Ordinary Portland cement (OPC) has been commonly used in many countries for centuries. It is relatively easy to get OPC into an active binder, as it is a common practice due to its wide availability and it being economically friendly. This may seem like perfect cement. However, OPC has a significant impact on the environment caused by the CO2 emitted during the process of manufacture, which plays a big role in the increase of greenhouse gases. Therefore, a more sustainable option has to be acquired. There has been on-going research about geopolymer for many years due to its vast amount of advantages. Davidovits first used the term “geopolymer” in the late 1970s (Geopolymer Institute 1996). Geopolymer based materials such as geopolymer cement,
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1.1 Geopolymer cement The term geopolymer cement and geopolymer concrete are often confused. However, the process of making concrete requires aggregates and cement. Cement would have a role similar to glue, binding all the aggregates together to provide strength. Hence, it is nearly impossible to produce concrete without the use of cement. For instance, Banah UK Ltd is UK’s cement based company that produces banahCEM™, which are promoted as geopolymer cement, whereas the Australian company Zeobond advertise its E-crete™ as geopolymer concrete. (Davidvovits, 2013) There are two main elements of creating geopolymer. These are alumina-silicate and alkaline solution, the former being the main source material. Geopolymer cement is claimed as an inorganic polymer material that can be formed at room temperature by using natural materials or industrial waste by-products as a source of material to form a solid binder, which is similar to OPC. One of the main differences between OPC and geopolymer cement is the manufacturing process. OPC requires high energy to manufacture raw materials in the cement kiln, requiring it to be heated to about 1450 degree Celsius in order for clinker to …show more content…
This distinction leads to a substantial effect on both the mechanical and chemical properties of geopolymer cement and it also provides a better resistant to heat, and other types of chemical attack. (Vam Dam, 2010) The formation of geopolymer is relatively simple. Chemically it is somewhat similar to the natural occurring zeolite materials (Davidovits, 1994). The process of creating geopolymer mainly relies on the alkaline solution reacting into the silicon Si and aluminium Al atoms in the source materials (Abdullah.M et al., 2011). This will result in a gel that binds aggregates together to form geopolymer concrete, which is normally assisted by the application of heat. Pozzolan is defined as a reactive aluminosilicates, which can be either glassy (natural volcanic glasses or man-made glasses eg: fly ash or silica fume) or poorly crystalline [metakaolin]. Pozzolanic material consists of reactive silica and alumina, they do not harden when mixed in water but react with dissolved calcium hydroxide (Ca(OH)2) ] to form develop a strong calcium silicate and calcium aluminate hydrates. The pozzolanic reaction: (Gartner, 2011)
1.1 Geopolymer cement The term geopolymer cement and geopolymer concrete are often confused. However, the process of making concrete requires aggregates and cement. Cement would have a role similar to glue, binding all the aggregates together to provide strength. Hence, it is nearly impossible to produce concrete without the use of cement. For instance, Banah UK Ltd is UK’s cement based company that produces banahCEM™, which are promoted as geopolymer cement, whereas the Australian company Zeobond advertise its E-crete™ as geopolymer concrete. (Davidvovits, 2013) There are two main elements of creating geopolymer. These are alumina-silicate and alkaline solution, the former being the main source material. Geopolymer cement is claimed as an inorganic polymer material that can be formed at room temperature by using natural materials or industrial waste by-products as a source of material to form a solid binder, which is similar to OPC. One of the main differences between OPC and geopolymer cement is the manufacturing process. OPC requires high energy to manufacture raw materials in the cement kiln, requiring it to be heated to about 1450 degree Celsius in order for clinker to …show more content…
This distinction leads to a substantial effect on both the mechanical and chemical properties of geopolymer cement and it also provides a better resistant to heat, and other types of chemical attack. (Vam Dam, 2010) The formation of geopolymer is relatively simple. Chemically it is somewhat similar to the natural occurring zeolite materials (Davidovits, 1994). The process of creating geopolymer mainly relies on the alkaline solution reacting into the silicon Si and aluminium Al atoms in the source materials (Abdullah.M et al., 2011). This will result in a gel that binds aggregates together to form geopolymer concrete, which is normally assisted by the application of heat. Pozzolan is defined as a reactive aluminosilicates, which can be either glassy (natural volcanic glasses or man-made glasses eg: fly ash or silica fume) or poorly crystalline [metakaolin]. Pozzolanic material consists of reactive silica and alumina, they do not harden when mixed in water but react with dissolved calcium hydroxide (Ca(OH)2) ] to form develop a strong calcium silicate and calcium aluminate hydrates. The pozzolanic reaction: (Gartner, 2011)