Concrete Modulus of Elasticity—How High is High
The requirements for achieving sufficient modulus of elasticity (MOE) of concrete is increasing not only for high-rise structures, but also for concrete precast/prestressed components and repair application. However, achieving high modulus of elasticity, while maintaining good workability, pumpability, and consolidation of concrete is of challenge for concrete producers and contractors. Key factors affecting MOE include mixture design, rheological properties, and construction practices also influence in-place MOE and its homogeneity. Testing of MOE of high-performance concrete also requires special attentions to achieve reliable data. The session will be beneficial for engineers, specifiers, concrete producers, contractors, and academic communities.
Contractors’ Day Session: Concrete Construction
The presentation will address construction, forming, mixture design, transportation, and engineering challenges faced in extreme conditions.
Controlling Fresh Properties of SCC for Adequate Placement (238)
Self-consolidating concrete (SCC) is known to be more sensitive to changes in constituent elements, mixture design, and mixing procedure, which can have significant consequences on placement. Especially controlling the water content, including the moisture content of the sand, is a challenge, limiting the practical implementation of SCC. This session will reveal different strategies to control the variation in fresh properties, making the session suitable to material producers, contractors, engineers, owners, and academics. This session, participants will be informed on: variations in concrete constituents, mixture design, mixing, transportation, and placement procedures influencing fresh SCC properties; which countermeasures can be taken to control these variations; the importance of an adequate quality control system for the successful implementation of SCC; and future perspectives in actively controlling fresh SCC properties.
Fiber-Reinforced Concrete—From Fresh Properties to Structural Design: New Tools, Guides, and Reports
During the past 3 years, ACI Committee 544 has developed five new documents addressing the testing and fresh concrete properties, mechanical properties, back calculation of tensile properties, structural design with fiber-reinforced concrete (FRC), design of elevated slabs with FRC, and design of precast tunnel lining with FRC. These published reports (ACI 544.6R, 544.7R, 544.8R, 544.9R, and 544.3R) are currently available for the engineering community and offer a completely fresh way to use, design, and implement FRC in a variety of applications. The purpose of this course is to dedicate a presentation to each document addressing its content, how the specific topics of documents interact with each other, as well ways to implement and incorporate the knowledge in these documents in the design and specification. The speakers are the members of the committee who were the primary authors of the documents.
FRP Design Methodology and Applications for Blast and Impact-Resistant Structures
ACI Committee 370 and ACI Subcommittee 440-F are jointly developing the standard “Blast Design Guidelines for Externally Bonded FRP Applications” to provide guidance for designing concrete and masonry wall panels with an application of fiber-reinforced polymer (FRP) that are subject to blast loading. The opening presentations in this two-part session will provide an overview of the proposed standard, while covering some basic blast design practices and introducing the underlying single-degree-of-freedom (SDOF) analysis methodology. Subsequent presentations will discuss alternate slab analysis approaches, as well as FRPs used as column reinforcement, catching systems, and anchors within a blast- and/or impact resistant design. Focused talks on FRP detailing and FRP manufacturers’ insights will also be presented.
New Innovations in Chemical Admixtures
Chemical admixtures is one of the fastest growing and innovative areas of concrete construction currently. This session will highlight new admixture technology and how these new admixtures bring value to concrete by improving plastic and hardened properties, providing improved economy, and changing the limits on how concrete can be used as a constructible material. Attendees will be provided with knowledge about chemical admixtures and how and where to use them effectively.
- Introduction to What’s New in Chemical Admixtures by Kari L. Yuers, Kryton International Inc.
- A Chemical Admixture with Carbon Nanotubes by Yuan Gao, Northwestern University; David J. Corr, Northwestern University; and Maria S. Konsta-Gdoutos, Northwestern University
- The Use of Microspheres as an Alternative to Entrained Air Bubbles for Providing Resistance to Freeze-Thaw and Salt Scaling by Michael D. A. Thomas, University of New Brunswick; and Edward G. Moffatt, University of New Brunswick
- New Generation of High-Range Water Reducers
by Suzanne Lianopoulos, BASF; and Thomas M. Vickers, BASF
- A New Generation of Micro-Particulate-Based Admixtures for Concrete by Christopher John Eagon, BASF; and Paul Horst Seiler, BASF Corp.
Quality Management: The Common Thread of Good Practice
The importance of quality and quality standards include reference to ISO 9001. Beyond the technical aspects, the practice of quality management is about people, relationships, and processes that can have a huge impact on results. Where does one find this type of content, and who will be so bold as to start this discussion? These topics are discussed in many committee meetings where of the most passionate debates revolve around them and how industry stakeholders work together. The concrete industry will benefit from a healthy discussion in a public forum on QMS implementation. The hosting of various speakers, topics, and perspectives will help to engage subject matter experts, highlight practices, and impact other committee documents.
