Pub Date : 2025-02-27DOI: 10.1016/j.conbuildmat.2025.140554
Qing Zhao , Yongqi Da , Tingshu He , Chen Shi , Yuliang Ke , Shuaiyang Li , Hang Wen , Jinliang Guo
The fluctuating quality of industrial waste gypsum and its irrational addition into cement easily lead to the growth of secondary ettringite in the precast concrete, then easily resulting in the loss of early strength and the reduced durability of precast concrete. In this study, the components of the cement itself were optimized, the effects of Na2SO4 or Na2CO3 on the early performance of non-gypsum cement and low-gypsum cement were investigated by adjusting the content of gypsum in cement, and the mechanism of synergistic activation of cement clinker by Na2SO4 or Na2CO3 and gypsum was revealed through the analyses of setting time, mortar strength, hydration temperature, QXRD, DTG and SEM. The results showed that the samples with 2 % Na2CO3 added to cement with 0.5 wt% gypsum content obtained excellent 12-hour compressive strength more than 15 MPa and the initial setting time was more than 45 min. which suggested the possible synergistic effect of a small amount of gypsum and Na2CO3, the hydration products Monosulfoaluminate, Monocarboaluminate and Aragonite provide nucleation seeds and growth space for C-S-H, thus contributing to the intensity development of the samples over a 12-h period. However, the above hypothesis needs to be confirmed by further studies.
{"title":"Effect of Na2SO4 and Na2CO3 on early performance of non-gypsum/ low-gypsum cement: Mechanism of synergistic activation with gypsum","authors":"Qing Zhao , Yongqi Da , Tingshu He , Chen Shi , Yuliang Ke , Shuaiyang Li , Hang Wen , Jinliang Guo","doi":"10.1016/j.conbuildmat.2025.140554","DOIUrl":"10.1016/j.conbuildmat.2025.140554","url":null,"abstract":"<div><div>The fluctuating quality of industrial waste gypsum and its irrational addition into cement easily lead to the growth of secondary ettringite in the precast concrete, then easily resulting in the loss of early strength and the reduced durability of precast concrete. In this study, the components of the cement itself were optimized, the effects of Na<sub>2</sub>SO<sub>4</sub> or Na<sub>2</sub>CO<sub>3</sub> on the early performance of non-gypsum cement and low-gypsum cement were investigated by adjusting the content of gypsum in cement, and the mechanism of synergistic activation of cement clinker by Na<sub>2</sub>SO<sub>4</sub> or Na<sub>2</sub>CO<sub>3</sub> and gypsum was revealed through the analyses of setting time, mortar strength, hydration temperature, QXRD, DTG and SEM. The results showed that the samples with 2 % Na<sub>2</sub>CO<sub>3</sub> added to cement with 0.5 wt% gypsum content obtained excellent 12-hour compressive strength more than 15 MPa and the initial setting time was more than 45 min. which suggested the possible synergistic effect of a small amount of gypsum and Na<sub>2</sub>CO<sub>3</sub>, the hydration products Monosulfoaluminate, Monocarboaluminate and Aragonite provide nucleation seeds and growth space for C-S-H, thus contributing to the intensity development of the samples over a 12-h period. However, the above hypothesis needs to be confirmed by further studies.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"470 ","pages":"Article 140554"},"PeriodicalIF":7.4,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143509510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Incorporating large amounts of mineral admixtures enhances admixture utilization efficiency, promoting resource conservation and carbon reduction, while simultaneously improving composite durability and reducing life-cycle costs. However, the limited reactivity of supplementary cementitious materials (SCMs) and the hysteresis of the pozzolanic reaction considerably influence the cement hydration, thereby modifying the hydrates and microstructure. Researches addressing the impact of high SCM content on hydration processes, mechanisms, product evolution, and microstructural changes of cementitious composites remain scarce. This study focuses on high FA content to develop a thermodynamic model for the hydration of cement and reaction of fly ash (FA), thereby quantitatively elucidating the influence of abundant FA on the hydration process and mechanisms, and analyzing the evolution of hydrates and microstructures. The results demonstrate that substantial incorporation of FA hinders water and ion diffusion, and the hydration reaction rate is primarily governed by the ion diffusion process. The Ca/Si ratio within matrix experienced a pronounced decline, despite the early acceleration of cement clinker hydration by FA. This reduction is attributed to the limited CaO content, which resulted in a considerable reduction in the content of each major hydrate. The substantial incorporation of the aluminium phase by FA nearly exhausts the ettringite. The model corroborated the initial high porosity of the high-FA-content mortar, revealing a negative correlation with both compressive strength and fracture toughness. The simulation results corresponded closely with the experimental data. This comprehensive model provides valuable insights into hydration mechanisms, product evolution, and porosity dynamics in high-mineral-admixture systems. Furthermore, it serves as a practical tool for preliminarily assessing the mechanical properties of ultra-high-content cementitious composites, enabling the efficient adjustment of mix design parameters based on fundamental material properties.
