This study conducted both experimental and numerical investigations on the capillary water absorption into AAS materials with varying mix proportions. The results demonstrate that the capillary water absorption of AAS mortars adheres to the square root of time (SRT) law until wetting front reaches the top surface of specimen. The isopropanol (IPA) absorption of AAS mortars also follows the SRT law, and the measured intrinsic capillary sorptivity for IPA and water are quite close. Through theoretical modeling and numerical simulation, the capillary absorption kinetics of different AAS mortars can all be accurately quantified using the Richards equation, regardless of the water retention curve model employed. These results suggest that the microstructure of AAS materials studied herein is stable during capillary water absorption. This may be attributed to the viscous characteristics of AAS materials, arising from the irreversible collapse and rearrangement of the nanostructure of C-A-S-H gels during drying.
{"title":"Capillary water absorption into alkali-activated slag materials: Experimental and numerical investigation","authors":"Fangzhou Ren, Jian Zhang, Jianxiang Yang, Xiangsheng Chen","doi":"10.1016/j.dibe.2024.100597","DOIUrl":"10.1016/j.dibe.2024.100597","url":null,"abstract":"<div><div>This study conducted both experimental and numerical investigations on the capillary water absorption into AAS materials with varying mix proportions. The results demonstrate that the capillary water absorption of AAS mortars adheres to the square root of time (SRT) law until wetting front reaches the top surface of specimen. The isopropanol (IPA) absorption of AAS mortars also follows the SRT law, and the measured intrinsic capillary sorptivity <span><math><msub><mrow><mi>S</mi></mrow><mrow><mtext>int</mtext></mrow></msub></math></span> for IPA and water are quite close. Through theoretical modeling and numerical simulation, the capillary absorption kinetics of different AAS mortars can all be accurately quantified using the Richards equation, regardless of the water retention curve model employed. These results suggest that the microstructure of AAS materials studied herein is stable during capillary water absorption. This may be attributed to the viscous characteristics of AAS materials, arising from the irreversible collapse and rearrangement of the nanostructure of C-A-S-H gels during drying.</div></div>","PeriodicalId":34137,"journal":{"name":"Developments in the Built Environment","volume":"21 ","pages":"Article 100597"},"PeriodicalIF":6.2,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143096797","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 : 2024-12-26DOI: 10.1016/j.dibe.2024.100596
Amira A. Shereiqi , Khalifa Al-Jabri , Mohammed S. Meddah , Kazi Md Abu Sohel , Alaa A. Saleh , Hamdy A. Abdel-Gawwad
Marble waste (MW) poses a significant environmental challenge due to its large quantities and difficulty in disposal. This study explored the full utilization of MW powder in creating binder. Combining MW with sodium silicate (Na2SiO3) results in the formation of calcium silicate hydrate (C-S-H) and pirssonite. The resulting binder demonstrated a compressive strength of 15–25 MPa after 28 days of air curing. Using metakaolin provides the system with dissolved aluminosilicate, which mitigates efflorescence through a neutralization process and enhances the compressive strength of the resulting hardened binder. Seawater also proved effective in reducing efflorescence by decreasing the solubility of pirssonite. Moreover, mixing seawater with Na2SiO3 induced the formation of nanoprecipitates, which positively affects the mechanical performance of the resultant binder. For sustainable building practices, using seawater as a mixing water for unreinforced building products is recommended. This conserves freshwater, making it available for other critical applications.
