Material Property Characterization of Ultra-High Performance Concrete

FHWA-HRT-06-103

AUGUST 2006

FOREWORD

Advances in the knowledge and understanding of the behaviors of concrete on the microstructural level have led to the development of the next generation of concrete, namely ultra-high performance concrete (UHPC). This report characterizes the material behaviors of one UHPC in terms of accepted concrete testing methodologies. The Federal Highway Administration (FHWA) has been investigating the optimal use of UHPC in highway bridges, and this report presents results from the first phase of this research program. Of primary importance, the results contained herein provide a starting point for bridge owners interested in advancing the state of bridge engineering through the use of extremely high strength and high durability concretes. This report presents both what can be achieved today through the use of a commercially available concrete as well as the types of advancements that can be achieved by reevaluating the traditional components and proportions normally present in cementitious structural materials.

Gary Henderson
Director, Office of Infrastructure
Research and Development

This document is disseminated under the sponsorship of the U.S. Department of Transportation in the interest of information exchange. The U.S. Government assumes no liability for the use of the information contained in this document. This report does not constitute a standard, specification, or regulation.

The U.S. Government does not endorse products or manufacturers. Trademarks or manufacturers’ names appear in this report only because they are considered essential to the objective of the document.

The Federal Highway Administration (FHWA) provides high-quality information to serve Government, industry, and the public in a manner that promotes public understanding. Standards and policies are used to ensure and maximize the quality, objectivity, utility, and integrity of its information. FHWA periodically reviews quality issues and adjusts its programs and processes to ensure continuous quality improvement.

Form DOT F 1700.7 (8-72)

SI* (Modern Metric) Conversion Factors

TABLE OF CONTENTS

1. INTRODUCTION
     1.1 INTRODUCTION
     1.2 OBJECTIVE
     1.3 SUMMARY OF APPROACH
     1.4 OUTLINE OF REPORT

2. BACKGROUND AND PREVIOUS WORK
     2.1 UHPC CONSTITUENT MATERIALS
     2.2 MANUFACTURER-SUPPLIED UHPC MATERIAL PROPERTIES
     2.3 STEEL FIBER MATERIAL PROPERTIES
     2.4 RELEVANT MATERIAL PROPERTY CHARACTERIZATION STUDIES
          2.4.1 Fiber Orientation Effect on Mechanical Properties
          2.4.2 Permeability of Cracked Concrete
          2.4.3 Creep and Shrinkage of UHPC
          2.4.4 Abrasion Resistance of HSC via ASTM C944

3. UHPC MATERIAL CHARACTERIZATION
     3.1 RESEARCH PLAN
          3.1.1 Batch and Specimen Nomenclature
          3.1.2 Test Matrix
     3.2 BATCHING, CASTING, AND CURING OF UHPC
     3.3 COMPRESSION TESTING
          3.3.1 Strength
          3.3.2 Strength, Modulus of Elasticity, and Strain Capacity With Time
          3.3.3 Linearity of UHPC Compressive Response
          3.3.4 Compression Specimen Geometry
          3.3.5 Demolding Age Effect on Compressive Strength
          3.3.6 Long-Term Delayed Steam Effect on Compressive Strength
          3.3.7 Fiber Effect on Compression Failure
          3.3.8 Load Rate Effect on Compression Testing Results
     3.4 TENSION TESTING
          3.4.1 Flexural Prism
          3.4.2 Split Cylinder
          3.4.3 Mortar Briquette
          3.4.4 Direct Tension
     3.5 FRACTURE TESTING
     3.6 PENETRATION RESISTANCE TESTING
     3.7 SHRINKAGE TESTING
          3.7.1 Long-Term Shrinkage Testing
          3.7.2 Early Age Shrinkage Testing
     3.8 CREEP TESTING
          3.8.1 Long-Term Creep Testing
          3.8.2 Early Age High-Stress Creep Testing
     3.9 COEFFICIENT OF THERMAL EXPANSION
     3.10 HEAT OF HYDRATION
     3.11 AIR VOID ANALYSIS
     3.12 STEEL FIBER DISPERSION TESTING
     3.13 DURABILITY TESTING
          3.13.1 Rapid Chloride Ion Penetrability Testing
          3.13.2 Chloride Penetration
          3.13.3 Scaling Resistance
          3.13.4 Abrasion Resistance
          3.13.5 Freeze-Thaw Resistance
          3.13.6 Alkali-Silica Reaction
     3.14 SPLIT-CYLINDER TENSION TESTING ON CRACKED CYLINDERS

