Masters Theses

Abstract

"In recent decades, engineers have sought a more sustainable method to dispose of concrete construction and demolition waste. One solution is to crush this waste concrete into a usable gradation for new concrete mixes. This not only reduces the amount of waste entering landfills but also alleviates the burden on existing sources of quality natural concrete aggregates. The objective of this study was to determine to effect of replacing coarse natural aggregates for recycled concrete aggregates (RCA) on the bond strength between deformed mild reinforcing steel and surrounding concrete. Two different RCA replacement levels were considered, 50% and 100%, and were compared to a standard Missouri Department of Transportation (MoDOT) mix design. All RCAs used were crushed from laboratory cured beams of the same MoDOT mix design containing 1 in. Potosi Dolomite crushed stone.

To evaluate bond strength, 18 direct pull-out specimens were tested with both #4 (No. 13) and #6 (No. 19) reinforcing bars and 9 full-scale beam specimens were tested with non-confined contact lap splices located at mid-span. The construction and test procedure of the direct pull-out specimens was based on RILEM 7-II-128. The full-scale beam splice specimens were based on a non-standard test procedure that is considered to be the most realistic stress state response for bond. Analysis of the test data indicates that replacing more than 50% of coarse natural aggregates results in diminished bond strength over concrete containing only virgin natural aggregates. This result suggests that the existing equation for development and splice length as reported in ACI 318 may require additional modification factors to account for the diminished bond strength associated with replacement of coarse virgin aggregates with RCA."--Abstract, page iii.

Advisor(s)

Volz, Jeffery S.

Committee Member(s)

Khayat, Kamal
Myers, John

Department(s)

Civil, Architectural and Environmental Engineering

Degree Name

M.S. in Civil Engineering

Sponsor(s)

Missouri. Department of Transportation
National University Transportation Center

Publisher

Missouri University of Science and Technology

Publication Date

Spring 2014

Pagination

xiv, 137 pages

Note about bibliography

Includes bibliographical references (pages 134-136).

Rights

© 2014 Amanda Renee Steele, All rights reserved.

Document Type

Thesis - Open Access

File Type

text

Language

English

Subject Headings

Aggregates (Building materials) -- Testing
Aggregates (Building materials) -- Recycling
Concrete -- Recycling
Reinforced concrete construction

Thesis Number

T 10483

Electronic OCLC #

882553915

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