{"title":"Modeling and analysis of hydration in cementitious composites with ultra-high dosage of fly ash: Hydrates and microstructure evolutions","authors":"Fei Xiang-peng , Guo Li-ping , Lu Jia-tao , Shen Hao-ran , Chen Hai-tao , Rui Zi-qing","doi":"10.1016/j.conbuildmat.2025.140557","DOIUrl":"10.1016/j.conbuildmat.2025.140557","url":null,"abstract":"<div><div>Incorporating large amounts of mineral admixtures enhances admixture utilization efficiency, promoting resource conservation and carbon reduction, while simultaneously improving composite durability and reducing life-cycle costs. However, the limited reactivity of supplementary cementitious materials (SCMs) and the hysteresis of the pozzolanic reaction considerably influence the cement hydration, thereby modifying the hydrates and microstructure. Researches addressing the impact of high SCM content on hydration processes, mechanisms, product evolution, and microstructural changes of cementitious composites remain scarce. This study focuses on high FA content to develop a thermodynamic model for the hydration of cement and reaction of fly ash (FA), thereby quantitatively elucidating the influence of abundant FA on the hydration process and mechanisms, and analyzing the evolution of hydrates and microstructures. The results demonstrate that substantial incorporation of FA hinders water and ion diffusion, and the hydration reaction rate is primarily governed by the ion diffusion process. The Ca/Si ratio within matrix experienced a pronounced decline, despite the early acceleration of cement clinker hydration by FA. This reduction is attributed to the limited CaO content, which resulted in a considerable reduction in the content of each major hydrate. The substantial incorporation of the aluminium phase by FA nearly exhausts the ettringite. The model corroborated the initial high porosity of the high-FA-content mortar, revealing a negative correlation with both compressive strength and fracture toughness. The simulation results corresponded closely with the experimental data. This comprehensive model provides valuable insights into hydration mechanisms, product evolution, and porosity dynamics in high-mineral-admixture systems. Furthermore, it serves as a practical tool for preliminarily assessing the mechanical properties of ultra-high-content cementitious composites, enabling the efficient adjustment of mix design parameters based on fundamental material properties.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"470 ","pages":"Article 140557"},"PeriodicalIF":7.4,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143511573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The utilisation of waste materials in construction reduces natural resource depletion and mitigates waste accumulation. This study investigates self-compacting recycled concrete (SCRC) prepared using circulating fluidised bed (CFB) fly ash as a supplementary cementitious material (SCM) and red mud (RM) as a viscosity-modifying agent (VMA). The fresh and hardened properties of SCRC, including compressive strength, carbonation resistance, drying shrinkage, surface resistivity, and leaching behaviour, were evaluated. Economic and environmental benefits were also assessed in terms of raw material cost and carbon emissions. Results show that RM effectively reduces segregation and mitigates the negative effects of CFB fly ash on carbonation resistance. Incorporating 15 wt% CFB fly ash increased the segregation rate by 6.1 % and the 28-day carbonation depth by 3.57 mm, while 15 wt% RM reduced these values by 7.5 % and 0.81 mm, respectively. Additionally, the combined use of CFB fly ash and RM significantly enhanced surface resistivity, with SCRC containing 15 wt% CFB fly ash and 20 wt% RM achieving an increase from 13.6 kΩ·cm to 49.4 kΩ·cm. However, this resistivity was lower than that of SCRC with 20 wt% CFB fly ash (62.3 kΩ·cm). The prepared SCRC also demonstrated excellent solidification of Na and heavy metals, with leaching concentrations meeting China’s groundwater safety standards. SCRC with 20 wt% RM exhibited the highest leaching levels after 28 days, with 153.8 mg/L for Na and 0.00953 mg/L, 0.00374 mg/L, and 0.00428 mg/L for Cr, Pb, and As, respectively. While SCRC prepared with CFB fly ash and RM showed significant carbon emission reductions compared to the control, cost savings were limited due to increased use of polycarboxylate superplasticisers at high dosages. This study provides comprehensive data to support the engineering application of CFB fly ash and RM in SCRC.