4. DISCUSSION OF RESULTS
     4.1 TENSILE BEHAVIOR OF UHPC
          4.1.1 Summary of Experimental Results
          4.1.2 Summary of Experimental Test Methods
     4.2 LOCAL AND GLOBAL MECHANICAL FAILURE MODES OF UHPC
     4.3 EFFECT OF CURING PROCEDURE ON UHPC PROPERTIES
     4.4 EARLY AGE STRENGTH GAIN OF UHPC
     4.5 COMPARISON OF CYLINDER AND CUBE COMPRESSION STRENGTH RESULTS
     4.6 SHRINKAGE BEHAVIOR OF UHPC
     4.7 LONG-TERM STABILITY OF UHPC
     4.8 MODULUS OF ELASTICITY OF UHPC
     4.9 COMPRESSIVE STRESS-STRAIN BEHAVIOR OF UHPC

5. CONCLUSIONS AND FUTURE RESEARCH
     5.1 INTRODUCTION
     5.2 CONCLUSIONS
     5.3 ONGOING AND FUTURE RESEARCH

REFERENCES

LIST OF FIGURES

Figure 1. Graph. Sample tensile stress-strain response for steel fiber reinforcement
Figure 2. Photos. Mixing of UHPC. (a) Water addition. (b) HRWA addition. (c) Prepaste consistency. (d) Fiber addition. (e) Finished mix
Figure 3. Graph. Mix time as affected by premix age
Figure 4. Graph. Final flow diameter as affected by premix age
Figure 5. Photos. (a) Grinding and (b) measuring of 76-mm (3-inch) diameter cylinders
Figure 6. Photos. 76-mm (3-inch) diameter cylinders (a) before and (b) after compression testing
Figure 7. Graph. Compressive strength and density of control cylinders
Figure 8. Graph. Compressive strength and cylinder end planeness of control cylinders
Figure 9. Photos. Modulus ring attachment (a) before and (b) during testing
Figure 10. Graph. Selected stress-strain responses for steam-treated UHPC (N1A)
Figure 11. Graph. Selected stress-strain responses for steam-treated UHPC (N1AxxA)
Figure 12. Graph. Selected stress-strain responses for untreated UHPC
Figure 13. Graph. Selected stress-strain responses for tempered steam-treated UHPC
Figure 14. Graph. Selected stress-strain responses for delayed steam-treated UHPC
Figure 15. Graph. Compressive strength gain from casting up to 8 weeks of age
Figure 16. Graph. Modulus of elasticity gain from casting up to 8 weeks of age
Figure 17. Graph. Strain at peak compressive stress from casting up to 8 weeks of age
Figure 18. Graph. Sample untreated stress-strain curve with linearity descriptors
Figure 19. Graph. Secant modulus from casting up to 8 weeks of age
Figure 20. Graph. Ratio of elastic to secant modulus from casting up to 8 weeks of age
Figure 21. Graph. Compressive stress to strength ratio at 1 percent stress drop from linear elastic
Figure 22. Graph. Compressive stress to strength ratio at 5 percent stress drop from linear elastic
Figure 23. Photo. Compression cubes and cylinders including (clockwise from upper left) 102-mm (4-inch), 76-mm (3-inch) overlength, 76-mm (3-inch), and 51-mm (2-inch) diameter cylinders and 51-mm (2-inch) and 100-mm (4-inch) cubes
Figure 24. Photos. (a) Cylinder and (b) cube compression testing
Figure 25. Photos. Compression failure of a steam-treated UHPC cylinder containing no fiber reinforcement (a) 1/6 second before failure, (b) 1/30 second before failure, (c) at failure, and (d) 1/10 second after failure
Figure 26. Photos. Prism flexural test setup for (a) a 229-mm (8.9-inch) span and (b) a 305-mm (11.9-inch) span
Figure 27. Graph. Examples of first crack shown on load-deflection response curves
Figure 28. Graph. ASTM C1018 load-deflection response results for steam-treated 51- by 51-mm (2- by 2-inch) prisms over a 152-mm (6-inch) span with third-point loading
Figure 29. Graph. ASTM C1018 load-deflection response results for untreated 51- by 51-mm (2- by 2-inch) prisms over a 152-mm (6-inch) span with third-point loading
Figure 30. Graph. ASTM C1018 load-deflection response results for tempered steamtreated 51- by 51-mm (2- by 2-inch) prisms over a 152-mm (6-inch) span with third-point loading
Figure 31. Graph. ASTM C1018 load-deflection response results for delayed steamtreated 51- by 51-mm (2- by 2-inch) prisms over a 152-mm (6-inch) span with third-point loading
