Pub Date : 2023-01-31DOI: 10.21809/rilemtechlett.2022.166
Tongren Zhu, M. Juenger, O. Isgor, L. Katz
Strategic blending of supplementary cementitious materials (SCMs) into ordinary portland cement (OPC) helps reduce energy use and greenhouse gas emissions from concrete production. Expanding thermodynamic databases to include new reaction products from blended cements improves computational approaches used to understand the impact of blending SCMs with cement. Determination of thermodynamic parameters of cement reaction products based on temperature-dependent solubility is widely used in cement research; however, assumptions, limitations, and potential errors due to intercorrelation of the thermodynamic parameters in these calculation methods are rarely discussed. Here, methods for obtaining thermodynamic parameters are critically reviewed, including discussion of experimental validation. The discussion herein provides useful guidance to improve and validate the process of determining thermodynamic parameters of new reaction products from SCM-OPC reactions.
{"title":"Methods of incorporation of new reaction products in thermodynamic databases of cementitious systems","authors":"Tongren Zhu, M. Juenger, O. Isgor, L. Katz","doi":"10.21809/rilemtechlett.2022.166","DOIUrl":"https://doi.org/10.21809/rilemtechlett.2022.166","url":null,"abstract":"Strategic blending of supplementary cementitious materials (SCMs) into ordinary portland cement (OPC) helps reduce energy use and greenhouse gas emissions from concrete production. Expanding thermodynamic databases to include new reaction products from blended cements improves computational approaches used to understand the impact of blending SCMs with cement. Determination of thermodynamic parameters of cement reaction products based on temperature-dependent solubility is widely used in cement research; however, assumptions, limitations, and potential errors due to intercorrelation of the thermodynamic parameters in these calculation methods are rarely discussed. Here, methods for obtaining thermodynamic parameters are critically reviewed, including discussion of experimental validation. The discussion herein provides useful guidance to improve and validate the process of determining thermodynamic parameters of new reaction products from SCM-OPC reactions.","PeriodicalId":36420,"journal":{"name":"RILEM Technical Letters","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47415124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-30DOI: 10.21809/rilemtechlett.2022.174
Sangmin Lee, J. Popovics
The characterization of in-place material properties is important for quality control and condition assessment of the built infrastructure. Although various methods have been developed to characterize structural materials in situ, many suffer limitations and cannot provide complete or desired characterization, especially for inhomogeneous and complex materials such as concrete and rock. Recent advances in machine learning and artificial neural networks (ANN) can help address these limitations. In particular, physics-informed neural networks (PINN) portend notable advantages over traditional physics-based or purely data-driven approaches. PINN is a particular form of ANN, where physics-based equations are embedded within an ANN structure in order to regularize the outputs during the training process. This paper reviews the fundamentals of PINN, notes its differences from traditional ANN, and reviews applications of PINN for selected material characterization tasks. A specific application example is presented where mechanical wave propagation data are used to characterize in-place material properties. Ultrasonic data are obtained from experiments on long rod-shaped mortar and glass samples; PINN is applied to these data to extract inhomogeneous wave velocity data, which can indicate mechanical material property variations with respect to length.
