Pub Date : 2024-11-20DOI: 10.1016/j.dibe.2024.100576
Samuel Pantaleo, Florent Gauvin, Katrin Schollbach, H.J.H. Brouwers
Silica aerogel stands out as an exceptional thermal insulation material and is a great candidate for modern and energy-efficient buildings. However, silica aerogel also faces many challenges, mainly due to its expensive, unsustainable and difficult synthesis process, but also its poor structural properties. Consequently, the main research focus for silica aerogel is to mitigate its brittleness in order to pave the way for broader applications, especially in the building field. Therefore, this study focuses on the development of composite materials aiming at solving the abovementioned drawbacks of silica aerogel, by using environmentally friendly latexes and reinforcement that are easy to process. Results show the positive effect of this reinforcement, even at a small amount (5% volume), on the composite's properties, with thermal conductivity at least equivalent, or better, to either in development or already established insulation materials in the market.
{"title":"Development of latex / silica aerogel composites for thermal insulation applications","authors":"Samuel Pantaleo, Florent Gauvin, Katrin Schollbach, H.J.H. Brouwers","doi":"10.1016/j.dibe.2024.100576","DOIUrl":"10.1016/j.dibe.2024.100576","url":null,"abstract":"<div><div>Silica aerogel stands out as an exceptional thermal insulation material and is a great candidate for modern and energy-efficient buildings. However, silica aerogel also faces many challenges, mainly due to its expensive, unsustainable and difficult synthesis process, but also its poor structural properties. Consequently, the main research focus for silica aerogel is to mitigate its brittleness in order to pave the way for broader applications, especially in the building field. Therefore, this study focuses on the development of composite materials aiming at solving the abovementioned drawbacks of silica aerogel, by using environmentally friendly latexes and reinforcement that are easy to process. Results show the positive effect of this reinforcement, even at a small amount (5% volume), on the composite's properties, with thermal conductivity at least equivalent, or better, to either in development or already established insulation materials in the market.</div></div>","PeriodicalId":34137,"journal":{"name":"Developments in the Built Environment","volume":"20 ","pages":"Article 100576"},"PeriodicalIF":6.2,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142705907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-19DOI: 10.1016/j.dibe.2024.100570
Dongchi Yao , Borja García de Soto
The construction industry is undergoing digitalization, but it is increasingly vulnerable to cyber attacks due to its slow pace in developing effective cyber risk assessment tools. This study develops a Machine Learning (ML)-centric approach to assess common cyber risks for construction projects. This approach comprises three components: (1) For risk prediction, a simulated dataset is generated using Monte Carlo simulations, which is utilized for model training. A two-phase model development strategy is proposed to select the optimal model for each risk. (2) For risk factor analysis, ML feature analysis methods are adapted to identify risk factors that contribute significantly to risks of specific projects. (3) For the risk reduction strategy, a greedy optimization algorithm is proposed to efficiently address high-contributing risk factors. To demonstrate the applicability of the developed approach, a case study is conducted on a real construction project.