{"title":"Synergistic reuse of red mud and circulating fluidised bed fly ash in self-compacting recycled concrete","authors":"Chun-Ran Wu , Bao-Jian Zhan , Wei Tang , Shi-Cong Kou","doi":"10.1016/j.conbuildmat.2025.140533","DOIUrl":"10.1016/j.conbuildmat.2025.140533","url":null,"abstract":"<div><div>The utilisation of waste materials in construction reduces natural resource depletion and mitigates waste accumulation. This study investigates self-compacting recycled concrete (SCRC) prepared using circulating fluidised bed (CFB) fly ash as a supplementary cementitious material (SCM) and red mud (RM) as a viscosity-modifying agent (VMA). The fresh and hardened properties of SCRC, including compressive strength, carbonation resistance, drying shrinkage, surface resistivity, and leaching behaviour, were evaluated. Economic and environmental benefits were also assessed in terms of raw material cost and carbon emissions. Results show that RM effectively reduces segregation and mitigates the negative effects of CFB fly ash on carbonation resistance. Incorporating 15 wt% CFB fly ash increased the segregation rate by 6.1 % and the 28-day carbonation depth by 3.57 mm, while 15 wt% RM reduced these values by 7.5 % and 0.81 mm, respectively. Additionally, the combined use of CFB fly ash and RM significantly enhanced surface resistivity, with SCRC containing 15 wt% CFB fly ash and 20 wt% RM achieving an increase from 13.6 kΩ·cm to 49.4 kΩ·cm. However, this resistivity was lower than that of SCRC with 20 wt% CFB fly ash (62.3 kΩ·cm). The prepared SCRC also demonstrated excellent solidification of Na and heavy metals, with leaching concentrations meeting China’s groundwater safety standards. SCRC with 20 wt% RM exhibited the highest leaching levels after 28 days, with 153.8 mg/L for Na and 0.00953 mg/L, 0.00374 mg/L, and 0.00428 mg/L for Cr, Pb, and As, respectively. While SCRC prepared with CFB fly ash and RM showed significant carbon emission reductions compared to the control, cost savings were limited due to increased use of polycarboxylate superplasticisers at high dosages. This study provides comprehensive data to support the engineering application of CFB fly ash and RM in SCRC.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"470 ","pages":"Article 140533"},"PeriodicalIF":7.4,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143509515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2025-02-27DOI: 10.1016/j.conbuildmat.2025.140516
Y. Tao, S.A. Hadigheh, S. Saha, Y. Wei
Cementitious composites with carbon fibres (CFs) have been developed as functional cement-based sensors for real-time structural health monitoring (SHM). However, few studies have investigated the piezoresistive performance of these cementitious composites under different external environmental conditions. This research studies the influence of carbon fibre-reinforced polymer (CFRP) recyclates on the electrical resistivity and piezoresistivity of cementitious composites under varying temperature, humidity and chloride-induced corrosion. The experiments involved the use of recycled carbon fibre (rCF) reclaimed through acid solvolysis and recycled CFRP (rCFRP) derived from mechanical recycling. Their performance in cementitious composites was evaluated against benchmarks containing virgin carbon fibre (vCF) offcuts and plain mortar without additives. The results show that while incorporating rCFRP increased the electrical resistivity of cementitious composites compared to those with CFs, the