International Concrete Abstracts Portal

ACI CODE-318-25 provisions for calculating horizontal joint shear force in beam-column joints of structures assigned to Seismic Design Category (SDC) A and B generally assume moment transfer to the joint is governed by the nominal flexural strength of the beam(s). There are cases, however, where moment transfer is governed by column flexural yielding or where both the beams and columns framing into the joint are expected to remain elastic. Examples can be found in roof joints and in joints with post-tensioned beams whose design is governed by serviceability conditions. Guidance is provided herein for determining horizontal shear force in joints where moment transfer is not governed by beam flexural yielding through an example roof joint between a cast-in-place post-tensioned beam and a reinforced concrete column.

This paper presents pedagogical tools that may be used in the instruction of torsional design of reinforced concrete beams for an advanced concrete design class geared for senior-level undergraduate and Master’s-level graduate students. Torsion design of reinforced concrete combines both with longitudinal steel requirements for flexural moments and transverse steel requirements for shear force, as therefore makes a useful framework for synthesizing many different beam design topics into an “advanced beam design” unit. For the benefit of the instructor, or even the enterprising student, this is followed by an overview of torsional demands and design in accordance with ACI 318-25. This paper presents course-level information about where and how a torsional design unit may be taught within an advanced concrete design course. Examples of physical demonstrations, example problems, and assessment methods are given to deliver content to students and to evaluate their ability to meet the stated learning objectives. The paper concludes with a discussion on the lessons that the author has learned from teaching this topic since 2020.

Prestressed concrete is used in a wide range of building and transportation structures where its improved performance and material efficiency is typically associated with longer spans, reduced structural thickness, and material savings compared with conventional reinforced concrete. However, there are some key differences in the behavior, limit states, serviceability, and strength design of prestressed concrete compared to cast-in-place concrete. The following three concepts were identified by the authors as the key differences, which are often associated with student confusion in an advanced prestressed concrete course: allowable stress, loss of prestress, and shear capacity. This paper presents an overview of how instructors can highlight the key differences between prestressed and reinforced concrete. Furthermore, this paper includes significant resources that can be used when starting a prestressed concrete course, including syllabus content, learning objectives, assessment tools, available technical resources and methods of integrating them into the course, and innovative teaching techniques that can aid in removing the bottleneck to learning often associated with the key prestressed concrete concepts. The paper also highlights lessons learned from the authors based on observations from several years of instruction.

Concrete bridges offer a combination of strength, durability, versatility, and sustainability that make them a preferred choice for many infrastructure projects. However, there are some unique differences between concrete building and bridge analysis and design. The following three concepts were identified by the authors as the most unique, and they are often associated with student confusion in a bridge analysis and design course: applied loads and limit states, shear capacity of prestressed concrete bridge girders, and bridge deck equivalent strip design. This paper presents an overview of the key concepts related to concrete bridge analysis and design that instructors can highlight. Furthermore, this paper includes significant resources that can be used when starting a bridge analysis and design course, including syllabus content, learning objectives, assessment tools and rubrics, available technical resources, and methods of integrating them into undergraduate and graduate level courses. Lastly, innovative teaching techniques are discussed that can aid in removing the difficulty often associated with teaching and learning about concrete bridges. The paper highlights lessons learned from the authors based on observations from several years of instruction.

This Symposium Volume reports on the latest advancements related to the various facets of modeling and performance assessment of concrete structures. The volume contains 10 papers that were presented at the ACI Convention held in Toronto on April 1st, 2025. The symposium was dedicated to celebrate Prof. Frank J. Vecchio’s extraordinary research contributions and accomplishments in the development of behavioral models and analytical tools for the assessment of concrete structures. The papers cover different aspects related to modeling and performance assessment of concrete structures including developments of the Modified Compression Field Theory, finite element modeling of punching shear in slabs, behavior and modeling of steel fiber reinforced concrete members subjected to torsion, modeling of concrete structures subjected to impact loading, behavior and modeling of slender walls, modeling of concrete frame elements, behavior and modeling of GFRP reinforced members, crack-based assessment of concrete structures, and advancements in modeling deterioration mechanisms and repaired concrete structures. Sincere acknowledgements are extended to all authors, speakers and reviewers as well as to ACI staff for making this symposium a success. Anca-Cristina Ferche, Editor Vahid Sadeghian, Editor