{"title":"Applications of physics-informed neural networks for property characterization of complex materials","authors":"Sangmin Lee, J. Popovics","doi":"10.21809/rilemtechlett.2022.174","DOIUrl":"https://doi.org/10.21809/rilemtechlett.2022.174","url":null,"abstract":"The characterization of in-place material properties is important for quality control and condition assessment of the built infrastructure. Although various methods have been developed to characterize structural materials in situ, many suffer limitations and cannot provide complete or desired characterization, especially for inhomogeneous and complex materials such as concrete and rock. Recent advances in machine learning and artificial neural networks (ANN) can help address these limitations. In particular, physics-informed neural networks (PINN) portend notable advantages over traditional physics-based or purely data-driven approaches. PINN is a particular form of ANN, where physics-based equations are embedded within an ANN structure in order to regularize the outputs during the training process. This paper reviews the fundamentals of PINN, notes its differences from traditional ANN, and reviews applications of PINN for selected material characterization tasks. A specific application example is presented where mechanical wave propagation data are used to characterize in-place material properties. Ultrasonic data are obtained from experiments on long rod-shaped mortar and glass samples; PINN is applied to these data to extract inhomogeneous wave velocity data, which can indicate mechanical material property variations with respect to length.","PeriodicalId":36420,"journal":{"name":"RILEM Technical Letters","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46475439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-12DOI: 10.21809/rilemtechlett.2022.160
L. Rossi, Luiz Miranda de Lima, Yubo Sun, F. Dehn, J. Provis, G. Ye, G. de Schutter
The production of cement and concrete contributes significantly to global greenhouse gas emissions. Alkali-activated concretes (AACs) are a family of existing alternative construction materials that could reduce the current environmental impact of Portland cement (PC) production and utilisation. Successful applications of AACs can be found in Europe and the former USSR since the 1950s and more recently in Australia, China and North America, proving their potential as construction materials. However, their utilisation is limited presently by the lack of normative and construction guidelines. Raw materials’ non-uniform global availability and variable intrinsic properties, coupled with the lack of specific testing methods, raise questions regarding reproducibility and reliability. The mechanical and chemical behaviour of AACs has been investigated extensively over the past decades, strengthening its potential as a sustainable substitute for traditional PC-based concrete. Although a wide amount of studies demonstrated that AACs could meet and even exceed the performance requirements provided by European design standards, a classification of these broad spectra of materials, as well as new analytical models linking the chemistry of the system components to the mechanical behaviour of the material, still need further development. This report gives an overview of the potential of alkali-activated systems technology, focusing on the limitations and challenges still hindering their standardisation and wider application in the construction field.
{"title":"Future perspectives for alkali-activated materials: from existing standards to structural applications","authors":"L. Rossi, Luiz Miranda de Lima, Yubo Sun, F. Dehn, J. Provis, G. Ye, G. de Schutter","doi":"10.21809/rilemtechlett.2022.160","DOIUrl":"https://doi.org/10.21809/rilemtechlett.2022.160","url":null,"abstract":"The production of cement and concrete contributes significantly to global greenhouse gas emissions. Alkali-activated concretes (AACs) are a family of existing alternative construction materials that could reduce the current environmental impact of Portland cement (PC) production and utilisation. Successful applications of AACs can be found in Europe and the former USSR since the 1950s and more recently in Australia, China and North America, proving their potential as construction materials. However, their utilisation is limited presently by the lack of normative and construction guidelines. Raw materials’ non-uniform global availability and variable intrinsic properties, coupled with the lack of specific testing methods, raise questions regarding reproducibility and reliability. The mechanical and chemical behaviour of AACs has been investigated extensively over the past decades, strengthening its potential as a sustainable substitute for traditional PC-based concrete. Although a wide amount of studies demonstrated that AACs could meet and even exceed the performance requirements provided by European design standards, a classification of these broad spectra of materials, as well as new analytical models linking the chemistry of the system components to the mechanical behaviour of the material, still need further development. This report gives an overview of the potential of alkali-activated systems technology, focusing on the limitations and challenges still hindering their standardisation and wider application in the construction field.","PeriodicalId":36420,"journal":{"name":"RILEM Technical Letters","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41476064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-27DOI: 10.21809/rilemtechlett.2022.167
A. Hamdan, Taehwan Kim, A. Hajimohammadi
The effects of chemical oxides and the surface area (SA) of slags on the initial reactivity of alkali-activated materials (AAMs) are coupled. It is well known that the reactivity of slag in AAMs is impacted by the SA, however, a quantitative measure of this effect was not provided in previous studies. For a proper understanding of the effect of slag chemistry on the reaction kinetics of AAMs, a quantitative description of the slags SA's effect is required. The reaction kinetics in the activated slags were monitored using isothermal calorimetry. The SAs of the pulverised slags were linked to the time-to-reach-the-main-peak (TTRP) of the reaction, the slope of the acceleration part of the main peak, and the total heat at one, three, and seven days. A 100% relative increase in SA caused a ~51%-75% relative decrease in TTRP. The slope of the acceleration stage also considerably increased with the SA of the slags. However, the effect of the SAs on the total heat was only distinct up to three days and then considerably reduced at seven days. The result of this study indicates that the effect of SA on the initial reactivity of AAMs cannot be simply considered using the proportional contribution. The outcome of this study can provide a promising measure to decouple the effects of SAs and the chemical compositions of slags on the reaction kinetics of AAMs by providing quantitative results for the effect SAs.