Figure 32. Graph. ASTM C1018 load-deflection response results for steam-treated 76- by 102-mm (3- by 4-inch) prisms over a 305-mm (12-inch) span with third-point loading
Figure 33. Graph. ASTM C1018 load-deflection response results for untreated 76- by 102-mm (3- by 4-inch) prisms over a 305-mm (12-inch) span with third-point loading
Figure 34. Graph. ASTM C1018 load-deflection response results for tempered steamtreated 76- by 102-mm (3- by 4-inch) prisms over a 305-mm (12-inch) span with third-point loading
Figure 35. Graph. ASTM C1018 load-deflection response results for delayed steamtreated 76- by 102-mm (3- by 4-inch) prisms over a 305-mm (12-inch) span with third-point loading
Figure 36. Graph. ASTM C1018 load-deflection response results for steam-treated 51- by 51-mm (2- by 2-inch) prisms over a 229-mm (9-inch) span with third-point loading
Figure 37. Graph. ASTM C1018 load-deflection response results for untreated 51- by 51-mm (2- by 2-inch) prisms over a 229-mm (9-inch) span with third-point loading
Figure 38. Graph. ASTM C1018 load-deflection response results for tempered steamtreated 51- by 51-mm (2- by 2-inch) prisms over a 229-mm (9-inch) span with third-point loading
Figure 39. Graph. ASTM C1018 load-deflection response results for delayed steam-treated 51- by 51-mm (2- by 2-inch) prisms over a 229-mm (9-inch) span with third-point loading
Figure 40. Graph. ASTM C1018 load-deflection response results for steam-treated 51- by 51-mm (2- by 2-inch) prisms over a 305-mm (12-inch) span with third-point loading
Figure 41. Graph. ASTM C1018 load-deflection response results for untreated 51- by 51-mm (2- by 2-inch) prisms over a 305-mm (12-inch) span with third-point loading
Figure 42. Graph. ASTM C1018 load-deflection response results for tempered steam-treated 51- by 51-mm (2- by 2-inch) prisms over a 305-mm (12-inch) span with third-point loading
Figure 43. Graph. ASTM C1018 load-deflection response results for delayed steam-treated 51- by 51-mm (2- by 2-inch) prisms over a 305-mm (12-inch) span with third-point loading
Figure 44. Graph. ASTM C1018 load-deflection response results for steam-treated 51- by 51-mm (2- by 2-inch) prisms over a 381-mm (15-inch) span with 76 mm (3 inches) between loads
Figure 45. Graph. ASTM C1018 load-deflection response results for untreated 51- by 51-mm (2- by 2-inch) prisms over a 381-mm (15-inch) span with 76 mm (3 inches) between loads
Figure 46. Graph. ASTM C1018 load-deflection response results for tempered steam-treated 51- by 51-mm (2- by 2-inch) prisms over a 381-mm (15-inch) span with 76 mm (3 inches) between loads
Figure 47. Graph. ASTM C1018 load-deflection response results for delayed steam-treated 51- by 51-mm (2- by 2-inch) prisms over a 381-mm (15-inch) span with 76 mm (3 inches) between loads
Figure 48. Equation. Flexural cracking strength of a concrete prism
Figure 49. Equation. AFGC correction factor for concrete prism flexural strength
Figure 50. Equation. Centerline deflection of a simply supported prismatic beam
Figure 51. Graph. Ratio of shear to flexural deflection for a third-point loaded prism
Figure 52. Graph. ASTM C1018 toughness results for steam-treated UHPC prisms
Figure 53. Graph. ASTM C1018 toughness results for untreated UHPC prisms
Figure 54. Graph. ASTM C1018 toughness results for tempered steam-treated UHPC prisms
Figure 55. Graph. ASTM C1018 toughness results for delayed steam-treated UHPC prisms
Figure 56. Graph. ASTM C1018 residual strength results for steam-treated prisms
Figure 57. Graph. ASTM C1018 residual strength results for untreated prisms
Figure 58. Graph. ASTM C1018 residual strength results for tempered steam-treated prisms
Figure 59. Graph. ASTM C1018 residual strength results for delayed steam-treated prisms
Figure 60. Equation. Tensile stress in an ASTM C496 split-cylinder test
