Static Mechanical Properties of UHPCC 1
1.1 Introduction . 1
1.2 Test Program 2
1.2.1 Raw Materials and Mixture Proportions . 2
1.2.2 Specimen Preparation and Curing 4
1.3 Instrumentation and Loading Scheme . 5
1.3.1 Cubic Compressive Test . 5
1.3.2 Axial Compressive Test 6
1.3.3 Direct Tensile Test 7
1.3.4 FourPoint Flexural Test . 8
1.3.5 ThreePoint Flexural Test 9
1.4 Test Results and Discussion 10
1.4.1 Compression Test 10
1.4.2 Direct Tension Test . 14
1.4.3 FourPoint Flexure Test 17
1.4.4 ThreePoint Flexure Test . 21
1.5 Summary . 27
References 28
2 Dynamic Compressive Mechanical Properties of UHPCC . 31
2.1 Introduction . 31
2.2 Specimen Preparation 32
2.3 SHPB Test 33
2.3.1 Test Device . 33
2.3.2 Test Technique 34
2.4 Test Results and Discussions . 37
2.4.1 Stress Equilibrium 37
2.4.2 Strain Rate Determination 38
2.4.3 Dynamic Failure Pattern . 39
2.4.4 Dynamic StressStrain Curve . 40
2.4.5 Dynamic Increase Factor . 44
2.4.6 Energy Absorption Capacity 48
ix
x Contents
2.5 ViscoElastic Damage Model 49
2.5.1 Nonlinear ViscoElastic Model 49
2.5.2 Model Calibration and Validation 51
2.6 Summary . 51
References 53
3 Dynamic Tensile Mechanical Properties of UHPCC 55
3.1 Introduction . 55
3.2 Specimen Preparation 56
3.3 Dynamic Spalling Test . 57
3.3.1 Test Device . 57
3.3.2 Test Technique 58
3.4 Test Results and Discussions . 61
3.4.1 Dynamic Failure Patterns 61
3.4.2 Dynamic Spalling Strength . 63
3.4.3 Relations Between the Critical Time to Fracture
and Dynamic Spalling Strength 66
3.4.4 Dynamic Increase Factor . 67
3.5 Summary . 70
References 71
4 Triaxial Compressive Behavior of UHPCC and Application
in the Numerical Analyses of Projectile Impact 73
4.1 Introduction . 73
4.2 A Review of the Existing Works on Triaxial Behavior
of Concrete 74
4.3 Mixing Optimization of UHPCC and Triaxial Compression
Test 76
4.3.1 Compositions . 76
4.3.2 Mixing Procedure 78
4.3.3 Triaxial Compression Test . 79
4.4 Results and Analysis . 80
4.4.1 Failure Pattern . 80
4.4.2 StressStrain Curve . 81
4.4.3 Failure Criteria 85
4.4.4 Toughness 90
4.5 Applications in the Numerical Analyses 92
4.5.1 Brief Introduction of HJC Constitutive Model . 92
4.5.2 HJC Model Parameters for HSC . 94
4.5.3 Validations 95
4.6 Summary . 98
References 101
Contents xi
5 Projectile Penetrations into Coarse Aggregated UHPCC
Targets 105
5.1 Introduction . 105
5.2 Basalt Aggregated UHPCC Target 108
5.2.1 Target 108
5.2.2 Projectile . 109
5.2.3 Test Setup 113
5.2.4 Test Results . 114
5.2.5 Discussions . 116
5.3 Corundum Aggregated UHPCC Target 121
5.3.1 Target and Projectile 121
5.3.2 Test Results . 122
5.3.3 Discussions . 127
5.4 Numerical Simulations Based on 3D Mesoscopic Concrete
Model 138
5.4.1 3D Mesoscopic Concrete Model . 138
5.4.2 Validations 148
5.4.3 Impact Resistance of Different Aggregated UHPC . 153
5.5 Summary . 158
References 161
6 Impact Resistance of Basalt Aggregated UHPSFRCFabric
Composite Panels Against Small Caliber Arm 163
6.1 Introduction . 163
6.2 Bullet Perforation Test . 165
6.2.1 Bullet 165
6.2.2 UHPBASFRC Panels . 165
6.2.3 Fabric Strengthening 167
6.2.4 Test Setup 169
6.3 Test Results . 170
6.3.1 Damage of Target 170
6.3.2 Dimension of Crater 174
6.3.3 Perforation Limit 175
6.3.4 Recovered Bullet 176
6.3.5 Damage of Aluminum Plate 177
6.4 Discussions . 177
6.4.1 Crater Dimensions 177
6.4.2 Terminal Ballistic Parameter . 179
6.4.3 Fabric Effect 183
6.5 Summary . 184
References 184
xii Contents
7 Impact Resistance of Armsector SteelCeramicUHPCC
Layered Composite Targets Against 30CrMnSiNi2A Steel
Projectiles 187
7.1 Introduction . 187