{"title":"Quantitative description of the effect of slag surface area on its reaction kinetics in sodium silicate-activated materials","authors":"A. Hamdan, Taehwan Kim, A. Hajimohammadi","doi":"10.21809/rilemtechlett.2022.167","DOIUrl":"https://doi.org/10.21809/rilemtechlett.2022.167","url":null,"abstract":"The effects of chemical oxides and the surface area (SA) of slags on the initial reactivity of alkali-activated materials (AAMs) are coupled. It is well known that the reactivity of slag in AAMs is impacted by the SA, however, a quantitative measure of this effect was not provided in previous studies. For a proper understanding of the effect of slag chemistry on the reaction kinetics of AAMs, a quantitative description of the slags SA's effect is required. The reaction kinetics in the activated slags were monitored using isothermal calorimetry. The SAs of the pulverised slags were linked to the time-to-reach-the-main-peak (TTRP) of the reaction, the slope of the acceleration part of the main peak, and the total heat at one, three, and seven days. A 100% relative increase in SA caused a ~51%-75% relative decrease in TTRP. The slope of the acceleration stage also considerably increased with the SA of the slags. However, the effect of the SAs on the total heat was only distinct up to three days and then considerably reduced at seven days. The result of this study indicates that the effect of SA on the initial reactivity of AAMs cannot be simply considered using the proportional contribution. The outcome of this study can provide a promising measure to decouple the effects of SAs and the chemical compositions of slags on the reaction kinetics of AAMs by providing quantitative results for the effect SAs.","PeriodicalId":36420,"journal":{"name":"RILEM Technical Letters","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41659937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-16DOI: 10.21809/rilemtechlett.2022.171
Viacheslav Troian, V. Gots, E. Keita, N. Roussel, U. Angst, R. Flatt
Besides the fact that concrete recycling allows to avoid landfills disposal and contributes to a closed-cycle economy, such option may be very much in demand in war struck regions such as Ukraine, which after the end of the war, are faced with the problem of rebuilding and reconstructing. Beyond this emergency, even in peacetime extensive parts of the building stock will sooner or later need to be replaced and concrete recycling is called to play an increasing role there. However, depending on the technology and degree to which aggregates are recycled, concrete may be characterized by poor workability, reduced mechanical properties, increased shrinkage and reduced durability. This deterioration in the properties of recycled concrete is usually attributed to the characteristics of the old cement mortar remaining on the surface of the recycled aggregates, which is best considered as an additional volume of hardened cement paste with fine aggregate and additional porosity. This article attempts to underline how such key concepts help frame the current state of knowledge about concrete recycling, understand the implications of existing regulations, in order to define pragmatic and efficient routes for broadening the use of concrete recycling in war struck regions, with specific examples regarding Ukraine.
{"title":"Challenges in material recycling for postwar reconstruction","authors":"Viacheslav Troian, V. Gots, E. Keita, N. Roussel, U. Angst, R. Flatt","doi":"10.21809/rilemtechlett.2022.171","DOIUrl":"https://doi.org/10.21809/rilemtechlett.2022.171","url":null,"abstract":"Besides the fact that concrete recycling allows to avoid landfills disposal and contributes to a closed-cycle economy, such option may be very much in demand in war struck regions such as Ukraine, which after the end of the war, are faced with the problem of rebuilding and reconstructing. Beyond this emergency, even in peacetime extensive parts of the building stock will sooner or later need to be replaced and concrete recycling is called to play an increasing role there.\u0000However, depending on the technology and degree to which aggregates are recycled, concrete may be characterized by poor workability, reduced mechanical properties, increased shrinkage and reduced durability. This deterioration in the properties of recycled concrete is usually attributed to the characteristics of the old cement mortar remaining on the surface of the recycled aggregates, which is best considered as an additional volume of hardened cement paste with fine aggregate and additional porosity. This article attempts to underline how such key concepts help frame the current state of knowledge about concrete recycling, understand the implications of existing regulations, in order to define pragmatic and efficient routes for broadening the use of concrete recycling in war struck regions, with specific examples regarding Ukraine.","PeriodicalId":36420,"journal":{"name":"RILEM Technical Letters","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44429296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-07DOI: 10.21809/rilemtechlett.2022.169
M. Sonebi, A. Abdalqader, S. Amziane, L. Dvorkin, E. Ghorbel, S. Kenai, J. Khatib, N. Lushnikova, A. Perrot
