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Title: Teaching the Equivalent Rectangular Stress Block

Author(s): J.Chris Carroll, Benjamin Z. Dymond, Anahid A. Behrouzi

Publication: Symposium Paper

Volume: 359


Appears on pages(s): 109-126

Keywords: curved RC bridge, demand-capacity ratio, displacement ductility, HDRBs, performance objectives, residual displacement, seismic fragility, shear strain of bearingactive learning, reinforced concrete, equivalent rectangular stress block, inquiry learning, p

DOI: 10.14359/51740293

Date: 11/1/2023

The equivalent rectangular stress block is the basis for determining the flexural strength of reinforced concrete members. Instructors commonly present the concept in two dimensions, contrary to its three-dimensional nature. Unfortunately, this can be particularly difficult for students to understand and visualize, especially for students with visual learning style preferences. This paper presents an overview of the equivalent rectangular stress block, select active learning methods, and four specific examples used by the authors to introduce the equivalent rectangular stress block in an undergraduate reinforced concrete design course. The first method focuses on understanding the terms associated with the equivalent rectangular stress block using a visual, hands-on learning activity; the second focuses on visualizing the internal forces and couple moment within a beam; the third uses a virtual three-dimensional model to derive the depth of the equivalent rectangular stress block; and the fourth illustrates the various stress blocks used in reinforced concrete flexure theory via physical three-dimensional models. Each description includes detailed instructions to create the resources and how to facilitate the related activities within a course. The overall goal is to provide educators with several examples that will help students better visualize the three-dimensional concept.