Pub Date : 2026-07-01Epub Date: 2025-12-30DOI: 10.1016/j.cscm.2025.e05740
Zhen Wang , Libing Jin , Panpan Liu , Xinya Liang , Tian Wu
Carbon steel is prone to corrosion in marine environments. This significantly deteriorates its bending mechanical properties and has the potential to compromise the long-term serviceability, safety and reliability of marine infrastructure. A combined experimental and numerical simulation approach was employed to investigate the degradation mechanisms affecting the bending performance of carbon steel in marine environments. This approach was used to systematically examine the corrosion morphology characteristics and the evolution of the three-point bending mechanical properties of corrosion carbon steel. This study was designed to quantitatively analyze the degradation relationship between thickness loss rate and bending performance through tensile tests and three-point bending tests conducted on 42 carbon steel specimens. A three-dimensional numerical simulation of corroded specimens was created based on a random method. The results indicate that: 1) the thickness loss rate of the specimens increased linearly as the exposed time increased. Conversely, the ultimate bending load was found to vary inversely with the loss of thickness. The ultimate bending load decreases by more than 31.9 % when the thickness loss rate reaches 7.9 %. 2) Through comparative analysis between computational and experimental results, an average relative error of merely 6.2 % was observed, confirming the reliability of the finite element analysis method. 3) Corrosion time is also a key factor influencing performance degradation: when corrosion time reaches 300 days and 400 days, the corresponding ultimate bending loads decrease by 41.7 % and 55.6 %, respectively.
{"title":"Three-point bending performance of carbon steel with random pitting corrosion in marine environments","authors":"Zhen Wang , Libing Jin , Panpan Liu , Xinya Liang , Tian Wu","doi":"10.1016/j.cscm.2025.e05740","DOIUrl":"10.1016/j.cscm.2025.e05740","url":null,"abstract":"<div><div>Carbon steel is prone to corrosion in marine environments. This significantly deteriorates its bending mechanical properties and has the potential to compromise the long-term serviceability, safety and reliability of marine infrastructure. A combined experimental and numerical simulation approach was employed to investigate the degradation mechanisms affecting the bending performance of carbon steel in marine environments. This approach was used to systematically examine the corrosion morphology characteristics and the evolution of the three-point bending mechanical properties of corrosion carbon steel. This study was designed to quantitatively analyze the degradation relationship between thickness loss rate and bending performance through tensile tests and three-point bending tests conducted on 42 carbon steel specimens. A three-dimensional numerical simulation of corroded specimens was created based on a random method. The results indicate that: 1) the thickness loss rate of the specimens increased linearly as the exposed time increased. Conversely, the ultimate bending load was found to vary inversely with the loss of thickness. The ultimate bending load decreases by more than 31.9 % when the thickness loss rate reaches 7.9 %. 2) Through comparative analysis between computational and experimental results, an average relative error of merely 6.2 % was observed, confirming the reliability of the finite element analysis method. 3) Corrosion time is also a key factor influencing performance degradation: when corrosion time reaches 300 days and 400 days, the corresponding ultimate bending loads decrease by 41.7 % and 55.6 %, respectively.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"24 ","pages":"Article e05740"},"PeriodicalIF":6.6,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145921669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-07-01Epub Date: 2025-12-05DOI: 10.1016/j.cscm.2025.e05644
Walid Mansour , Mohamed H. El-Naqeeb , Sabry Fayed , Taher A. Tawfik
This research experimentally and numerically investigates the feasibility of using low-cost timber plates to enhance the shear behavior of reinforced concrete (RC) beams. Seven simply supported beams with a shear span-to-depth ratio (a/d) of 1.8 were tested under three-point bending, including one control specimen and six strengthened beams. Two strengthening techniques, externally bonded (EB) and near-surface mounted (NSM), were examined using three attachment methods: epoxy only, 10 mm diameter anchor bolts only, and a combination of both. A 3D finite element model (FEM) was developed in ABAQUS V2017 to evaluate the influence of increasing the a/d ratio from 1.8 to 3.1 on the ultimate load, stiffness, and toughness of the strengthened beams.
Experimental
results showed that timber plates, regardless of the strengthening technique, effectively restricted the propagation of the main shear crack and diverted it into multiple secondary cracks. Externally bonded specimens achieved higher ultimate loads than NSM specimens due to the absence of groove-induced reductions in the concrete section. The use of anchor bolts, either alone or in combination with epoxy, prevented debonding and produced the highest ultimate loads, reaching 91 kN and 92 kN, respectively, representing increases of 21.3 % and 22.7 % over the control beam. Both attachment methods also exhibited stiffness improvements of 10.8 % compared to the control beam. Numerical analysis indicated that increasing the a/d ratio from 1.8 to 3.1 led to reductions in stiffness of 43 %-47 %, ultimate load of 18 %-30 %, and toughness of 7 %-30 %.