{"title":"Evaluating the dual role of sea water and metakaolin in the performance, efflorescence mitigation, and phase composition of sodium silicate-activated marble powder","authors":"Amira A. Shereiqi , Khalifa Al-Jabri , Mohammed S. Meddah , Kazi Md Abu Sohel , Alaa A. Saleh , Hamdy A. Abdel-Gawwad","doi":"10.1016/j.dibe.2024.100596","DOIUrl":"10.1016/j.dibe.2024.100596","url":null,"abstract":"<div><div>Marble waste (MW) poses a significant environmental challenge due to its large quantities and difficulty in disposal. This study explored the full utilization of MW powder in creating binder. Combining MW with sodium silicate (Na<sub>2</sub>SiO<sub>3</sub>) results in the formation of calcium silicate hydrate (C-S-H) and pirssonite. The resulting binder demonstrated a compressive strength of 15–25 MPa after 28 days of air curing. Using metakaolin provides the system with dissolved aluminosilicate, which mitigates efflorescence through a neutralization process and enhances the compressive strength of the resulting hardened binder. Seawater also proved effective in reducing efflorescence by decreasing the solubility of pirssonite. Moreover, mixing seawater with Na<sub>2</sub>SiO<sub>3</sub> induced the formation of nanoprecipitates, which positively affects the mechanical performance of the resultant binder. For sustainable building practices, using seawater as a mixing water for unreinforced building products is recommended. This conserves freshwater, making it available for other critical applications.</div></div>","PeriodicalId":34137,"journal":{"name":"Developments in the Built Environment","volume":"21 ","pages":"Article 100596"},"PeriodicalIF":6.2,"publicationDate":"2024-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143096795","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 : 2024-12-25DOI: 10.1016/j.dibe.2024.100595
Gen Li , Jie Yang , Hao Li , Jiaxiang Liew , Jiasheng Huang
Iron-based alkaline solid wastes provide substrates for carbon mineralization, addressing global warming. However, the mechanisms of CO2 transport and adsorption within their porous structures are not fully understood. Using advanced grand canonical Monte Carlo (GCMC) methods, this study explores CO2 transport and adsorption in iron-based alkaline wastes under different humidity conditions. The results show that FeO and Fe2O3 reduce the CO2 adsorption capacity in calcium hydroxide (CH) nanopores, a key component of these wastes. The presence of iron-based solids causes inhomogeneous porewater distribution, diminishing CO2 dissolution and adsorption on the gas-liquid interface. By analyzing adsorption energy and CO2 diffusion coefficients, we found that iron-based porous systems have lower CO2 transport efficiency and storage capacity, highlighting their limited carbonation potential. The weak CO2-surface interactions in these wastes are identified as the primary challenge to improving carbon mineralization. These findings provide crucial insights for enhancing the sustainable use of iron-based alkaline wastes.
{"title":"Enhancing sustainable utilization of iron-based alkaline solid wastes for carbon mineralization: Insights into CO2 transport and adsorption dynamics","authors":"Gen Li , Jie Yang , Hao Li , Jiaxiang Liew , Jiasheng Huang","doi":"10.1016/j.dibe.2024.100595","DOIUrl":"10.1016/j.dibe.2024.100595","url":null,"abstract":"<div><div>Iron-based alkaline solid wastes provide substrates for carbon mineralization, addressing global warming. However, the mechanisms of CO<sub>2</sub> transport and adsorption within their porous structures are not fully understood. Using advanced grand canonical Monte Carlo (GCMC) methods, this study explores CO<sub>2</sub> transport and adsorption in iron-based alkaline wastes under different humidity conditions. The results show that FeO and Fe<sub>2</sub>O<sub>3</sub> reduce the CO<sub>2</sub> adsorption capacity in calcium hydroxide (CH) nanopores, a key component of these wastes. The presence of iron-based solids causes inhomogeneous porewater distribution, diminishing CO<sub>2</sub> dissolution and adsorption on the gas-liquid interface. By analyzing adsorption energy and CO<sub>2</sub> diffusion coefficients, we found that iron-based porous systems have lower CO<sub>2</sub> transport efficiency and storage capacity, highlighting their limited carbonation potential. The weak CO<sub>2</sub>-surface interactions in these wastes are identified as the primary challenge to improving carbon mineralization. These findings provide crucial insights for enhancing the sustainable use of iron-based alkaline wastes.</div></div>","PeriodicalId":34137,"journal":{"name":"Developments in the Built Environment","volume":"21 ","pages":"Article 100595"},"PeriodicalIF":6.2,"publicationDate":"2024-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143096800","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 : 2024-12-18DOI: 10.1016/j.dibe.2024.100594
Iman Asadi , Guomin Ji , Gerald Steiner , Mohammad hajmohammadian baghban
This study investigates the integration of Microencapsulated Phase Change Materials (MPCM) into cement mortar to enhance its thermal performance while assessing its mechanical and physical properties. MPCMs, known for their high thermal energy storage capacity, help stabilize indoor temperatures by absorbing and releasing heat during phase transitions. Cement mortars with varying cement-to-sand ratios and volumetric fractions (VF) of MPCM were tested for workability, density, compressive strength, water absorption, and thermal conductivity. Microstructural analysis using X-ray CT imaging was also conducted. Results show that incorporating MPCMs reduces workability (with a maximum water-to-cement ratio increase to 0.68), density (up to 18.3%), and compressive strength (up to 46.3%), highlighting the trade-offs between thermal performance and structural integrity.