Figure 61. Photos. Split-cylinder tensile test including (a) standard test setup, (b) lateral expansion measuring apparatus, and (c) UHPC cylinder during test
Figure 62. Graph. Typical response for a UHPC cylinder during the ASTM C496 test
Figure 63. Chart. Average tensile cracking results from the ASTM C496 test
Figure 64. Chart. Average split cylinder peak strength from the ASTM C496 test
Figure 65. Photos. AASHTO T132 setup including (a) test grips and (b) specimen
Figure 66. Graph. Load-displacement response for steam-treated briquettes (28 days)
Figure 67. Graph. Load-displacement response for steam-treated briquettes (56 days)
Figure 68. Graph. Load-displacement response for steam-treated briquettes (84 days)
Figure 69. Graph. Load-displacement response for untreated briquettes (28 days)
Figure 70. Graph. Load-displacement response for untreated briquettes (56 days)
Figure 71. Graph. Load-displacement response for untreated briquettes (84 days)
Figure 72. Graph. Load-displacement for tempered steam-treated briquettes (28 days)
Figure 73. Graph. Load-displacement for tempered steam-treated briquettes (56 days)
Figure 74. Graph. Load-displacement for tempered steam-treated briquettes (84 days)
Figure 75. Graph. Load-displacement for delayed steam-treated briquettes (28 days)
Figure 76. Graph. Load-displacement for delayed steam-treated briquettes (56 days)
Figure 77. Graph. Load-displacement for delayed steam-treated briquettes (84 days)
Figure 78. Chart. Tensile cracking strength of UHPC briquettes
Figure 79. Chart. Postcracking peak strength of UHPC briquettes
Figure 80. Chart. Area under the load-displacement response curve after cracking
Figure 81. Chart. Ratio of postcracking to precracking areas under the load-displacement curve
Figure 82. Photos. (a) Notched cylinder and (b) testing of an unnotched cylinder
Figure 83. Photo. Test setup for 102- by 51-mm (4- by 2-inch) notched prisms loaded on a 406-mm (16-inch) span
Figure 84. Photo. Resistance foil gage to monitor crack propagation
Figure 85. Photos. Prism M1P00 after (a) 86 mm (3.6 inches) and (b) 98 mm (3.8 inches) of crack extension
Figure 86. Photo. Prism M2P03 after 93 mm (3.63 inches) of crack extension
Figure 87. Graph. Load-CMOD response for steam-treated prism M1P00
Figure 88. Graph. Load-CMOD response for steam-treated prism M1P01
Figure 89. Graph. Load-CMOD response for steam-treated prism M1P02
Figure 90. Graph. Load-CMOD response for steam-treated prism M1P03
Figure 91. Graph. Load-CMOD response for untreated prism M2P00
Figure 92. Graph. Load-CMOD response for untreated prism M2P01
Figure 93. Graph. Load-CMOD response for untreated prism M2P02
Figure 94. Graph. Load-CMOD response for untreated prism M2P03
Figure 95. Graph. Long-term shrinkage results
Figure 96. Equation. Shrinkage as a function of time after casting
Figure 97. Photo. Embeddable vibrating wire gage
Figure 98. Graph. Early age shrinkage
Figure 99. Photos. (a) Creep cylinders in load frame and (b) measurement of creep
Figure 100. Graph. Long-term creep results
Figure 101. Equation. Creep as a function of time after loading
Figure 102. Photo. Short-term creep test setup
Figure 103. Graph. Early age creep behavior of 55 to 65 MPa (7,975 to 9,425 psi) UHPC
Figure 104. Graph. Early age creep behavior of 86 MPa (12,470 psi) UHPC
Figure 105. Graph. Heat generated in 152-mm (6-inch) diameter cylinders during initial curing
Figure 106. Graph. Heat generated in 152-mm (6-inch) diameter cylinders from casting through steaming
Figure 107. Graph. Heat signature for 152-mm (6-inch) diameter cylinders in a wellinsulated calorimeter
Figure 108. Graph. Fiber dispersion analysis results for cylinders impacted on an ASTM C230 flow table
Figure 109. Photos. Fiber dispersion analysis photographs for a 645-mm2 (1.3-inch2) area in the (a) bottom, (b) lower middle, (c) upper middle, and (d) top of a cast cylinder