rCFRP specimens demonstrated more consistent and repeatable piezoresistive behaviour under cyclic loading in both low and high-humidity environments. Under 30 % humidity conditions, the rCFRP specimen achieved an average stress sensitivity (SS) of 0.42 %/MPa and a gauge factor (GF) of 17.50. The piezoresistivity decreased after exposure to chloride-induced corrosion. However, the behaviour remained stable through a well-distributed conductive network, which proved more effective than ionic conduction pathways. These findings demonstrate the potential of rCFRP-based cementitious sensors for SHM applications, offering both technical effectiveness and environmental sustainability.
{"title":"Pulverised CFRP waste and reclaimed carbon fibre for cement-based sensors: Investigating electrical resistivity and piezoresistivity under varying environmental conditions","authors":"Y. Tao, S.A. Hadigheh, S. Saha, Y. Wei","doi":"10.1016/j.conbuildmat.2025.140516","DOIUrl":"10.1016/j.conbuildmat.2025.140516","url":null,"abstract":"<div><div>Cementitious composites with carbon fibres (CFs) have been developed as functional cement-based sensors for real-time structural health monitoring (SHM). However, few studies have investigated the piezoresistive performance of these cementitious composites under different external environmental conditions. This research studies the influence of carbon fibre-reinforced polymer (CFRP) recyclates on the electrical resistivity and piezoresistivity of cementitious composites under varying temperature, humidity and chloride-induced corrosion. The experiments involved the use of recycled carbon fibre (rCF) reclaimed through acid solvolysis and recycled CFRP (rCFRP) derived from mechanical recycling. Their performance in cementitious composites was evaluated against benchmarks containing virgin carbon fibre (vCF) offcuts and plain mortar without additives. The results show that while incorporating rCFRP increased the electrical resistivity of cementitious composites compared to those with CFs, the rCFRP specimens demonstrated more consistent and repeatable piezoresistive behaviour under cyclic loading in both low and high-humidity environments. Under 30 % humidity conditions, the rCFRP specimen achieved an average stress sensitivity (SS) of 0.42 %/MPa and a gauge factor (GF) of 17.50. The piezoresistivity decreased after exposure to chloride-induced corrosion. However, the behaviour remained stable through a well-distributed conductive network, which proved more effective than ionic conduction pathways. These findings demonstrate the potential of rCFRP-based cementitious sensors for SHM applications, offering both technical effectiveness and environmental sustainability.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"470 ","pages":"Article 140516"},"PeriodicalIF":7.4,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143509743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To advance the cement industry’s decarbonization goals, this research introduces 'low lime – low carbon clinker (L3C2)’ as an alternative to conventional Portland clinker, proposing a switch from a hydraulic binder to a carbonatable non-hydraulic binder using limestone mining rejects, which are discarded due to low calcium oxide (CaO) content, high-magnesia (MgO) and high-silica (SiO2) content. By maintaining a lower calcium oxide to silicon dioxide ratio (C/S ratio) of 1.0–1.5 (compared to 3.1–3.2 for conventional clinker), along with magnesia content up to 15 % in the raw material feed, L3C2 can significantly promote the formation of carbonatable Ca/Mg-silicate mineral phases, that increases the CO2 uptake and reduces its carbon footprint by up to 50 % which requires shorter curing times (up to 7 days). The lower C/S ratio in L3C2 allows better utilization of discarded limestone mining rejects in the pyro-process, reducing the rejection ratio and providing a novel, implementable method to resolve the mining waste management issue and mitigate carbon emissions in cement production.
