Preface	6
	Organization	8
	Conference Committees	8
	Conference Chair	8
	Conference Vice Chair	8
	International Scientific Committee	8
	Local Organizing Committee	9
	Contents	11
	RILEM Publications	15
	RILEM Proceedings (PRO)	15
	RILEM Reports (REP)	24
	Materials and Processing	26
	Fresh and Hardened Properties of 3D Printable Geopolymer Cured in Ambient Temperature	27
	Abstract	27
	1 Introduction	27
	2 Materials and Methods	28
	2.1 Materials and Mixture Proportions	28
	2.2 3D Printing Apparatus	29
	2.3 Printing of 3D Printable Geopolymer	29
	2.4 Characterization Methods	29
	3 Results and Discussions	31
	3.1 Extrudability	31
	3.2 Open Time	31
	3.3 Shape Retention Ability	32
	3.4 Compressive Strength	32
	4 Conclusion	34
	References	35
	Evolution of Concrete/Formwork Interface in Slipforming Process	36
	Abstract	36
	1 Introduction	36
	2 Interfacial Behavior of Fresh Concrete: Physical Phenomena	38
	2.1 Chemistry Origin and Hydration Consequences	38
	2.2 Pore Water Pressure and Granular Stress (Terzaghi Equation)	39
	3 Experimental Procedures	40
	3.1 Materials and Mixing Procedure	40
	3.2 Device and Procedure	40
	4 Experimental Results and Discussions	41
	4.1 Cement Hydration Characterization	41
	4.2 Tangential Stress	42
	4.3 Friction Law	44
	4.4 Hypothesis of Mechanisms	45
	5 Conclusion and Perspectives	46
	Acknowledgements	46
	References	46
	Experience in Online Modification of Rheology and Strength Acquisition of 3D Printable Mortars	48
	Abstract	48
	1 Introduction	48
	2 Materials and Methods	49
	2.1 3D Printable Formulations and Preparation	49
	2.2 Lab-Scale Extrusion Testing	51
	2.3 Early Age Characterization Methods	52
	3 Results	54
	3.1 Texturometry	54
	3.2 Scissometry	57
	3.3 Lab Scale Extrusion	58
	4 Discussion	59
	Acknowledgements	61
	References	61
	A Framework for Performance-Based Testing of Fresh Mixtures for Construction-Scale 3D Printing	63
	Abstract	63
	1 Introduction	63
	2 Experimental Program	64
	2.1 The Step-by-Step Testing Procedure	64
	2.2 Concrete Printing Setup, and Printing Mixtures Proportions	66
	3 Testing and Results	67
	4 Future Work	72
	5 Conclusions	74
	References	74
	Characterization of 3D Printing Mortars Made with OPC/CSA Mixes	77
	Abstract	77
	1 Introduction	77
	2 Materials and Methods	78
	3 Results	80
	4 Conclusion	83
	Acknowledgments	83
	References	83
	Rheological and Water Transport Properties of Cement Pastes Modified with Diutan Gum and Attapulgite/Palygorskite Nanoclays for 3D Concrete Printing	85
	Abstract	85
	1 Introduction	85
	2 Materials and Methods	86
	2.1 Materials	86
	2.2 Methods	87
	3 Results	88
	3.1 Sustained Stress Results	88
	3.2 Water Retention Capacity	89
	4 Conclusion	92
	Acknowledgments	92
	References	92
	Rheological Control of 3D Printable Cement Paste and Mortars	94
	Abstract	94
	1 Introduction	94
	2 Materials and Methods	95
	3 Results and Discussion	97
	3.1 Printing Mixtures A and B	97
	3.2 Rheometry	98
	3.3 Simulations of Flow Properties	101
	4 Conclusion	102
	References	103
	Adapting Smart Dynamic Casting to Thin Folded Geometries	105
	Abstract	105
	1 Introduction	105
	2 Slipforming Process Model	107
	3 Materials and Methods	108
	3.1 Initial Robotic Experiments	109
	3.2 Offline Tests	110
	3.3 Online Tests	111
	3.4 Robotic Experiment as Material Evaluation	111
	4 Experimental Results	112
	4.1 Initial Robotic Experiments	112
	4.2 Offline Tests	112
	4.3 Online Tests	113
	4.4 Robotic Experiment as Material Evaluation	113
	5 Discussion of Results from Online, Offline and Robotic Experiments	114