{"title":"Impact of microencapsulated phase change materials (PCMs) on the thermal and mechanical performance of cement mortar","authors":"Iman Asadi , Guomin Ji , Gerald Steiner , Mohammad hajmohammadian baghban","doi":"10.1016/j.dibe.2024.100594","DOIUrl":"10.1016/j.dibe.2024.100594","url":null,"abstract":"<div><div>This study investigates the integration of Microencapsulated Phase Change Materials (MPCM) into cement mortar to enhance its thermal performance while assessing its mechanical and physical properties. MPCMs, known for their high thermal energy storage capacity, help stabilize indoor temperatures by absorbing and releasing heat during phase transitions. Cement mortars with varying cement-to-sand ratios and volumetric fractions (VF) of MPCM were tested for workability, density, compressive strength, water absorption, and thermal conductivity. Microstructural analysis using X-ray CT imaging was also conducted. Results show that incorporating MPCMs reduces workability (with a maximum water-to-cement ratio increase to 0.68), density (up to 18.3%), and compressive strength (up to 46.3%), highlighting the trade-offs between thermal performance and structural integrity.</div></div>","PeriodicalId":34137,"journal":{"name":"Developments in the Built Environment","volume":"21 ","pages":"Article 100594"},"PeriodicalIF":6.2,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143096793","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 : 2024-12-16DOI: 10.1016/j.dibe.2024.100589
Nourhan M. Waly , Hamdy Hassan , Ryo Murata , David J. Sailor , Hatem Mahmoud
This study aims to reduce uncertainty in key thermal performance parameters of Cooling Load Temperature Difference CLTD and U-values used to estimate the energy demand of buildings in hot arid regions. A developed methodology that combines experimental and mathematical approaches is employed. A coupled experimental approach (QIRT/THM) is introduced with modifications to improve the results accuracy. The experimental approach achieved up to 93% correlation coefficient with the standard data estimation. Despite the high correlation, estimated cooling loads using tabular data and the experimental values, hold a potential difference of up to 36%. A correction equation was suggested to narrow the calculations gap under specific context. These findings could have substantial implications for reducing uncertainty by standardizing the thermal performance of buildings. Recognizing the substantial impact of building envelopes, the findings contribute to more accurate estimations which play a significant role in narrowing the Energy Performance Gap in hot climate regions.