{"title":"Comparative analysis of the shear response of RC beams strengthened with externally applied and near-surface mounted timber plates","authors":"Walid Mansour , Mohamed H. El-Naqeeb , Sabry Fayed , Taher A. Tawfik","doi":"10.1016/j.cscm.2025.e05644","DOIUrl":"10.1016/j.cscm.2025.e05644","url":null,"abstract":"<div><div>This research experimentally and numerically investigates the feasibility of using low-cost timber plates to enhance the shear behavior of reinforced concrete (RC) beams. Seven simply supported beams with a shear span-to-depth ratio (a/d) of 1.8 were tested under three-point bending, including one control specimen and six strengthened beams. Two strengthening techniques, externally bonded (EB) and near-surface mounted (NSM), were examined using three attachment methods: epoxy only, 10 mm diameter anchor bolts only, and a combination of both. A 3D finite element model (FEM) was developed in ABAQUS V2017 to evaluate the influence of increasing the a/d ratio from 1.8 to 3.1 on the ultimate load, stiffness, and toughness of the strengthened beams.</div></div><div><h3>Experimental</h3><div>results showed that timber plates, regardless of the strengthening technique, effectively restricted the propagation of the main shear crack and diverted it into multiple secondary cracks. Externally bonded specimens achieved higher ultimate loads than NSM specimens due to the absence of groove-induced reductions in the concrete section. The use of anchor bolts, either alone or in combination with epoxy, prevented debonding and produced the highest ultimate loads, reaching 91 kN and 92 kN, respectively, representing increases of 21.3 % and 22.7 % over the control beam. Both attachment methods also exhibited stiffness improvements of 10.8 % compared to the control beam. Numerical analysis indicated that increasing the a/d ratio from 1.8 to 3.1 led to reductions in stiffness of 43 %-47 %, ultimate load of 18 %-30 %, and toughness of 7 %-30 %.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"24 ","pages":"Article e05644"},"PeriodicalIF":6.6,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145921671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-07-01Epub Date: 2026-01-03DOI: 10.1016/j.cscm.2026.e05753
Serena Spadavecchia , Giovanna Montesano , Concetta Rispoli , Martina Mercurio , Mario Cesarano , Assunta Campanile , Barbara Liguori , Paola Petrosino , Piergiulio Cappelletti
The long-lasting performance of ancient pozzolanic mortars highlights the advanced expertise of Roman builders. By intentionally mixing lime with specific volcanic materials, like ash or sand, the Romans developed hydraulic mortars and concretes that could harden even underwater and exhibit high mechanical strength. Furthermore, these pozzolanic additives accelerated the setting process via hydraulic reactions, offering a faster alternative to the slow carbonation of pure slaked lime. This study provides the first integrated reconstruction of the technological choices and historical evolution of the Brick Amphitheater of Nola by linking the provenance and compositional variability of volcanic aggregates to its different building phases. Due to the site's complex historical stratigraphy and multiple construction phases, a targeted, non-invasive sampling strategy was adopted. Eighteen bedding mortar samples from the Amphitheater structures and adjoining Late Antique walls were analyzed using an integrated analytical including Polarized Optical Microscopy, X-Ray Powder Diffraction, Field Emission Scanning Electron Microscopy with Energy-Dispersive X-Ray Spectroscopy, Mercury Intrusion Porosimetry, Differential Thermal Analysis and Thermogravimetric Analysis. The research aims to distinguish construction phases and trace the evolution of building techniques by i) identifying the geological provenance of raw materials, ii) analyzing the mortar mix design, and iii) reconstructing the site's chronology. Results confirmed that raw materials were locally sourced, employing aggregates from Somma-Vesuvius district, as well as recycled Neapolitan Yellow Tuff, highlighting the Roman builders' expertise in selecting and combining local volcanic aggregates with hydrated lime to produce natural hydraulic mortars. The observed hydraulicity is attributed to the binder-aggregate interaction, evidenced by reaction rims and the formation of calcium-aluminum-silicate-hydrate (C-A-S-H) gels. Mortars from the Amphitheater structures display optimized binder-aggregate ratios and well-compacted pore networks, contrasting with the greater heterogeneity, increased porosity and mixed aggregate origins of mortars from Late Antique walls. These findings reflect intentional and consistent material selection and formulation, also reflecting chronological and functional evolution of the site.
