A review on the efficiency of different supplementary cementitious materials as a partial replacement for Portland cement in concrete

The effects of global warming and climate change are important and have attracted the attention of many researchers. Global warming is a result of the presence of increasing amounts of greenhouse gases in the atmosphere. Carbon dioxide, which is largely emitted into the atmosphere during the manufacture of cement clinker, is one of the greenhouse gases. Hence, researchers have explored the use of some waste materials and naturally occurring minerals as a partial replacement for cement in concrete. These materials are often referred to as supplementary cementitious materials (SCMs). Apart from the potential benefits of these SCMs for the properties of concrete, they also bring about a reduction in the amount of waste in landfill sites, as these wastes can cause land, water, and air pollution, thereby posing threats to human health. However, despite the potential benefits of SCMs in the cement and construction industry, they have not been fully utilized especially in developing countries in Africa. This may be due to low awareness of the potential benefits of SCMs among the stakeholders in the construction industry, and also limited availability. Nevertheless, due to extensive research into the usability of different materials as SCM, various materials are available in the construction market as binder systems. Thus, selecting the appropriate binder system to get the desired result for a particular concrete might be difficult for construction personnel. Hence, this study presents a review of the effects of various SCMs on the mechanical and durability properties of concrete. Six SCMs are reviewed. These SCMs include fly ash, silica fume, which are industry by-products; metakaolin, limestone calcined clay, which are naturally occurring minerals; rice husk ash, which is an agricultural waste material; and limestone-fly ash, which is a combination of an industrial by-product and a naturally occurring material. Firstly, an overview of the mechanical and durability properties of concrete is presented. This includes the presentation of general factors affecting the mechanical and durability properties of concrete. Subsequently, the effect of the various SCMs on mechanical (such as strength, elastic modulus, creep, and shrinkage) and durability properties (freeze-thaw, acid attack, sulphate attack, chloride-induced corrosion, carbonation-induced corrosion, and alkali-silica reaction) of concrete are presented. The review shows that the inclusion of appropriate dosage of these SCMs in concrete or mortar enhances their properties. Certain limitations of these SCMs are also discussed. This study also identifies areas of further research in relation to the properties of concrete produced with the SCMs.

Grantor

Department of Civil Engineering

Year dc:date.issued

2022

Author dc:creator

• Taiwo, Ridwan A

Advisors dc:contributor.advisor

• Alexander, Mark
• Leo, Emmanuel

• civil engineering

Handle dc:identifier.uri

http://hdl.handle.net/11427/36564

OAI identifier oai:identifier

oai:open.uct.ac.za:11427/36564