{"title":"Experimental approach to reduce uncertainty in estimating the thermal performance of buildings’ envelopes in hot climates","authors":"Nourhan M. Waly , Hamdy Hassan , Ryo Murata , David J. Sailor , Hatem Mahmoud","doi":"10.1016/j.dibe.2024.100589","DOIUrl":"10.1016/j.dibe.2024.100589","url":null,"abstract":"<div><div>This study aims to reduce uncertainty in key thermal performance parameters of Cooling Load Temperature Difference CLTD and U-values used to estimate the energy demand of buildings in hot arid regions. A developed methodology that combines experimental and mathematical approaches is employed. A coupled experimental approach <em>(QIRT/THM)</em> is introduced with modifications to improve the results accuracy. The experimental approach achieved up to 93% correlation coefficient with the standard data estimation. Despite the high correlation, estimated cooling loads using tabular data and the experimental values, hold a potential difference of up to 36%. A correction equation was suggested to narrow the calculations gap under specific context. These findings could have substantial implications for reducing uncertainty by standardizing the thermal performance of buildings. Recognizing the substantial impact of building envelopes, the findings contribute to more accurate estimations which play a significant role in narrowing the Energy Performance Gap in hot climate regions.</div></div>","PeriodicalId":34137,"journal":{"name":"Developments in the Built Environment","volume":"21 ","pages":"Article 100589"},"PeriodicalIF":6.2,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143096792","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 : 2024-12-15DOI: 10.1016/j.dibe.2024.100590
Tianzhen Li , Xiaonan Tang , Jun Xia
The mining and crushing of limestone and travertine generate substantial quantities of powder and debris, which are typically discarded as solid waste in landfills, posing environmental concerns. To promote waste utilization, this study introduced an innovative pervious concrete combined with travertine aggregate substituting natural aggregate and limestone powder (LSP) as a cement substitute (TALPPC). Different properties of TALPPC were tested and characterized. The results showed that incorporating 5–20% LSP into TALPPC marginally decreased compressive strength, but TALPPC became lighter and had good freeze-thaw resistance. LSP's addition mitigated permeability and porosity by filling concrete pores proportional to its content. Notably, TALPPC demonstrated peak Pb2+ immobilization under the ternary competitive mechanism, with LSP enhancing heavy metal ion adsorption. The laboratory-scale TALPPC pavements displayed remarkable heavy metal adsorption capacities and significantly reduced runoff. Given its waste recycling potential, CO2 mitigation, and engineering suitability, the utilization of 15% LSP in TALPPC production was advised.
{"title":"Multi-functional properties of low-carbon travertine aggregate pervious concrete modified by waste limestone powder","authors":"Tianzhen Li , Xiaonan Tang , Jun Xia","doi":"10.1016/j.dibe.2024.100590","DOIUrl":"10.1016/j.dibe.2024.100590","url":null,"abstract":"<div><div>The mining and crushing of limestone and travertine generate substantial quantities of powder and debris, which are typically discarded as solid waste in landfills, posing environmental concerns. To promote waste utilization, this study introduced an innovative pervious concrete combined with travertine aggregate substituting natural aggregate and limestone powder (LSP) as a cement substitute (TALPPC). Different properties of TALPPC were tested and characterized. The results showed that incorporating 5–20% LSP into TALPPC marginally decreased compressive strength, but TALPPC became lighter and had good freeze-thaw resistance. LSP's addition mitigated permeability and porosity by filling concrete pores proportional to its content. Notably, TALPPC demonstrated peak Pb<sup>2+</sup> immobilization under the ternary competitive mechanism, with LSP enhancing heavy metal ion adsorption. The laboratory-scale TALPPC pavements displayed remarkable heavy metal adsorption capacities and significantly reduced runoff. Given its waste recycling potential, CO<sub>2</sub> mitigation, and engineering suitability, the utilization of 15% LSP in TALPPC production was advised.</div></div>","PeriodicalId":34137,"journal":{"name":"Developments in the Built Environment","volume":"21 ","pages":"Article 100590"},"PeriodicalIF":6.2,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143096789","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 : 2024-12-15DOI: 10.1016/j.dibe.2024.100593
Mehrdad Alizadeh, Payam Asadi, Mohammad Reza Eftekhar, Davood Mostofinejad
Recycled rubber presents a promising approach to enhancing the seismic performance of reinforced concrete (RC) structures and promoting sustainability. Incorporating rubber into the concrete matrix can help address the environmental issue of waste tire disposal while improving conventional concrete's ductility and energy absorption. However, increasing rubber content can paradoxically reduce energy absorption. Therefore, achieving optimal bonding between rubber and cement is crucial to maximizing the benefits of rubberized concrete (RuC). This study aims to overcome these challenges by exploring the potential of a pre-mixing technique to improve the overall seismic performance of RuC structures. To this end, the study investigates the cyclic flexural response of RC beams containing 15% rubber content, focusing on a novel pre-mixing technique designed to enhance rubber-cement bonding. Mechanical experiments were conducted on specimens, including conventional concrete (CC), unmodified RuC, and pre-mixed RuC. The study analyzes the impact of rubber content and pre-mixing on the energy absorption and ductility of the flexural hinge, evaluating factors such as pinching behavior and stiffness degradation. Results demonstrate that, to achieve 70% of their ultimate strength after peak load, pre-mixed beams exhibit a 235% higher cumulative energy absorption compared to both CC and unmodified RuC beams. Notably, pre-mixed beams exhibited significantly less pinching behavior and experienced a substantial reduction in both strength and stiffness degradation (52% and 30%, respectively) during successive cycles compared to unmodified rubberized beams. Further studies are recommended to investigate the effects of mixing composition on optimizing performance.