建筑行业正在经历数字化，但由于其在开发有效网络风险评估工具方面进展缓慢，越来越容易受到网络攻击。本研究开发了一种以机器学习（ML）为中心的方法，用于评估建筑项目的常见网络风险。该方法由三部分组成：(1) 在风险预测方面，使用蒙特卡罗模拟生成模拟数据集，用于模型训练。建议采用两阶段模型开发策略，为每种风险选择最佳模型。(2) 在风险因素分析方面，采用 ML 特征分析方法来识别对特定项目风险有重大影响的风险因素。(3) 在风险降低策略方面，提出了一种贪婪优化算法，以有效解决高贡献风险因素。为了证明所开发方法的适用性，我们在一个实际建筑项目中进行了案例研究。
{"title":"Assessing cyber risks in construction projects: A machine learning-centric approach","authors":"Dongchi Yao , Borja García de Soto","doi":"10.1016/j.dibe.2024.100570","DOIUrl":"10.1016/j.dibe.2024.100570","url":null,"abstract":"<div><div>The construction industry is undergoing digitalization, but it is increasingly vulnerable to cyber attacks due to its slow pace in developing effective cyber risk assessment tools. This study develops a Machine Learning (ML)-centric approach to assess common cyber risks for construction projects. This approach comprises three components: (1) For risk prediction, a simulated dataset is generated using Monte Carlo simulations, which is utilized for model training. A two-phase model development strategy is proposed to select the optimal model for each risk. (2) For risk factor analysis, ML feature analysis methods are adapted to identify risk factors that contribute significantly to risks of specific projects. (3) For the risk reduction strategy, a greedy optimization algorithm is proposed to efficiently address high-contributing risk factors. To demonstrate the applicability of the developed approach, a case study is conducted on a real construction project.</div></div>","PeriodicalId":34137,"journal":{"name":"Developments in the Built Environment","volume":"20 ","pages":"Article 100570"},"PeriodicalIF":6.2,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142705905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-19DOI: 10.1016/j.dibe.2024.100577
Evgenia Spyridonos , Yanan Guo , Marta Gil Pérez , Hanaa Dahy
The utilisation of bio-based materials has significantly increased in recent years, driven by a growing awareness of environmentally friendly alternatives in the construction industry. This study introduces innovative natural fibre pultruded profiles for load-bearing applications in structural systems. By employing pultrusion technology with flax fibres and customised plant-based matrix, linear and unidirectional biocomposite profiles were developed. These profiles were used in the creation of LightPRO Shell, an active-bending structure combining biocomposite profiles with a membrane outer skin, demonstrating their mechanical properties and suitability for such applications. The paper focuses on the geometrical and structural design development of the structure employing computational design tools for optimisation, ensuring design parameters and performance requirements were met. The final structure, a 10-m span doubly curved gridshell, features a continuous perimeter beam and consists of 44 profiles ranging from 6 to 12.5 m, showcasing the potential of natural fibre biocomposites as sustainable alternatives in construction.
{"title":"Geometrical and structural design development of an active-bending structure from natural fibre pultruded profiles: The LightPRO shell","authors":"Evgenia Spyridonos , Yanan Guo , Marta Gil Pérez , Hanaa Dahy","doi":"10.1016/j.dibe.2024.100577","DOIUrl":"10.1016/j.dibe.2024.100577","url":null,"abstract":"<div><div>The utilisation of bio-based materials has significantly increased in recent years, driven by a growing awareness of environmentally friendly alternatives in the construction industry. This study introduces innovative natural fibre pultruded profiles for load-bearing applications in structural systems. By employing pultrusion technology with flax fibres and customised plant-based matrix, linear and unidirectional biocomposite profiles were developed. These profiles were used in the creation of LightPRO Shell, an active-bending structure combining biocomposite profiles with a membrane outer skin, demonstrating their mechanical properties and suitability for such applications. The paper focuses on the geometrical and structural design development of the structure employing computational design tools for optimisation, ensuring design parameters and performance requirements were met. The final structure, a 10-m span doubly curved gridshell, features a continuous perimeter beam and consists of 44 profiles ranging from 6 to 12.5 m, showcasing the potential of natural fibre biocomposites as sustainable alternatives in construction.</div></div>","PeriodicalId":34137,"journal":{"name":"Developments in the Built Environment","volume":"20 ","pages":"Article 100577"},"PeriodicalIF":6.2,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142705904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We aim to address that home-made design and assembly can be effective to investigate several sizes and natures of construction materials. This study offers a new design that accepts different powder and bio-based materials to enhance the functionality of construction elements. We developed a system in which a numerical controlled machine is coupled with a 6 axis articulated-arm to selectively bind a mineral powder bed with liquid’s droplets. A home-made frame has been designed and built to adapt the geometrical space that allows the displacement of the numerical controlled machine and the articulated arm. The powder deposition is carried out using a tank controlled by an Arduino board. In parallel, we propose a fluid deposition system using a pressurized tank and a valve jetting that allows the deposition of millimetric liquid droplet. 3D printing tests using cement particles, water retention agent, and a composite of cement with hemp aggregates were carried out to validate the prototype. We then highlight, as a proof of concept, that an innovative selective binding 3D printer could bring new composites or biobased materials in construction industry.