{"title":"Decoding Roman construction techniques through a multiproxy study of pozzolanic mortars from the Brick Amphitheater of Nola (Campania, Southern Italy)","authors":"Serena Spadavecchia , Giovanna Montesano , Concetta Rispoli , Martina Mercurio , Mario Cesarano , Assunta Campanile , Barbara Liguori , Paola Petrosino , Piergiulio Cappelletti","doi":"10.1016/j.cscm.2026.e05753","DOIUrl":"10.1016/j.cscm.2026.e05753","url":null,"abstract":"<div><div>The long-lasting performance of ancient pozzolanic mortars highlights the advanced expertise of Roman builders. By intentionally mixing lime with specific volcanic materials, like ash or sand, the Romans developed hydraulic mortars and concretes that could harden even underwater and exhibit high mechanical strength. Furthermore, these pozzolanic additives accelerated the setting process via hydraulic reactions, offering a faster alternative to the slow carbonation of pure slaked lime. This study provides the first integrated reconstruction of the technological choices and historical evolution of the Brick Amphitheater of Nola by linking the provenance and compositional variability of volcanic aggregates to its different building phases. Due to the site's complex historical stratigraphy and multiple construction phases, a targeted, non-invasive sampling strategy was adopted. Eighteen bedding mortar samples from the Amphitheater structures and adjoining Late Antique walls were analyzed using an integrated analytical including Polarized Optical Microscopy, X-Ray Powder Diffraction, Field Emission Scanning Electron Microscopy with Energy-Dispersive X-Ray Spectroscopy, Mercury Intrusion Porosimetry, Differential Thermal Analysis and Thermogravimetric Analysis. The research aims to distinguish construction phases and trace the evolution of building techniques by i) identifying the geological provenance of raw materials, ii) analyzing the mortar mix design, and iii) reconstructing the site's chronology. Results confirmed that raw materials were locally sourced, employing aggregates from Somma-Vesuvius district, as well as recycled Neapolitan Yellow Tuff, highlighting the Roman builders' expertise in selecting and combining local volcanic aggregates with hydrated lime to produce natural hydraulic mortars. The observed hydraulicity is attributed to the binder-aggregate interaction, evidenced by reaction rims and the formation of calcium-aluminum-silicate-hydrate (C-A-S-H) gels. Mortars from the Amphitheater structures display optimized binder-aggregate ratios and well-compacted pore networks, contrasting with the greater heterogeneity, increased porosity and mixed aggregate origins of mortars from Late Antique walls. These findings reflect intentional and consistent material selection and formulation, also reflecting chronological and functional evolution of the site.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"24 ","pages":"Article e05753"},"PeriodicalIF":6.6,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145921676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-07-01Epub Date: 2025-12-30DOI: 10.1016/j.cscm.2025.e05734
Jiří Němeček , Jan Procházka , Patricie Halodová , Jiří Němeček
This article investigates the interplay between microstructure, focused ion beam (FIB) micro-beam preparation, and micromechanical properties of cement pastes derived from Portland cement CEM I-42.5R. It identifies and quantifies the effects of gallium FIB processing on individual cement phases, including inner and outer hydration products, Portlandite, and residual clinker. A detailed methodology is presented for preparing cantilever micro-beams, emphasizing critical steps such as phase selection, imaging, ion milling, transport, and mechanical testing. Several adverse factors are identified: continuous electron beam imaging increases surface roughness and reduces tensile strength; high ion beam currents (1 nA under the given experimental configuration and FIB settings) cause local heating, leading to water evaporation, densification, and phase transformations in C–S–H gels and Portlandite. Additional challenges include ion beam drift, which distorts beam geometry, and vacuum-induced moisture cycling, which promotes micro-cracking. Best practices are proposed to mitigate these issues, including the use of low ion beam currents (0.2–1 nA), minimized electron beam exposure, stable environmental control to prevent moisture cycling, and careful phase selection. The article provides examples of both good and incorrect practices, offering practical guidelines for reliable FIB-based micromechanical testing of cement pastes.
