Civil Engineering ETDs

Publication Date

Fall 8-29-2018

Abstract

The Brazilian indirect tension test is used to investigate possible correlations between progressive damage and associated permeability changes. The test offers ease of replicability with a damage behavior known to lead to fracture openings as a tool for interpreting the indirect tensile strength of concrete and rocks. This behavior can lend insight into the nature of tensile damage and fracture progression in association with changes in permeability. The nature of these brittle materials is known to exhibit rapid failures in the Brazilian indirect tension test and require a method to retard the progression of damage for the possibility of acquiring permeability measurements. Experimental results are replicated and investigated using the finite-discrete element method, which allows for the replication of both the elastic and post-peak fractured behaviors seen within the test. The model results are used to interpret the progression of damage and its type. Investigations of a sample pre-damaged with a drop tower is also made to observe a differing damage mechanism. The model validates the methodology behind what is called the stiff Brazilian indirect tension test and results from the models indicate that damage progression initiates near the contact points as shear separations, quickly followed by tensile separations along the line of fracture. The FDEM code used is observed to be a useful method for continued investigations into future modifications to the Brazilian indirect tension test for a broader damage and permeability correlation objective.

Keywords

FDEM, Fracture, Simulation, Modeling, Concrete, Rock

Sponsors

Los Alamos National Laboratory (LANL), New Mexico Consortium (NMC)

Document Type

Thesis

Language

English

Degree Name

Civil Engineering

Level of Degree

Masters

Department Name

Civil Engineering

First Committee Member (Chair)

Mahmoud Reda Taha

Second Committee Member

John Stormont

Third Committee Member

Esteban Rougier

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