Abstract

Portland limestone cement, PLC, has been produced by inter-grinding clinker with crushed limestone and gypsum. The crushed limestone introduced in PLC manufacturing as a partial replacement of the clinker serves in conserving energy and reducing CO2 emissions. Since CO2 is a main greenhouse gas that contributes to global warming, its reduction has gained attention. Therefore, the importance of PLC appears in improving concrete sustainability through reduction in greenhouse gas emissions and energy consumed in the cement industry. Europe, Canada and U.S.A took the lead in developing research studies upon allowing the incorporation of limestone in Portland cement. Currently, Egypt is taking steps into the production of PLC to promote a sustainable and environmentally friendly concrete. Yet, little work has been conducted on PLC while other international attempts on its incorporation did not tackle heavily it interaction with admixtures. This work aims primarily at investigating the performance of Portland limestone cement concrete incorporating chemical and mineral admixtures. Sixteen concrete mixtures were prepared with various levels of limestone while incorporating plasticizing admixtures and silica fume. The experimental program involved testing Portland cement, fresh concrete and hardened concrete. The tests performed on hardened concrete were, compressive strength, flexural strength, resistance to chloride ion penetration, sulphate and corrosion attacks. Results of this work reveals a somewhat similar behavior of PLC concrete when compared to OPC concrete with regards to compressive and flexural strength; yet, strength decreased with higher incorporation of Portland limestone cement. Furthermore, addition of superplasticizing agent and silica fume had the highest compressive and flexural strength values. Portland limestone concrete outperformed conventional concrete upon exposure to chloride ion penetration. The increase in limestone cement incorporation with the addition of superplasticizer and silica fume admixtures reduced the chloride permeability the most. It also demonstrated a lower mass loss and strength reduction upon exposure to sulphate attack. Lower corrosion risk was attained by PLC concrete compared to conventional concrete. Future work needs to be performed to investigate long term behavior of PLC concrete’s resistance to carbonation, elevated temperatures, freeze and thaw. Effectiveness of other chemical and mineral admixtures such as fly ash and blast furance slag should be examined in order to evaluate PLC’s performance upon their incorporation. Applicators are encouraged to make use of PLC concrete in non-strategic structures in an attempt to improve concrete’s sustainability and alleviate negative environmental impact.

Degree Name

MS in Construction Engineering

Date of Award

6-1-2015

Online Submission Date

April 2015

First Advisor

Abou-Zeid, Mohamed Nagib

Committee Member 1

Salah Eldin, Omaima

Committee Member 2

Breakah, Tamer

Document Type

Thesis

Extent

120 p.

Library of Congress Subject Heading 1

Cement industries.

Library of Congress Subject Heading 2

Portland cement industry.

Rights

The author retains all rights with regard to copyright. The author certifies that written permission from the owner(s) of third-party copyrighted matter included in the thesis, dissertation, paper, or record of study has been obtained. The author further certifies that IRB approval has been obtained for this thesis, or that IRB approval is not necessary for this thesis. Insofar as this thesis, dissertation, paper, or record of study is an educational record as defined in the Family Educational Rights and Privacy Act (FERPA) (20 USC 1232g), the author has granted consent to disclosure of it to anyone who requests a copy.

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Approval has been obtained for this item

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