Materials and Structures最新文献

Investigation of the influence of mixture and microstructural properties on the thermal conductivity of asphalt concrete using the transient heat transfer method 利用瞬态传热法研究混合料和微观结构特性对沥青混凝土导热性能的影响

IF 3.8 3区工程技术

Materials and Structures Pub Date : 2024-09-11 DOI: 10.1617/s11527-024-02456-1

Duygu Demirtürk, Hande Isik Ozturk, Murat Guler

{"title":"Investigation of the influence of mixture and microstructural properties on the thermal conductivity of asphalt concrete using the transient heat transfer method","authors":"Duygu Demirtürk, Hande Isik Ozturk, Murat Guler","doi":"10.1617/s11527-024-02456-1","DOIUrl":"https://doi.org/10.1617/s11527-024-02456-1","url":null,"abstract":"The structural performance of asphalt concrete is highly dependent on its thermal properties, especially in regions where daily or seasonal temperature variations are significant. In mechanistic design methods, thermal properties (specific heat, thermal conductivity, and coefficient of thermal expansion) are necessary to estimate the thermal behavior of asphalt concrete. However, the measurement of these properties is still a challenge, not only because of the heterogeneous structure of asphalt concrete but also because of the limitations imposed by the size of the test samples and the reliability of the measurement methods. In this study, a practical method, the Transient Plane Source (TPS), is proposed to measure the thermal conductivity of laboratory-produced asphalt concrete samples. To determine how thermal conductivity is affected by the maximum aggregate size, air voids, and aggregate source, a series of asphalt mixtures are compacted using the Superpave gyratory compactor to produce test samples. To determine the possible relationship between microstructural and thermal properties, which has not been investigated in previous studies, an image analysis is also performed to calculate the number of contact points and the total aggregate area in each sample. The statistical analyses show that all mixture properties, i.e., maximum aggregate size, air void content, and aggregate source, are significant, with the aggregate source having the greatest influence on the thermal conductivity of the samples. It is also shown that the TPS method is sensitive to the properties of the contact area, which significantly affects the reliability of the measurements.","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142220017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effects of exposure sequence and GGBS cement replacement on performance of concrete subjected to carbonation and chloride ingress 暴露顺序和 GGBS 水泥替代物对受碳化和氯化物侵蚀的混凝土性能的影响

IF 3.8 3区工程技术

Materials and Structures Pub Date : 2024-09-10 DOI: 10.1617/s11527-024-02438-3

Grace A. Blackshaw, Jessica C. Forsdyke, Janet M. Lees

{"title":"Effects of exposure sequence and GGBS cement replacement on performance of concrete subjected to carbonation and chloride ingress","authors":"Grace A. Blackshaw, Jessica C. Forsdyke, Janet M. Lees","doi":"10.1617/s11527-024-02438-3","DOIUrl":"https://doi.org/10.1617/s11527-024-02438-3","url":null,"abstract":"In a variety of applications, such as in tidal zones, abutments of bridges and concrete tunnel linings, reinforced concrete is exposed to both carbonation and chloride ingress. The exposure can be either simultaneous or sequential. However, durability design rarely considers synergistic effects due to carbonation and chloride ingress, even though this may have detrimental consequences for performance. Comparative implications of exposure sequence across different concrete compositions are also unknown. In this study, an experimental investigation on the effects of the sequence of carbonation and chloride ingress was conducted, using two concretes which differ by 50% cement replacement with ground granulated blast furnace slag (GGBS). Specimens were exposed to a combination of 10% CO2 accelerated carbonation and immersion in 3% sodium chloride solution, in either sequence, and compared with companion samples subjected to only one of these aggressive environments. The extent of carbonation was measured using phenolphthalein indicator solution, while silver nitrate and Rapid Chloride Testing provided indicators of the chloride ingress. For both concrete mixes, specimens with prior chloride ingress exhibited a decreased rate of carbonation when compared to specimens with no prior exposure. Conversely, specimens with prior carbonation displayed an increased rate of chloride ingress compared to non-carbonated counterparts and a step in the acid soluble chloride content in the region of the carbonation front. The concrete composition appeared to play a role since a greater increase in chloride diffusion coefficient due to prior carbonation was observed in the mix with 50% GGBS replacement than the mix without. These findings suggest that in concrete structures exposed to air and saline environments, the effects of sequential exposure should be characterised.","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142220019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Optimal content of bio-fibers in structural ice 结构冰中生物纤维的最佳含量