7.2 Impact Test on 10CrNi3MoV21A Armor SteelSiC
CeramicUHPCC Composite Targets and Numerical
Simulations . 190
7.2.1 Impact Test . 190
7.2.2 Numerical Simulations 201
7.3 Impact Test on NP450 Armor SteelUHPCC and NP500
Armor SteelUHPCC Composite Targets and Numerical
Simulations . 217
7.3.1 Impact Test . 217
7.3.2 Numerical Simulations 222
7.4 Summary . 232
References 233
8 Response of UHPCCFST Subjected to LowVelocity Impact 237
8.1 Introduction . 237
8.2 Test Program 239
8.2.1 UHPCCFST Specimens . 239
8.2.2 Axial Compression Test . 240
8.2.3 DropHammer Impact Test . 243
8.3 Test Results and Discussions . 244
8.3.1 Axial Compression 244
8.3.2 Lateral Impact Resistance 245
8.3.3 Impact ForceTime History 246
8.3.4 DeflectionTime History . 247
8.4 Calibration of K&C Model Parameters for UHPCC 248
8.4.1 Brief Introduction of K&C Model 249
8.4.2 Calibration 251
8.5 Numerical Simulation 260
8.5.1 Present Test . 260
8.5.2 Yoo et al. 2015 Test 264
8.6 Summary . 266
References 267
9 Dynamic Responses of Reinforced UHPCC Members Under
LowVelocity Lateral Impact 271
9.1 Introduction . 271
9.2 Test Program 274
9.2.1 Specimen Fabrication . 274
9.2.2 DropHammer Impact Test . 275
Contents xiii
9.3 Test Results and Discussions . 277
9.3.1 FailureMode 277
9.3.2 Impact ForceTime History 280
9.3.3 DeflectionTime History . 284
9.3.4 Energy Dissipation 287
9.4 Numerical Simulation 288
9.4.1 FE Model . 288
9.4.2 Calibration 289
9.4.3 Comparisons of Numerical Results with Test Data . 300
9.5 Further Validations 304
9.5.1 Reinforced UHPCMembers 305
9.5.2 UHPCFSTMembers . 310
9.6 Summary . 313
References 315
10 Residual Axial Capacity of UHPCCFST Column Under
Contact Explosion . 319
10.1 Introduction . 319
10.2 Review of the ExistingWorks 321
10.3 UHPCCFST Columns . 322
10.3.1 Fabrications . 323
10.3.2 Steel Tube 324
10.3.3 UHPCC 325
10.4 Field Contact Explosion Test . 325
10.4.1 Test Setup 325
10.4.2 Test Results . 327
10.5 Axial Compression Test 329
10.5.1 Test Setup 329
10.5.2 Test Results . 330
10.6 Numerical Simulation 336
10.6.1 FE Model . 336
10.6.2 Material Model 338
10.6.3 Loading Scheme . 345
10.7 Comparisons with Test Data . 346
10.7.1 Damage and Failure Modes of Columns . 346
10.7.2 Residual Axial Capacity and Failure Mode
of Columns . 350
10.8 Parametric Study 355
10.8.1 Steel Tube Thickness and Strength . 355
10.8.2 Core Concrete Strength and CrossSectional
Diameter . 357
10.8.3 Influence of Varied Parameters on Damage Index 362
10.9 Summary . 363
References 364
xiv Contents
11 Experimental and Numerical Study of UHPCCFST Columns
Subjected to CloseRange Explosion 369
11.1 Introduction . 369
11.2 Explosion Test on UHPCCFST Column . 371
11.2.1 Specimens 371
11.2.2 Test Setup 373
11.2.3 Test Results and Analyses 373
11.3 Analytical Methods for Predicting the Dynamic Responses
of UHPCCFST Columns 377
11.3.1 ALEMethod 377
11.3.2 VelocityMethod . 381
11.3.3 SDOFMethod 384
11.3.4 Comparisons of Predictions by Different Methods . 388
11.4 Further Numerical Analyses and Discussion . 389
11.5 Summary . 392
References 393
12 Experimental Study on the Residual Seismic Resistance
of UHPCC Filled Steel Tube UHPCCFST After Contact
Explosion . 397
12.1 Introduction . 397
12.2 UHPCCFST Specimens . 399
12.2.1 Steel Tube 399
12.2.2 UHPCC 400
12.2.3 Fabrications . 401
12.3 Contact Explosion Test . 403
12.3.1 Test Setup 403
12.3.2 Test Results and Discussions . 404
12.4 LowFrequency Cyclic Loading Test 408
12.4.1 Test Setup 408
12.4.2 Test Results and Discussions . 409
12.5 Assessment of Residual Seismic Resistance
of the Postblast Column . 423
12.6 Summary . 426
References 427