我们的目标是解决自制设计和组装可以有效研究多种尺寸和性质的建筑材料的问题。这项研究提供了一种新的设计，可接受不同的粉末和生物基材料，以增强建筑构件的功能。我们开发了一种系统，将数控机床与 6 轴铰接臂相结合，选择性地将矿物粉末床与液滴结合在一起。我们设计并建造了一个自制框架，以调整几何空间，使数控机床和关节臂能够位移。粉末沉积是通过一个由 Arduino 板控制的水箱进行的。与此同时，我们还提出了一种流体沉积系统，使用一个加压罐和一个阀门喷射器，可以沉积毫米级的液滴。为了验证原型，我们使用水泥颗粒、保水剂以及水泥与麻骨料的复合材料进行了 3D 打印测试。然后，作为概念验证，我们强调创新的选择性结合 3D 打印机可为建筑行业带来新型复合材料或生物基材料。
{"title":"Design and validation of a selective binding 3D printer for bio-based construction materials","authors":"Valentine Danché, Mamma Bouaouich, Abdeslam Benamara, Alexandre Pierre, Khadim Ndiaye, T.T. Ngo","doi":"10.1016/j.dibe.2024.100579","DOIUrl":"10.1016/j.dibe.2024.100579","url":null,"abstract":"<div><div>We aim to address that home-made design and assembly can be effective to investigate several sizes and natures of construction materials. This study offers a new design that accepts different powder and bio-based materials to enhance the functionality of construction elements. We developed a system in which a numerical controlled machine is coupled with a 6 axis articulated-arm to selectively bind a mineral powder bed with liquid’s droplets. A home-made frame has been designed and built to adapt the geometrical space that allows the displacement of the numerical controlled machine and the articulated arm. The powder deposition is carried out using a tank controlled by an Arduino board. In parallel, we propose a fluid deposition system using a pressurized tank and a valve jetting that allows the deposition of millimetric liquid droplet. 3D printing tests using cement particles, water retention agent, and a composite of cement with hemp aggregates were carried out to validate the prototype. We then highlight, as a proof of concept, that an innovative selective binding 3D printer could bring new composites or biobased materials in construction industry.</div></div>","PeriodicalId":34137,"journal":{"name":"Developments in the Built Environment","volume":"20 ","pages":"Article 100579"},"PeriodicalIF":6.2,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142719758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-17DOI: 10.1016/j.dibe.2024.100574
L.L. Wu , D.L. Zou , Y.F. Hao
This study proposes a two-layer fusion model (stacking-CARF) to predict the dynamic compressive strength of eco-friendly ultra-high performance concrete (UHPC). Before building the prediction model, a well-balanced UHPC dynamic compression dataset is created using the anomaly detection algorithm. Subsequently, it is experimentally determined that the stacking-CARF model consisting of categorical boosting, random forest and linear regression outperforms other prominent ensemble learning and stacked models, and can be used as a robust strength prediction tool. Moreover, Explainable Artificial Intelligence is utilized to elucidate the intricate relationship between material proportions and dynamic compressive strength from both global and local perspectives, offering insights challenging to quantify using traditional methods. In particular, the interaction analysis affirms the role of reasonable replacement ratios between cement and supplementary cementitious materials in enhancing sustainability and cleaner production practices. Finally, a Python-based graphical user interface is developed to facilitate the implementation of the stacking-CARF model in engineering applications.
