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International Concrete Abstracts Portal

Showing 1-5 of 7720 Abstracts search results

Document: 

SP359_02

Date: 

November 1, 2023

Author(s):

Lisa E. Burris, Kenneth C. Hover, Anton K. Schindler, Aleksandra Radlinska

Publication:

Symposium Papers

Volume:

359

Abstract:

Concrete continues to be the most widely used material in the world, second only to water. Concrete is used in most civil infrastructure systems, but it often remains inadequately understood by the profession. For civil engineers to adapt to a world requiring ever-increasing efficiency, durability, and sustainability, and in which novel material formulations and products are introduced monthly, engineers must be able to make decisions as to the acceptability of these materials, and their effect on the performance of civil infrastructure. Essential to that ability is students’ understanding of the basics of cement hydration and its relationship to property development in the fresh and hardened concrete state. Towards that goal, this paper presents the basics of cement hydration, resources for learning more about the subject, and approaches to transferring knowledge to undergraduate-level students, through both lecture- and lab-based activities. Topics addressed include prioritization of topics for undergraduate civil engineering students to learn with regards to cement hydration processes, approaches to effective teaching of these topics including active learning in the classroom and laboratory, as well as knowledge exchange strategies, assessment techniques, and lessons learned from past experiences teaching these topics.


Document: 

SP359_09

Date: 

November 1, 2023

Author(s):

J.Chris Carroll, Anahid A. Behrouzi, Karl F. Meyer

Publication:

Symposium Papers

Volume:

359

Abstract:

Nonrectangular cross sections are a common occurrence in reinforced concrete design typically taking the form of flanged beam sections, circular columns, and square or rectangular columns subject to biaxial bending. Instructors typically introduce the theory behind nonrectangular beams using two-dimensional sketches of flanged sections. Students can struggle to visualize the examples when presented in two dimensions; deciphering the multiple resultant compressive forces and their corresponding moment arms are particularly difficult. This paper presents an overview of nonrectangular beam theory and select active learning methods along with three specific examples used by the authors to teach nonrectangular beams in an undergraduate reinforced concrete design course. The first method is a simple problem-based learning example to dissuade students from “plug and chug” calculations using improper equations; the second method illustrates three cases for a traditional flanged T-beam section using physical three-dimensional models; and the third method uses virtual three-dimensional models to derive the depth of the equivalent stress block and corresponding nominal flexural strength for various cross sections. Each description provides the reader with the best practices to implement the respective technique. Lastly, the authors provide some lessons learned from their past implementations. The overall goal is to provide educators with examples to simplify the presentation of nonrectangular beams theory.


Document: 

SP359_05

Date: 

November 1, 2023

Author(s):

Armen Amirkhanian and Eleanor Skelton

Publication:

Symposium Papers

Volume:

359

Abstract:

This paper presents an introduction to three common non-destructive testing techniques and effective methods to instruct students on the theory, application, advantages, and disadvantages. The document will outline teaching plans for resistivity measurements, ultrasonic pulse velocity measurements, and cover meter measurements. These three methods generally require inexpensive equipment and short preparation times for classroom demonstrations. Additionally, the first two methods have well established ASTM or AASHTO testing procedures that will aid the instructor in presenting the material, even with little to no experience with the techniques. From an instructional standpoint, various experiential learning pedagogies will be discussed to enhance the student learning outcomes. The exercises and lessons presented in the document are the result of many NDT course offerings at various universities. As such, the lessons learned from each exercise will be presented to further guide new instructors to succeed in teaching the material effectively the first time their course is offered.


Document: 

SP359_04

Date: 

November 1, 2023

Author(s):

Jacob D. Henschen, Daniel Blood, Shiho Kawashima, Heather A. Kirkvold

Publication:

Symposium Papers

Volume:

359

Abstract:

Additive manufacturing using material deposition methods continues to be a rapidly expanding field. Researchers have now begun to adapt these manufacturing methods to include cementitious materials. The impact on concrete design and construction methods are expected to undergo significant changes as a result of this new technology. However, as with adopting any new technology, knowledge transfer is critical to assure successful implementation. For engineers, this knowledge transfer begins with their coursework and faculty who can encourage students to explore new areas and readily apply what they learn. Since the field of printing concrete is still emerging, many of the applications and impacts of the technology are not adequately characterized. Furthermore, the technology itself has not been fully investigated or included in design literature. Incorporating ambiguity, multi-disciplinary teams, and open-ended problems successfully in undergraduate and graduate courses can be challenging. The goal of this paper is to advise faculty who wish to incorporate additive manufacturing topics related to cementitious materials in their courses.


Document: 

SP359_03

Date: 

November 1, 2023

Author(s):

Kacie C. D’Alessandro, Andrei Ramniceanu, Jacob D. Henschen, Matt O’Reilly

Publication:

Symposium Papers

Volume:

359

Abstract:

This paper presents pedagogical techniques used to teach fresh and hardened properties of concrete. Fresh properties of concrete include the evaluation of slump, unit weight, and air content. The hardened properties of concrete include compressive and tensile strengths. Students typically have little to no prior experience working with concrete. Since concrete structures date back to Ancient Rome, many students assume concrete is a basic material that has not changed in centuries, and they do not view concrete as an engineered material. Therefore, their understanding of how concrete is an engineered material and its use is essential. This paper focuses on how both fresh and hardened concrete properties are taught in the classroom to best introduce students to concrete as an engineered material. The pedagogical methods focus on engaging students using experiential education through hands-on laboratory activities, projects, and game-based learning activities. Examples of the pedagogical approaches are presented herein, and they are supported by lessons learned by the authors based on their experience implementing these methods in the classroom. two environmental conditions, sustained elevated temperatures (ST) and freeze-thaw (FT) cycles. The concrete cylinders were wrapped with a single layer of GFRP and CFRP wrap. GFRP wraps improved concrete strength by up to 30% and ductility in excess of 600% for ambient condition specimens, while the enhancements in strength and ductility under the same conditions by CFRP wraps were about 70% and 700%, respectively. The strength enhancements were reduced severely for specimens tested under ST protocol beyond the glass transition temperature (Tg) with a minor reduction in ductility enhancement. On the other hand, freeze-thaw conditioning showed minimal effect on strength and ductility enhancements provided by the FRP wraps. The current and past findings were then used to suggest environmental reduction factors for the design of FRP wraps. A comparison of these factors with ACI 440.2R-17 showed that environmental factors suggested by the ACI code were not applicable at temperatures beyond Tg.


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