{"title":"Recycling Potential of Construction Materials: A Comparative Approach","authors":"Matan Mayer","doi":"10.3390/constrmater4010013","DOIUrl":"https://doi.org/10.3390/constrmater4010013","url":null,"abstract":"Recovery and re-utilization of materials are regarded as key strategies for reducing greenhouse gas emissions in the built environment. Within those end-of-use scenarios, recycling is one of the widely used tactics, demonstrated by established infrastructure and developed supply chain networks in many geographic locations. While recycling is an increasingly common practice in the built environment, accurately defining recycling quality in order to compare technologies and material types remains methodologically contested. This is mainly due to the vast spectrum of scenarios that typically fall under the term ‘recycling’. Remanufacturing, downcycling, upcycling, and even direct reuse are all referred to as types of recycling in non-scientific circles, depending on the sector they occur in. The main challenge in assessing the material recovery quality of those solutions is that they exist on a continuum without clear divisions. Within that context, this article presents and compares four methods for assessing recyclability. The featured methods measure recycling potential from different perspectives: economic dimensions of the recycling industry; patterns of resource depletion; the energy cost of recycling; and the carbon intensity of recovery processes. The scientific foundations of the four methods are presented and a range of widely used construction materials are tested. The performance of materials is then compared across the four assessment methods to note observations and gain insights. Some of the materials are found to consistently outperform others, whereas some materials perform well on one method while performing poorly on others. This comparative study is followed by a discussion that looks at the limitations of each approach and reasons, or lack thereof, for the adoption of one method over the others in industry and academia. Lastly, the article looks at future research trajectories and examines the path ahead for recycling in the construction industry.","PeriodicalId":514455,"journal":{"name":"Construction Materials","volume":"67 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139853806","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}
Anilé Ossorio Domínguez, Romildo Dias Toledo Filho, José Antônio da Cunha Ponciano Gomes, Ralph dos Santos Silva, E. A. de Souza, Adriana Barbosa da Silva
{"title":"Study of Reinforced Concrete with the Addition of Pozzolanic against the Penetration of Chlorides through Electrochemical Impedance Spectroscopy","authors":"Anilé Ossorio Domínguez, Romildo Dias Toledo Filho, José Antônio da Cunha Ponciano Gomes, Ralph dos Santos Silva, E. A. de Souza, Adriana Barbosa da Silva","doi":"10.3390/constrmater4010011","DOIUrl":"https://doi.org/10.3390/constrmater4010011","url":null,"abstract":"The present work analyzes the behavior in terms of corrosion resistance of three reinforced concrete formulations over a period of 1 year. The samples were subject to a monitoring methodology using the Electrochemical Impedance Spectroscopy (EIE) technique, working only with the real component over time. Three mixtures were used, one conventional without pozzolanic addition (REF) and two others with pozzolanic additions, rice husk ash (RHA) and metakaolin (MK). Prototypes were created and exposed to the action of a 165 g/L NaCl sodium chloride solution. The characterization of the materials was carried out by determining the chloride diffusion profile (ASTM 1556), analyzing images using tomography and with the support of analytical techniques such as X-ray fluorescence and X-ray diffraction. The monitoring methodology using EIE demonstrated the positive effect of the insertion of pozzolans, rice husk ash (RHA) and metakaolin (MK) in delaying the process of chloride diffusion in the concrete, resulting in greater resistance to corrosion. The EIE also showed that the active mineral addition in concrete, resulting in aluminum-silicic composition (MK), had a predominant protective effect on the steel/concrete interface against the attack of chloride ions.","PeriodicalId":514455,"journal":{"name":"Construction Materials","volume":"35 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139868907","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}
{"title":"Using Repeated Light-Weight Deflectometer Test Data to Predict Flexible Pavement Responses Based on the Mechanistic–Empirical Design Method","authors":"D. Kuttah","doi":"10.3390/constrmater4010012","DOIUrl":"https://doi.org/10.3390/constrmater4010012","url":null,"abstract":"This study investigated the potential of lightweight deflectometer (LWD) data in predicting layer moduli and response measurements within the Mechanistic–Empirical Pavement Design Guide. To achieve this goal, field repeated LWD tests and laboratory repeated load triaxial tests were carried out on granular base material compacted at 3% and 6% water content, sandy subgrade soil compacted at 3%, 4% and 9% water content and silty sand subgrade soil compacted at 8% and 10% water content. The results revealed that substituting traditional repeated load triaxial (RLT) data with LWD data for predicting these parameters was notably effective for cohesionless materials, especially for unbound granular materials (UGMs) compacted at optimum water content. The accuracy and reliability of predictions were remarkably high, showcasing the potential of LWD to enhance efficiency and precision in pavement design