Concrete structures are subjected to shrinkage since the moment when the water makes contact with the cement. From that moment on, depending on the concrete composition and its curing conditions, chemical, autogenous and drying shrinkage might increase the risk of early-age cracking. Once a crack is formed, it may become the preferential path for the ingress of many aggressive agents inside the structure increasing the probability of damage due to corrosion, carbonation and other mechanisms.The use of superabsorbent polymers (SAPs) has been extensively studied to reduce the shrinkage cracking risk in mortar specimens by acting as internal curing agent to mitigate autogenous shrinkage. In this paper, a commercially available SAP was investigated as shrinkage reducing agentby means of internal curing in concrete specimens. The shrinkage of the concrete was monitored for 28 days with both a demountable mechanical strain gauge (DEMEC) and optical fiber sensors (SOFO).The SAP-containing concrete showed a complete mitigation of autogenous shrinkage during 28 days of measurement, for both methods. The SOFO sensors showed the occurrence of cracks after 7 days for the reference mixture, while for the SAP containing mixture, no crack was identified during the 28 days of measurements.
{"title":"Monitoring the Early-Age Shrinkage Cracking of Concrete with Superabsorbent Polymers by Means of Optical Fiber (SOFO) Sensors","authors":"J. R. T. Filho, D. Snoeck, N. Belie","doi":"10.23967/dbmc.2020.099","DOIUrl":"https://doi.org/10.23967/dbmc.2020.099","url":null,"abstract":"Concrete structures are subjected to shrinkage since the moment when the water makes contact with the cement. From that moment on, depending on the concrete composition and its curing conditions, chemical, autogenous and drying shrinkage might increase the risk of early-age cracking. Once a crack is formed, it may become the preferential path for the ingress of many aggressive agents inside the structure increasing the probability of damage due to corrosion, carbonation and other mechanisms.The use of superabsorbent polymers (SAPs) has been extensively studied to reduce the shrinkage cracking risk in mortar specimens by acting as internal curing agent to mitigate autogenous shrinkage. In this paper, a commercially available SAP was investigated as shrinkage reducing agentby means of internal curing in concrete specimens. The shrinkage of the concrete was monitored for 28 days with both a demountable mechanical strain gauge (DEMEC) and optical fiber sensors (SOFO).The SAP-containing concrete showed a complete mitigation of autogenous shrinkage during 28 days of measurement, for both methods. The SOFO sensors showed the occurrence of cracks after 7 days for the reference mixture, while for the SAP containing mixture, no crack was identified during the 28 days of measurements.","PeriodicalId":409611,"journal":{"name":"XV International Conference on Durability of Building Materials and Components. eBook of Proceedings","volume":"1944 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129132975","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}
. One of the design team’s tasks is assuring that their project has a low negative impact on the environment. This comes from regulations as well as expectations of direct benefits (reduction of operating cost, the project’s improved image in the eyes of the public, etc.). To fulfill this task, one needs to define criteria for assessing the design options. These are to correspond to the individual qualities of the project, and they should be significant and possible to assess. The paper, divided into two parts, presents a review of the literature concerning the criteria for the assessment of design solutions defined as "green" or “environmentally friendly”. Part I presented the method of the analysis and investigates into the number and type of criteria adopted in the sample of papers being the object of analysis. This part focuses on the ways of defining criteria values, weights, and methods of multicriteria assessment.
