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Title

Assessment of Thermal Cycling of Ultra-High-Performance Concrete

Organization

Department: Nuclear Eng'g & Health Physics

University: Idaho State University College: Science & Engineering Department: Nuclear Eng'g & Health Physics 23

Document Attachments

Resource	Length	Width	Thickness
Paper	0	0	0

Specimen Elements

City

Pocatello

Coverage

Unknown to Unknown

Creator

Michael E. Benson

Publisher

Idaho State University

Type

Thesis

Is Complete

No

Date Published

7/11/2023

Archive

digital

City: Pocatello

Degree

Master

Document Attachments

Abstracts

Ultra-High-Performance Concrete (UHPC) is a versatile and robust concrete that is currently used in civil engineering projects. With a new fleet of small modular reactors (SMR) and microreactor concepts being investigated, there is interest in UHPC for applications in the nuclear industry. ANSI/ANS 6.4.2 is a document from the NRC that lays out what physical and chemical properties need to be known about a shielding material before it can be approved for use in nuclear facilities. The goal of this research was to test how UHPC holds up to thermal loads and gamma irradiation with respect to the compressive strength of the concrete. Three different experiments were designed to test the robustness of the concrete. One test was a combination of heating samples and irradiating them. The other two are testing how the concrete holds up to various types of thermal loads. Four identical box ovens were utilized in testing the concrete. The UHPC mix that was used was LaFarge’s Ductal UHPC mix. A generic mix of Portland cement concrete was used as a comparison to the UHPC to provide a baseline for the performance of UHPC. Before any thermal loading or irradiation, the strength of UHPC was found to be about twice that of normal concrete. After exposure to heat the strength of the UHPC increases up to three to four times stronger than that of traditional concrete. After exposure to radiation and heat the strength of the UHPC was just slightly stronger than its baseline value. There is a possibility of explosive spalling for the UHPC at high temperatures. In fact, during the experiment several samples experienced explosive spalling when the temperature of the oven went above 275 ℃, which suggests a limiting temperature for applications. It was determined that UHPC is a viable concrete that can be used in nuclear reactors of all sizes and types. Concrete would not experience thermal loads above 250 ℃ during normal operation in a traditional reactor and the robustness of UHPC compared to the traditional concrete is beneficial.