Figure 110. Photos. (a) Cylinder and (b) setup for rapid chloride ion penetrability test
Figure 111. Graph. Average current passed versus time results for three sets of cylinders
Figure 112. Graph. Chloride ion content results after 90 days of ponding
Figure 113. Photos. (a) Cylinder before and (b) after 90 days of chloride ponding
Figure 114. Photo. Scaling slab before initiating ASTM C672 testing
Figure 115. Photo. Scaling slab after ASTM C672 testing
Figure 116. Photo. Surface deterioration of a vertical surface after 70-plus-145 cycles of wetting/drying with a chloride solution in a freezing/thawing environment
Figure 117. Photo. ASTM C944 abrasion test setup
Figure 118. Photo. Steel cast surface untreated and steam-treated abrasion specimens after 8 and 10 minutes of abrading, respectively
Figure 119. Chart. ASTM C944 weight loss (grams) per abrading
Figure 120. Chart. Average weight loss (grams) per abrading
Figure 121. Chart. Linear best-fit weight loss (grams) per abrading
Figure 122. Photo. Resonant frequency testing of a freeze/thaw prism
Figure 123. Photos. Freeze-thaw prism (a) before testing and (b) after 564 cycles
Figure 124. Graph. Resonant frequency of freeze/thaw prisms
Figure 125. Graph. Relative dynamic modulus of elasticity of freeze/thaw prisms
Figure 126. Graph. Mass change of prisms during freeze-thaw testing
Figure 127. Graph. Resonant frequency of prisms maintained at room temperature in a laboratory environment or in a water bath
Figure 128. Graph. Relative dynamic modulus of elasticity of prisms maintained at room temperature in a laboratory environment or in a water bath
Figure 129. Graph. Mass change of prisms maintained at room temperature in a laboratory environment or in a water bath
Figure 130. Photo. Length comparator for ASR measurements
Figure 131. Graph. ASTM C1260 alkali-silica reactivity expansion results
Figure 132. Photo. Crack in a split cylinder tensile specimen
Figure 133. Photo. Crack in a split-cylinder tensile specimen under 350x magnification
Figure 134. Chart. Split-cylinder peak strength results
Figure 135. Equation. Concrete tensile strength approximation
Figure 136. Graph. Compressive strength gain as a function of time after casting
Figure 137. Equation. Compressive strength at any age after casting
Figure 138. Equation. ACI 318 approximation of modulus of elasticity
Figure 139. Equation. ACI 318 approximation of modulus of elasticity including density
Figure 140. Equation. Comité Européen du Beton approximation for modulus of elasticity (metric units)
Figure 141. Equation. Comité Européen du Beton approximation for modulus of elasticity (English units)
Figure 142. Equation. Kakizaki approximation for modulus of elasticity
Figure 143. Equation. ACI 363 approximation for modulus of elasticity
Figure 144. Equation. Ma approximation for modulus of elasticity
Figure 145. Graph. Modulus of elasticity as a function of 28-day compressive strength
Figure 146. Equation. Approximation for UHPC modulus of elasticity (in psi)
Figure 147. Graph. Modulus of elasticity as a function of compressive strength
Figure 148. Equation. UHPC modulus of elasticity approximation (in psi) for compressive strengths up to 131 MPa (19 ksi)
Figure 149. Graph. Compressive stress-strain behavior compared with linear elastic response
Figure 150. Graph. Normalized compressive stress-strain results for steam-treated UHPC
Figure 151. Graph. Deviation from linear elastic compressive behavior for steam-treated UHPC
Figure 152. Equation. Deviation of compressive stress-strain response from linear elastic behavior
Figure 153. Equation. Compressive stress-strain behavior defined as a function of the deviation from linear elastic behavior
Figure 154. Graph. Compressive stress-strain response approximations

