A STUDY ON THE USE OF FURNACE SLAG, FLY ASH AND CALCINED CLAY AS CEMENTITIOUS MATERIALS
Session
Civil Engineering, Infrastructure and Environment
Description
Materials with a certain binding capacity have been decisive in the development and evolution of construction. This evolution has led to Portland cement and reinforced concrete being the most widely used materials in the construction industry. On the other hand, the cement industry is one of the main sources of C02 emissions and it has been estimated that those emissions reach a value of 1 ton of C02 per ton of clinker, thus Portland cement contributes with about 5% to the global production of CO2. Consequently there is a need for alternative binders with cementing capabilities, which do not harm the environment and can also bring benefits. Although the amount of waste/by-products currently used,is small compared to what is produced, studies are being carried out all over the world to find new applications for these cementitious materials thus contributing to reducing the amount of C02 released that comes from the construction industry. Industrial wastes, as well as materials of natural origin, can be used as supplementary cementitious materials to reduce clinker factor in cement (and as a consequence CO2 emissions in the atmosphere),including here : fly ash, furnace slag and calcined clay. These materials can be used as mineral additives in the preparation of Portland cement, as additives in grinding or in the mixture of two or more fine materials that partially replace Portland cement.Besides the environmental part,the production of cement with fly ash and furnace slag can exhibit benefits such as improved workability,increased setting time and higher sulfate resistance than ordinary Portland cement. Furthermore the use of calcined clay promises a reduction of up to 40% CO2 emissions compared to Ordinary Portland Cement (OPC) at lower investment and production costs. It is also a low carbon, sustainable,and cost effective technology.In this paper, the compressive strength of the mortars prepared with furnace slag,fly ash and calcined clay, coming from different deposits of Albania, was tested after 2,7 and 28 days and the results were compared with that of OPC concrete (CEM I 42.5 R).The 2-days compressive strength of the mortars containing ash and slag reached a maximum of 55% of the OPC compressive strength value and after 28 days it went up to 65%,whereas the mortars containing calcined clay reached approximately 80% of the control sample compressive resistance after 28 days.These results are promising but the influence of several factors should be further studied.
Keywords:
Supplementary cementitious materials, Clinker, Fly ash, Furnace slag, Calcined clay, Compressive strength, Ordinary Portland Cement.
Proceedings Editor
Edmond Hajrizi
ISBN
978-9951-550-50-5
Location
UBT Kampus, Lipjan
Start Date
29-10-2022 12:00 AM
End Date
30-10-2022 12:00 AM
DOI
10.33107/ubt-ic.2022.195
Recommended Citation
Hoxhaj, Maria; Hyseni, Xhino; Vito, Sonila; and Boci, Ilirjana, "A STUDY ON THE USE OF FURNACE SLAG, FLY ASH AND CALCINED CLAY AS CEMENTITIOUS MATERIALS" (2022). UBT International Conference. 197.
https://knowledgecenter.ubt-uni.net/conference/2022/all-events/197
A STUDY ON THE USE OF FURNACE SLAG, FLY ASH AND CALCINED CLAY AS CEMENTITIOUS MATERIALS
UBT Kampus, Lipjan
Materials with a certain binding capacity have been decisive in the development and evolution of construction. This evolution has led to Portland cement and reinforced concrete being the most widely used materials in the construction industry. On the other hand, the cement industry is one of the main sources of C02 emissions and it has been estimated that those emissions reach a value of 1 ton of C02 per ton of clinker, thus Portland cement contributes with about 5% to the global production of CO2. Consequently there is a need for alternative binders with cementing capabilities, which do not harm the environment and can also bring benefits. Although the amount of waste/by-products currently used,is small compared to what is produced, studies are being carried out all over the world to find new applications for these cementitious materials thus contributing to reducing the amount of C02 released that comes from the construction industry. Industrial wastes, as well as materials of natural origin, can be used as supplementary cementitious materials to reduce clinker factor in cement (and as a consequence CO2 emissions in the atmosphere),including here : fly ash, furnace slag and calcined clay. These materials can be used as mineral additives in the preparation of Portland cement, as additives in grinding or in the mixture of two or more fine materials that partially replace Portland cement.Besides the environmental part,the production of cement with fly ash and furnace slag can exhibit benefits such as improved workability,increased setting time and higher sulfate resistance than ordinary Portland cement. Furthermore the use of calcined clay promises a reduction of up to 40% CO2 emissions compared to Ordinary Portland Cement (OPC) at lower investment and production costs. It is also a low carbon, sustainable,and cost effective technology.In this paper, the compressive strength of the mortars prepared with furnace slag,fly ash and calcined clay, coming from different deposits of Albania, was tested after 2,7 and 28 days and the results were compared with that of OPC concrete (CEM I 42.5 R).The 2-days compressive strength of the mortars containing ash and slag reached a maximum of 55% of the OPC compressive strength value and after 28 days it went up to 65%,whereas the mortars containing calcined clay reached approximately 80% of the control sample compressive resistance after 28 days.These results are promising but the influence of several factors should be further studied.