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 concreteâ€™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 PLCâ€™s performance upon their incorporation. Applicators are encouraged to make use of PLC concrete in non-strategic structures in an attempt to improve concreteâ€™s sustainability and alleviate negative environmental impact.
MS in Construction Engineering
Abou-Zeid, Mohamed Nagib
Committee Member 1
Salah Eldin, Omaima
Committee Member 2
Library of Congress Subject Heading 1
Library of Congress Subject Heading 2
Portland cement industry.
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(2015).Performance of PLC concrete incorporating chemical and mineral admixtures [Master’s thesis, the American University in Cairo]. AUC Knowledge Fountain.
Hussain, Sara Mohsen. Performance of PLC concrete incorporating chemical and mineral admixtures. 2015. American University in Cairo, Master's thesis. AUC Knowledge Fountain.