{"title":"Interplay between FIB processing, microstructure, and micromechanics in cement pastes","authors":"Jiří Němeček , Jan Procházka , Patricie Halodová , Jiří Němeček","doi":"10.1016/j.cscm.2025.e05734","DOIUrl":"10.1016/j.cscm.2025.e05734","url":null,"abstract":"<div><div>This article investigates the interplay between microstructure, focused ion beam (FIB) micro-beam preparation, and micromechanical properties of cement pastes derived from Portland cement CEM I-42.5R. It identifies and quantifies the effects of gallium FIB processing on individual cement phases, including inner and outer hydration products, Portlandite, and residual clinker. A detailed methodology is presented for preparing cantilever micro-beams, emphasizing critical steps such as phase selection, imaging, ion milling, transport, and mechanical testing. Several adverse factors are identified: continuous electron beam imaging increases surface roughness and reduces tensile strength; high ion beam currents (<span><math><mo>></mo></math></span>1 nA under the given experimental configuration and FIB settings) cause local heating, leading to water evaporation, densification, and phase transformations in C–S–H gels and Portlandite. Additional challenges include ion beam drift, which distorts beam geometry, and vacuum-induced moisture cycling, which promotes micro-cracking. Best practices are proposed to mitigate these issues, including the use of low ion beam currents (0.2–1 nA), minimized electron beam exposure, stable environmental control to prevent moisture cycling, and careful phase selection. The article provides examples of both good and incorrect practices, offering practical guidelines for reliable FIB-based micromechanical testing of cement pastes.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"24 ","pages":"Article e05734"},"PeriodicalIF":6.6,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145921818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study investigated the fresh and hardened properties of controlled low-strength material (CLSM) using ground coal bottom ash (GBA) mixed with ground calcium carbide residue (GCR) as the primary binder. Sieved coal bottom ash (SBA) fully replaced the river sand by volume. The effects of sodium metasilicate pentahydrate (SM) at 2 %, 4 %, 6 %, and 8 % by weight of binder as a solid activator for one-part CLSM were also examined. Fresh and hardened properties, including flowability, hardening time, bleeding, ball drop, unconfined compressive strength (UCS), and elastic modulus, were evaluated. The microstructures of the CLSM pastes were analyzed using X-ray diffraction (XRD) and scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS). All CLSM mixtures exhibited high flowability (>200 mm). The proportions of GBA and GCR significantly influenced the fresh and hardened properties. Replacing river sand with SBA resulted in lightweight CLSM; however, complete replacement increased hardening time, bleeding, and ball drop value and reduced UCS. An optimal SM dosage of approximately 4 % resulted in a 28-day UCS of 2.54 MPa, bleeding of 0.6 %, hardening time of 33 h, and a ball drop value of 68.5 mm, meeting typical CLSM requirements. XRD and SEM-EDS results revealed that the GCR acted as a crucial source of calcium oxide. Their effective reaction to strength development in C-S-H and N-A-S-H gels, particularly when activated by 4 % SM, positively contributed to the observed compressive strength and denser matrix of the CLSM. Incorporating GBA, GCR, and SBA offers a sustainable, low-carbon approach for CLSM production, promoting waste valorization and conserving natural resources.
{"title":"Utilization of industrial by-products as binders and fine aggregates for one-part lightweight controlled low-strength materials: Turning waste to value approach","authors":"Warayut Dokduea, Potchara Praneedpolkrang, Weerachart Tangchirapat, Chai Jaturapitakkul","doi":"10.1016/j.cscm.2025.e05676","DOIUrl":"10.1016/j.cscm.2025.e05676","url":null,"abstract":"<div><div>This study investigated the fresh and hardened properties of controlled low-strength material (CLSM) using ground coal bottom ash (GBA) mixed with ground calcium carbide residue (GCR) as the primary binder. Sieved coal bottom ash (SBA) fully replaced the river sand by volume. The effects of sodium metasilicate pentahydrate (SM) at 2 %, 4 %, 6 %, and 8 % by weight of binder as a solid activator for one-part CLSM were also examined. Fresh and hardened properties, including flowability, hardening time, bleeding, ball drop, unconfined compressive strength (UCS), and elastic modulus, were evaluated. The microstructures of the CLSM pastes were analyzed using X-ray diffraction (XRD) and scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS). All CLSM mixtures exhibited high flowability (>200 mm). The proportions of GBA and GCR significantly influenced the fresh and hardened properties. Replacing river sand with SBA resulted in lightweight CLSM; however, complete replacement increased hardening time, bleeding, and ball drop value and reduced UCS. An optimal SM dosage of approximately 4 % resulted in a 28-day UCS of 2.54 MPa, bleeding of 0.6 %, hardening time of 33 h, and a ball drop value of 68.5 mm, meeting typical CLSM requirements. XRD and SEM-EDS results revealed that the GCR acted as a crucial source of calcium oxide. Their effective reaction to strength development in C-S-H and N-A-S-H gels, particularly when activated by 4 % SM, positively contributed to the observed compressive strength and denser matrix of the CLSM. Incorporating GBA, GCR, and SBA offers a sustainable, low-carbon approach for CLSM production, promoting waste valorization and conserving natural resources.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"24 ","pages":"Article e05676"},"PeriodicalIF":6.6,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145718688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-07-01Epub Date: 2025-12-16DOI: 10.1016/j.cscm.2025.e05704
Guodong Zhu , Donghe Zhang , Lei Zhang , Ke Li , Kaidi Liu , Bin Guo , Jie Xu