{"title":"Enhancing hysteretic behavior in rubberized reinforced concrete beams through a pre-mixing technique","authors":"Mehrdad Alizadeh, Payam Asadi, Mohammad Reza Eftekhar, Davood Mostofinejad","doi":"10.1016/j.dibe.2024.100593","DOIUrl":"10.1016/j.dibe.2024.100593","url":null,"abstract":"<div><div>Recycled rubber presents a promising approach to enhancing the seismic performance of reinforced concrete (RC) structures and promoting sustainability. Incorporating rubber into the concrete matrix can help address the environmental issue of waste tire disposal while improving conventional concrete's ductility and energy absorption. However, increasing rubber content can paradoxically reduce energy absorption. Therefore, achieving optimal bonding between rubber and cement is crucial to maximizing the benefits of rubberized concrete (RuC). This study aims to overcome these challenges by exploring the potential of a pre-mixing technique to improve the overall seismic performance of RuC structures. To this end, the study investigates the cyclic flexural response of RC beams containing 15% rubber content, focusing on a novel pre-mixing technique designed to enhance rubber-cement bonding. Mechanical experiments were conducted on specimens, including conventional concrete (CC), unmodified RuC, and pre-mixed RuC. The study analyzes the impact of rubber content and pre-mixing on the energy absorption and ductility of the flexural hinge, evaluating factors such as pinching behavior and stiffness degradation. Results demonstrate that, to achieve 70% of their ultimate strength after peak load, pre-mixed beams exhibit a 235% higher cumulative energy absorption compared to both CC and unmodified RuC beams. Notably, pre-mixed beams exhibited significantly less pinching behavior and experienced a substantial reduction in both strength and stiffness degradation (52% and 30%, respectively) during successive cycles compared to unmodified rubberized beams. Further studies are recommended to investigate the effects of mixing composition on optimizing performance.</div></div>","PeriodicalId":34137,"journal":{"name":"Developments in the Built Environment","volume":"21 ","pages":"Article 100593"},"PeriodicalIF":6.2,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143096788","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 : 2024-12-15DOI: 10.1016/j.dibe.2024.100587
Faris Elghaish , Sandra Matarneh , Farzad Pour Rahimian , Essam Abdellatef , David Edwards , Obuks Ejohwomu , Mohammed Abdelmegid , Chansik Park
With the increasing utilisation of deep learning (DL) for detecting and classifying distress in concrete surfaces, the demand for accurate and precise models has risen. This study proposes a novel empirical approach of multilayer optimisation for two prominent DL models, namely ResNet101 and Xception, to classify distress in concrete surfaces. Both models were trained using 20,000 images depicting various types of cracks and tested with another set of 20,000 images. Four algorithms (Sequential Motion Optimisation (SMO), shuffled frog-leaping algorithm (SFLA), grey wolf optimisation (GWO), walrus optimisation (WO)) were then applied to enhance classification accuracy. After evaluating the DL models’ overall performance, the four algorithms were grouped into two layers. The first layer comprised SMO, SFLA, GWO and their combined application. Subsequently, the second stage implemented the WO optimiser to enhance performance further. The outcomes demonstrated a substantial positive impact on the accuracy of both CNN models. Specifically, ResNet101 achieved 98.9% accuracy and Xception reached 99.2% accuracy. In the accuracy breakdown, ResNet101 achieved 97.6% accuracy and Xception achieved 98.3% accuracy in the first stage, compared to 87.4% for Xception and 83.1% for ResNet101 before optimisation. Given that this approach achieves over 99% accuracy in detecting cracks on concrete surfaces, it offers a significant improvement in the efficiency and cost-effectiveness of structural health surveys for large buildings. Furthermore, it provides structural engineers with precise data to accurately determine and implement the required maintenance actions.