{"title":"Selecting Criteria for Assessing \"Environmentally-Friendly\" Material Options in Construction: Part I","authors":"R. Bucoń, A. Czarnigowska","doi":"10.23967/dbmc.2020.177","DOIUrl":"https://doi.org/10.23967/dbmc.2020.177","url":null,"abstract":". One of the design team’s tasks is assuring that their project has a low negative impact on the environment. This comes from regulations as well as expectations of direct benefits (reduction of operating cost, the project’s improved image in the eyes of the public, etc.). To fulfill this task, one needs to define criteria for assessing the design options. These are to correspond to the individual qualities of the project, and they should be significant and possible to assess. The paper, divided into two parts, presents a review of the literature concerning the criteria for the assessment of design solutions defined as \"green\" or “environmentally friendly”. Part I presented the method of the analysis and investigates into the number and type of criteria adopted in the sample of papers being the object of analysis. This part focuses on the ways of defining criteria values, weights, and methods of multicriteria assessment.","PeriodicalId":409611,"journal":{"name":"XV International Conference on Durability of Building Materials and Components. eBook of Proceedings","volume":"110 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134119776","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}
Durability in aggressive environments is an important factor to extend the service life of concrete and the use ternary blended cements (limestone filler + calcined clays) can contribute to this purpose. In sulfate environments, the effects of supplementary cementing materials depend on the concentration, Portland cement and the progress of hydration reactions. Low level of limestone filler replacement influences the stabilization of AFt due to formation of monocarboaluminate, but high replacement increases the effective w/c and the capillary porosity promoting sulfate penetration. The use of active pozzolans suppresses the sulfate attack by minimizing both ettringite and gypsum formation. It is generally assumed that curing prior to sulfate exposure should be extended to allow the development of the pozzolanic reaction and subsequent reduction of portlandite content, pore size structure refinement and permeability reduction. However, in most field applications, concretes exposed to sulfate attack are cast in situ and thus, these are exposed to sulfate since early ages. This paper evaluates the sulfate resistance of an illitic-calcined clay and limestone filler when the cement is exposed immediately to aggressive environments. In this paper, the external sulfate resistance of blended cements containing 30% replacement of limestone filler and/or calcined clay (C30F, C30CC and C15F15CC) are analysed. Two different calcined clays from Buenos Aires, Argentina were selected. Mortar prisms and cement paste cubes were fabricated and exposed to a sodium sulfate solution after 2 days. Comparison of sulfate resistance was based on the expansion, mass variation, visual appearance and compressive strength . Furthermore, the evolution of microstructure of blended cements exposed to sodium sulfate solution was characterized by XRD tests on the external surface and the core of cement-
{"title":"Sulfate Resistance of Blended Cements (Limestone Illite Calcined Clay) Exposed Without Previous Curing","authors":"A. Rossetti, T. Ikumi, I. Segura, E. Irassar","doi":"10.23967/dbmc.2020.224","DOIUrl":"https://doi.org/10.23967/dbmc.2020.224","url":null,"abstract":"Durability in aggressive environments is an important factor to extend the service life of concrete and the use ternary blended cements (limestone filler + calcined clays) can contribute to this purpose. In sulfate environments, the effects of supplementary cementing materials depend on the concentration, Portland cement and the progress of hydration reactions. Low level of limestone filler replacement influences the stabilization of AFt due to formation of monocarboaluminate, but high replacement increases the effective w/c and the capillary porosity promoting sulfate penetration. The use of active pozzolans suppresses the sulfate attack by minimizing both ettringite and gypsum formation. It is generally assumed that curing prior to sulfate exposure should be extended to allow the development of the pozzolanic reaction and subsequent reduction of portlandite content, pore size structure refinement and permeability reduction. However, in most field applications, concretes exposed to sulfate attack are cast in situ and thus, these are exposed to sulfate since early ages. This paper evaluates the sulfate resistance of an illitic-calcined clay and limestone filler when the cement is exposed immediately to aggressive environments. In this paper, the external sulfate resistance of blended cements containing 30% replacement of limestone filler and/or calcined clay (C30F, C30CC and C15F15CC) are analysed. Two different calcined clays from Buenos Aires, Argentina were selected. Mortar prisms and cement paste cubes were fabricated and exposed to a sodium sulfate solution after 2 days. Comparison of sulfate resistance was based on the expansion, mass variation, visual appearance and compressive strength . Furthermore, the evolution of microstructure of blended cements exposed to sodium sulfate solution was characterized by XRD tests on the external surface and the core of cement-","PeriodicalId":409611,"journal":{"name":"XV International Conference on Durability of Building Materials and Components. eBook of Proceedings","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131009146","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}
: Concrete is the main material used in the construction industry not only for the ability to produce infinite variety of shapes for precast forms and for its characteristics of high resistance to compression, but primarily for their low manufacturing cost. Nonetheless, the production by mixing cement, fine aggregate, coarse aggregate and water, using natural raw materials such as stone, sand and water, despite being plentiful, represent the consumption of millions of tons of natural resources. Thus, the continuous search for new solutions is fundamental in order to not only further lower the manufacturing costs of this essential component in construction, but also to seek alternative materials, those of origin in processes of sustainability.