within this context. Conversely, for cohesive road materials, the study emphasized the importance of considering specific material properties and water content when integrating LWD into the Mechanistic–Empirical Pavement Design Guide. The distinctive characteristics and behaviors of cohesive materials necessitate a nuanced approach. This understanding is critical to ensuring the accuracy and reliability of pavement design and assessment across diverse conditions. In summary, the study presents a promising avenue for utilizing LWD data in cohesionless road materials, offering potential cost and time-saving advantages. Additionally, it underscores the necessity of tailored approaches when considering material properties and moisture content for cohesive materials, thereby advancing the field of pavement engineering by providing insights for improved practices and adaptable frameworks.","PeriodicalId":514455,"journal":{"name":"Construction Materials","volume":"14 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139809363","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}
Anilé Ossorio Domínguez, Romildo Dias Toledo Filho, José Antônio da Cunha Ponciano Gomes, Ralph dos Santos Silva, E. A. de Souza, Adriana Barbosa da Silva
{"title":"Study of Reinforced Concrete with the Addition of Pozzolanic against the Penetration of Chlorides through Electrochemical Impedance Spectroscopy","authors":"Anilé Ossorio Domínguez, Romildo Dias Toledo Filho, José Antônio da Cunha Ponciano Gomes, Ralph dos Santos Silva, E. A. de Souza, Adriana Barbosa da Silva","doi":"10.3390/constrmater4010011","DOIUrl":"https://doi.org/10.3390/constrmater4010011","url":null,"abstract":"The present work analyzes the behavior in terms of corrosion resistance of three reinforced concrete formulations over a period of 1 year. The samples were subject to a monitoring methodology using the Electrochemical Impedance Spectroscopy (EIE) technique, working only with the real component over time. Three mixtures were used, one conventional without pozzolanic addition (REF) and two others with pozzolanic additions, rice husk ash (RHA) and metakaolin (MK). Prototypes were created and exposed to the action of a 165 g/L NaCl sodium chloride solution. The characterization of the materials was carried out by determining the chloride diffusion profile (ASTM 1556), analyzing images using tomography and with the support of analytical techniques such as X-ray fluorescence and X-ray diffraction. The monitoring methodology using EIE demonstrated the positive effect of the insertion of pozzolans, rice husk ash (RHA) and metakaolin (MK) in delaying the process of chloride diffusion in the concrete, resulting in greater resistance to corrosion. The EIE also showed that the active mineral addition in concrete, resulting in aluminum-silicic composition (MK), had a predominant protective effect on the steel/concrete interface against the attack of chloride ions.","PeriodicalId":514455,"journal":{"name":"Construction Materials","volume":"58 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139808819","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}
{"title":"Using Repeated Light-Weight Deflectometer Test Data to Predict Flexible Pavement Responses Based on the Mechanistic–Empirical Design Method","authors":"D. Kuttah","doi":"10.3390/constrmater4010012","DOIUrl":"https://doi.org/10.3390/constrmater4010012","url":null,"abstract":"This study investigated the potential of lightweight deflectometer (LWD) data in predicting layer moduli and response measurements within the Mechanistic–Empirical Pavement Design Guide. To achieve this goal, field repeated LWD tests and laboratory repeated load triaxial tests were carried out on granular base material compacted at 3% and 6% water content, sandy subgrade soil compacted at 3%, 4% and 9% water content and silty sand subgrade soil compacted at 8% and 10% water content. The results revealed that substituting traditional repeated load triaxial (RLT) data with LWD data for predicting these parameters was notably effective for cohesionless materials, especially for unbound granular materials (UGMs) compacted at optimum water content. The accuracy and reliability of predictions were remarkably high, showcasing the potential of LWD to enhance efficiency and precision in pavement design within this context. Conversely, for cohesive road materials, the study emphasized the importance of considering specific material properties and water content when integrating LWD into the Mechanistic–Empirical Pavement Design Guide. The distinctive characteristics and behaviors of cohesive materials necessitate a nuanced approach. This understanding is critical to ensuring the accuracy and reliability of pavement design and assessment across diverse conditions. In summary, the study presents a promising avenue for utilizing LWD data in cohesionless road materials, offering potential cost and time-saving advantages. Additionally, it underscores the necessity of tailored approaches when considering material properties and moisture content for cohesive materials, thereby advancing the field of pavement engineering by providing insights for improved practices and adaptable frameworks.","PeriodicalId":514455,"journal":{"name":"Construction Materials","volume":"32 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139869064","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}
Vincent Claude, Stéphane Charron, Sébastien Hustin, Fabrice de Barquin