IF 3.8 3区工程技术

Materials and Structures Pub Date : 2024-09-10 DOI: 10.1617/s11527-024-02455-2

Alessandro P. Fantilli, Barbara Frigo, Farmehr M. Dehkordi

引用次数: 0

Understanding progressive aging of bitumen-rubber composite binder and its separate phases considering biphase interactions 考虑双相相互作用，了解沥青-橡胶复合粘结剂及其各相的渐进老化过程

IF 3.8 3区工程技术

Materials and Structures Pub Date : 2024-09-05 DOI: 10.1617/s11527-024-02449-0

Tao Wang, Jiaxu Ma, Jie Ma, Xiaopei Cai, Yaping Cui, Ruilin Ning, Jin Li

{"title":"Understanding progressive aging of bitumen-rubber composite binder and its separate phases considering biphase interactions","authors":"Tao Wang, Jiaxu Ma, Jie Ma, Xiaopei Cai, Yaping Cui, Ruilin Ning, Jin Li","doi":"10.1617/s11527-024-02449-0","DOIUrl":"https://doi.org/10.1617/s11527-024-02449-0","url":null,"abstract":"Bitumen-rubber composite binder (BRCB) has great potential to construct durable road pavement infrastructures that can withstand the environmental aging. However, the aging behavior of BRCB has not been fully investigated so far, especially from the perspective of biphase system with the phase interactions consideration. Therefore, this study investigated the progressive aging behavior of BRCB in terms of separate bitumen phase and rubber phase as well as the biphase interactions, to further understand the mechanisms behind. The results showed that the bitumen phase gradually dominated rheological performance of BRCB with the progressive aging. On the contrast, the fatigue resistance of BRCB was constantly controlled by its rubber phase in the aging process. Secondly, the rubber phase gradually dissolved during the aging with a decrease in the crosslinking density, although the change rate slowed down with the aging duration. The breakdown pattern of rubber structure was further identified as the simultaneous scission of crosslinking bonds and main chains. Besides, biphase interactions during progressive aging primarily included the absorption of light components from bitumen phase into rubber phase and the release of long rubber molecular chains and fillers from rubber phase into bitumen phase. Overall, the progressive aging of BRCBs can be considered as the combined effect of the secondary bitumen-rubber biphase interactions after the first-stage production and thermal oxidation of the bitumen phase.<h3 data-test=\"abstract-sub-heading\">Graphical abstract</h3>\u0000","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142220020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Influence of fiber orientation on the behavior of macro synthetic fiber in short- and long-term pullout tests 纤维取向对大型合成纤维在短期和长期拉伸试验中行为的影响

IF 3.8 3区工程技术

Materials and Structures Pub Date : 2024-09-04 DOI: 10.1617/s11527-024-02447-2

Thais S. Rocha, Daniel C. T. Cardoso, Luís A. G. Bitencourt

{"title":"Influence of fiber orientation on the behavior of macro synthetic fiber in short- and long-term pullout tests","authors":"Thais S. Rocha, Daniel C. T. Cardoso, Luís A. G. Bitencourt","doi":"10.1617/s11527-024-02447-2","DOIUrl":"https://doi.org/10.1617/s11527-024-02447-2","url":null,"abstract":"Synthetic fibers deforming over time can be a concern in structural design, particularly in serviceability limit states. Short-term pullout tests are commonly used to predict fiber–matrix interactions, but even in this case, an individualized evaluation of the pullout behavior of single fibers oriented parallel to the load direction may not be sufficient to predict the efficiency of the composite. In the present work, short- and long-term pullout tests were performed with fibers oriented at angles of 15°, 30°, and 45° to the direction of the load to investigate the influence of macro synthetic fibers orientation on fiber–matrix interactions. In short-term tests, optical microscopy images were obtained on the pulled-out fibers to correlate the surface degradation of the fibers with the stress versus strain curves. In quasi-static pullout (short-term), small reductions in pullout strength were observed for all fibers and angles, in addition to an intensive degradation of their surfaces owing to the significant snubbing effect of this type of fiber. In contrast, for the long-term tests, a creep reduction was observed with increasing fiber inclination angle caused by the creep reduction of the fiber due to non-axial loading and additional force components produced by the deviation of the axial force. The parameters of Burgers rheological model were written as a function of the fiber orientation angle, with excellent adjustment to the experimental data.","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142220022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Microstructure analysis of cement-biochar composites 水泥-生物炭复合材料的微观结构分析