{"title":"Viability of Production and Application of Concrete with Addition of Fibers of Polyethylene Terephthalate (PET) Bottles for Construction","authors":"E. Rodrigues","doi":"10.23967/dbmc.2020.169","DOIUrl":"https://doi.org/10.23967/dbmc.2020.169","url":null,"abstract":": Concrete is the main material used in the construction industry not only for the ability to produce infinite variety of shapes for precast forms and for its characteristics of high resistance to compression, but primarily for their low manufacturing cost. Nonetheless, the production by mixing cement, fine aggregate, coarse aggregate and water, using natural raw materials such as stone, sand and water, despite being plentiful, represent the consumption of millions of tons of natural resources. Thus, the continuous search for new solutions is fundamental in order to not only further lower the manufacturing costs of this essential component in construction, but also to seek alternative materials, those of origin in processes of sustainability.","PeriodicalId":409611,"journal":{"name":"XV International Conference on Durability of Building Materials and Components. eBook of Proceedings","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132633748","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}
Takato Ishida, R. Kitagaki, Hideaki Hagihara, Y. Elakneswaran
. Multi-scale analysis of photodegradation are conducted for pigmented coating containing acrylic urethane + TiO 2 pigment and for non-pigmented coating containing only acrylic urethane. We discuss the intrinsic differences in the photodegradation mechanism between the pigmented and non-pigmented coatings and the effect of the interface between the pigment and the binder. Photo-aging tests are conducted using artificial ultraviolet (UV) irradiation under conditions of 60 °C and dry atmosphere. The results of Fourier transform infrared spectroscopy (FTIR), solvent swelling experiments, ultrasonic measurements of elastic moduli
{"title":"Intrinsic Differences on the Photodegradation Mechanisms between Pigmented and Non-Pigmented Coatings Determined by Multi-Scale Analysis","authors":"Takato Ishida, R. Kitagaki, Hideaki Hagihara, Y. Elakneswaran","doi":"10.23967/dbmc.2020.087","DOIUrl":"https://doi.org/10.23967/dbmc.2020.087","url":null,"abstract":". Multi-scale analysis of photodegradation are conducted for pigmented coating containing acrylic urethane + TiO 2 pigment and for non-pigmented coating containing only acrylic urethane. We discuss the intrinsic differences in the photodegradation mechanism between the pigmented and non-pigmented coatings and the effect of the interface between the pigment and the binder. Photo-aging tests are conducted using artificial ultraviolet (UV) irradiation under conditions of 60 °C and dry atmosphere. The results of Fourier transform infrared spectroscopy (FTIR), solvent swelling experiments, ultrasonic measurements of elastic moduli","PeriodicalId":409611,"journal":{"name":"XV International Conference on Durability of Building Materials and Components. eBook of Proceedings","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130998664","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}
. Mould growth is a biodeterioration phenomenon that jeopardizes the integrity, functionality and durability of building envelopes. The performance to withstand biodeterioration depends on the critical hygrothermal conditions inside the envelope. These conditions are subject to the configuration of building envelopes, and climate exposure, accounting for both the outdoor weather and indoor environments' conditions. These critical conditions are likely to intensify in response to the changing climate, and hence, modification and adaptation of the envelopes' configuration will be required. An understanding of the implications of envelope configurations' choices is required to set up guidelines for forthcoming building envelope design. Parametric analyses are a potent source of insight to investigate how the input parameters influence the desired outcome. In light of this, a parametric analysis is carried out to investigate the performance of three building envelopes to withstand mould growth. The impact of climate change in the performance evaluation is accounted for by employing both historic and future climate change scenarios in which the global climate temperature change is forecast to be 3.5 o C. Input parameters related to the simulation of mould growth are also investigated. Recommendations to current building envelope design guidelines are drawn for the performance evaluation to withstand mould growth.