{"title":"Exploring the compositional effect of eco-friendly ultra-high performance concrete on dynamic strength based on stacking algorithm and explainable artificial intelligence","authors":"L.L. Wu , D.L. Zou , Y.F. Hao","doi":"10.1016/j.dibe.2024.100574","DOIUrl":"10.1016/j.dibe.2024.100574","url":null,"abstract":"<div><div>This study proposes a two-layer fusion model (stacking-CARF) to predict the dynamic compressive strength of eco-friendly ultra-high performance concrete (UHPC). Before building the prediction model, a well-balanced UHPC dynamic compression dataset is created using the anomaly detection algorithm. Subsequently, it is experimentally determined that the stacking-CARF model consisting of categorical boosting, random forest and linear regression outperforms other prominent ensemble learning and stacked models, and can be used as a robust strength prediction tool. Moreover, Explainable Artificial Intelligence is utilized to elucidate the intricate relationship between material proportions and dynamic compressive strength from both global and local perspectives, offering insights challenging to quantify using traditional methods. In particular, the interaction analysis affirms the role of reasonable replacement ratios between cement and supplementary cementitious materials in enhancing sustainability and cleaner production practices. Finally, a Python-based graphical user interface is developed to facilitate the implementation of the stacking-CARF model in engineering applications.</div></div>","PeriodicalId":34137,"journal":{"name":"Developments in the Built Environment","volume":"20 ","pages":"Article 100574"},"PeriodicalIF":6.2,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142705903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-17DOI: 10.1016/j.dibe.2024.100575
Melaku N. Seifu , Daeik Jang , G.M. Kim , Solmoi Park
The addition of NaHCO3 has the potential to enhance properties of concrete by facilitating internal carbonation. This study investigates the effects of the incorporation of NaHCO3 into ordinary Portland cement-blast furnace slag paste. The results show that the addition of NaHCO3 had an impact on the hydration process and increased the heat of hydration on all the slag samples. NaHCO3 caused internal carbonation and facilitated the formation of calcium carbonate and different carbon-based AFm phases, such as monocarbonate. The incorporation of NaHCO3 improved the pore structure of the paste and enhanced resistance against chloride penetration. The chloride migration coefficient of the Portland cement paste sample was reduced up to 96.5% with the incorporation of 2% NaHCO3 at 70% slag replacement. The compressive strength of the samples also showed an improvement with 1% NaHCO3 addition increasing the early age strength and 2% NaHCO3 addition increasing the matured age strength.
{"title":"Improving properties of Portland cement-blast furnace slag blended paste through sodium bicarbonate-induced carbonation","authors":"Melaku N. Seifu , Daeik Jang , G.M. Kim , Solmoi Park","doi":"10.1016/j.dibe.2024.100575","DOIUrl":"10.1016/j.dibe.2024.100575","url":null,"abstract":"<div><div>The addition of NaHCO<sub>3</sub> has the potential to enhance properties of concrete by facilitating internal carbonation. This study investigates the effects of the incorporation of NaHCO<sub>3</sub> into ordinary Portland cement-blast furnace slag paste. The results show that the addition of NaHCO<sub>3</sub> had an impact on the hydration process and increased the heat of hydration on all the slag samples. NaHCO<sub>3</sub> caused internal carbonation and facilitated the formation of calcium carbonate and different carbon-based AFm phases, such as monocarbonate. The incorporation of NaHCO<sub>3</sub> improved the pore structure of the paste and enhanced resistance against chloride penetration. The chloride migration coefficient of the Portland cement paste sample was reduced up to 96.5% with the incorporation of 2% NaHCO<sub>3</sub> at 70% slag replacement. The compressive strength of the samples also showed an improvement with 1% NaHCO<sub>3</sub> addition increasing the early age strength and 2% NaHCO<sub>3</sub> addition increasing the matured age strength.</div></div>","PeriodicalId":34137,"journal":{"name":"Developments in the Built Environment","volume":"20 ","pages":"Article 100575"},"PeriodicalIF":6.2,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142719759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-17DOI: 10.1016/j.dibe.2024.100573
Pedro Mêda , Judith Fauth , Christian Schranz , Hipólito Sousa , Harald Urban
In the context of the European Union's push for a sustainable and digitally integrated construction sector, this research explores the relationship between Digital Building Permits (DBP) and Digital Building Logbooks (DBL). The study aims to diagnose and identify the synergies and challenges in aligning these data-driven concepts throughout the building life-cycle. Using a focus group methodology, the research gathered qualitative data on the perceptions of DBP and DBL among professionals with diverse backgrounds. The findings reveal significant overlaps and potential for integrated data management, enhancing regulatory compliance, efficiency, and sustainability. While DBP and DBL can function independently, their full potential is realised through a cohesive framework that supports continuous data updates and stakeholder collaboration, facilitating the “golden thread” of information essential for effective digital twin applications. Future research should further explore the detailed processes and data exchanges necessary to implement this framework successfully.