IF 3.8 3区工程技术

Materials and Structures Pub Date : 2024-09-04 DOI: 10.1617/s11527-024-02452-5

Renata Lorenzoni, Patrick Cunningham, Tobias Fritsch, Wolfram Schmidt, Sabine Kruschwitz, Giovanni Bruno

{"title":"Microstructure analysis of cement-biochar composites","authors":"Renata Lorenzoni, Patrick Cunningham, Tobias Fritsch, Wolfram Schmidt, Sabine Kruschwitz, Giovanni Bruno","doi":"10.1617/s11527-024-02452-5","DOIUrl":"https://doi.org/10.1617/s11527-024-02452-5","url":null,"abstract":"The use of biochar as a concrete constituent has been proposed to reduce the massive carbon footprint of concrete. Due to the low density and complex porosity of biochar, microstructural analysis of Portland cement-biochar composites is challenging. This causes challenges to the improvement of the micro-scale understanding of biochar composite behavior. This work advances the microstructural understanding of Portland cement composites with 0, 5, and 25 volume percent (vol%) of cement replaced with wood biochar by applying common characterization techniques of mercury intrusion porosimetry (MIP), gas sorption, scanning electron microscopy, and isothermal heat flow calorimetry (HFC) in conjunction with 1H nuclear magnetic resonance (NMR) and micro-X-ray computed tomography (XCT) analysis techniques. The combination of these techniques allows a multi-scale investigation of the effect of biochar on the microstructure of cement paste. NMR and XCT techniques allow the observation and quantification of the pore space. HFC and MIP confirmed that biochar absorbs moisture and reduces the effective water-cement ratio. Gas sorption, MIP, and NMR shows that 5 vol% replacement does not significantly affect the gel and capillary pore structures. Results from XCT (supported by MIP and NMR) show that biochar can reduce the formation of larger pores. Importantly, XCT results suggest that biochar can act as a flaw in the microstructure which could explain reductions in the mechanical properties. Overall, the mechanical properties already analyzed in the literature are consistent with the microstructural changes observed, and these results highlight the need to carefully tailor the volume fraction of biochar to control its effect on the paste microstructure.","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142220023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Report of RILEM TC 281-CCC: A critical review of the standardised testing methods to determine carbonation resistance of concrete RILEM TC 281-CCC 报告：对确定混凝土抗碳化性的标准化测试方法的严格审查

IF 3.8 3区工程技术

Materials and Structures Pub Date : 2024-09-03 DOI: 10.1617/s11527-024-02424-9

Susan A. Bernal, Yuvaraj Dhandapani, Yogarajah Elakneswaran, Gregor J. G. Gluth, Elke Gruyaert, Maria C. G. Juenger, Barbara Lothenbach, Kolawole A. Olonade, Marlene Sakoparnig, Zhenguo Shi, Charlotte Thiel, Phillip Van den Heede, Hanne Vanoutrive, Stefanie von Greve-Dierfeld, Nele De Belie, John L. Provis