{"title":"Low lime – low carbon cement: Achieving sustainability through reduction of CO2 emissions and utilizing limestone mining rejects","authors":"Supriya Tamta , Reetam Chaudhury , Usha Sharma , Mohd. Hanifa , P.C. Thapliyal , L.P. Singh","doi":"10.1016/j.conbuildmat.2025.140476","DOIUrl":"10.1016/j.conbuildmat.2025.140476","url":null,"abstract":"<div><div>To advance the cement industry’s decarbonization goals, this research introduces 'low lime – low carbon clinker (L3C2)’ as an alternative to conventional Portland clinker, proposing a switch from a hydraulic binder to a carbonatable non-hydraulic binder using limestone mining rejects, which are discarded due to low calcium oxide (CaO) content, high-magnesia (MgO) and high-silica (SiO<sub>2</sub>) content. By maintaining a lower calcium oxide to silicon dioxide ratio (C/S ratio) of 1.0–1.5 (compared to 3.1–3.2 for conventional clinker), along with magnesia content up to 15 % in the raw material feed, L3C2 can significantly promote the formation of carbonatable Ca/Mg-silicate mineral phases, that increases the CO<sub>2</sub> uptake and reduces its carbon footprint by up to 50 % which requires shorter curing times (up to 7 days). The lower C/S ratio in L3C2 allows better utilization of discarded limestone mining rejects in the pyro-process, reducing the rejection ratio and providing a novel, implementable method to resolve the mining waste management issue and mitigate carbon emissions in cement production.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"470 ","pages":"Article 140476"},"PeriodicalIF":7.4,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143509513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2025-02-27DOI: 10.1016/j.conbuildmat.2025.140530
Jinhe Gao , Jun Ke , Yahang Tang , Weihao Zhou , Qingrui Lu , Baokui Chen
To address the erosion of concrete structures caused by acid rain and industrial pollution and to enhance the acid resistance of cement-based materials, this paper investigates and compares the fluidity and strength of cement mortar at different ages under acidic conditions by incorporating fly ash (FA), blast furnace slag (BFS), polypropylene fibres (PF), and sodium silicate (SS), either singly or in various combinations and proportions. The results indicated that adding a small amount of PF reduces the fluidity of cement mortar but enhances its compressive strength. Increasing the FA content based on 0.5 % PF helps improve the fluidity of cement mortar. However, incorporating BFS powder into the mix with 0.5 % PF slightly reduces fluidity. When the BFS powder replacement exceeds 30 %, the strength is lower than that of the reference cement group. The addition of SS based on 0.5 % PF, 15 % FA, and 30 % BFS powder reduces the fluidity of cement mortar. With an SS content of 1.5 %, the compressive strength of the cement mortar improves in the later stages.
