Document Type

Thesis - University Access Only

Award Date

2001

Degree Name

Master of Science (MS)

Department / School

Civil and Environmental Engineering

Abstract

The American Concrete Institute (ACI) defines high strength concrete (HSC) as concrete that has a compressive strength in excess of 6,000 psi. HSC has been developed over the past 40 years and is used mainly in the high-rise building industry. The use of HSC is slowly being applied to highway structures. On account of this new application, the material properties of the concrete must be accurately determined to ensure the safety and serviceability of the resulting structure. South Dakota Department of Transportation project SD98-06 used the first commercially produced concrete with compressive strengths in excess of 10,000 psi in the State of South Dakota. The goal of the research that has accompanied this project is to measure and describe the physical properties of this new concrete mix. This thesis is an analysis of the testing related to determining the modulus of elasticity of the concrete. Through the applied testing and analysis it is evident that the modulus of elasticity for this mix is substantially larger than the modulus for normal strength concrete. Using linear regression techniques, the following equation to estimate the modulus of elasticity by relating the compressive strength and the unit weight was developed.

E = ( 39,000fj; + 2,000,000) (~)1.5 145

E = Static modulus of elasticity, psi

J; = Compressive strength of concrete at time of test, psi

w e = Concrete unit weight, lbs/ft3

This equation was then compared to the accepted ACI equations for estimating the modulus of elasticity for normal and high strength concrete. The resulting empirical equation produces estimates that are greater than the estimates given by the accepted equations. Though not statistically similar, the equation is within ± 20% of the other investigated equations. The increased modulus values are attributed to use of quartzite as the coarse aggregate.

Library of Congress Subject Headings

High strength concrete -- Testing
Concrete bridges -- South Dakota -- Design and construction Elasticity

Format

application/pdf

Number of Pages

162

Publisher

South Dakota State University

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