A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Circular Approaches for Waste Based Geopolymer Feedstocks
Geopolymer cements exhibit high-strength properties while producing ~60% lower CO2 emissions compared with Portland cement manufacture. Much of this offset has been achieved by the use of waste based materials like Fly Ash and GGBS. These pozzolanic materials are becoming increasingly scarce and expensive limiting the expansion of these low carbon alternatives. A number of new waste derived materials have been identified for use as Geopolymer feedstocks including historic slags, dredgings, bottom ashes, waste clays and mine tailings. This paper reviews these alternative waste based feedstocks and their role within a circular economy. The chemical composition and properties of these materials, as well as the factors that affect the performance of geopolymer cements made from them are compared. Key factors are shown to be the Si and Al presence and ratio and the availibility of alkaline cations (Na+, K+, Ca+2). A number of deterious componets common in these alternative wastes are identified including presence of organic matter and chlorides. A case study evaluating the use of treated municipal soil waste from construction sites is presented utilising filter cake produced in Teesside (UK). A digital Taguchi design matrix was established to identify significant variables in the final geopolymer UCS, this included soil chemistry, water content and alkali components. The maximum UCS recorded across all geopolymer mixtures was 25 MPa. The paper concludes that alternative, circular waste based feedstocks have the potential to be used to produce high-performance geopolymer cements. However, further research is needed to pre-treat these materials and to develop cost-effective, consistent and scalable production methods.
Circular Approaches for Waste Based Geopolymer Feedstocks
Geopolymer cements exhibit high-strength properties while producing ~60% lower CO2 emissions compared with Portland cement manufacture. Much of this offset has been achieved by the use of waste based materials like Fly Ash and GGBS. These pozzolanic materials are becoming increasingly scarce and expensive limiting the expansion of these low carbon alternatives. A number of new waste derived materials have been identified for use as Geopolymer feedstocks including historic slags, dredgings, bottom ashes, waste clays and mine tailings. This paper reviews these alternative waste based feedstocks and their role within a circular economy. The chemical composition and properties of these materials, as well as the factors that affect the performance of geopolymer cements made from them are compared. Key factors are shown to be the Si and Al presence and ratio and the availibility of alkaline cations (Na+, K+, Ca+2). A number of deterious componets common in these alternative wastes are identified including presence of organic matter and chlorides. A case study evaluating the use of treated municipal soil waste from construction sites is presented utilising filter cake produced in Teesside (UK). A digital Taguchi design matrix was established to identify significant variables in the final geopolymer UCS, this included soil chemistry, water content and alkali components. The maximum UCS recorded across all geopolymer mixtures was 25 MPa. The paper concludes that alternative, circular waste based feedstocks have the potential to be used to produce high-performance geopolymer cements. However, further research is needed to pre-treat these materials and to develop cost-effective, consistent and scalable production methods.
Circular Approaches for Waste Based Geopolymer Feedstocks
Hughes, David (author)
2023-11-30
Hughes , D 2023 , ' Circular Approaches for Waste Based Geopolymer Feedstocks ' , International Conference on Ceramics and Geomaterials in Central Africa , Yaoundé , Cameroon , 28/11/23 - 1/12/23 pp. 12 . < https://www.cacers.org/wp-content/uploads/sites/13/2023/11/Book4-abstract-online-final.pdf >
Conference paper
Electronic Resource
English
DDC:
690
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