The physical-mechanical,chemical,and durability characteristics of alkali-activated materials(AAMs)have been widely investigated.However,a critical gap in the literature is the lack of a comprehensive overview of rece...The physical-mechanical,chemical,and durability characteristics of alkali-activated materials(AAMs)have been widely investigated.However,a critical gap in the literature is the lack of a comprehensive overview of recently published literature regarding the life cycle assessment(LCA)of these binders.This study aims to fill that gap by conducting a systematic literature review of globally published literature on the topic.This paper consolidates knowledge by searching different databases,focusing on LCA studies that used AAMs as pastes,mortars,concretes,bricks,and rammed earth/soil blocks.The selected articles were reviewed and categorized based on precursors,alkaline activators,functional units,system boundaries,life cycle inventory databases,allocation,impact methodologies,and software used.Additionally,this paper also critically analyzes the key challenges of LCA for AAMs.The major challenges were identified as selecting a functional unit,subjectivity in boundary systems,and data interpretation.This work concludes that AAMs show substantial advantages in global warming potential compared to ordinary Portland cement-based materials;however,the average of other categories such as marine ecotoxicity and ozone layer depletion has been reported to be higher than for the reference samples.展开更多
Geopolymers are inorganic adhesive synthesized from industrial waste such as fly ash thus the development of wood geopolymer composite would be a low carbon footprint material.Geopolymers,being a non-formaldehyde adhe...Geopolymers are inorganic adhesive synthesized from industrial waste such as fly ash thus the development of wood geopolymer composite would be a low carbon footprint material.Geopolymers,being a non-formaldehyde adhesive can be used as an alternative binder for wood based composites where environmentally friendly and sustainability of product is important.In this study flyash as precursor is been used in the development of wood geopolymer composite product.Flyash is activated with a combination of sodium hydroxide and sodium silicate solutions at a weight ratio of 1:2.5 for geopolymer formation.The study investigated the properties of wood geopolymer composite made with ratios of wood particle to flyash percentage(23/77),(37/62),(44/55),(50/50)and(57/43).Geopolymer formation was observed by X-ray Diffraction(XRD)and Fourier transform infrared spectroscopy(FTIR).Influence of wood particles in wood geopolymer composite were observed by Scanning electron microscope.The study shows that the water absorption and thickness selling properties of all the formulations of wood geopolymer composites are comparable with the medium density particle board and cement-bonded particleboard according to the IS:3087-2005 standard and IS:12406:respectively.Highest mechanical properties and good bond strength was obtained by the composite containing 23%wood particle ratio with 77%percent flyash.However,still improvement in mechanical properties is needed to achieve the mechanical properties comparable to cement bonded particle board.展开更多
基金supported by the Alexander von Humboldt Foundation,International Climate Protection Fellowship(Ref 3.5—1157991-IRN-IKS)This financial support is gratefully appreciated by Morteza Nikravan.Rafia Firdous and Dietmar Stephan highly acknowledge Bundesministerium fur Wirtschaft und Energie(BMWi)for funding number 16KN046744.
文摘The physical-mechanical,chemical,and durability characteristics of alkali-activated materials(AAMs)have been widely investigated.However,a critical gap in the literature is the lack of a comprehensive overview of recently published literature regarding the life cycle assessment(LCA)of these binders.This study aims to fill that gap by conducting a systematic literature review of globally published literature on the topic.This paper consolidates knowledge by searching different databases,focusing on LCA studies that used AAMs as pastes,mortars,concretes,bricks,and rammed earth/soil blocks.The selected articles were reviewed and categorized based on precursors,alkaline activators,functional units,system boundaries,life cycle inventory databases,allocation,impact methodologies,and software used.Additionally,this paper also critically analyzes the key challenges of LCA for AAMs.The major challenges were identified as selecting a functional unit,subjectivity in boundary systems,and data interpretation.This work concludes that AAMs show substantial advantages in global warming potential compared to ordinary Portland cement-based materials;however,the average of other categories such as marine ecotoxicity and ozone layer depletion has been reported to be higher than for the reference samples.
基金We thank Indian plywood Industries research and training Institute,an autonomous body of Ministry of environment forest and climate change funded this research project.I thank my co-authors for helping me in the study,analysis,and interpretation of data and in writing the manuscript should be declared.
文摘Geopolymers are inorganic adhesive synthesized from industrial waste such as fly ash thus the development of wood geopolymer composite would be a low carbon footprint material.Geopolymers,being a non-formaldehyde adhesive can be used as an alternative binder for wood based composites where environmentally friendly and sustainability of product is important.In this study flyash as precursor is been used in the development of wood geopolymer composite product.Flyash is activated with a combination of sodium hydroxide and sodium silicate solutions at a weight ratio of 1:2.5 for geopolymer formation.The study investigated the properties of wood geopolymer composite made with ratios of wood particle to flyash percentage(23/77),(37/62),(44/55),(50/50)and(57/43).Geopolymer formation was observed by X-ray Diffraction(XRD)and Fourier transform infrared spectroscopy(FTIR).Influence of wood particles in wood geopolymer composite were observed by Scanning electron microscope.The study shows that the water absorption and thickness selling properties of all the formulations of wood geopolymer composites are comparable with the medium density particle board and cement-bonded particleboard according to the IS:3087-2005 standard and IS:12406:respectively.Highest mechanical properties and good bond strength was obtained by the composite containing 23%wood particle ratio with 77%percent flyash.However,still improvement in mechanical properties is needed to achieve the mechanical properties comparable to cement bonded particle board.