{"title":"Impact of Climate Change in Building Envelope Design: The Performance to Withstand Mould Growth","authors":"K. Gradeci, A. Nocente, N. Labonnote, P. Rüther","doi":"10.23967/dbmc.2020.173","DOIUrl":"https://doi.org/10.23967/dbmc.2020.173","url":null,"abstract":". Mould growth is a biodeterioration phenomenon that jeopardizes the integrity, functionality and durability of building envelopes. The performance to withstand biodeterioration depends on the critical hygrothermal conditions inside the envelope. These conditions are subject to the configuration of building envelopes, and climate exposure, accounting for both the outdoor weather and indoor environments' conditions. These critical conditions are likely to intensify in response to the changing climate, and hence, modification and adaptation of the envelopes' configuration will be required. An understanding of the implications of envelope configurations' choices is required to set up guidelines for forthcoming building envelope design. Parametric analyses are a potent source of insight to investigate how the input parameters influence the desired outcome. In light of this, a parametric analysis is carried out to investigate the performance of three building envelopes to withstand mould growth. The impact of climate change in the performance evaluation is accounted for by employing both historic and future climate change scenarios in which the global climate temperature change is forecast to be 3.5 o C. Input parameters related to the simulation of mould growth are also investigated. Recommendations to current building envelope design guidelines are drawn for the performance evaluation to withstand mould growth.","PeriodicalId":409611,"journal":{"name":"XV International Conference on Durability of Building Materials and Components. eBook of Proceedings","volume":"125 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131320518","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}
P. Perumal, Tirthankar Paul, T. Luukkonen, J. Röning, P. Kinnunen, M. Illikainen
. The main aim of the work is to study the effect of different fibres (steel, glass and basalt) on resistance of blast furnace slag-based alkali-activated mortar in acidic environment. The alkali-activated slag mortars were exposed to 5% sulfuric and acetic acid solutions for 30 days. Mass change, compressive strength and microstructural changes were evaluated. In plain mortar, it was observed that 70% of the strength was retained in acetic acid environment whereas only 20% of residual strength remains in sulphuric acid environment. FTIR spectroscopy shows the degradation of the matrix, which implies the alkali-activated mortar was more vulnerable in sulphuric acid environment due to its aggressive nature compared to acetic acid. Decalcification and formation of calcium acetate also hinders the further progress of damage in acetic acid attack. Fibres helped in improving the performance of the mortar by holding the matrix together when the degradation occurred in acidic environment. Compared to plain mortar, incorporation of steel fibres exhibited a maximum strength retention of 19% in acetic acid and 7% in sulphuric acid, followed by glass and basalt fibres. SEM images clearly show the debonding of fibres and disintegration of matrix in acidic environment, which resulted in strength loss.
{"title":"Performance of Fibre-Reinforced Slag-Based Alkali Activated Mortar in Acidic Environment","authors":"P. Perumal, Tirthankar Paul, T. Luukkonen, J. Röning, P. Kinnunen, M. Illikainen","doi":"10.23967/dbmc.2020.109","DOIUrl":"https://doi.org/10.23967/dbmc.2020.109","url":null,"abstract":". The main aim of the work is to study the effect of different fibres (steel, glass and basalt) on resistance of blast furnace slag-based alkali-activated mortar in acidic environment. The alkali-activated slag mortars were exposed to 5% sulfuric and acetic acid solutions for 30 days. Mass change, compressive strength and microstructural changes were evaluated. In plain mortar, it was observed that 70% of the strength was retained in acetic acid environment whereas only 20% of residual strength remains in sulphuric acid environment. FTIR spectroscopy shows the degradation of the matrix, which implies the alkali-activated mortar was more vulnerable in sulphuric acid environment due to its aggressive nature compared to acetic acid. Decalcification and formation of calcium acetate also hinders the further progress of damage in acetic acid attack. Fibres helped in improving the performance of the mortar by holding the matrix together when the degradation occurred in acidic environment. Compared to plain mortar, incorporation of steel fibres exhibited a maximum strength retention of 19% in acetic acid and 7% in sulphuric acid, followed by glass and basalt fibres. SEM images clearly show the debonding of fibres and disintegration of matrix in acidic environment, which resulted in strength loss.","PeriodicalId":409611,"journal":{"name":"XV International Conference on Durability of Building Materials and Components. eBook of Proceedings","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125605772","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}
