proportions
3.2.1 Economy
3.2.2 Strength
3.2.3 Durability
3.2.4 Placeability
3.3 Low-Density Aggregates
3.3.1 Absorption and moisture content
3.3.2 Gradation
3.3.3 Fineness modulus
3.4 Water-Cement/Water-Cementitious Ratio
3.5 Air Entrainment
3.6 Estimating First Trial Mixture Proportions
3.6.1 Method 1–weight method (specific gravity pycnomet
3.6.2 Method 2–volumetric method (damp, loose volume)
3.7 Adjusting Mixture Proportions
3.7.1 Volume considerations
3.7.2 Method 1–weight method (specific gravity pycnomet
3.7.3 Method 2–volumetric method (damp, loose volume)
3.7.4 Adjustment procedures
3.7.5 Controlling proportions in the field
3.8 Mixture Proportions Comparison
4—Concrete Production
4.1 General Considerations
4.2 Batching
4.2.1 Batch-plant and mixer types
4.2.2 Measuring and batching
4.2.3 Batching low-density coarse aggregate
4.2.4 Batching low-density fine aggregate
4.2.5 Adding admixtures
4.3 Mixing
4.3.1 Charging the mixer
4.3.2 Plant mixers
4.3.3 Truck mixers
4.4 Mixer Operation
4.4.1 Transportation and waiting time
4.4.2 Temperature effects
5—Conveying and Placing
5.1 General Considerations
5.2 Pumping
5.2.1 General considerations
5.2.2 Aggregate moisture conditioning
5.2.3 Moisture retention
5.2.4 Pumps and pump systems
5.2.5 Mixture proportions
5.2.6 Coarse low-density aggregate
5.2.7 Fine low-density aggregate
5.2.8 Water and slump
5.2.9 Cementitious materials
5.2.10 Admixtures
5.2.11 Pumpability tests
5.2.12 Field control
5.2.13 Planning
5.2.14 Other requirements
5.3 Conveyor Belts
5.4 Placing
5.5 Consolidation
6—Other Construction Considerations
6.1 Forms
6.2 Finishing
6.3 Curing
6.4 Surface
6.5 Job Controls
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