{"title":"Effect of multi-doped composite material on fluidity and compressive strength of cement mortar under acid erosion","authors":"Jinhe Gao , Jun Ke , Yahang Tang , Weihao Zhou , Qingrui Lu , Baokui Chen","doi":"10.1016/j.conbuildmat.2025.140530","DOIUrl":"10.1016/j.conbuildmat.2025.140530","url":null,"abstract":"<div><div>To address the erosion of concrete structures caused by acid rain and industrial pollution and to enhance the acid resistance of cement-based materials, this paper investigates and compares the fluidity and strength of cement mortar at different ages under acidic conditions by incorporating fly ash (FA), blast furnace slag (BFS), polypropylene fibres (PF), and sodium silicate (SS), either singly or in various combinations and proportions. The results indicated that adding a small amount of PF reduces the fluidity of cement mortar but enhances its compressive strength. Increasing the FA content based on 0.5 % PF helps improve the fluidity of cement mortar. However, incorporating BFS powder into the mix with 0.5 % PF slightly reduces fluidity. When the BFS powder replacement exceeds 30 %, the strength is lower than that of the reference cement group. The addition of SS based on 0.5 % PF, 15 % FA, and 30 % BFS powder reduces the fluidity of cement mortar. With an SS content of 1.5 %, the compressive strength of the cement mortar improves in the later stages.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"470 ","pages":"Article 140530"},"PeriodicalIF":7.4,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143509667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2025-02-27DOI: 10.1016/j.conbuildmat.2025.140584
Stefany dos Anjos Coronel , Ramoel Serafini , Dimas Alan Strauss Rambo , Renan Pícolo Salvador , Luís Antônio Guimarães Bitencourt Júnior
The Double-Edge Wedge Splitting (DEWS) test presents several advantages as an indirect test to determine the post-crack tensile parameters of steel fiber-reinforced concrete (SFRC). However, practical challenges related to the preparation of notched and wedged specimens, as well as the precise control of crack opening using extensometers, limit its large-scale applicability. This study aimed to assess the feasibility of a simplified DEWS test by eliminating the need for extensometers through a geometric correlation between crack opening and stroke displacement. The experimental program evaluated three SFRC mix designs with commercial steel fiber contents of 20, 40, and 60 kg/m3, comparing the conventional and simplified DEWS methodologies. The molding procedure resulted in a significant increase in terms of post-cracking strength for both the serviceability limit state (SLS) and the ultimate limit state (ULS) for fiber contents of 40 and 60 kg/m3. However, no significant difference in post-crack tensile strength was observed between the specimen preparation methods for the group with a fiber content of 20 kg/m3. The correlation between crack opening and stroke displacement proved to be adequate, with an average error of around 10 %, being higher for lower fiber volumes. The study contributes to advancing testing methodologies by offering a more efficient and cost-effective approach for determining the post-cracking properties of SFRC, potentially informing future standardization efforts and promoting optimized practices in the construction industry.
{"title":"Effect of DEWS test simplification on the design post-crack parameters of steel fiber reinforced concrete with different fiber contents","authors":"Stefany dos Anjos Coronel , Ramoel Serafini , Dimas Alan Strauss Rambo , Renan Pícolo Salvador , Luís Antônio Guimarães Bitencourt Júnior","doi":"10.1016/j.conbuildmat.2025.140584","DOIUrl":"10.1016/j.conbuildmat.2025.140584","url":null,"abstract":"<div><div>The Double-Edge Wedge Splitting (DEWS) test presents several advantages as an indirect test to determine the post-crack tensile parameters of steel fiber-reinforced concrete (SFRC). However, practical challenges related to the preparation of notched and wedged specimens, as well as the precise control of crack opening using extensometers, limit its large-scale applicability. This study aimed to assess the feasibility of a simplified DEWS test by eliminating the need for extensometers through a geometric correlation between crack opening and stroke displacement. The experimental program evaluated three SFRC mix designs with commercial steel fiber contents of 20, 40, and 60 kg/m<sup>3</sup>, comparing the conventional and simplified DEWS methodologies. The molding procedure resulted in a significant increase in terms of post-cracking strength for both the serviceability limit state (SLS) and the ultimate limit state (ULS) for fiber contents of 40 and 60 kg/m<sup>3</sup>. However, no significant difference in post-crack tensile strength was observed between the specimen preparation methods for the group with a fiber content of 20 kg/m<sup>3</sup>. The correlation between crack opening and stroke displacement proved to be adequate, with an average error of around 10 %, being higher for lower fiber volumes. The study contributes to advancing testing methodologies by offering a more efficient and cost-effective approach for determining the post-cracking properties of SFRC, potentially informing future standardization efforts and promoting optimized practices in the construction industry.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"470 ","pages":"Article 140584"},"PeriodicalIF":7.4,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143509512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2025-02-27DOI: 10.1016/j.conbuildmat.2025.140432
