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CONTENTS I~RODU~N Lo STATEMENT OF THE PR-LEM ~0 REPORT ORGANIZATION. 3.0 BACK=OU~ . 3.1 History ...... =2 Need for Was Rudy =3 Study Scope =4 may Libations. 0 USE OF EMS REPORT NCLUS~NS AND R=O~EN~IONS # e 2 Lo SOB SELECTION A-/OR DESIGN PROCEDURE . ~ ~ ~ ~ Hi. C2 Protege Wan T~ I ~ Recommended . L3 Pr~e~re an T~ ~ Is Recommended . 1.4 Procedure Wan 1~ ~ Is ~comme~ed 1.5 Procedure Wan 1~ ~ Is Recommended Hi 2 e 2 4 4 10 10 12 13 14 20
2.0 HEATED AND UNHEATED SLABS . . 3.0 NONRECTANGULAR SLABS 4.0 SLABS ON UNSTABLE SOILS 5.0 SLABS OF UNUSUAL CONFIGURATION 6.0 QUALITY CONTROL PRACTICES 111 RESEARCH RECOMMENDATIONS 1.0 GENERAL 2.0 SOILS RESEARCH . . 22 2.1 Investigation of Granular Mats or Stabilized Soil Mats . 23 2.2 Soil/Moisture Relationships 2.3 Swelling Properties of Clay Soils . . .... .. . 2.4 Stabilization of Soils for Residential Construction . . 2.5 Identification of Problem Soil Areas . . . 3.0 SLAB RESEARCH ....... 3.1 Field Investigation 3.2 Cracking of Slabs 3.3 Effect of Partition Loads on Unreinforced Slabs . 3. 4 Maximum Deformation of Unreinforced Slabs 3.5 Effective Stiffness of Stiffened Slabs .... 3.6 Effect of Slab Stiffness on Superstructure 3.7 Controlled Design and Construction. .... 3. 8 Investigation of Other Stii fened-Slab Designs 3.9 Investigation of Prestressed and Precast Slabs 4. 0 PRIORITY. IV SUPPLEMENTARY INFORMATION PART A: SELECTION AND DESIGN OF SLABS 1.0 FUNCTIONS OF SLABS-ON-GROUND viii 24 . . . . . . . . . . 25 25 26 26 26 26 27 27 27 28
2.0 FUNDAMENTAL FACTORS OF SLAB DESIGN AND CONSTRUCTION . 3.0 SELECTION OF SLAB TYPE . 3.1 Types of Slab-on-Ground . 3.1.1 Slab Type I. 3.1.2 Slab Type II 3.1. 3 Slab Type III 3.1.4 Slab Type IV 3.2 Soil Investigation 3.3 Climatic Rating . . . . . . . . . 31 32 32 32 32 33 33 34 ........ 34 3.4 Correlation of Climate and Soil for Selection of Slab . . 37 4.0 CRITERIA FOR TYPE I SLABS 4.1 General . 4.2 Site..... 4.3 Dimensions 4.4 Irregular Shapes . . . 4.5 Weakened-Plane Joints 4.6 Embedment in Slab 4. 7 Loads . 4.8 Openings . 5.0 CRITERIA FOR TYPE II SLABS . 5.1 General. 5.2 Dimensions 5.3 Reinforcement. . . 5.4 Embedment in Slab 5.5 Irregular Shapes . 5.6 Loads . 5.7 Openings 39 · . . . 39 41 41 . . . 41 42 42 43 6.0 EXAMPLE OF PROCEDURE FOR DETERMINING WHETHER A TYPE I OR II SLAB IS APPROPRIATE, AND APPLICATION OF CRITERIA...... 6.1 General......... 6.2 Determination of Slab Type . 6.3 Procedure . 7.0 DESIGN OF TYPE III SLABS ix 43 43 43 45 45 46 46 46