Airport runways are the lifeline of the aviation industry, and their maintenance plays a crucial role in ensuring flight safety. How to thoroughly remove the stubborn aircraft tire tread rubber layer under extreme working conditions (rainy/snow season) while ensuring the integrity of the cement or asphalt runway surface structure is an urgent technical challenge that needs to be overcome in the field of runway maintenance. This paper conducts laser rubber layer of different thicknesses removal tests on runways with different base structures (cement/asphalt) using nanosecond pulsed lasers under various laser conditions (power/spot overlap rate) and surface dry or wet states (sunny weather/rainy season/post-snow conditions). The laser rubber removal process database under different weather conditions was obtained using an optical microscope, high-speed camera, and pendulum friction coefficient tester, revealing the coupling mechanisms of laser ice breaking and water hazard penetration to remove rubber. The mapping relationship between the cleaning mechanism and laser conditions, rubber deposition thickness, and cleaning effect was established. There is a linear relationship between the laser ablation depth (Y) and the logarithm of laser energy (X): Y= 1.1X-0.31. The initial cleaning threshold for rubber deposition is 0.28 J/cm2, and under sunny conditions, chemical combustion removal accounts for 2.24 % - 33.4 % of the entire removal mechanism, with optical thermal ablation mechanism dominating. Under the unit area (1 cm2), the laser energy consumed by 1 mm of ice layer is 1.8 J/cm2. Under the action of the laser, the upper surface of the ice layer is melted, and the remaining laser passes through the ice layer and melts the bottom by heating the rubber deposit. Under the rainy season conditions, the plasma plume area decreases, the interaction between the pulsed laser and rubber deposition weakens, and the damage to the runway is reduced under the same laser flux, but it is not sufficient to completely avoid the excessive thermal effects. The research results can provide a solution to the safety dilemma of airport operations during rainy and winter seasons, and promote the construction of "safe, green, and smart" airports.
{"title":"Laser-induced ice breaking and water penetration in extreme weather for precise rubber deposit removal on airport runways","authors":"Guodong Zhu , Donghe Zhang , Lei Zhang , Ke Li , Kaidi Liu , Bin Guo , Jie Xu","doi":"10.1016/j.cscm.2025.e05704","DOIUrl":"10.1016/j.cscm.2025.e05704","url":null,"abstract":"<div><div>Airport runways are the lifeline of the aviation industry, and their maintenance plays a crucial role in ensuring flight safety. How to thoroughly remove the stubborn aircraft tire tread rubber layer under extreme working conditions (rainy/snow season) while ensuring the integrity of the cement or asphalt runway surface structure is an urgent technical challenge that needs to be overcome in the field of runway maintenance. This paper conducts laser rubber layer of different thicknesses removal tests on runways with different base structures (cement/asphalt) using nanosecond pulsed lasers under various laser conditions (power/spot overlap rate) and surface dry or wet states (sunny weather/rainy season/post-snow conditions). The laser rubber removal process database under different weather conditions was obtained using an optical microscope, high-speed camera, and pendulum friction coefficient tester, revealing the coupling mechanisms of laser ice breaking and water hazard penetration to remove rubber. The mapping relationship between the cleaning mechanism and laser conditions, rubber deposition thickness, and cleaning effect was established. There is a linear relationship between the laser ablation depth (Y) and the logarithm of laser energy (X): Y= 1.1X-0.31. The initial cleaning threshold for rubber deposition is 0.28 J/cm<sup>2</sup>, and under sunny conditions, chemical combustion removal accounts for 2.24 % - 33.4 % of the entire removal mechanism, with optical thermal ablation mechanism dominating. Under the unit area (1 cm<sup>2</sup>), the laser energy consumed by 1 mm of ice layer is 1.8 J/cm<sup>2</sup>. Under the action of the laser, the upper surface of the ice layer is melted, and the remaining laser passes through the ice layer and melts the bottom by heating the rubber deposit. Under the rainy season conditions, the plasma plume area decreases, the interaction between the pulsed laser and rubber deposition weakens, and the damage to the runway is reduced under the same laser flux, but it is not sufficient to completely avoid the excessive thermal effects. The research results can provide a solution to the safety dilemma of airport operations during rainy and winter seasons, and promote the construction of \"safe, green, and smart\" airports.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"24 ","pages":"Article e05704"},"PeriodicalIF":6.6,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145788421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-07-01Epub Date: 2025-12-12DOI: 10.1016/j.cscm.2025.e05692
Jiahuan Yu, Yuhan Li, Song Huang
Research on steel pipe reinforced concrete has advanced significantly, yet its role in construction still requires more exploration. This study examines a new type of structure similar to steel pipe concrete columns, known as Oil-Filled Steel Pipe (OFST), which consist of circular steel tubes filled with anti-wear hydraulic oil. Despite being a derivative of steel, there is limited global research on these columns, with most studies focusing on their use in mechanical devices rather than as structural elements in buildings. Therefore, investigating OFST is highly relevant. This paper evaluates their axial compressive load capacity and analyzes steel pipe concrete structures to enhance understanding. Findings show that both the length and slenderness ratio of the columns significantly affect their load-bearing capacity, with increases in either reducing capacity. Additionally, a higher diameter-to-thickness ratio decreases axial pressure-bearing capacity, indicating that thicker walls enhance the load-bearing capacity. Notably, OFST have a higher load-bearing capacity than empty steel pipes when there is no internal pressure, but internal pressure reduces this capacity.