Rating Methods for Defining Performance of Existing Concrete Bridges
The main objective of this session is to provide an overview of methodologies for rating existing concrete bridge components including bridge deck, superstructure, and substructure, using both LRFR and LFR approaches. Presentations will include case studies of load rating concrete bridges with various structural configurations such as typical prestressed I-girders, reinforced and prestressed multi-cell box girder bridges, segmental concrete bridges, bridges with large horizontal curvatures and complex geometry (for example, concrete arch and rigid frame bridges), and bridges with insufficient plans or details. Presentations will also emphasize relevant refined analysis methods that extend beyond traditional AASHTO rating methods such as finite element modeling, grillage modeling and diagnostic load testing. This session will be of interest to bridge owners, operators, design engineers, and researchers.
Repair of Concrete Session in Memory of Tony Murray
This session is a concrete repair session to honor the contributions of Tony Murray (who passed in 2016) to ACI and the concrete repair community. Tony was Chair of ACI Committees 503, 546, and 563, and a member of CLC, TAC, 364, 503, 546, 562, 563, and TRRC. He was a Fellow of ACI and speaker over many years at ACI concrete repair seminars. He was also an engineer, materials expert, and owned a structural concrete repair construction company. The session will include speakers from the concrete repair and materials community and the topics that reflect Tony’s wide range of knowledge in concrete repair and materials.
Seismic Repair and Retrofit of Concrete Bridges
Bridges are essential components of transportation systems. The failure and damage of bridges not only affects its immediate users, but also brings serious aftermath to earthquake events. With the increase in transportation demand and more stringent seismic performance requirements, bridge retrofit and repair is
an important task for engineers and researchers. Bridge retrofits usually involve functional upgrades (such as deck widening) and seismic upgrades (such as strengthening seismic load path). The effects of the two upgrades are usually coupled and need to be analyzed. Many of the existing bridges do not meet the
requirements in current design codes and thus cannot be analyzed using standard methods. Therefore, more sophisticated analysis and customized solution are needed. While providing structural upgrade solutions to seismic issues, engineers also need to reduce the interruption to the traffic as much as possible. Development and implementation of innovative retrofit and repair methods are expected to upgrade deficient bridges to current standards and minimize traffic interruption. The main objective of this session is to present results from
recent research studies (experimental/numerical/analytical) and practical examples of existing bridge retrofit and repair. This session will provide a forum for practicing engineers and researchers to share and discuss the various issues related to design and construction issues of existing bridges.
Settlement Cracking from Theory to Practice
Settlement of concrete is a phenomenon that takes place during the early hours after concrete is cast. This can be a problem in structures having top bars where the settlement of the fresh concrete around the reinforcement can cause cracking and/or a weak plane right above the reinforcement. This session includes presentations providing explanations from research studies and actual projects on the topic of concrete settlement, tests methods developed to measure this phenomenon, and techniques available to reduce it.
The Role of Cracking on Corrosion of Reinforced Concrete
Cracking is often considered detrimental to the corrosion resistance of reinforced concrete structures, but the magnitude of this effect is less clear. Crack size, location, and depth all may affect the impact of cracking on corrosion, and there is debate as to whether small cracks are detrimental to corrosion resistance. Presentations will highlight recent research into the effect of cracking on corrosion resistance of concrete and the effectiveness of crack mitigation/repair. This session will be of interest to contractors, engineers, and owners who wish to learn how cracking can impact the service life of structures they design, build, and use.
- Chloride Ingress at Cracks by Neal S. Berke, Tourney Consulting Group, LLC
- Influence of Cracks on Corrosion Initiation of Corrosion Resistant Reinforcement by Soundar Sriram G. Balakumaran, Virginia Department of Transportation; Michael C. Brown, WSP USA; and Richard E. Weyers, Associated Materials Engineers
- Effect of Early-Age Cracking on Corrosion Initiation in Reinforced Concrete by James D. Lafikes, University of Kansas; David Darwin, University of Kansas; Matthew O’Reilly, University of Kansas; and Omid Farshadfar, Thornton Tomasetti
- Performance of Cracked High-Performance Concrete in a Harsh Marine Environment by Edward G. Moffatt, University of New Brunswick; Andrew Fahim, University of New Brunswick; and Herwing Lopez-Calvo, University of New Brunswick
- Effect of Cracking on Reinforced Concrete Corrosion by Brian M. Pailes, Rutgers University
Blast Resistance of Precast Concrete
This session will provide ACI members an overview of research performed through private and industry funding over the last decade. Presentations will highlight full-scale, high-explosive and shock tube test programs, analysis methodologies, and design response limits. This session is appropriate for researchers, practitioners, and students.