{"title":"Twinning the path of digital building permits and digital building logbooks – Diagnosis and challenges","authors":"Pedro Mêda , Judith Fauth , Christian Schranz , Hipólito Sousa , Harald Urban","doi":"10.1016/j.dibe.2024.100573","DOIUrl":"10.1016/j.dibe.2024.100573","url":null,"abstract":"<div><div>In the context of the European Union's push for a sustainable and digitally integrated construction sector, this research explores the relationship between Digital Building Permits (DBP) and Digital Building Logbooks (DBL). The study aims to diagnose and identify the synergies and challenges in aligning these data-driven concepts throughout the building life-cycle. Using a focus group methodology, the research gathered qualitative data on the perceptions of DBP and DBL among professionals with diverse backgrounds. The findings reveal significant overlaps and potential for integrated data management, enhancing regulatory compliance, efficiency, and sustainability. While DBP and DBL can function independently, their full potential is realised through a cohesive framework that supports continuous data updates and stakeholder collaboration, facilitating the “golden thread<strong>”</strong> of information essential for effective digital twin applications. Future research should further explore the detailed processes and data exchanges necessary to implement this framework successfully.</div></div>","PeriodicalId":34137,"journal":{"name":"Developments in the Built Environment","volume":"20 ","pages":"Article 100573"},"PeriodicalIF":6.2,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142705906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-16DOI: 10.1016/j.dibe.2024.100572
Sejal Sanjay Shanbhag , Manish K. Dixit , Petros Sideris
In the United States reducing greenhouse gas emissions associated with building construction by 90% by 2050 necessitates significant measures to be undertaken within the construction industry. Such measures include advanced construction techniques and bio-based material solutions such as hempcrete. This paper explores the mix design development and environmental impact assessment of hempcrete with an aim of reducing embodied impacts and achieving carbon negativity. Hempcrete being increasingly incorporated into both conventional and cutting-edge construction methods such as large-scale 3D printing is recognized as a carbon-negative material due to sequestered carbon in its constituent materials. Particularly, with the high carbon footprint associated with traditional Portland cement concrete, hempcrete presents a viable and low-carbon or even carbon-negative option for emerging construction techniques. The degree to which hempcrete achieves carbon negativity is contingent upon the proportion of hemp and lime within the mix design. Consequently, a comprehensive Life Cycle Assessment (LCA) is essential for evaluating the carbon-reduction potential of hempcrete. This study conducts a cradle-to-gate LCA of various hempcrete mix designs including a hybrid LCA of the environmental impact of domestically cultivated hemp. The results show that the global warming potential (GWP) of industrial hemp is −1.72 kgCO2e/kg. The LCA of different mix designs reveals that carbon negativity is reached when the hempcrete composition includes no less than 20% hemp by weight. Moreover, findings underscore the importance of including lime's carbon absorption in calculations to attain carbon negativity as incorporation of hemp alone may not be adequate. The study concludes that optimizing the constituents of hempcrete to achieve carbon negativity is vital for effective climate mitigation and adaptation strategies.
{"title":"Examining the global warming potential of hempcrete in the United States: A cradle-to-gate life cycle assessment","authors":"Sejal Sanjay Shanbhag , Manish K. Dixit , Petros Sideris","doi":"10.1016/j.dibe.2024.100572","DOIUrl":"10.1016/j.dibe.2024.100572","url":null,"abstract":"<div><div>In the United States reducing greenhouse gas emissions associated with building construction by 90% by 2050 necessitates significant measures to be undertaken within the construction industry. Such measures include advanced construction techniques and bio-based material solutions such as hempcrete. This paper explores the mix design development and environmental impact assessment of