The behavior of large shear inserts in concrete

Author

Kenneth Eduardo Fricke

Date of Award

12-1992

Degree Type

Dissertation

Degree Name

Doctor of Philosophy

Major

Civil Engineering

Major Professor

Edwin G. Burdette

Committee Members

David Goodpasture, Ray Krieg, Eric Drumm

Abstract

One of the engineering problems encountered in the design of the Department of Energy Gas Centrifuge Enrichment Plant (GCEP) in Piketon, Ohio was the design of the mount system supporting the machines. A major factor in this design was the determination of the concrete bearing capacity around steel inserts having an embedment length/diameter ratio approaching unity. Tests were performed on eight inserts that were cast into a prototype reinforced concrete slab similar to the concrete floor slab designed for the GCEP facility. An eccentric shear load was applied to each insert and the bearing capacity of the concrete was determined. The results indicated that the ratio of the bearing capacity to the concrete compressive strength, f_b/f’_c, averaged about 3.8, or about 4.5 times greater than allowed by the ACI Concrete Code. The results were compared with various methods commonly used to determine bearing capacity of shear inserts and found to differ widely. A closer agreement was found with the bearing capacity determined for brackets embedded in concrete columns. The first part of the dissertation discusses the concrete insert tests in detail, and the second part discusses a nonlinear finite element analysis (FEA) that was performed to model the insert tests and try to reproduce the behavior obtained in the field tests. The computer code ADINA, which has a nonlinear concrete material model in its library, was used for this study. The results of this study were inconclusive. The FEA was only able to reproduce about half of the load-displacement curves obtained during the tests, stopping well short of ultimate failure as observed during the tests. Many problems with equilibrium were encountered after one or more elements were totally crushed in the FEA. Various parameters were modified during the study, with little success.

Recommended Citation

Fricke, Kenneth Eduardo, "The behavior of large shear inserts in concrete. " PhD diss., University of Tennessee, 1992.
https://trace.tennessee.edu/utk_graddiss/10883