PONTIFICIA UNIVERSIDAD CATOLICA DE CHILE ESCUELA DE INGENIERIA ENTRAINED AIR AS A RHEOLOGY MODIFYING AGENT FOR 3D PRINTED CONCRETE CLAUDIA EUGENIN SOTO Thesis submitted to the Office of Research and Graduate Studies in partial fulfillment of the requirements for the Degree of Master of Science in Engineering Advisors: MAURICIO LOPEZ CASANOVA WERNHER BREVIS VERGARA Santiago de Chile, December 2020 © MMXX, Claudia Andrea Eugenin Soto PONTIFICIA UNIVERSIDAD CATOLICA DE CHILE ESCUELA DE INGENIERIA ENTRAINED AIR AS A RHEOLOGY MODIFYING AGENT FOR 3D PRINTED CONCRETE CLAUDIA EUGENIN SOTO Members of the Committee: MAURICIO LÓPEZ CASANOVA WERNHER BREVIS VERGARA ÁLVARO GONZÁLEZ VACCAREZZA TOMÁS VIVANCO LARRAÍN RODRIGO ESCOBAR MORAGAS Thesis submitted to the Office of Research and Graduate Studies in partial fulfillment of the requirements for the Degree of Master of Science in Engineering Santiago de Chile, December 2020 To the women who have silently paved the road for us in STEM and to those who will continue doing it ACKNOWLEDGEMENTS This thesis is dedicated to my family: my parents Jorge Eugenin and Claudia Soto for their unfaltering support and encouragement, and the rest of my household Jorge, Josefa, Joaquin, Ignacia, Pablo and Gaby, for their patient companionship during all these years. I would like to thank professor Mauricio López for his support not only in my research but for his teachings on life, and professor Wernher Brevis for his support and encouragement in an area of knowledge unknown to me. This work would also not have been possible without the support of my friend and colleague, Iván Navarrete, who patiently helped me whenever he could. I would also like to thank my friends from the office and especially those in “Tesis en Cuarentena”, for their understanding, assistance and support: Aldo, Matías, Jeison, Alex, Tomás, Karla, José Luis, Alejandro, Juan Cristóbal, Fabián, Camilo, Nibaldo, Natalia, Claudia, Leonardo. The office was always a great place to work thanks to the welcoming Edith and William, as well as the warm presence of Pilar, Selma, Claudio, Ximena and Marcela. I would also like to acknowledge the members of the research group for their assistance: Felipe, José Carlos, Mauricio, Pedro and the team from the laboratory, Luis and Sthefanie. I would like to thank Fabrice Toussaint and Hélène Lombois-Burger for their welcome at LafargeHolcim during my internship in France. Much of what was learned from that experience contributed to this thesis. This work would not have been possible without the support of my friends Ivania Yovanovic and Anita Bernal every step of the way, as well as the support of Arantxa Ereche and Trinidad Mesías. Finally, for his unfaltering support and patience even at a distance, merci beaucoup Hugo Poiblanc. ii TABLE OF CONTENTS Page DEDICATION ............................................................................................................. ii ACKNOWLEDGEMENTS ......................................................................................... ii TABLE OF CONTENTS ............................................................................................ iii LIST OF FIGURES ..................................................................................................... vi LIST OF TABLES ....................................................................................................... x NOMENCLATURE AND ABBREVIATIONS ........................................................ xii ABSTRACT ............................................................................................................... xv RESUMEN ................................................................................................................ xvi 1. STRUCTURE OF THESIS ................................................................................ 1 2. INTRODUCTION .............................................................................................. 2 2.1. 3DCP as a sustainable construction solution ............................................... 3 2.2. State of the art of 3DCP ............................................................................... 5 2.3. Challenges of 3DCP..................................................................................... 9 3. SUMMARY OF CONDUCTED WORK ......................................................... 12 3.1. Research gap .............................................................................................. 12 3.2. Hypothesis ................................................................................................ 12 3.3. Objectives ................................................................................................. 12 3.3.1 General objective ............................................................................. 12 3.3.2 Specific objectives ......................................................................... 12 3.4. Methodology ............................................................................................ 13 4. AIR BUBBLES AS AN ADMIXTURE FOR PRINTABLE CONCRETE - A REVIEW OF THE RHEOLOGICAL EFFECT OF ENTRAINED AIR ......... 15 4.1. Abstract ...................................................................................................... 15 4.2. Introduction ................................................................................................ 16 4.3. Material requirements for 3DCP................................................................ 19 4.3.1. Definition of printability ................................................................ 19 4.3.2. Relevant rheological concepts ........................................................ 21 4.3.3. A review of structural build-up and its mechanisms ...................... 23 4.4. Obtaining a printable mixture .................................................................... 27 4.4.1. Measuring printability .................................................................... 27 4.4.2. Successful printable mixtures ......................................................... 31 4.5. Effect of entrained air on rheological properties ....................................... 37 4.5.1. Air entrained yield stress fluids ...................................................... 37 4.5.2. Air entrained concrete .................................................................... 42 4.5.3. Types of air entraining agent .......................................................... 49 4.6. Effect of AEA on printability .................................................................... 53 4.7. Further research & conclusions ................................................................. 53 5. EXPERIMENTAL FINDINGS ........................................................................ 56 5.1. Air volume fraction assessment for air-entrained mortar .......................... 56 5.1.1. Materials and methods ................................................................... 56 5.1.2. Results ............................................................................................ 59 5.2. Rheological assessment of air-entrained cement paste .............................. 66 5.2.1. Materials and methods ................................................................... 66 5.2.2. Experimental results ....................................................................... 68 5.3. Empirical and rheological tests for air-entrained mortar ........................... 74 5.3.1. Materials and methods ................................................................... 74 5.3.2. Mini-slump test .............................................................................. 76 5.3.3. Shear vane test ................................................................................ 77 5.3.4. Penetrometry .................................................................................. 80 5.4. Relations found between experiments and conclusions ............................ 84 5.4.1. Static yield stress comparison between air entrained cement paste and air entrained mortar ............................................................................. 84 5.4.2. Conclusions .................................................................................... 88 6. MODEL EVALUATION IN THE CONTEXT OF AIR-ENTRAINED CEMENT PASTE .............................................................................................................. 90 6.1. Theoretical framework ............................................................................... 90 6.1.1. Rheological models for concrete .................................................... 90 6.1.2. Proposed models for air-entrained cement paste ............................ 92 6.1.3. Parameters for 3DCP ...................................................................... 96 6.2. Experimental data found in literature ........................................................ 97 6.2.1. Static yield stress results versus rheological models ...................... 99 6.2.2. Plastic viscosity results versus rheological models ...................... 102 6.3. Conclusions .............................................................................................. 105 7. CONCLUSIONS & FURTHER RESEARCH ............................................... 106 7.1. General conclusions ................................................................................. 106 7.2. Further research ....................................................................................... 107 REFERENCES ........................................................................................................