Constructability: From Definition to Industry Practice
This session presents constructability review perspectives from the different parties: design professionals, construction managers, concrete contractors, and ready mix producers. All industry professionals should attend to learn how each party views their responsibility for a constructability review and how that interacts with the other parties’ constructability review.
History of Concrete
This session, includes presentations of historical aspects of concrete and concrete construction practice. Attendees will gain a greater understanding and appreciation of the development of the concrete industry.
Hot Topic Session: Busting 90 Minutes
The ASTM C94 90-minute time limitation has been around for over 80 years and committee members are now discussing its removal! The committee is now reviewing current science and modern design techniques for concrete mixtures by considering the time limit to be determined by the specifier and/or ready mix producer. This session will explain why this proposed change is being debated and give examples of scenarios showing expanded time limits of 2 or more hours. We’ll show how the pot-life of concrete can be extended without harm and why the typical 90-minute limit has become an antiquated standard. Examples of successful projects will illustrate the capabilities possible where longer time limits have been implemented.
Hot Topic Session: Can Codes and Standards Improve the Performance and Longevity of Existing Concrete Structures?
Over the past 30 years, concrete repair professionals have recognized a need to improve the performance of concrete repair practice. Various references indicate that approximately 50% of concrete repairs fail within a period of 10 years. The premature failure of concrete repairs creates a series of problems, including:
- Safety risks associated with potential falling debris hazards
- Risks associated with unsafe structures
- Costs in the billions of dollars associated with the repair and re-repair of concrete structures
The concrete industry has developed several new standards and codes specifically to improve the design side of concrete repair practice. These include ACI 562, Concrete Repair Code; ACI 563, Concrete Repair Specifications; and ACI 437.2, Standard for Load Testing of Existing Concrete Structures. While the ACI 562 code is gaining acceptance at the state level, it has not been adopted into the International Existing Building Code, largely because of resistance from some anti-code design professionals. The hot topic session will aim to explore five viewpoints on how to improve concrete repair practice from the perspective of design professionals, contractors, and academics.
Materials Science Aspects Related to Digital Manufacturing (3-D Printing) of Cementitious Materials
The field of digital manufacturing (3-D printing) of concrete is rapidly evolving. An understanding of material properties and processing related parameters, and how they influence the properties of three-dimensional (3-D) printed structural components, is essential to ensure further advances in this nascent field. The proposed sessions will provide new information on selection of binder materials and combinations for successful 3-D printing; rheological characterization of cementitious materials as applied to digital manufacturing; the role of interfaces in the plastic and hardened stages; and microstructural architectures achievable by digital manufacturing to enable novel, multi-functional cementitious composites with special properties. This session will be valuable for researchers and students, and industrial entities interested in digital manufacturing and material processing.
- Rheological Control of 3D Printable Cement Paste and Mortars by Scott Jones, National Institute of Standards and Technology; Dale Bentz, National Institute of Standards and Technology; Nicos Martys, National Institute of Standards and Technology; and William George, National Institute of Standards and Technology
- How the Rigidity-To-Thixotropy Transition in Rheology Affects the Shape Stability of Dense Suspensions? by Iman Mehdipour, University of California, Los Angeles; Gaurav Sant, University of California, Los Angeles; H. Atahan (ITU); and N. Neithalath (ASU)
- Mechanical Response and Micro-CT Characterization of 3D Printed Cement Paste Elements with Controlled Architecture by Jan Olek, Purdue University; Mohamadreza Moini, Purdue University; Pablo Zavattieri, Purdue University; and Jeffrey Youngblood, Purdue University
- Microstructural Packing, Rheology, and Ram Extrusion Characteristics of 3-D-Printable Cementitious Binders by Sooraj Nair, Arizona State University; Aashay Arora, Arizona State University; Hussam Alghamdi, Arizona State University; and Narayanan Neithalath, Arizona State University
- Approaches to Producing Additively Manufactured Concrete Mixtures by Raissa Ferron, University of Texas at Austin
Seismic Rehabilitation—From Analysis to Practical Application
This session will present the latest advances in seismic rehabilitation of existing concrete buildings that have come out of recent research projects and experiences from recent earthquakes around the world. The session will present results of evaluation studies applied to existing structures using current ASCE 41, ACI 369.1R-17, or other local seismic evaluation and retrofit standards. Attendees will also be presented with information on recent research results of laboratory experiments of retrofitted structural components. An overview of ongoing activities within ACI 369 to update the ACI 369.117 standard will also be presented.