In recent decades, most of construction activities have been taking place in developing countries such as the Middle East and North Africa region. The expansion in infrastructure has great impact in the technological, social, economic and environmental transformation of this region. Construction sector contribution to Gross Domestic Product (GDP) varies throughout the region and ranges between 2-10%. Currently, sustainable construction requires integrated and comprehensive sustainable design including careful choice of materials and methods. Materials that are locally available and require less energy to produce and transport would pave the way to more sustainable practices. Many countries in the region have realised the benefits of using local building materials on the economy, society and environment. This paper outlines the key trends and opportunities of using sustainable and affordable local building materials in the region to respond to the global climate change crisis and to promote more sustainable and environmentally friendly practices. The current practice of using various building materials such as bio-based materials, treated municipal solid waste incineration bottom ash (MSWI-BA), construction and demolition waste, gypsum-containing by-products (phosphorgypsum, FGD gypsum, borogypsum and others) and rammed earth will be reviewed. It is concluded that the use of these local building materials in construction activities would foster the development of the society. However, some of these materials are already developed and reached the implementation stage while most of them are still at R&D stage. Therefore, there is an urgent need for a comprehensive local and regional strategies to enhance the utilization of these materials.
{"title":"Trends and opportunities of using local sustainable building materials in the Middle East and North Africa region","authors":"M. Sonebi, A. Abdalqader, S. Amziane, L. Dvorkin, E. Ghorbel, S. Kenai, J. Khatib, N. Lushnikova, A. Perrot","doi":"10.21809/rilemtechlett.2022.169","DOIUrl":"https://doi.org/10.21809/rilemtechlett.2022.169","url":null,"abstract":"In recent decades, most of construction activities have been taking place in developing countries such as the Middle East and North Africa region. The expansion in infrastructure has great impact in the technological, social, economic and environmental transformation of this region. Construction sector contribution to Gross Domestic Product (GDP) varies throughout the region and ranges between 2-10%. Currently, sustainable construction requires integrated and comprehensive sustainable design including careful choice of materials and methods. Materials that are locally available and require less energy to produce and transport would pave the way to more sustainable practices. Many countries in the region have realised the benefits of using local building materials on the economy, society and environment. This paper outlines the key trends and opportunities of using sustainable and affordable local building materials in the region to respond to the global climate change crisis and to promote more sustainable and environmentally friendly practices. The current practice of using various building materials such as bio-based materials, treated municipal solid waste incineration bottom ash (MSWI-BA), construction and demolition waste, gypsum-containing by-products (phosphorgypsum, FGD gypsum, borogypsum and others) and rammed earth will be reviewed. It is concluded that the use of these local building materials in construction activities would foster the development of the society. However, some of these materials are already developed and reached the implementation stage while most of them are still at R&D stage. Therefore, there is an urgent need for a comprehensive local and regional strategies to enhance the utilization of these materials.","PeriodicalId":36420,"journal":{"name":"RILEM Technical Letters","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45944209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-02DOI: 10.21809/rilemtechlett.2022.139
J. Kolawole, R. Combrinck, W. Boshoff
Understanding the plastic (settlement/shrinkage) cracking phenomena of early-age concrete is important in-order to establish a holistic approach to minimise its occurrence. One of the factors associated with early-age concrete is the rheo-related behaviour which occur simultaneously within the timeframe known for plastic cracking. It is therefore useful to establish their links to broaden the knowledge of plastic cracking. This study is a novel evaluation of the influence of rheo-physical and rheo-viscoelastic behaviour on the plastic cracking behaviour by systematically altering these behaviours of formulated concrete mixes and extensively characterising them. The theory and frameworks for linking the behaviours were presented and established via statistical and analytical approaches. Significant rheo-related parameters found to influence plastic cracking phenomena include yield stress, structuration, creep and stress relaxation. The rheo-mechanics modelling suggests that the plastic cracking initiation tends to be a ductile failure that is pressure insensitive and sufficiently represented by von Mises criteria. This study opens up a consciousness to start evaluating mitigation strategies directed towards the materials optimisation of concrete mixtures to minimise the occurrence of plastic cracking in early-age concrete.