Hyun Jin Kim , Kunze Li , Selahattin Akdag , Chengguo Zhang , Joung Oh , Pengfei Jiang , Patrick T. Spicer , Per B. Zetterlund , Serkan Saydam
Thin spray-on liner (TSL) is a thin layer of polymeric liner that provides substantial support to the underlying rock mass. TSLs exhibit high tensile, bond, and flexural strengths with short curing time, making them a practical alternative to conventional supporting systems such as shotcrete. Various laboratory tests and field applications have demonstrated that TSLs play crucial roles in underground mines, including prevention of gas leakage, mitigation of rock burst damage, and reduction in weathering of rock masses. However, despite their widespread use over the past decades, TSL applications face limitations due to the lack of standardized testing methods and comprehensive understanding of materials involved. To fully explore the potential of TSL technology, this paper aims to examine the compositions of TSL materials, the chemical and physical interactions during curing, various testing methods for determining TSL properties, and the practical applications of TSL. This review intends to provide valuable insights for researchers and industry professionals, with a focus on enhancing safety and efficiency across a wide range of TSL applications.
{"title":"Thin spray-on liners (TSLs) as surface support in underground mining: A review","authors":"Hyun Jin Kim , Kunze Li , Selahattin Akdag , Chengguo Zhang , Joung Oh , Pengfei Jiang , Patrick T. Spicer , Per B. Zetterlund , Serkan Saydam","doi":"10.1016/j.conbuildmat.2025.140432","DOIUrl":"10.1016/j.conbuildmat.2025.140432","url":null,"abstract":"<div><div>Thin spray-on liner (TSL) is a thin layer of polymeric liner that provides substantial support to the underlying rock mass. TSLs exhibit high tensile, bond, and flexural strengths with short curing time, making them a practical alternative to conventional supporting systems such as shotcrete. Various laboratory tests and field applications have demonstrated that TSLs play crucial roles in underground mines, including prevention of gas leakage, mitigation of rock burst damage, and reduction in weathering of rock masses. However, despite their widespread use over the past decades, TSL applications face limitations due to the lack of standardized testing methods and comprehensive understanding of materials involved. To fully explore the potential of TSL technology, this paper aims to examine the compositions of TSL materials, the chemical and physical interactions during curing, various testing methods for determining TSL properties, and the practical applications of TSL. This review intends to provide valuable insights for researchers and industry professionals, with a focus on enhancing safety and efficiency across a wide range of TSL applications.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"470 ","pages":"Article 140432"},"PeriodicalIF":7.4,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143509514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2025-02-27DOI: 10.1016/j.conbuildmat.2025.140623
Wei Hong , Kuanjiang Liu , Luchun Yan , Shanglin Song , Yukun Cao , Honggang Gao
This study developed a multifunctional experimental setup to simulate the snow and ice melting process on full-scale road surfaces under real-world conditions. Intelligent monitoring sensors were employed to assess the real-time pavement status, enabling the measurement of key parameters such as wet skid resistance and the time required for deicing agents to completely melt the ice. The integration of refrigeration equipment and intelligent sensors ensures reliable, reproducible measurements, making this setup a valuable tool for standardized product testing. Additionally, the deicing effectiveness of three different agents was evaluated, and the feasibility of pre-application deicing methods was analyzed. The results reveal a clear linear relationship between the dissolution efficiency of deicing agents and their concentration. Increasing the concentration or dosage of deicing agents accelerates the melting of snow and ice on the road surface. Moreover, the pre-application of deicing agents proves highly effective in preventing early ice formation and promoting more rapid deicing. These findings open new avenues for research into various deicing agents and methods, which are crucial for advancing snow and ice melting technologies on highways.