{"title":"Experimental study on axial compressive capacity of oil-filled steel pipe","authors":"Jiahuan Yu, Yuhan Li, Song Huang","doi":"10.1016/j.cscm.2025.e05692","DOIUrl":"10.1016/j.cscm.2025.e05692","url":null,"abstract":"<div><div>Research on steel pipe reinforced concrete has advanced significantly, yet its role in construction still requires more exploration. This study examines a new type of structure similar to steel pipe concrete columns, known as Oil-Filled Steel Pipe (OFST), which consist of circular steel tubes filled with anti-wear hydraulic oil. Despite being a derivative of steel, there is limited global research on these columns, with most studies focusing on their use in mechanical devices rather than as structural elements in buildings. Therefore, investigating OFST is highly relevant. This paper evaluates their axial compressive load capacity and analyzes steel pipe concrete structures to enhance understanding. Findings show that both the length and slenderness ratio of the columns significantly affect their load-bearing capacity, with increases in either reducing capacity. Additionally, a higher diameter-to-thickness ratio decreases axial pressure-bearing capacity, indicating that thicker walls enhance the load-bearing capacity. Notably, OFST have a higher load-bearing capacity than empty steel pipes when there is no internal pressure, but internal pressure reduces this capacity.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"24 ","pages":"Article e05692"},"PeriodicalIF":6.6,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145788437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-07-01Epub Date: 2025-12-12DOI: 10.1016/j.cscm.2025.e05688
Joseph Pugh , Diane Gardner , Riccardo Maddalena
Waste Foundry Sand (WFS), a by-product of the cast metal industry is produced in quantities exceeding 100 million tons annually. Being a high-quality silica sand, it poses a potential solution for reuse within concrete as a fine aggregate replacement; simultaneously addressing the increasingly critical issue of foundry waste generation and mitigating the overextraction of natural aggregates for concrete production in line with United Nations Sustainable Development Goals. It is widely understood that partial WFS substitution as a fine aggregate within concrete is not only acceptable but often beneficial, however the variability in the properties of WFS concrete has yet to be systematically tracked and categorised. This state-of the-art-review provides a succinct and detailed assessment of the typical impact of WFS on concrete performance, highlighting variability in properties, and recent advancements for optimisation. Analysis of the lesser examined facets, such as WFS treatment and combination with supplementary cementitious materials is undertaken to provide a robust methodology for WFS concrete optimisation via effective research collation and impact categorisation. Existing studies on long-term durability, and life cycle assessment in terms of both environment and economics, are highlighted as lacking comprehensive insight and thus create a framework for future research.