{"title":"Understanding the role of rheology in the plastic settlement and shrinkage cracking of early age concrete","authors":"J. Kolawole, R. Combrinck, W. Boshoff","doi":"10.21809/rilemtechlett.2022.139","DOIUrl":"https://doi.org/10.21809/rilemtechlett.2022.139","url":null,"abstract":"Understanding the plastic (settlement/shrinkage) cracking phenomena of early-age concrete is important in-order to establish a holistic approach to minimise its occurrence. One of the factors associated with early-age concrete is the rheo-related behaviour which occur simultaneously within the timeframe known for plastic cracking. It is therefore useful to establish their links to broaden the knowledge of plastic cracking. This study is a novel evaluation of the influence of rheo-physical and rheo-viscoelastic behaviour on the plastic cracking behaviour by systematically altering these behaviours of formulated concrete mixes and extensively characterising them. The theory and frameworks for linking the behaviours were presented and established via statistical and analytical approaches. Significant rheo-related parameters found to influence plastic cracking phenomena include yield stress, structuration, creep and stress relaxation. The rheo-mechanics modelling suggests that the plastic cracking initiation tends to be a ductile failure that is pressure insensitive and sufficiently represented by von Mises criteria. This study opens up a consciousness to start evaluating mitigation strategies directed towards the materials optimisation of concrete mixtures to minimise the occurrence of plastic cracking in early-age concrete.","PeriodicalId":36420,"journal":{"name":"RILEM Technical Letters","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42239285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-28DOI: 10.21809/rilemtechlett.2022.158
Qing-feng Liu
Concrete durability degradation problems have received considerable attention in both research field and concrete industry during recent decades. To better understand the underlying mechanisms, various numerical models have been put forward aiming at widely concerned scientific issues involved in the entire life cycle of concrete structures: ionic transport in porous medium, degradations induced by multiple factors, as well as the prediction and rehabilitation method to prolong the service life. This letter aims to summarise the major contributions to these interrelated scientific issues particularly from the modelling perspective. The digital characterization of concrete heterogeneity and its influence on ionic transport behaviour will be firstly reviewed. Subsequently, concrete deterioration mechanisms induced by various factors and their internal coupling relationships are discussed in details. Meanwhile, promising electrochemical repair techniques with multi-fold advantages including chloride removal, corrosion inhibition, ASR mitigation and crack repair are systematically summarized. Finally, existing research gaps and future opportunities in these areas have also been visited, which is hoped to break the ice in this challenging field and promote the sustainable development of the concrete industry.
{"title":"Progress and research challenges in concrete durability: ionic transport, electrochemical rehabilitation and service life prediction","authors":"Qing-feng Liu","doi":"10.21809/rilemtechlett.2022.158","DOIUrl":"https://doi.org/10.21809/rilemtechlett.2022.158","url":null,"abstract":"Concrete durability degradation problems have received considerable attention in both research field and concrete industry during recent decades. To better understand the underlying mechanisms, various numerical models have been put forward aiming at widely concerned scientific issues involved in the entire life cycle of concrete structures: ionic transport in porous medium, degradations induced by multiple factors, as well as the prediction and rehabilitation method to prolong the service life. This letter aims to summarise the major contributions to these interrelated scientific issues particularly from the modelling perspective. The digital characterization of concrete heterogeneity and its influence on ionic transport behaviour will be firstly reviewed. Subsequently, concrete deterioration mechanisms induced by various factors and their internal coupling relationships are discussed in details. Meanwhile, promising electrochemical repair techniques with multi-fold advantages including chloride removal, corrosion inhibition, ASR mitigation and crack repair are systematically summarized. Finally, existing research gaps and future opportunities in these areas have also been visited, which is hoped to break the ice in this challenging field and promote the sustainable development of the concrete industry.","PeriodicalId":36420,"journal":{"name":"RILEM Technical Letters","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44526633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-14DOI: 10.21809/rilemtechlett.2022.164
Atolo Tuinukuafe, K. S. T. Chopperla, J. Weiss, J. Ideker, B. Isgor
Ex-situ leaching (ESL) methods have typically yielded higher sodium and potassium concentrations than pore solutions obtained using the conventional high-pressure extraction approach since ESL concentrations require a back-calculation to account for dilution. This paper proposes a new method for adjusting the concentrations obtained from ESL. Thermodynamic calculations were used to determine the total pore solution content, and a pore partitioning model was then used to separate the total solution into gel and capillary assignments. Using the refined pore solution volumes to adjust the concentrations from ESL improved the correlation to PSE concentrations.