. The service life of buildings and components is extremely difficult to model and predict, mainly due to the uncertainty and variability associated with the degradation phenomena. These uncertainties are usually related with the intrinsic randomness of natural phenomena, such as the environmental degradation agents. In order to deal with these uncertainties, in this study, a stochastic approach is used, to model the service life of timber claddings. For this purpose, a logistic regression analysis is used to evaluate the probability of timber claddings to reach the end of their service life over time. Moreover, the impact of the environmental exposure conditions (e.g. facades orientation, distance from the ocean, exposure to damp and exposure to wind/rain action), which influence the degradation and service life of timber claddings, is also evaluated. The proposed models are applied to 150 timber claddings, located in Valdivia (South Chile), which have been analysed during an extensive fieldwork survey. The results obtained in this study aid the definition of maintenance plans, in a technically informed manner, in order to promote the conservation of these claddings, which are an important symbol of the local identity of this region, depicting a complexity of cultural values, inherited by Spanish and German colonisations.
{"title":"Probabilistic Approach to the Service Life Prediction of Timber Claddings","authors":"Ana Silva, A. J. Prieto","doi":"10.23967/dbmc.2020.114","DOIUrl":"https://doi.org/10.23967/dbmc.2020.114","url":null,"abstract":". The service life of buildings and components is extremely difficult to model and predict, mainly due to the uncertainty and variability associated with the degradation phenomena. These uncertainties are usually related with the intrinsic randomness of natural phenomena, such as the environmental degradation agents. In order to deal with these uncertainties, in this study, a stochastic approach is used, to model the service life of timber claddings. For this purpose, a logistic regression analysis is used to evaluate the probability of timber claddings to reach the end of their service life over time. Moreover, the impact of the environmental exposure conditions (e.g. facades orientation, distance from the ocean, exposure to damp and exposure to wind/rain action), which influence the degradation and service life of timber claddings, is also evaluated. The proposed models are applied to 150 timber claddings, located in Valdivia (South Chile), which have been analysed during an extensive fieldwork survey. The results obtained in this study aid the definition of maintenance plans, in a technically informed manner, in order to promote the conservation of these claddings, which are an important symbol of the local identity of this region, depicting a complexity of cultural values, inherited by Spanish and German colonisations.","PeriodicalId":409611,"journal":{"name":"XV International Conference on Durability of Building Materials and Components. eBook of Proceedings","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126561436","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}
Liselotte De Ligne, J. Bulcke, J. Baetens, B. Baets, J. Acker
Bio-based materials are gaining importance in the building industry, as the focus on sustainability and life-cycle-assessment has increased substantially over the last decade. Wood and wood-engineered products as well as insulation materials made from cellulose, wood, flax, hemp, etc. are increasingly used. These materials are made from renewable resources and with considerably lower energy consumption than various other building materials, such as insulation polymers, steel and concrete. As steel can corrode and concrete can rot, so can bio-based building materials degrade over time when exposed to those conditions that favour decay. Since fungi cause not only aesthetical degradation, but can also severely compromise the structural integrity of a building component this is critical for any service life approach. Consequently, a proper understanding of the fungal susceptibility of bio-based materials is needed, both for optimal application of bio-based materials as for the design of new materials. Based on a combination of tests we try to unravel the role of the material’s chemical components, structure and moisture dynamics on its fungal susceptibility, as well as the interaction between those material characteristics. In a first test set-up, the ‘paste test’, the material’s structure is removed and fungal growth is assessed over time in 2D, with only the material’s chemical components playing a role. In the second test set-up, the ‘X-ray CT test’, fungal development is assessed non-destructively in 3D with X-ray CT, giving an indication of moisture production and distribution over time, in relation to the material’s structure. By comparing the results, we have a better idea of how much each material characteristic influences fungal susceptibility. This knowledge can then be used for optimising fungal testing of bio-based materials, ensuring optimal application and providing the building industry with the confidence they need to pave the way to a more sustainable future.