{"title":"Report of RILEM TC 281-CCC: A critical review of the standardised testing methods to determine carbonation resistance of concrete","authors":"Susan A. Bernal, Yuvaraj Dhandapani, Yogarajah Elakneswaran, Gregor J. G. Gluth, Elke Gruyaert, Maria C. G. Juenger, Barbara Lothenbach, Kolawole A. Olonade, Marlene Sakoparnig, Zhenguo Shi, Charlotte Thiel, Phillip Van den Heede, Hanne Vanoutrive, Stefanie von Greve-Dierfeld, Nele De Belie, John L. Provis","doi":"10.1617/s11527-024-02424-9","DOIUrl":"https://doi.org/10.1617/s11527-024-02424-9","url":null,"abstract":"The chemical reaction between CO2 and a blended Portland cement concrete, referred to as carbonation, can lead to reduced performance, particularly when concrete is exposed to elevated levels of CO2 (i.e., accelerated carbonation conditions). When slight changes in concrete mix designs or testing conditions are adopted, conflicting carbonation results are often reported. The RILEM TC 281-CCC ‘Carbonation of Concrete with Supplementary Cementitious Materials’ has conducted a critical analysis of the standardised testing methodologies that are currently applied to determine carbonation resistance of concrete in different regions. There are at least 17 different standards or recommendations being actively used for this purpose, with significant differences in sample curing, pre-conditioning, carbonation exposure conditions, and methods used for determination of carbonation depth after exposure. These differences strongly influence the carbonation depths recorded and the carbonation coefficient values calculated. Considering the importance of accurately determining carbonation potential of concrete, not just for predicting their durability performance, but also for determining the amount of CO2 that concrete can re-absorb during or after its service life, it is imperative to recognise the applicability and limitations of the results obtained from different tests. This will enable researchers and practitioners to adopt the most appropriate testing methodologies to evaluate carbonation resistance, depending on the purpose of the conclusions derived from such testing (e. g. materials selection, service life prediction, CO2 capture potential).","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142220021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Automated analysis of the void structure in hardened concrete based on shape from focus 根据聚焦形状自动分析硬化混凝土中的空隙结构

IF 3.8 3区工程技术

Materials and Structures Pub Date : 2024-08-29 DOI: 10.1617/s11527-024-02448-1

Gui Li, Marianne Tange Hasholt, Vedrana Andersen Dahl, Ole Mejlhede Jensen

引用次数: 0

Timber-timber composite (TTC) joints made of short-supply chain beech: Push-out tests of inclined screw connectors 用短链榉木制成的木材-木材复合材料（TTC）连接件：倾斜螺钉连接件的推出试验

IF 3.8 3区工程技术

Materials and Structures Pub Date : 2024-08-22 DOI: 10.1617/s11527-024-02443-6

Martina Sciomenta, Pasqualino Gualtieri, Luca Spera, Francesco Contu, Massimo Fragiacomo

引用次数: 0

Hydromechanical performances and durability of compressed earth blocks stabilised with metakaolin-based geopolymer binder 使用偏高岭土基土工聚合物粘结剂加固的压缩土块的水力学性能和耐久性能

IF 3.8 3区工程技术

Materials and Structures Pub Date : 2024-08-21 DOI: 10.1617/s11527-024-02446-3

Kader Banaou Djibo, Seick Omar Sore, Philbert Nshimiyimana, David Yao Akodenyon, Adamah Messan

{"title":"Hydromechanical performances and durability of compressed earth blocks stabilised with metakaolin-based geopolymer binder","authors":"Kader Banaou Djibo, Seick Omar Sore, Philbert Nshimiyimana, David Yao Akodenyon, Adamah Messan","doi":"10.1617/s11527-024-02446-3","DOIUrl":"https://doi.org/10.1617/s11527-024-02446-3","url":null,"abstract":"Demographic growth and the need for housing remain significant issues. Compressed earth bricks (CEB) are appropriate materials due to their availability and thermal properties, but different considerations hinder their adoption. The influence of water on the mechanical properties and durability of CEBs stabilised with an alkali-activated geopolymer binder has yet to be thoroughly investigated. Thus, this study assessed the hydromechanical performance and durability of compressed earth bricks (CEBs) stabilised with an alkali-activated geopolymer binder. Dry mixes consisting of lateritic earth and 5—20% metakaolin (MK) binder, with respect to the dry mass of the earth, were prepared. A solution of NaOH at a concentration of 12 M was used to activate MK. The wet mixes were then statically compressed using a manual press at a stress of about 3.5 MPa. The dried CEBs were subjected to progressive mechanical characterisation after exposure to different water content and durability indicators assessment. A satisfactory mathematical correlation was established between the relative compressive strength and water content of the CEBs. CEBs stabilised with geopolymer binder showed increased stability to water, and their absorption capacity was relatively below the recommended 20% threshold. The abrasion resistance coefficient improved after the wetting–drying (W-D) cycles and was above the recommended 7 cm2/g.","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0