{"title":"Estimating Na+ and K+ concentrations of the pore solution based on ex-situ leaching tests and thermodynamic modeling","authors":"Atolo Tuinukuafe, K. S. T. Chopperla, J. Weiss, J. Ideker, B. Isgor","doi":"10.21809/rilemtechlett.2022.164","DOIUrl":"https://doi.org/10.21809/rilemtechlett.2022.164","url":null,"abstract":"Ex-situ leaching (ESL) methods have typically yielded higher sodium and potassium concentrations than pore solutions obtained using the conventional high-pressure extraction approach since ESL concentrations require a back-calculation to account for dilution. This paper proposes a new method for adjusting the concentrations obtained from ESL. Thermodynamic calculations were used to determine the total pore solution content, and a pore partitioning model was then used to separate the total solution into gel and capillary assignments. Using the refined pore solution volumes to adjust the concentrations from ESL improved the correlation to PSE concentrations.","PeriodicalId":36420,"journal":{"name":"RILEM Technical Letters","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68366562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-23DOI: 10.21809/rilemtechlett.2022.156
A. Tabaković
The global road network spans 64.3million km and is of huge significance for the social and economic development. The level of investment in road construction and maintenance is high, e.g. EU €44billion/year (2019), China €614.7billion/year (2019) and US €94billion/year (2019). Despite the level of investment, there has been minimal investment in the development of new asphalt technologies, particularly when compared with R&D investment in other industries, such as the automotive industry. Despite the limited investment, there have been some innovations in asphalt technology. For the past 20 years, researchers have developed bio-inspired asphalt technology, self-healing and bio-binders and have applied them to asphalt pavements. This research has emerged as a response to global warming and the need to reduce both carbon emissions and reliance on oil in asphalt technology. This paper charts the development of two bio-inspired technologies and considers their significance in relation to the need to reduce carbon emissions and oil dependence (in line with the UN strategic goals, specifically: SDG 9, 11 and 12). This paper considers the potential benefits of bio-inspired technologies and outlines the current barriers to their further development. This paper aims to begin a conversation with stakeholders on how to speed up the acceptance of bio-inspired asphalt technologies and their adoption in road design, construction and maintenance. Or is it the case that we have reached the end of the road for bio-inspired road construction materials?
{"title":"Is this the end of the road for bio-inspired road construction materials?","authors":"A. Tabaković","doi":"10.21809/rilemtechlett.2022.156","DOIUrl":"https://doi.org/10.21809/rilemtechlett.2022.156","url":null,"abstract":"The global road network spans 64.3million km and is of huge significance for the social and economic development. The level of investment in road construction and maintenance is high, e.g. EU €44billion/year (2019), China €614.7billion/year (2019) and US €94billion/year (2019). Despite the level of investment, there has been minimal investment in the development of new asphalt technologies, particularly when compared with R&D investment in other industries, such as the automotive industry.\u0000Despite the limited investment, there have been some innovations in asphalt technology. For the past 20 years, researchers have developed bio-inspired asphalt technology, self-healing and bio-binders and have applied them to asphalt pavements. This research has emerged as a response to global warming and the need to reduce both carbon emissions and reliance on oil in asphalt technology.\u0000This paper charts the development of two bio-inspired technologies and considers their significance in relation to the need to reduce carbon emissions and oil dependence (in line with the UN strategic goals, specifically: SDG 9, 11 and 12). This paper considers the potential benefits of bio-inspired technologies and outlines the current barriers to their further development. This paper aims to begin a conversation with stakeholders on how to speed up the acceptance of bio-inspired asphalt technologies and their adoption in road design, construction and maintenance. Or is it the case that we have reached the end of the road for bio-inspired road construction materials?","PeriodicalId":36420,"journal":{"name":"RILEM Technical Letters","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46112139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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