{"title":"Influence of the Addition of Carbon Fibres on Gypsum–PCM Mixtures","authors":"Vincent Claude, Stéphane Charron, Sébastien Hustin, Fabrice de Barquin","doi":"10.3390/constrmater4010009","DOIUrl":"https://doi.org/10.3390/constrmater4010009","url":null,"abstract":"This study investigated the influence of carbon fibre addition on the thermal performances of gypsum compositions doped with 20 wt % of phase-change material (PCM) microspheres. The influences of the length (150 µm/3 mm) and additive amount (0.5/2/4 wt %) of the carbon fibres were investigated. Characterizations were performed throughout the various preparation steps to check that the materials aligned with the construction standards. The consistency of compositions with 3 mm carbon fibres did not seem to be suitable for construction implementation. On the contrary, thanks to an adequate amount of thinning additive, the compositions with 150 µm carbon fibres showed acceptable implementation properties. The materials were tested in a climatic chamber under temperature cycles that were either favourable (15 °C/40 °C) or unfavourable (20 °C/40 °C) for the regeneration process of the PCM. Tests with a plateau at 40 °C/15 °C were also performed to obtain a better understanding of the thermal behaviours. The tests were performed using walls with thicknesses of either 15 mm or 30 mm. The results show that, in all cases, the addition of carbon fibres was not beneficial to the thermal performance of the PCM. These observations were in opposition to those of other studies in the literature. We hypothesized that the performances of these composite materials would be different under convective or conductive fluxes. It was also shown that, in unfavourable conditions (20 °C/40 °C), the large thickness of 30 mm could not be fully regenerated, even in the compositions with carbon fibres. However, the PCM of boxes with 15 mm thick walls was deactivated faster (after ~400 min) than that of those with 30 mm thick walls (after ~700 min). Finally, the laboratory results were compared with the results of a previous large-scale study. It was estimated that, despite a surface-to-volume ratio that was 25 times higher, the energy storage efficiency was only increased by a factor of 2.6 between our laboratory study and the large-scale study. Hence, the PCM storage process seems to be mainly involved in maintaining the temperature of the gypsum walls rather than the temperature of the air.","PeriodicalId":514455,"journal":{"name":"Construction Materials","volume":"39 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139882802","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}
D. Achillopoulou, Angeliki Kosta, N. K. Stamataki, A. Montalbano, F. Choffat
{"title":"Efficiency of CFRP Strengthening Measures for Reinforced Concrete Structural Members Using Toughened Epoxies","authors":"D. Achillopoulou, Angeliki Kosta, N. K. Stamataki, A. Montalbano, F. Choffat","doi":"10.3390/constrmater4010010","DOIUrl":"https://doi.org/10.3390/constrmater4010010","url":null,"abstract":"This paper aims to investigate the interface efficiency of Carbon Fiber Reinforced Polymers (CFRP) adhesively bonded on concrete, a commonly used retrofitting measure applied for enhancing the deformability and strength of decaying structures or existing ones with low capacity. The efficiency quantification is expressed with the Interface Capacity Index (IC). The index correlates the thickness and strength of each layer of the strengthening system and accounts for the transferred loads (ICL) and the strain distribution that causes the failure propagation on the concrete substrate (ICfp). The investigation focuses on different CFRP strengthening schemes (laminated fabrics, prefabricated plates, Near Surface Mounted bars-NSM) applied to concrete substrates using different adhesive layers. Two cases were studied for different levels of concrete’s integrity: (a) healthy and (b) containing corrosion products. The experimental results were used to calibrate the numerical models and to evaluate the effects of different strengthening strategies. The results show the tendency of the strengthening systems to shift the interface performance from fully elastic to non-linear. Further, the quantification of the efficiency of retrofitting can be addressed by accounting for the mechanical and geometrical properties at the interface level, representing different failure modes and integration levels.","PeriodicalId":514455,"journal":{"name":"Construction Materials","volume":"160 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139813069","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}
Vincent Claude, Stéphane Charron, Sébastien Hustin, Fabrice de Barquin
{"title":"Influence of the Addition of Carbon Fibres on Gypsum–PCM Mixtures","authors":"Vincent Claude, Stéphane Charron, Sébastien Hustin, Fabrice de Barquin","doi":"10.3390/constrmater4010009","DOIUrl":"https://doi.org/10.3390/constrmater4010009","url":null,"abstract":"This study investigated the influence of carbon fibre addition on the thermal performances of gypsum compositions doped with 20 wt % of phase-change material (PCM) microspheres. The influences of the length (150 µm/3 mm) and additive amount (0.5/2/4 wt %) of the carbon fibres were investigated. Characterizations were performed throughout the various preparation steps to check that the materials aligned with the construction standards. The consistency of compositions with 3 mm carbon fibres did not seem to be suitable for construction implementation. On the contrary, thanks to an adequate amount of thinning additive, the compositions with 150 µm carbon fibres showed acceptable implementation properties. The materials were tested in a climatic chamber under temperature cycles that were either favourable (15 °C/40 °C) or unfavourable (20 °C/40 °C) for the regeneration process of the PCM. Tests with a plateau at 40 °C/15 °C were also performed to obtain a better understanding of the thermal behaviours. The tests were performed using walls with thicknesses of either 15 mm or 30 mm. The results show that, in all cases, the addition of carbon fibres was not beneficial to the thermal performance of the PCM. These observations were in opposition to those of other studies in the literature. We hypothesized that the performances of these composite materials would be different under convective or conductive fluxes. It was also shown that, in unfavourable conditions (20 °C/40 °C), the large thickness of 30 mm could not be fully regenerated, even in the compositions with carbon fibres. However, the PCM of boxes with 15 mm thick walls was deactivated faster (after ~400 min) than that of those with 30 mm thick walls (after ~700 min). Finally, the laboratory results were compared with the results of a previous large-scale study. It was estimated that, despite a surface-to-volume ratio that was 25 times higher, the energy storage efficiency was only increased by a factor of 2.6 between our laboratory study and the large-scale study. Hence, the PCM storage process seems to be mainly involved in maintaining the temperature of the gypsum walls rather than the temperature of the air.","PeriodicalId":514455,"journal":{"name":"Construction Materials","volume":"44 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139823217","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}
D. Achillopoulou, Angeliki Kosta, N. K. Stamataki, A. Montalbano, F. Choffat
{"title":"Efficiency of CFRP Strengthening Measures for Reinforced Concrete Structural Members Using Toughened Epoxies","authors":"D. Achillopoulou, Angeliki Kosta, N. K. Stamataki, A. Montalbano, F. Choffat","doi":"10.3390/constrmater4010010","DOIUrl":"https://doi.org/10.3390/constrmater4010010","url":null,"abstract":"This paper aims to investigate the interface efficiency of Carbon Fiber Reinforced Polymers (CFRP) adhesively bonded on concrete, a commonly used retrofitting measure applied for enhancing the deformability and strength of decaying structures or existing ones with low capacity. The efficiency quantification is expressed with the Interface Capacity Index (IC). The index correlates the thickness and strength of each layer of the strengthening system and accounts for the transferred loads (ICL) and the strain distribution that causes the failure propagation on the concrete substrate (ICfp). The investigation focuses on different CFRP strengthening schemes (laminated fabrics, prefabricated plates, Near Surface Mounted bars-NSM) applied to concrete substrates using different adhesive layers. Two cases were studied for different levels of concrete’s integrity: (a) healthy and (b) containing corrosion products. The experimental results were used to calibrate the numerical models and to evaluate the effects of different strengthening strategies. The results show the tendency of the strengthening systems to shift the interface performance from fully elastic to non-linear. Further, the quantification of the efficiency of retrofitting can be addressed by accounting for the mechanical and geometrical properties at the interface level, representing different failure modes and integration levels.","PeriodicalId":514455,"journal":{"name":"Construction Materials","volume":"89 12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139872720","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}
Florian Gerland, Tim Vaupel, Thomas Schomberg, Olaf Wünsch
{"title":"Analysing the Influence of Fibers on Fresh Concrete Rheometry by the Use of Numerical Simulation","authors":"Florian Gerland, Tim Vaupel, Thomas Schomberg, Olaf Wünsch","doi":"10.3390/constrmater4010008","DOIUrl":"https://doi.org/10.3390/constrmater4010008","url":null,"abstract":"Measuring the flow properties of fiber-laden fresh concrete poses a substantial challenge because not only the fraction of fibers but also their orientation process during the measurement influence the measured quantities. Numerical simulations of the flow in a ball probe rheometer are used to determine the fiber orientation process during the measurement of the flow properties and its influence on the measured variables. Through analytical considerations and comparison with measurement results, it can be shown that the constitutive law applied can reproduce the real flow behavior very well, taking the fiber orientation into account. At the same time, it is investigated why no orientation influence on the torque is recognizable in the experimental measurement curves, although the orientation process demonstrably exceeds the duration of the measurement process. The results show that fluid inertia is overcome before the recognizable onset of fiber orientation, and the spatially inhomogeneous flow minimises the impact of the orientation process on torque. The simulation model aligns well with experimental outcomes, indicating a linear increase in effective viscosity with increasing fiber volume fraction. The findings can be used to accurately measure the objective material parameters of the orientation-considering constitutive law using ball probe rheometers, so that an accurate prediction of the flow process of fresh concrete with fibers is made possible, for example for the simulation of formwork fillings.","PeriodicalId":514455,"journal":{"name":"Construction Materials","volume":"65 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139596902","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}