{"title":"A state-of-the-art review of Waste Foundry Sand concrete from an optimisation perspective","authors":"Joseph Pugh , Diane Gardner , Riccardo Maddalena","doi":"10.1016/j.cscm.2025.e05688","DOIUrl":"10.1016/j.cscm.2025.e05688","url":null,"abstract":"<div><div>Waste Foundry Sand (WFS), a by-product of the cast metal industry is produced in quantities exceeding 100 million tons annually. Being a high-quality silica sand, it poses a potential solution for reuse within concrete as a fine aggregate replacement; simultaneously addressing the increasingly critical issue of foundry waste generation and mitigating the overextraction of natural aggregates for concrete production in line with United Nations Sustainable Development Goals. It is widely understood that partial WFS substitution as a fine aggregate within concrete is not only acceptable but often beneficial, however the variability in the properties of WFS concrete has yet to be systematically tracked and categorised. This state-of the-art-review provides a succinct and detailed assessment of the typical impact of WFS on concrete performance, highlighting variability in properties, and recent advancements for optimisation. Analysis of the lesser examined facets, such as WFS treatment and combination with supplementary cementitious materials is undertaken to provide a robust methodology for WFS concrete optimisation via effective research collation and impact categorisation. Existing studies on long-term durability, and life cycle assessment in terms of both environment and economics, are highlighted as lacking comprehensive insight and thus create a framework for future research.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"24 ","pages":"Article e05688"},"PeriodicalIF":6.6,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145788438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Reinforced concrete (RC) structures have become increasingly prevalent in infrastructure construction. Ensuring their safety and managing maintenance within limited budgets necessitates effective health monitoring techniques, with non-destructive testing (NDT) methods playing a critical role. Among these, acoustic wave sound emission diagnostics traditionally rely on specialized expertise and sophisticated. This reliance may introduce potential inaccuracies due to interpretive errors and the limited availability of experts. This study focuses on the development of an AI-driven evaluation method for tapping sound analysis using an unsupervised deep learning approach. A laboratory case study was conducted using five RC beams of 2 m length and 0.2 m square cross section, subjected to electrochemical acceleration to simulate random corrosion in steel reinforcements. A total of 6075 tapping sound samples were collected and analyzed using frequency-domain transformations and clustering algorithms. Results showed that the proposed method generated an anomaly index that correlated with both the mass loss of steel reinforcement and surface crack severity. This case study highlights the potential of combining acoustic-based NDT with AI-driven analysis to support early-stage damage detection and improve condition assessment of RC structures.
{"title":"Application of unsupervised AI-assisted acoustic wave sound analysis for non-destructive detection of steel corrosion induced deterioration","authors":"Nopphanan Phannakham , Katsufumi Hashimoto , Yasuhiko Sato , Naoshi Ueda","doi":"10.1016/j.cscm.2025.e05702","DOIUrl":"10.1016/j.cscm.2025.e05702","url":null,"abstract":"<div><div>Reinforced concrete (RC) structures have become increasingly prevalent in infrastructure construction. Ensuring their safety and managing maintenance within limited budgets necessitates effective health monitoring techniques, with non-destructive testing (NDT) methods playing a critical role. Among these, acoustic wave sound emission diagnostics traditionally rely on specialized expertise and sophisticated. This reliance may introduce potential inaccuracies due to interpretive errors and the limited availability of experts. This study focuses on the development of an AI-driven evaluation method for tapping sound analysis using an unsupervised deep learning approach. A laboratory case study was conducted using five RC beams of 2 m length and 0.2 m square cross section, subjected to electrochemical acceleration to simulate random corrosion in steel reinforcements. A total of 6075 tapping sound samples were collected and analyzed using frequency-domain transformations and clustering algorithms. Results showed that the proposed method generated an anomaly index that correlated with both the mass loss of steel reinforcement and surface crack severity. This case study highlights the potential of combining acoustic-based NDT with AI-driven analysis to support early-stage damage detection and improve condition assessment of RC structures.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"24 ","pages":"Article e05702"},"PeriodicalIF":6.6,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145788510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-07-01Epub Date: 2025-12-13DOI: 10.1016/j.cscm.2025.e05689
Xiaoning Han , Zaiqiang Hu , Hongru Li , Chen Yu , Bobo Zhang , Yan Yin , Longfei Zhang