hempcrete with an aim of reducing embodied impacts and achieving carbon negativity. Hempcrete being increasingly incorporated into both conventional and cutting-edge construction methods such as large-scale 3D printing is recognized as a carbon-negative material due to sequestered carbon in its constituent materials. Particularly, with the high carbon footprint associated with traditional Portland cement concrete, hempcrete presents a viable and low-carbon or even carbon-negative option for emerging construction techniques. The degree to which hempcrete achieves carbon negativity is contingent upon the proportion of hemp and lime within the mix design. Consequently, a comprehensive Life Cycle Assessment (LCA) is essential for evaluating the carbon-reduction potential of hempcrete. This study conducts a cradle-to-gate LCA of various hempcrete mix designs including a hybrid LCA of the environmental impact of domestically cultivated hemp. The results show that the global warming potential (GWP) of industrial hemp is −1.72 kgCO<sub>2</sub>e/kg. The LCA of different mix designs reveals that carbon negativity is reached when the hempcrete composition includes no less than 20% hemp by weight. Moreover, findings underscore the importance of including lime's carbon absorption in calculations to attain carbon negativity as incorporation of hemp alone may not be adequate. The study concludes that optimizing the constituents of hempcrete to achieve carbon negativity is vital for effective climate mitigation and adaptation strategies.</div></div>","PeriodicalId":34137,"journal":{"name":"Developments in the Built Environment","volume":"20 ","pages":"Article 100572"},"PeriodicalIF":6.2,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142719755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-08DOI: 10.1016/j.dibe.2024.100571
Zhou Zhang, Chaolin Wang, Yu Zhao, Kun Zhang, Mingxuan Shen
This study aims to investigate the influence of corn cob particles on pore structure of mortar. By using NMR technology, the pore parameters of fast-hardening sulfoaluminate cement mortar (SAC) and ordinary Portland cement mortar (PO) were measured and compared. The influence of corncob particles on the mechanical properties of eco-mortar was evaluated by uniaxial compression test. The results indicate that medium and large pores of both SAC and PO increases with corn cob particle, as well as the porosity. The fractal dimensions of harmful and multiple harmful pores are negatively correlated with the volume fraction of corn cob particles. The addition of corn cob particles reduced the overall fractal dimension of the mortar and decreased the complexity of internal pores. The probability density function of grayscale values transitions from being “thin and tall” to “short and wide”, with an increasing proportion of high grayscale values. This leads to an increase in the proportion of large pores within the mortar, resulting in a continuous deterioration of pore structure. The addition of corn cob particles greatly reduces the strength of SAC and PO, but the peak stress of SAC is higher than that of PO. When corn cob particle content is 30 wt% and 50 wt%, the peak stress of SAC is increased by 23.37% and 14.25%, respectively, compared with the peak stress of PO.
本研究旨在探讨玉米芯颗粒对砂浆孔隙结构的影响。利用核磁共振技术，测量并比较了快速硬化硫铝酸盐水泥砂浆（SAC）和普通硅酸盐水泥砂浆（PO）的孔隙参数。通过单轴压缩试验评估了玉米芯颗粒对生态砂浆机械性能的影响。结果表明，随着玉米芯颗粒的增加，SAC 和 PO 的中孔和大孔以及孔隙率也随之增加。有害孔隙和多重有害孔隙的分形尺寸与玉米芯颗粒的体积分数呈负相关。玉米芯颗粒的加入降低了砂浆的整体分形维度，并减少了内部孔隙的复杂性。灰度值的概率密度函数从 "又细又高 "过渡到 "又短又宽"，灰度值高的比例越来越大。这导致砂浆内部大孔隙比例增加，导致孔隙结构不断恶化。玉米芯颗粒的加入大大降低了 SAC 和 PO 的强度，但 SAC 的峰值应力高于 PO。当玉米芯颗粒含量为 30 wt% 和 50 wt% 时，SAC 的峰值应力比 PO 的峰值应力分别增加了 23.37% 和 14.25%。
{"title":"Study on the pore structure of eco-regenerated mortar using corn cob based on nuclear magnetic resonance","authors":"Zhou Zhang, Chaolin Wang, Yu Zhao, Kun Zhang, Mingxuan Shen","doi":"10.1016/j.dibe.2024.100571","DOIUrl":"10.1016/j.dibe.2024.100571","url":null,"abstract":"<div><div>This study aims to investigate the influence of corn cob particles on pore structure of mortar. By using NMR technology, the pore parameters of fast-hardening sulfoaluminate cement mortar (SAC) and ordinary Portland cement mortar (PO) were measured and compared. The influence of corncob particles on the mechanical properties of eco-mortar was evaluated by uniaxial compression test. The results