	6 Conclusion	116
	Acknowledgements	116
	References	116
	Enhancing Printable Concrete Thixotropy by High Shear Mixing	118
	Abstract	118
	1 Introduction	118
	2 Methods and Materials	119
	2.1 Materials	119
	2.2 Mixing Protocol	119
	2.3 Rheological Measurements	119
	2.4 Isothermal Calorimetry	120
	2.5 Dynamic Light Scattering Measurements	120
	3 Results	120
	3.1 Rheological Measurements	120
	3.2 Isothermal Calorimetry	120
	3.3 Dynamic Light Scattering Measurements	123
	4 Discussion	123
	5 Conclusion	124
	References	124
	Discrete Element Simulations of Rheological Response of Cementitious Binders as Applied to 3D Printing	126
	Abstract	126
	1 Introduction	126
	2 Discrete Element Method (DEM) and the Model Used	127
	2.1 Burger’s Model	127
	2.2 Calibration of Burger’s Model Using Mini Slump Test	129
	3 Extrusion Experiments and DEM Modeling	131
	3.1 Extrusion-Based 3D Printing and Extrusion Rheology	131
	3.2 DEM Modeling of Extrusion Rheology and Printing	133
	4 Conclusions	135
	Acknowledgments	135
	References	136
	Mechanics and Structure	137
	Three-Dimensional Printing Multifunctional Engineered Cementitious Composites (ECC) for Structural Elements	138
	Abstract	138
	1 Introduction	138
	2 Experimental Program	140
	2.1 Materials	140
	2.2 Mix Processing	141
	2.3 Test Specimens	141
	2.4 Test Methods	143
	3 Experimental Results and Discussions	145
	3.1 Printability	145
	3.2 Nitrogen Oxides Abatement	145
	3.3 Mechanical Properties	146
	4 Conclusions	149
	Acknowledgements	150
	References	150
	Large Scale Testing of Digitally Fabricated Concrete (DFC) Elements	152
	Abstract	152
	1 Introduction	152
	2 TU/e 3D Concrete Printing and Scale Effects	153
	3 Nyborg Studio	155
	3.1 Project and Design	155
	3.2 Test Program en Specimens	156
	3.3 Printing	157
	3.4 Observations Before Testing	158
	3.5 Vertical Flexural Test	159
	3.6 Compression Test	160
	3.7 Impact Test	162
	3.8 Overall Conclusion on Structural Performance	162
	4 Bicycle Bridge Gemert	163
	4.1 Project and Design	163
	4.2 Test Program	164
	4.3 Printing	164
	4.4 4-Point Bending Test	165
	4.5 In-Situ Test	165
	5 Discussion and Conclusion	168
	Acknowledgements	169
	References	169
	Method of Enhancing Interlayer Bond Strength in 3D Concrete Printing	171
	Abstract	171
	1 Introduction	171
	2 Materials and Methods	172
	2.1 Mix Proportions	172
	2.2 3D Printing Process	173
	2.3 Testing Methods	174
	3 Results and Discussion	175
	3.1 Cube Tests	175
	3.2 Flow Table Tests	175
	3.3 Interlayer Bond Strength	176
	4 Conclusion	178
	Acknowledgements	178
	References	179
	Exploiting the Potential of Digital Fabrication for Sustainable and Economic Concrete Structures	180
	Abstract	180
	1 Introduction	180
	2 Requirements of Mass-Market Concrete Structures	182
	2.1 Necessity of Reinforcement	182
	2.2 Limited Use of Geometrical Complexity	182
	3 Benefits of Digital Fabrication for Structural Concrete	183
	3.1 Key Potentials	183
	3.2 Crack Initiators by 3D Printing Weak Interfaces	184
	4 Conclusion and Outlook	188
	Acknowledgements	189
	References	189
	Alternative Reinforcements for Digital Concrete Construction	190
	Abstract	190
	1 3D-Printed Steel Reinforcement	190
	1.1 Introduction	190
	1.2 Materials, Manufacture and Testing Techniques	191
	1.3 Experimental Results	191
	2 3D-Printed Strain-Hardening Cement-Based Composites	193
	2.1 Introduction	193
	2.2 Materials, Manufacture and Testing Techniques	194
	2.3 Experimental Results	195
	3 Summary	197
	References	198