{"title":"Multi-level optimisation of feature extraction networks for concrete surface crack detection","authors":"Faris Elghaish , Sandra Matarneh , Farzad Pour Rahimian , Essam Abdellatef , David Edwards , Obuks Ejohwomu , Mohammed Abdelmegid , Chansik Park","doi":"10.1016/j.dibe.2024.100587","DOIUrl":"10.1016/j.dibe.2024.100587","url":null,"abstract":"<div><div>With the increasing utilisation of deep learning (DL) for detecting and classifying distress in concrete surfaces, the demand for accurate and precise models has risen. This study proposes a novel empirical approach of multilayer optimisation for two prominent DL models, namely ResNet101 and Xception, to classify distress in concrete surfaces. Both models were trained using 20,000 images depicting various types of cracks and tested with another set of 20,000 images. Four algorithms (Sequential Motion Optimisation (SMO), shuffled frog-leaping algorithm (SFLA), grey wolf optimisation (GWO), walrus optimisation (WO)) were then applied to enhance classification accuracy. After evaluating the DL models’ overall performance, the four algorithms were grouped into two layers. The first layer comprised SMO, SFLA, GWO and their combined application. Subsequently, the second stage implemented the WO optimiser to enhance performance further. The outcomes demonstrated a substantial positive impact on the accuracy of both CNN models. Specifically, ResNet101 achieved 98.9% accuracy and Xception reached 99.2% accuracy. In the accuracy breakdown, ResNet101 achieved 97.6% accuracy and Xception achieved 98.3% accuracy in the first stage, compared to 87.4% for Xception and 83.1% for ResNet101 before optimisation. Given that this approach achieves over 99% accuracy in detecting cracks on concrete surfaces, it offers a significant improvement in the efficiency and cost-effectiveness of structural health surveys for large buildings. Furthermore, it provides structural engineers with precise data to accurately determine and implement the required maintenance actions.</div></div>","PeriodicalId":34137,"journal":{"name":"Developments in the Built Environment","volume":"21 ","pages":"Article 100587"},"PeriodicalIF":6.2,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143096995","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 : 2024-12-09DOI: 10.1016/j.dibe.2024.100592
Bruna S. Santos , Wesley B.S. Machini , Gina Matias , Nelson F.S.T. Moreira , Paulo M.M. Portugal , Isabel Torres , António Tadeu , João A.S. Almeida
In this work, a comparative study on the mechanical, microstructural and chemical properties of mortars with enhanced chemical resistance was performed to investigate the effects of sulphuric acid attack. For this, specimens of ordinary and improved formulations were immersed in water and sulphuric acid at pH 0.0 for 14 days, assessing the relative residual compressive strength and corrosion depth. The sulphuric acid attack resulted in pronounced changes in the mechanical properties and severe corrosion for the ordinary mortar. In contrast, the improved mortars exhibited moderate to high acid resistance (relative residual strengths up to 94.6% and minimal corrosion depth of 0.5 mm). A significant quality gain of up to 49% and 180% was also observed when comparing the improved mortars with a reference mortar resistant to acid in terms of relative residual compressive strength and corrosion depth, respectively. The effect of sulphuric acid attack on the microstructure and chemical composition of mortars was further evaluated by mercury intrusion porosimetry (MIP), attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), and scanning electron microscopy with energy dispersive X-ray (SEM-EDX).