<div><div>Due to the high initial moisture content of tailings mud, the use of fiber-cement for solidification poses issues of low strength and poor durability. Superabsorbent polymer (SAP) has provided an opportunity to solve this problem because of their high water-absorbance characteristics. This study systematically investigated the influence of SAP on the strength and durability of fiber-cement-stabilized tailings mud (FCS tailings mud) through unconfined compression tests and dry<img>wet cycle tests. Based on the experimental results, a comprehensive parameter <span><math><msub><mrow><mi>C</mi></mrow><mrow><msub><mrow><mi>q</mi></mrow><mrow><mi>u</mi></mrow></msub></mrow></msub></math></span> and a durability parameter <span><math><msub><mrow><mi>R</mi></mrow><mrow><msub><mrow><mi>q</mi></mrow><mrow><mi>u</mi></mrow></msub></mrow></msub></math></span> were established for quantitative evaluation, which indicated that the mix proportion of 0.3 % SAP, 0.2 % fiber, and 12 mm fiber length was optimal. Under a fixed fiber content (0.2 %) and length (12 mm), an increase in SAP content from 0 % to 0.3 % resulted in an enhancement of 217.16 % in the initial strength and 244.46 % in the strength after the maximum number of cycles. The results demonstrate that SAP is effective in enhancing both the strength and durability of FCS tailings mud. Furthermore, a constitutive model accurately describing the stress-strain relationship of the stabilized material was developed. By introducing a degradation factor <em>D</em>, the initial strength was effectively correlated with the deteriorated strength, leading to the development of a strength prediction model that integrates both curing conditions and the number of cycles. Furthermore, ICP-MS analysis confirmed that the incorporation of SAP effectively suppressed the leaching of Cu, Zn, and Pb ions from the FCS tailings mud. Finally, through microscopic tests such as XRD, ESEM-EDS, and SEM, the reinforcement mechanism and the dry<img>wet cycle degradation mechanism of SAP-reinforced fiber-cement-stabilized tailings mud (SRFCS tailings mud) were revealed. The results indicate that during the curing process, in the specimen with an appropriate amount of SAP, SAP, by filling pores and regulating the internal humidity, provides a favorable environment for the enhancing effects of fiber and cement; however, in the specimen with excessive SAP, SAP increases the inter-particle spacing and weakens the fiber-soil interfacial bonding, consequently leading to a decrease in strength. During the dry<img>wet cycles, the specimen with an appropriate amount of SAP can, by regulating moisture migration, delay the rapid permeation and evaporation of water, and provide water for the continuous hydration of cement, thereby enhancing durability, which is specifically manifested as mesopores occupying the dominant position in the total pore area after cycling; conversely, in the specimen with an excessive amount of SAP, the uneve
{"title":"Investigation of the mechanical properties and microscopic mechanisms of fiber-cement-stabilized tailings mud reinforced with a superabsorbent polymer","authors":"Xiaoning Han , Zaiqiang Hu , Hongru Li , Chen Yu , Bobo Zhang , Yan Yin , Longfei Zhang","doi":"10.1016/j.cscm.2025.e05689","DOIUrl":"10.1016/j.cscm.2025.e05689","url":null,"abstract":"<div><div>Due to the high initial moisture content of tailings mud, the use of fiber-cement for solidification poses issues of low strength and poor durability. Superabsorbent polymer (SAP) has provided an opportunity to solve this problem because of their high water-absorbance characteristics. This study systematically investigated the influence of SAP on the strength and durability of fiber-cement-stabilized tailings mud (FCS tailings mud) through unconfined compression tests and dry<img>wet cycle tests. Based on the experimental results, a comprehensive parameter <span><math><msub><mrow><mi>C</mi></mrow><mrow><msub><mrow><mi>q</mi></mrow><mrow><mi>u</mi></mrow></msub></mrow></msub></math></span> and a durability parameter <span><math><msub><mrow><mi>R</mi></mrow><mrow><msub><mrow><mi>q</mi></mrow><mrow><mi>u</mi></mrow></msub></mrow></msub></math></span> were established for quantitative evaluation, which indicated that the mix proportion of 0.3 % SAP, 0.2 % fiber, and 12 mm fiber length was optimal. Under a fixed fiber content (0.2 %) and length (12 mm), an increase in SAP content from 0 % to 0.3 % resulted in an enhancement of 217.16 % in the initial strength and 244.46 % in the strength after the maximum number of cycles. The results demonstrate that SAP is effective in enhancing both the strength and durability of FCS tailings mud. Furthermore, a constitutive model accurately describing the stress-strain relationship of the stabilized material was developed. By introducing a degradation factor <em>D</em>, the initial strength was effectively correlated with the deteriorated strength, leading to the development of a strength prediction model that integrates both curing conditions and the number of cycles. Furthermore, ICP-MS analysis confirmed that the incorporation of SAP effectively suppressed the leaching of Cu, Zn, and Pb ions from the FCS tailings mud. Finally, through microscopic tests such as XRD, ESEM-EDS, and SEM, the reinforcement mechanism and the dry<img>wet cycle degradation mechanism of SAP-reinforced fiber-cement-stabilized tailings mud (SRFCS tailings mud) were revealed. The results indicate that during the curing process, in the specimen with an appropriate amount of SAP, SAP, by filling pores and regulating the internal humidity, provides a favorable environment for the enhancing effects of fiber and cement; however, in the specimen with excessive SAP, SAP increases the inter-particle spacing and weakens the fiber-soil interfacial bonding, consequently leading to a decrease in strength. During the dry<img>wet cycles, the specimen with an appropriate amount of SAP can, by regulating moisture migration, delay the rapid permeation and evaporation of water, and provide water for the continuous hydration of cement, thereby enhancing durability, which is specifically manifested as mesopores occupying the dominant position in the total pore area after cycling; conversely, in the specimen with an excessive amount of SAP, the uneve","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"24 ","pages":"Article e05689"},"PeriodicalIF":6.6,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145788586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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