- Guidance on Nonlinear Modeling of RC Buildings by Laura Lowes, University of Washington
- Overview of the NIST-ATC Project on Benchmarking of Evaluation Methodologies for Existing Buildings by Siamak Sattar, National Institute of Standards and Technology
- Evaluation of Seismic Assessment Procedures for Existing Reinforced Concrete Structures Damaged in the 2016 Meinong Earthquake by Laura Lowes, University of Washington; Dawn Lehman, University of Washington; and J. Sumearil, University of Washington
- ASCE 41 versus TEASPA: Comparison of Seismic Evaluation Results of RC Frame Buildings Damaged During 2016 Meinong Earthquake, Taiwan by Jiun-Wei Lai, University of California, Berkeley; ShyhJiann Hwang, National Taiwan University; Insung Kim, Degenkolb Engineers; Daniel Zepeda, Degenkolb Engineers; Garrett Hagen, Degenkolb Engineers; and Kirk Johnston, Degenkolb Engineers
- Performance of a Nonductile RC Building for the FEMA P695 Far-Fault Ground Motion Data Set, by Adolfo Matamoros, University of Texas at San Antonio; Andres Lepage, University of Kansas; Anil Suwal, University of Texas at San Antonio
- Ongoing Activities for Future Updates of the ACI Standard 369.1-17 by Insung Kim, Degenkolb Engineers; Sergio Brena, University of Massachusetts; Adolfo Matamoros, University of Texas at San Antonio; Garrett Hagen, Degenkolb Engineers; and Arne Halterman, Holmes Culley
- Quantifying Benefits of Seismic Retrofitting Gravity Columns Using CFRP Jackets Based on Nonlinear Modeling Parameters per ACI 369.1 by Saeed Fathali, Structural Technologies; Bill Graft, ImageCat; and Mohammad Jalalpour, Structural Technologies
- Seismic Evaluation of Beam-Column Assemblages Strengthened with FRP and Anchored with Spike Anchors by Elias Saqan, American University in Dubai; Hayder Rasheed, Kansas State University; and Tarek Alkhrdaji, Structural Technologies
- Seismic Performance of Repaired Lightly Reinforced Concrete Walls by Christopher Motter, Washington State University
- Repaired Reinforced Concrete Wall Buildings in Chile after 2010 Earthquake by Matias Hube, Pontifical Catholic University of Chile
- Residual Capacity of Damaged and Epoxy-Repaired Reinforced Concrete Plastic Hinges by Kai Marder, University of Auckland; Kenneth Elwood, University of Auckland; Christopher Motter, Washington State University
Specifications for Repair of Concrete in Buildings
In developing 563, topics emerged for which the industry does not have consensus, or for scope that is currently under study and is not ready for standardization. A round table discussion of repair trends and new work needed in the future will be convened by the incoming chair of 563, with input from the session speakers.
Sustainable and Low-Cementitious-Materials-Content Self-Consolidating Concrete
The use of self-consolidating concrete (SCC) can contribute to increased productivity, an improved working environment, and improved concrete mechanical behavior and durability. However, use of SCC is still generally low, mainly due to the high cost associated with the high cement content and admixtures. The effective reduction of cement and cementitious materials contents in SCC mixtures will reduce cost and also minimize environmental impact. Among other benefits of reduced cement content leading to reduced paste content is reduced concrete shrinkage and thereby reduced risk for crack formation. This section includes presentations on the benefits, design, and performance of SCC with low cementitious materials content.
- Particle Packing and Mixture Design Approach for Eco-SCC by Kamal Khayat, Missouri S&T; Olafur Wallevik, Innovation Center Iceland; and Behrouz Esmaeilkhanian, Beton Provincial Ltee
- Sustainable Self-Consolidating Concrete: Utilization of Limestone Powders by Natalia Cardelino, Mercer University; Kimberly Kurtis, Georgia Institute of Technology; and Russell Gentry, Georgia Institute of Technology
- The Rheology of Control Flow Concrete by G. Terry Harris, GCP Applied Technologies; Klaus Alexander Rieder, GCP Applied Technologies; Elizabeth Burns, GCP Applied Technologies; Joshua Curto, GCP Applied Technologies; and N. Tregger, GCP Applied Technologies
- Eco-Efficient Self-Consolidating Concrete (Eco-SCC) with Low Powder Content and Recycled Concrete Aggregate by Jiong Hu, University of Nebraska–Lincoln
The Role of Materials in Sustainable Concrete Construction
ACI 130’s Sustainability of Concrete Materials book will have been approved and published by the time of the Las Vegas convention. Therefore, this session will introduce the ACI community to this new publication.