{"title":"Mortars with enhanced chemical resistance: Effects of sulphuric acid exposure","authors":"Bruna S. Santos , Wesley B.S. Machini , Gina Matias , Nelson F.S.T. Moreira , Paulo M.M. Portugal , Isabel Torres , António Tadeu , João A.S. Almeida","doi":"10.1016/j.dibe.2024.100592","DOIUrl":"10.1016/j.dibe.2024.100592","url":null,"abstract":"<div><div>In this work, a comparative study on the mechanical, microstructural and chemical properties of mortars with enhanced chemical resistance was performed to investigate the effects of sulphuric acid attack. For this, specimens of ordinary and improved formulations were immersed in water and sulphuric acid at pH 0.0 for 14 days, assessing the relative residual compressive strength and corrosion depth. The sulphuric acid attack resulted in pronounced changes in the mechanical properties and severe corrosion for the ordinary mortar. In contrast, the improved mortars exhibited moderate to high acid resistance (relative residual strengths up to 94.6% and minimal corrosion depth of 0.5 mm). A significant quality gain of up to 49% and 180% was also observed when comparing the improved mortars with a reference mortar resistant to acid in terms of relative residual compressive strength and corrosion depth, respectively. The effect of sulphuric acid attack on the microstructure and chemical composition of mortars was further evaluated by mercury intrusion porosimetry (MIP), attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), and scanning electron microscopy with energy dispersive X-ray (SEM-EDX).</div></div>","PeriodicalId":34137,"journal":{"name":"Developments in the Built Environment","volume":"21 ","pages":"Article 100592"},"PeriodicalIF":6.2,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143096791","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}
Three-dimensional Ground penetrating radar (3D-GPR) has been widely applied in nondestructive testing of concealed cracks within asphalt pavement. However, due to the weak GPR echo characteristics of concealed cracks and their susceptibility to environmental noise, automatic recognition of crack echo features has always faced significant challenges. To address this issue, numerous semi-rigid base crack images were collected and extracted using feature point tensor voting with 3D-GPR's efficient, non-destructive road structure detection. In this paper, the radar image is gridded by the ECA-ResNet network, and the center point of the detected crack grid is used as the feature point, and the continuous path of the crack is reconstructed by the tensor voting algorithm. The results show that this method achieves 90% crack extraction, which is superior to traditional target detection networks such as YOLOv5 and Fast R-CNN, providing an effective tool for rapid non-destructive detection of pavement cracks.
{"title":"Three-dimensional ground-penetrating radar-based feature point tensor voting for semi-rigid base asphalt pavement crack detection","authors":"Zhiyong Huang , Guoyuan Xu , Xiaoning Zhang , Bo Zang , Huayang Yu","doi":"10.1016/j.dibe.2024.100591","DOIUrl":"10.1016/j.dibe.2024.100591","url":null,"abstract":"<div><div>Three-dimensional Ground penetrating radar (3D-GPR) has been widely applied in nondestructive testing of concealed cracks within asphalt pavement. However, due to the weak GPR echo characteristics of concealed cracks and their susceptibility to environmental noise, automatic recognition of crack echo features has always faced significant challenges. To address this issue, numerous semi-rigid base crack images were collected and extracted using feature point tensor voting with 3D-GPR's efficient, non-destructive road structure detection. In this paper, the radar image is gridded by the ECA-ResNet network, and the center point of the detected crack grid is used as the feature point, and the continuous path of the crack is reconstructed by the tensor voting algorithm. The results show that this method achieves 90% crack extraction, which is superior to traditional target detection networks such as YOLOv5 and Fast R-CNN, providing an effective tool for rapid non-destructive detection of pavement cracks.</div></div>","PeriodicalId":34137,"journal":{"name":"Developments in the Built Environment","volume":"21 ","pages":"Article 100591"},"PeriodicalIF":6.2,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143096794","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}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号