13 Experimental and Numerical Studies on Dynamic Behavior
of Reinforced UHPCC Panel Under MediumRange
Explosions 431
13.1 Introduction . 431
13.2 Review of the ExistingWork . 432
13.3 Field Blast Test . 435
13.3.1 Specimen . 435
13.3.2 Test Setup 436
13.3.3 Test Results and Discussions . 439
Contents xv
13.4 Numerical Simulation 453
13.4.1 FE Model . 453
13.4.2 Material Model of UHPCC . 454
13.4.3 Material Model of NSC 463
13.4.4 Material Models for Rebar and Support . 463
13.5 Comparisons of Numerical Results with Test Data . 464
13.5.1 OverpressuresTime History 464
13.5.2 DeflectionTime History . 466
13.5.3 Postblast Damage 466
13.6 Summary . 468
References 470
14 Constitutive Modelling of UHPCC Material Under Impact
and Blast Loadings 475
14.1 Introduction . 475
14.2 UHPCC Material Model 478
14.2.1 Brief Introduction of the Original KongFang
Concrete Model . 478
14.2.2 New Tensile Damage Model 480
14.2.3 Parameter Calibration . 484
14.3 Single Element Tests . 489
14.3.1 Unconfined Uniaxial Tests . 489
14.3.2 Triaxial Compression Test . 490
14.4 Experimental Validation 491
14.4.1 UHPCCFST Column Subjected to Low Speed
Impact . 492
14.4.2 UHPCCFST Column Subjected to Near
Explosion 495
14.4.3 Reinforced UHPCC Slab Subjected to Blast
Loading 498
14.5 Summary . 500
References 501
內容試閱：
Compared with the normal strength concrete NSC, ultrahigh performance cementitious composites UHPCC is a relativity new type of cementitious materials which consists of very low watertobinder ratio, high amount of highrange water reducer, fine aggregates and highstrength steel or organic fibers. With the prominent mechanical properties, e.g., high compressive and tensile strength, high ductility, high fracture energy and very lowpermeability,UHPCChas been becoming the most prospective construction cementbased material for both civil and military engineering structures, such as fortifications, nuclear waste storage containments, highway bridges, highrise buildings, to resist highspeed projectile penetration, lowvelocity impact and blast, as well as earthquake loadings. Therefore, investigations on the static and dynamic mechanical properties as well as the impact and blast resistance of UHPCC are essential and important for the design and safety assessment of protective structures. In this book, the related work conducted by authors are presented and the main contents are as follows：
Chapter 1：Aseries of cubicaxial compressive, direct tensile, fourpoint and threepoint flexural tests on UHPCC specimens are presented, in which the effects of six volume fractions 0 ~ 2.5% and two types microstraight and hooked of steel fibers on the static mechanical properties of UHPCC are examined.
Chapter 2： The SHPB test on UHPCC specimens is presented, in which the effects of strain rate ranges from 17.6 to 328.4 s1 and two typical steel fibers microstraight and hooked with three volume fractions of 0%, 1.0% and 2.0% on the dynamic compressive mechanical properties of UHPCC are analyzed.
Chapter 3： By using a 50 mmdiameter conic variable crosssectional SHPB, the dynamic spalling test on cylindrical UHPCC specimens is given, and the influences of the tensile strain rate range from 14.3 to 214.8 s1, and two typical steel fibers microstraight and hooked with three volume fractions of 0%, 1.0% and 2.0% on the dynamic tensile mechanical properties of UHPCC are studied.
Chapter 4： The triaxial compressive behavior of UHPCC under high confining pressure up to 100 MPa is experimentally studied, and the failure criteria and toughness of UHPCC under triaxial compression are discussed.