	Additive Manufacturing and Characterization of Architectured Cement-Based Materials via X-ray Micro-computed Tomography	199
	Abstract	199
	1 Introduction	200
	2 Methods	200
	2.1 3D-Printing Setup	200
	2.2 Ink Design, Mixing Procedure, and Curing	202
	2.3 Slicing and Design	203
	2.4 Micro-CT and Scanning Specimens	203
	3 Results and Discussion	204
	3.1 3D-Printed Lamellar Architecture Micro-CT (0.4X and 4X Scans)	204
	3.2 Cast Specimen in 0.4X Micro-CT (0.4X Scan)	209
	4 Summary	211
	Acknowledgements	211
	References	211
	Hardened Properties of 3D Printable ‘One-Part’ Geopolymer for Construction Applications	213
	Abstract	213
	1 Introduction	213
	2 Experimental Procedures	215
	2.1 Materials and Mixture Proportions	215
	2.2 Mixing, Printing, Curing and Testing of Specimens	215
	3 Results and Discussion	217
	3.1 Compressive Strength	217
	3.2 Flexural Strength	218
	3.3 Inter-layer Strength	219
	4 Conclusions	220
	Acknowledgements	221
	References	221
	Bond Strength in 3D Printed Geopolymer Mortar	223
	Abstract	223
	1 Introduction	223
	2 Materials and Methods	224
	3 Results and Discussion	226
	4 Conclusions	228
	Acknowledgement	229
	References	229
	Potentials of Steel Fibres for Mesh Mould Elements	230
	Abstract	230
	1 Introduction	230
	1.1 Background About the Mesh Mould Project	230
	1.2 Mechanical Behaviour of Mesh Mould Elements	231
	2 Experimental Program	233
	2.1 Test Specimens	233
	2.2 Experimental Setup	234
	2.3 Material Properties	234
	3 Results and Discussion	236
	3.1 Predicted Behaviour of the Mesh	236
	3.2 Four-Point Bending Test	236
	4 Conclusions and Outlook	238
	Acknowledgments	239
	References	239
	Capillary Water Intake by 3D-Printed Concrete Visualised and Quantified by Neutron Radiography	240
	Abstract	240
	1 Introduction	240
	2 Experimental	241
	3 Results and Discussion	243
	3.1 Fine-Grained 3D-Printed Concrete (Mixture A)	243
	3.2 Portland Cement-Based 3D-Printed Concrete with Internal Curing by SAP (Mixture G)	245
	References	247
	Corrosion Challenges and Opportunities in Digital Fabrication of Reinforced Concrete	248
	Abstract	248
	1 Introduction	248
	2 Corrosion Challenges in Digital Fabrication	249
	2.1 Corrosion Challenges in “Steel Welding” Technology	250
	2.2 Corrosion Challenges in “Slipforming” Technology	251
	2.3 Corrosion Challenges in “3D Printing by Layer Extrusion” Technology	253
	3 Opportunities for Corrosion Protection	253
	4 Conclusion	254
	References	255
	The Effect of Print Parameters on the (Micro)structure of 3D Printed Cementitious Materials	257
	Abstract	257
	1 Introduction	257
	2 Materials and Methods	258
	2.1 Materials and Mix Composition	258
	2.2 3D Printing Process	258
	2.3 Surface Roughness	259
	2.4 Mechanical Properties Testing	260
	2.5 Porosity Measurements and Pore Size Distribution	261
	3 Results and Discussion	262
	3.1 Surface Roughness	262
	3.2 Compressive Strength	262
	3.3 Inter-layer Bonding Strength	263
	3.4 Microstructure and Porosity	264
	4 Conclusions	266
	Acknowledgements	267
	References	267
	Compressive Strength and Dimensional Accuracy of Portland Cement Mortar Made Using Powder-Based 3D Printing for Construction Applications	268
	Abstract	268
	1 Introduction	268
	2 Experimental Procedures	271
	2.1 Materials	271
	2.2 Printing Process and Test Methods	271
	3 Results and Discussions	273
	3.1 Linear Dimensional Accuracy	273
	3.2 Compressive Strength	274
	4 Conclusions	275
	References	276
	Impact of 3D Printing Direction on Mechanical Performance of Strain-Hardening Cementitious Composite (SHCC)	278