{"title":"Reliable testing of snow and ice melting on road using a multifunctional experimental setup","authors":"Wei Hong , Kuanjiang Liu , Luchun Yan , Shanglin Song , Yukun Cao , Honggang Gao","doi":"10.1016/j.conbuildmat.2025.140623","DOIUrl":"10.1016/j.conbuildmat.2025.140623","url":null,"abstract":"<div><div>This study developed a multifunctional experimental setup to simulate the snow and ice melting process on full-scale road surfaces under real-world conditions. Intelligent monitoring sensors were employed to assess the real-time pavement status, enabling the measurement of key parameters such as wet skid resistance and the time required for deicing agents to completely melt the ice. The integration of refrigeration equipment and intelligent sensors ensures reliable, reproducible measurements, making this setup a valuable tool for standardized product testing. Additionally, the deicing effectiveness of three different agents was evaluated, and the feasibility of pre-application deicing methods was analyzed. The results reveal a clear linear relationship between the dissolution efficiency of deicing agents and their concentration. Increasing the concentration or dosage of deicing agents accelerates the melting of snow and ice on the road surface. Moreover, the pre-application of deicing agents proves highly effective in preventing early ice formation and promoting more rapid deicing. These findings open new avenues for research into various deicing agents and methods, which are crucial for advancing snow and ice melting technologies on highways.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"470 ","pages":"Article 140623"},"PeriodicalIF":7.4,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143509686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2025-02-27DOI: 10.1016/j.conbuildmat.2025.140527
Shijie Wang , Fangzhou Ren , Yanshen Song , George Papadakis , Yi Yang , Hang Yin
Calcium Silicate Hydrate (C-S-H) gel is crucial for concrete’s mechanical integrity, yet the inherent randomness of defects in silicate chains complicates the standardization of molecular models. In this work, we developed a program to generate C-S-H models with randomly distributed defects for specified calcium-to-silicon ratios. Our findings show that defect randomness affects water molecule distribution, influencing both mechanical behavior and transport properties. While stiffness matrices exhibit some variation, elastic constants follow consistent trends. Tensile and shear simulations revealed that fracture behavior and shear resistance depend on water distribution, which acts as a lubricant. In transport simulations, defect variation impacted diffusion through differing adsorption sites. The results demonstrate that the standardized modeling program provides a convenient pathway for investigating defect randomness, which has a significant impact on the large deformation and transport behavior of C-S-H. This makes it an essential component of bottom-up multiscale mechanism research on cementitious materials.
{"title":"Issues of standardizing C-S-H molecular models: Random defect distribution and its effects on material performance","authors":"Shijie Wang , Fangzhou Ren , Yanshen Song , George Papadakis , Yi Yang , Hang Yin","doi":"10.1016/j.conbuildmat.2025.140527","DOIUrl":"10.1016/j.conbuildmat.2025.140527","url":null,"abstract":"<div><div>Calcium Silicate Hydrate (C-S-H) gel is crucial for concrete’s mechanical integrity, yet the inherent randomness of defects in silicate chains complicates the standardization of molecular models. In this work, we developed a program to generate C-S-H models with randomly distributed defects for specified calcium-to-silicon ratios. Our findings show that defect randomness affects water molecule distribution, influencing both mechanical behavior and transport properties. While stiffness matrices exhibit some variation, elastic constants follow consistent trends. Tensile and shear simulations revealed that fracture behavior and shear resistance depend on water distribution, which acts as a lubricant. In transport simulations, defect variation impacted diffusion through differing adsorption sites. The results demonstrate that the standardized modeling program provides a convenient pathway for investigating defect randomness, which has a significant impact on the large deformation and transport behavior of C-S-H. This makes it an essential component of bottom-up multiscale mechanism research on cementitious materials.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"470 ","pages":"Article 140527"},"PeriodicalIF":7.4,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143511574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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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