Chapter 5： The impact resistance of coarse aggregated UHPCC target against the medium caliber projectile is studied. The highspeed projectile penetration tests on UHPCC targets with the striking velocities at 510 to 1320 ms as well as the comparable projectile penetration test onUHPCASFRCare presented. The influence of coarse aggregates strength on the impact resistance of UHPCC targets is discussed based on the 3D mesoscopic concrete model.
Chapter 6： Aiming to protect person and valuable equipment from the perforated small caliber arms and scabbing fragments, the 7.62 mm API bullet impacting test on bare and rear fabric CFRP or UHMWPE strengthened UHPBASFRC panels is given and the excellent impact resistance of bare and composite UHPBASFRC panels is validated.
Chapter 7： The medium caliber projectile impact resistance of armor steelceramicUHPCClayered composite targets against 30CrMnSiNi2A steel projectiles is experimentally studied. The numerical simulations are further performed by calibrating the Johnson and Cook JC constitutive model parameters of the 10CrNi3MoV21A, NP450 and NP500 armor steel.
Chapter 8： The impact behavior of UHPCCFST under transverse impact load is investigated experimentally and numerically. Three UHPCCFST specimens subjected to lowvelocity impact by using a drophammer impact device are examined experimentally. The model parameters of K&C model for UHPCC are calibrated by using the existing static and dynamic experimental data. Then, a FE analysis model is established to predict the dynamic responses of UHPCCFSTs under transverse impact load.
Chapter 9： A total of eleven steel bar reinforced UHPCC and two reinforced NSC control specimens subjected to drophammer impact are studied. The outstanding impact resistance of UHPC members is validated and assessed quantitatively. The model parameters and the parameters generation method of continuous surface cap CSC model for UHPCC are calibrated and fully validated.
Chapter 10： The test on five UHPCCFST specimens under contact explosion of TNT charges is given, and the original axial capacity of the intact columns and the residual axial capacity of the blastdamaged columns are further evaluated though the axial compression tests. Besides, the damage and failure modes of UHPCCFST are numerically reproduced, and the related parametric influences are discussed.
Chapter 11： The field test of four circular UHPCCFST specimens under the closerange TNT charge explosion with the scaled standoff distance of 0.12 ~ 0.14 mkg13 is presented. The dynamic responses of those specimens are analyzed by three different methods, i.e.,ALEmethod, velocity loading method andSDOFmethod, and the velocity method is recommended by considering both the accuracy and efficiency of computation.
Chapter 12： The residual seismic resistance RSR of UHPCCFST specimens after contact explosion is studied experimentally. The specimens are firstly subjected to blast loadings, in which the TNT charge weights are 1 ~ 3 kg and the height of bursts are set to 250 mm. Furthermore, the RSR of UHPCCFST specimens are examined through the lowfrequency horizontal cyclic loading test in two perpendicular directions. A composite damage index is proposed to evaluate the RSR of the postblast columns.
Chapter 13： The field tests and numerical simulations of the blastresistant behavior of oneway simply supported reinforced UHPCC panels and NSC control panels are performed. The explosion tests are in different scaled distances 0.5 ~ 1.0 mkg13 with enddetonated cylindrical charges. The blast loadings induced by the mediumrange explosions and the constitutive model parameters of UHPC are mainly concerned. The proposed FE model, numerical algorithm and the calibrated model parameters are fully verified by comparing to the test data.
Chapter 14： A new constitutive model of UHPCC material under impact and blast loadings is developed, which involves proposing a new tensile damage model for UHPCC which is then incorporated into the KongFang material model recently developed, and calibrating parameters of this modified material model based on existing test data. Single element tests are firstly conducted to demonstrate the performances of the proposed material model. Then, three selected experiments are numerically simulated and compared with corresponding experimental data and good agreements are observed.
Professor Qi Hu Qian is our guide though the study of protective structures. The late Prof. Zhao Yuan Chen from Tsinghua University and Prof. Wei Sun from Southeast University always encouraged us to develop new blastimpactresistant materials and structures. We are grateful to them for introducing and helping us to continue to walk along this path with everincreasing interest.
The present book is the result of a cooperative effort of our team. The authors would like to thank the our colleagues and postgraduates, who are Jianzhong Liu, Genmao Ren, Yong Peng, Ziguo Wang, Yangxiu Zhai, Yuehua Cheng. The authors would also like to take this opportunity to thank the longtern support provided by National Natural Science Foundation of China. We hope this book will serve as a useful source of information for scientists, engineers and students active in protective structure research.
Nanjing, China Qin Fang
Shanghai, China Hao Wu
Nanjing, China Xiangzhen Kong
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