7.1 Effect of Superstructure 7.2 Effect of Soil Behavior . . 7.3 Support Index 7.4 7.5 Increase of Support Index (C) Determination of Support Index (C) for Compressible Soils (2. 5 < qu/w < 7. 5) 7.6 Typical Stiffened-Slab Cross Section . . 7.7 Analysis of Type Ill Slabs ...... 7.8 Design of Type m Slabs. . . 7. 8.1 Determination of Effective PI, PVC- Meter Reading, or Percentage Swell of Soil 7.8.2 Effective Load Hi) on Slab 7.8.3 Determination of Effective Load (w) . 7. 8.4 Limiting Values of Variables . 7.8.5 Use of Charts for Design . . 7.8.6 Design Sequence 7.8. 7 Top Slab . 7. 8.8 Excluded Parameters 49 54 56 58 59 ...... 65 65 68 69 69 71 76 . . 83 84 7.8.9 Use of 24,000-psi Steel (ASTM A-432) or WWF. . 85 7.9 Design of Type m Slabs on Compressible Soils _ (7.5 ~ qu/w 2 2 .5) . . . . . . . . . . . . . . . . . 8 5 7.9.1 Behavior of Compressible Soils under Uniform Load (w) 86 7. 9.2 Assumed Reactions and Corresponding Support Index (C) for Slabs on Compressible Soils 87 7.9.3 Design Sequence 91 7.10 Related Design Considerations . . . . . . . . . . . 92 7.10.1 Concentrated Loads on the Slab . . . . . . . . 92 7.10.2 Limiting Reinforcement . . . . . . . . . . . 92 7.10.3 Embedment of Conduits in the Slab . . . . . . 93 7.10.4 Other Stiffened-Slab Designs . . . . . . . . . 93 7.11 Example 1-Design of Type m Slabs Supported on Expansive Soils 94 7.11. 1 Determination of Slab Type . . . . . . . . . . 94 7.11.2 Application of Type III Procedure . . . . . . . 95 7.11.3 Design of Slab One-Analytical and Chart Procedures 97 7.11.4 Design of Slab Two-Chart Procedure Only . . . 103 7.11.5 Discussion of Design. . . . . . . . . . . . . 107 x
7.12 Example 2-Design of Type III Slabs Supported on Expansive Soils: &allow Beams ......... 7 .12.1 Determination of Slab Type 7.12.2 Application of Type III Procedure 7.12.3 Design of Slab One . 7.12.4 Design of Slab Two .... 7.13 Example 1-Design of Type III Slabs Supported on Compressible Soils ....... 7.13.1 Given Conditions ........ 7.13.2 Application of Type III Procedure. · - 7.14 Example 2-Design of Type III Slabs Supported on Compressible Soils ......... 8.0 DESIGN OF TYPE IV SLABS PART B: QUAI1TY CONTROL 1.0 GENERAL . . . 2.0 SITE PREPARATION 2.1 Fills ......... 2.1.1 Controlled Fills . . 2.1.2 Uncontrolled Fills 2.1.3 Cut-and-Fill.... 2.1.4 Construction of Fills 2.1.5 Fill Materials 2.2 Natural Moisture Control 2.3 Site Drainage ...... 3.0 SLAB MATERIALS ....... 3.1 Concrete Quality . 3.2 Test for Concrete Consistency. . 3.3 Admixtures .......... 4.0 CONCRETE PRACTICES.... 4.1 Engineer or Architect Supervision . . . . . . 4.2 Ready-Mix Concrete without Engineer or Architect Supervision 110 110 112 113 115 115 117 . . . . . . . 122 126 127 129 129 129 129 130 130 130 130 131 131 132 132 132 xi
4.3 On-Site Mixing ........ 4.4 Concrete Placing and Finishing . 4.5 Curing Practices PART C: SOILS 1.0 GENERAL 2.0 UNIFIED SOIL C LASSIFICATION SYSTEM 2.1 Identification and Classification 2.2 Aids to Soil Identification 2.3 Major Soil Classes ..... 3.0 PROBLEM SOILS . 3.1 Loess . 3.2 Highly Compressible Clays 3.3 Expansive Clays ..... 3.4 Highly Plastic Soils.... 3.5 Sands and Silts...... 4.0 UNDISTURBED CONDITION OF SOILS . 4.1 Natural Density of Sands and Silts 4.2 Consistency of Cohesive Soils . . 5.0 NONPROBLEM SOILS APPENDIXES APPENDS A DESIGN TABLES . APPENDS B DEFINITIONS AND ABBREVIATIONS . APPENDS C TECHNICAL REFERENCES ........ APPENDS D UNIFIED SOIL CLASSIFICATION CHART . xii 136 137 137 138 138 139 139 140 140 140 141 141 141 143 143 ......... 145 · . ~ . 283 . 287 . . 289