LIST OF TABLES

Table 1. Typical UHPC composition
Table 2. Manufacturer-supplied material characteristics
Table 3. Chemical composition of steel fibers
Table 4. Batching descriptions with associated specimens and curing regimes
Table 5. Batching descriptions with associated specimens and curing regimes for nonstandardized batches
Table 6. Batching and casting properties of steam-treated and untreated UHPC
Table 7. Batching and casting properties of batches cast to complete the study by addressing special issues
Table 8. Control cylinder compressive strength results from the M and N deliveries
Table 9. Control cylinder compressive strength results from the L delivery
Table 10. Strength, modulus of elasticity, and strain at peak stress results at various ages after casting
Table 11. Compressive stress-strain response linearity at various ages after casting
Table 12. Cylinder and cube compressive strength results
Table 13. Demolding age effect on 28-day compressive strength results
Table 14. Long-term delayed steam effect on compressive strength
Table 15. Load rate effect on compression testing results
Table 16. ASTM C1018 strength results
Table 17. Definition of toughness indices (from ASTM C1018 FIG. X1.1)
Table 18. ASTM C1018 toughness results
Table 19. Split tensile strength normalized by 28-day compressive strength
Table 20. First-crack parameters determined by instantaneous lateral expansion of cylinder and aural observations
Table 21. Fiber influence on postcracking behavior
Table 22. Direct tension test results
Table 23. Penetration resistance results
Table 24. Long-term shrinkage
Table 25. Early age shrinkage rate
Table 26. Long-term creep results
Table 27. Early age creep results
Table 28. Coefficient of thermal expansion results
Table 29. Air void analysis results
Table 30. Rapid chloride ion penetrability results
Table 31. Effect of a water bath on the compressive strength of steam-treated and untreated UHPC
Table 32. Timetable for ASTM C1260 specimens
Table 33. ASTM C1260 alkali-silica reactivity expansion results
Table 34. Crack width and split-cylinder peak strength results for ponded cylinders
Table 35. UHPC material characterization results for average tensile properties of UHPC
Table 36. Average UHPC material properties presented according to curing treatment
Table 37. Compressive strength and modulus of elasticity results
Table 38. Constants for equation in figure 152

FHWA-HRT-06-103