	Abstract	278
	1 Introduction	278
	2 Materials and Methods	280
	2.1 Experimental Program	280
	2.2 Micromechanical Modelling	281
	3 Results and Discussion	282
	3.1 Experimental Results on Mechanical Properties	282
	3.2 Modelling of Fibre-Bridging Constitutive Relations of SHCCs	284
	4 Conclusions	286
	References	287
	Applications and More	289
	Feasibility of Using Low CO2 Concrete Alternatives in Extrusion-Based 3D Concrete Printing	290
	Abstract	290
	1 Introduction	290
	2 Binder Mix and Fresh Property of 3D Printable Concrete	291
	2.1 Literature Survey of 3D Printable Binder Mix	291
	2.2 Fresh Property of 3D Printable Concrete	291
	3 Constraint and Opportunity to Develop SCMs-Based Printable Concrete	294
	4 Conclusion	295
	References	296
	Experimental Investigation on the Mechanical Strength and Thermal Conductivity of Extrudable Foamed Concrete and Preliminary Views on Its Potential Application in 3D Printed Multilayer Insulating Panels	298
	Abstract	298
	1 Introduction	298
	2 Materials and Methods	299
	3 Results and Discussion	300
	3.1 Extrusion Process	300
	3.2 Compressive Strength	301
	3.3 Indirect Tensile Strength	302
	3.4 Thermal Conductivity	303
	4 Outlook: Multilayer Insulating Panels	306
	5 Conclusion	306
	References	307
	Development of a Shotcrete 3D-Printing (SC3DP) Technology for Additive Manufacturing of Reinforced Freeform Concrete Structures	308
	Abstract	308
	1 Introduction	308
	1.1 Additive Manufacturing with Concrete	309
	1.2 Potential of Shotcrete 3D Printing as an Additive Manufacturing Technique	309
	1.3 Challenges of Shotcrete 3D Printing	310
	2 Offline Process Control Based on Experimental Knowledge	311
	3 Online Measurement and Process Control for SC3DP	312
	3.1 Measurement and Control Concepts for Layer-Based Additive Manufacturing	313
	3.2 Online Geometry Measuring for Shotcrete 3D Printing	314
	3.3 Control Concept for Shotcrete 3D Printing and Experimental Implementation	314
	4 Case Study: Multidirectional Printing and Introducing of Reinforcement	316
	5 Conclusion	317
	References	318
	Challenges of Real-Scale Production with Smart Dynamic Casting	320
	Abstract	320
	1 Introduction	320
	2 Fabrication and Challenges	321
	2.1 Overall Fabrication Concept	322
	3 Fabrication Challenges	323
	3.1 Formwork, Actuation and Friction	323
	3.2 Material Processing	324
	4 Design and Production	326
	4.1 Material Characterization	326
	4.2 Structural Design	327
	4.3 Material Processing Challenges: Reinforcement Integration	329
	5 Conclusion	330
	Acknowledgments	330
	References	330
	The Tectonics of Digitally Fabricated Concrete. A Case for Robotic Hot Wire Cutting	332
	Abstract	332
	1 Introduction	332
	1.1 Form, Surface and Composition	332
	2 Digital Fabrication Technologies in Concrete Architecture	333
	2.1 Evaluating Existing and Emerging Solutions	333
	2.2 Expanding Form, Surface and Composition	335
	2.3 Critical Issues for Digital Fabrication in Concrete	336
	3 A Case for Robotic Hot Wire Cutting	337
	3.1 Description	337
	3.2 Ruled Concrete Panels	337
	3.3 The CorkCrete Arch	339
	4 Conclusion	340
	Acknowledgements	341
	References	341
	Compliance, Stress-Based and Multi-physics Topology Optimization for 3D-Printed Concrete Structures	344
	Abstract	344
	1 Introduction	344
	2 Compliance-Based Topology Optimization	347
	3 Stress-Based Topology Optimization	349
	4 Multi-physics Topology Optimization	350
	5 Conclusions and Final Remarks	351
	Acknowledgements	352
	References	352
	Author Index	354