List of Illustrations Figure 1 Climatic Ratings (Cw) for Continental United States 38 2 Typical Type I Slabs ...... .... ..... Method of Supporting Partition Loads in Excess of 500 PLF Typical Type 1I Slabs.... .... .... .... Support Assumptions . . . . . ... . . . . . . .. Support Index (C) Based on Criterion for Soil Sensitivit., _ Climatic Rating (Cw) .......... 7 Curve Relating PI to FHA- PVC Reading 8 9 10 11 Determining Cr for Slab on Compressible Soil Variation of Cr with Ratio qu/w . Typical Type HI Slab Section . . . . . . . . . . . . . . . . . . . . . . . . - Assumed Ground Reaction Conditions to Permit One-Dimensional Slab Analysis . ... e e ~ e e e e e e e 12 Limiting Cases of Support for Type III Slab Analysis 13 Hypothetical Soil Profile with Variable PI. 14 ~ e Steel Ratio (p) in Terms of Load Index [w (I '/b)] and Depth Ratio (Q/d) for ^/L = 1/200 . . e e e e e ~ ~ e ~ e 15 Steel Ratio (p) in Terms of Load Index [A (t'/b)] and Depth Ratio ~/d) for AIL = 1/300 . e e e e 16 Steel Ratio (p) in Terms of Load Index [w (I '/b)] and Depth Ratio (~/d) for ~/L = 1/360 . 7 Z Use p Curve and Z/p vs. p Curve 18 Stress Pattern in Clay Compressible Soils under Absolutely Flexible and Absolutely Rigid Slabs . e 19 Loading and Reaction Assumptions for Slab Supported on Compressible Soils e ~ e ~ 20 Slab Layout and Reinforcement-Parae Tell Design Example 21 Slab Layout and Reinforcement-Para. 7~12 Design Example 22 Optimum Compaction Requirements for Slab Site Based on Plasticity Index and Climatic Rating (Percent of Standard or Modified Proctor Density) 40 42 44 53 55 57 58 59 ..... 60 1 61 · · · 66 72 ~3 86 88 . . 108 . 116 . 128 · . . X111
List of Tables Table I Slab-Type Recommendations Based on Soil and Climatic Conditions . It Opinion WWF Reinforcement between Design Joints for Type II Slabs .. .. .. e ~ ~ · - e e e · e e · - Permissible Differential Settlements for Stiffened Slabs to Minimize Utility Damage to Superstructure Values of the Steel Ratio Function (Z) . . e Concrete Mixes - Volumetric Basis. . . Relative Density of Sands . . . e e e e Consistency of Undisturbed Clay Soils. . . Slab 24 x 40 It: L/~ = 200. Slab 24 x 40 It: L/6 = 300 . Slab 24 x 40 It: L/~ = 360 . Slab 30 x 50 It: L/^ = 200 . Slab 30 x 50 It: L/~ = 300 . Slab 30 x 50 ft.: L/^ = 360 . Slab 36 x 72 It: L/~ = 200. Slab 36 x 72 It: L/^ = 300 . Slab 36 x 72 It: L/~ = 360 Slab 30 x 30 It: L/^ = 200 . Slab 30 x 30 It: L/^ = 300 . Slab 30 x 30 It: L/^ = 360 . Slab 35 x 35 It: L/~ = 200 . Slab 35 x 35 It: L/~\ = 300. Slab 35 x 35 It: L/^ = 360 . III IV V VI VE vm A B C IX A B C X A B C XI A B C XII A B C xiv . . 45 50 76 135 142 142 151 156 162 168 178 189 201 211 223 236 245 255 266 271 277
Criteria for Selection and Design of Residential Slabs-on-Ground