indicate that medium and large pores of both SAC and PO increases with corn cob particle, as well as the porosity. The fractal dimensions of harmful and multiple harmful pores are negatively correlated with the volume fraction of corn cob particles. The addition of corn cob particles reduced the overall fractal dimension of the mortar and decreased the complexity of internal pores. The probability density function of grayscale values transitions from being “thin and tall” to “short and wide”, with an increasing proportion of high grayscale values. This leads to an increase in the proportion of large pores within the mortar, resulting in a continuous deterioration of pore structure. The addition of corn cob particles greatly reduces the strength of SAC and PO, but the peak stress of SAC is higher than that of PO. When corn cob particle content is 30 wt% and 50 wt%, the peak stress of SAC is increased by 23.37% and 14.25%, respectively, compared with the peak stress of PO.</div></div>","PeriodicalId":34137,"journal":{"name":"Developments in the Built Environment","volume":"20 ","pages":"Article 100571"},"PeriodicalIF":6.2,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-05DOI: 10.1016/j.dibe.2024.100567
Changyuan Liu , Xin Wang , Xinquan Chang , Zhishen Wu , Huang Huang , Mohammad Noori , Wael A. Altabey
Owing to the low measuring range of traditional fiber Bragg grating (FBG) sensors and the complexity, imprecision, and lack of practicality in existing large-strain sensors, this paper introduces a novel type of large-strain sensor based on pre-relaxation and continuous sensing technology. This design aims to realize the whole-process strain monitoring of prestressed fiber reinforced polymer (FRP) plates. Static tensile tests were conducted on 9 large-strain sensor specimens. The effects of pre-relaxation degree, section number, pre-tension time, and prestressing level were evaluated. The results reveal that, the pre-relaxed sensor, proved its efficacy in capturing the strain pertinent to the post-tensioned operational state of the FRP plate, and a sensing performance of up to 18,923 με can be facilitated and further extended by a pre-relaxation and continuous sensing technique. Moreover, it is recommended that during the fabrication of the large-strain sensor, two pre-tensions be applied, with a prestressing level between 115% and 125% of the pre-relaxation degree.
由于传统的光纤布拉格光栅（FBG）传感器测量范围小，且现有的大应变传感器复杂、不精确、缺乏实用性，本文介绍了一种基于预松弛和连续传感技术的新型大应变传感器。该设计旨在实现对预应力纤维增强聚合物（FRP）板材的全过程应变监测。对 9 个大应变传感器试样进行了静态拉伸试验。评估了预松弛度、截面数、预拉伸时间和预应力水平的影响。结果表明，预松弛传感器在捕捉玻璃钢板后张力工作状态的相关应变方面证明了其有效性，而且通过预松弛和连续传感技术，可以促进并进一步扩展高达 18,923 με 的传感性能。此外，建议在制造大应变传感器时施加两个预张力，预应力水平介于预松弛度的 115% 和 125% 之间。
{"title":"Innovative design and sensing performance of a novel large-strain sensor for prestressed FRP plates","authors":"Changyuan Liu , Xin Wang , Xinquan Chang , Zhishen Wu , Huang Huang , Mohammad Noori , Wael A. Altabey","doi":"10.1016/j.dibe.2024.100567","DOIUrl":"10.1016/j.dibe.2024.100567","url":null,"abstract":"<div><div>Owing to the low measuring range of traditional fiber Bragg grating (FBG) sensors and the complexity, imprecision, and lack of practicality in existing large-strain sensors, this paper introduces a novel type of large-strain sensor based on pre-relaxation and continuous sensing technology. This design aims to realize the whole-process strain monitoring of prestressed fiber reinforced polymer (FRP) plates. Static tensile tests were conducted on 9 large-strain sensor specimens. The effects of pre-relaxation degree, section number, pre-tension time, and prestressing level were evaluated. The results reveal that, the pre-relaxed sensor, proved its efficacy in capturing the strain pertinent to the post-tensioned operational state of the FRP plate, and a sensing performance of up to 18,923 με can be facilitated and further extended by a pre-relaxation and continuous sensing technique. Moreover, it is recommended that during the fabrication of the large-strain sensor, two pre-tensions be applied, with a prestressing level between 115% and 125% of the pre-relaxation degree.</div></div>","PeriodicalId":34137,"journal":{"name":"Developments in the Built Environment","volume":"20 ","pages":"Article 100567"},"PeriodicalIF":6.2,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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