{"title":"Bio-Based Building Materials-How to Unravel the Role of Material Characteristics on Fungal Susceptibility?","authors":"Liselotte De Ligne, J. Bulcke, J. Baetens, B. Baets, J. Acker","doi":"10.23967/dbmc.2020.195","DOIUrl":"https://doi.org/10.23967/dbmc.2020.195","url":null,"abstract":"Bio-based materials are gaining importance in the building industry, as the focus on sustainability and life-cycle-assessment has increased substantially over the last decade. Wood and wood-engineered products as well as insulation materials made from cellulose, wood, flax, hemp, etc. are increasingly used. These materials are made from renewable resources and with considerably lower energy consumption than various other building materials, such as insulation polymers, steel and concrete. As steel can corrode and concrete can rot, so can bio-based building materials degrade over time when exposed to those conditions that favour decay. Since fungi cause not only aesthetical degradation, but can also severely compromise the structural integrity of a building component this is critical for any service life approach. Consequently, a proper understanding of the fungal susceptibility of bio-based materials is needed, both for optimal application of bio-based materials as for the design of new materials. Based on a combination of tests we try to unravel the role of the material’s chemical components, structure and moisture dynamics on its fungal susceptibility, as well as the interaction between those material characteristics. In a first test set-up, the ‘paste test’, the material’s structure is removed and fungal growth is assessed over time in 2D, with only the material’s chemical components playing a role. In the second test set-up, the ‘X-ray CT test’, fungal development is assessed non-destructively in 3D with X-ray CT, giving an indication of moisture production and distribution over time, in relation to the material’s structure. By comparing the results, we have a better idea of how much each material characteristic influences fungal susceptibility. This knowledge can then be used for optimising fungal testing of bio-based materials, ensuring optimal application and providing the building industry with the confidence they need to pave the way to a more sustainable future.","PeriodicalId":409611,"journal":{"name":"XV International Conference on Durability of Building Materials and Components. eBook of Proceedings","volume":"434 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133466836","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}
. This study examined durability of mortar after repairing crack using alginate gel films (1.5 wt.%) mixed with healing agents under seawater splayed condition. The healing agents consist of Bacillus subtilis (natto) as an aerobic microorganism and glucose as an organic carbon source, thereby producing insoluble calcium carbonate in the gel films in the presence of calcium ions. In this study, repaired mortar was dried under room condition for half year and exposed at seawater splayed condition for another half year. After that, surface condition, elastic wave velocity was measured. In addition, the inside situation in the crack was observed by X ray computed tomography. Based on the results of elastic wave velocity, the property of repair material in mortar was improved under the seawater splayed condition. Additionally the substance in crack derived from healing agents was remained even after seawater splayed exposure.
{"title":"Effect of Crack Repair by Bio-Based Materials Using Alginate and Bacillus Subtilis under Wet and Dry Environment Part-II","authors":"T. Nishida, K. Kawaai, A. Saito","doi":"10.23967/dbmc.2020.053","DOIUrl":"https://doi.org/10.23967/dbmc.2020.053","url":null,"abstract":". This study examined durability of mortar after repairing crack using alginate gel films (1.5 wt.%) mixed with healing agents under seawater splayed condition. The healing agents consist of Bacillus subtilis (natto) as an aerobic microorganism and glucose as an organic carbon source, thereby producing insoluble calcium carbonate in the gel films in the presence of calcium ions. In this study, repaired mortar was dried under room condition for half year and exposed at seawater splayed condition for another half year. After that, surface condition, elastic wave velocity was measured. In addition, the inside situation in the crack was observed by X ray computed tomography. Based on the results of elastic wave velocity, the property of repair material in mortar was improved under the seawater splayed condition. Additionally the substance in crack derived from healing agents was remained even after seawater splayed exposure.","PeriodicalId":409611,"journal":{"name":"XV International Conference on Durability of Building Materials and Components. eBook of Proceedings","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124516752","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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