ACI’s International Programs, Chapters, and Aspirations
Presented By: Cary Kopczynski
Affiliation: Cary Kopczynski and Company
The Bridges in Italy: State of The Art, Case Studies, Research in Progress and Rational Approaches to Select Intervention Priorities
Presented By: Marco Prisco
Affiliation: Politecnico Di Milano
Description: The collapse risk is a factor associated to the construction of any structure or infrastructure: maintenance and monitoring are actions aimed at reducing this risk, but they cannot reduce it to zero.
The lack of a plan of maintenance procedures, established by the designer at the construction time, jointed to the neglecting of robustness principle in the conceptual design as well as of some possible extreme events correlated to the infrastructure far- and near-field are the main causes of the collapses observed. The lack of a generalized consent of the technical and scientific community on the procedures to be pursued at the end of the expected life contribute also to increase the scattering of safety conditions in many infrastructures used in the road traffic. After a generalized discussion on the main causes of collapse occurred in Italy, the significant difference between the railway from the road infrastructures is proposed. An analysis of few case studies like that one of Annone overpass, or that one on SP10 crossing the highway A14 near Ancona, as well as a discussion on the uncertainties in the diagnosis of historical bridges like Azzone bridge or on the critical aspects met in the design of intervention on relatively old bridges made of steel or post-tensioned reinforced concrete will be instrumental at giving a faceted overview of this complex problem that the next Model Code will try to deal with an organic vision. Finally, a brief nod on the main activities in progress to overcome this critical situation at both regional and national levels is outlined.
Recent Advances on High-Performance Bio-Based Cement Composites and Concrete (View from Brazil)
Presented By: R.D. Filho
Description: In recent years, a great deal of interest has been created worldwide on the potential applications of bio-based materials such as bamboo, vegetable fibres and bio-aggregates in the construction sector. These materials have been considered promising materials because they are abundant, renewable and biodegradable, low cost and energy saving, and present high specific strength and stiffness. There are, however, important questions regarding the use of such materials in construction that need to be responded: (i) How to improve the durability of bio-based building materials and systems? (ii) How the matrix, reinforcement and processing techniques need to be tailored to allow the production of high performance bio-based composites and bio-concrete? (iv) Can vegetable fibers acts as a Self-healing conveyer in ultra-high strength steel fibre reinforced concrete? (v) How Climate Change can be mitigated by using bio-based building materials in Construction? In this presentation the above questions will be responded based on the results of the research activities carried out at the Federal University of Rio de Janeiro-Brazil in the last few years.
Recent Development and Application of 3-D Printing Concrete in China
Presented By: Yamei Zhang
Affiliation: Southeast University
Description: 3D concrete printing technology has been developing very quickly around the world in recent years. I will introduce the new developments of 3D printing concrete (3DPC) technology from the mix design, the printing of concrete with coarse aggregate, the impact of ambient relative humidity, wind and the strength of 3D printed concrete. Some typical applications of 3DPC in China will be briefly introduced. Finally, the challenges facing the application of 3DPC will be briefly discussed.
Emphasizing Technologies for Low-Carbon Lean-Construction (TLC2) (An Indian Perspective)
Presented By: Ravindra Gettu
Affiliation: IIT Madras
Description: In most emerging economies of the World, such India, major construction is expected during this decade in both infrastructure and housing sectors. This presents a great opportunity for more efficient, responsible, and sustainable technologies to be implemented. This would require the consolidation and research, if needed, in the areas of waste processing, lean technologies, scaling-up and policy changes for large-scale adoption. Waste processing would go beyond fly ash, waste clay and slag, to consider construction and demolition waste, and non-recyclable plastics. Analytical tools, life estimation and demonstration of techniques such as 3D-printing need to be applied for lean philosophies to be applied at the site. Scaling-up would require test beds, simulation, visualization, and adoption management. Policy notes, road maps and influencing stakeholders will be needed for large-scale changes. Though the challenges may appear daunting, international collaboration and strengthening of local centres of excellence could provide the relevant solutions.
IIT Madras has initiated a project along these lines with the participation of about 20 of its faculty members, 30 research scholars, and several collaborators from around the globe (https://civil.iitm.ac.in/pcoe/tlc/). The talk would present recent results, goals, and the potential collaboration with entities such as ACI and RILEM in this initiative.
The Challenges and Opportunities of New Materials and Advanced Numerical Tools for the Development of Innovative and Sustainable Built Environment (A Portuguese Vision)
Presented By: Joaquim Barros
Affiliation: University of Minho
Description: During the last decades significant advances have been made on new reinforcements for increasing the durability and life cycle of concrete structures. By restraining the crack width, fiber reinforcement is opening new opportunities for the development of innovative systems, not only for new construction, but also for the rehabilitation. By using more efficient fibers or more than one type of fibers (hybrid fiber reinforcement) and proper matrices, the complete elimination of conventional steel reinforcements is being explored not only to decrease significantly the deadweight of the construction system, but also to speed up its production. However, innovation is required on the mixing methodology of fiber reinforced cement-based materials (FRC) by taking advantage of the artificial intelligence, on the production technology in order to orient the fibers for an efficient use of their reinforcement mechanisms by using advanced prefabrication industry, and on the modeling and design by simulating reliably the phenomena governing the serviceability and ultimate limit design scenarios. Fibers from tire recycling industry have also been used with notable efficiency for producing thin panels. However, the control of the geometry and mechanical properties of these fibers at the end of the recycling process, as well the technology of their addition during the production process of the panels or other constructions systems must be improved to justify the cost investment on the recycling process.