Construction and Building Materials最新文献_第9页

Study on uniaxial compressive properties and microfracture toughness of interface transition zones in recycled sand concrete

IF 7.4 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Construction and Building Materials

Pub Date : 2025-04-19 DOI: 10.1016/j.conbuildmat.2025.141365

Henan Shi , Huajian Li , Fali Huang , Liangshun Li , Haoliang Dong , Zhiqiang Yang

This study investigates the uniaxial compression behavior of recycled sand concrete (RSC) prism and cube with different recycled sand contents and strength grades. The characteristic parameters of the stress-strain curves are analyzed, and a constitutive model is developed based on the energy evolution relationship of RSC during loading. The microfracture toughness of the interfacial transition zone (ITZ) in RSC is evaluated using the nanoscratch method. Classical size effect theory is used to characterise the strength of RSC with different height to thickness ratios in combination with finite element simulation and experiment. The results show that the peak stress and modulus of the C20 RSC increase with the RS content. Conversely, the C40 and C60 RSCs are observed to be highest when the RS content is 50 %. The Poisson's ratio of RSC exhibits a range of 0.192–0.388, which exceeds the typical value of 0.2 for ordinary concrete. This highlights the significant transverse deformation characteristic of RSC. The microfracture toughness of ITZ shows a consistent trend in accordance with the variation of the peak stress. It can be observed that an increased microfracture toughness serves to improve the macromechanical properties of RSC. The total strain energy and dissipation energy can be increased by the addition of RS in a manner dependent on the water/binder ratio, which in turn leads to improved ductility and toughness. The compressive constitutive relationship of RSC, established by combining dissipation energy with statistical damage theory, shows a high degree of correlation with experimental values, thus allowing the description of the constitutive behaviour of RSC. The strength of RSC is consistent with size effect laws, including Weibull size effect law (WSEL), Bazant size effect law (BSEL) and Carpinteri size effect law (CSEL). In particular, CSEL has a correlation coefficient of more than 0.95 when compared with experimental values.

{"title":"Study on uniaxial compressive properties and microfracture toughness of interface transition zones in recycled sand concrete","authors":"Henan Shi , Huajian Li , Fali Huang , Liangshun Li , Haoliang Dong , Zhiqiang Yang","doi":"10.1016/j.conbuildmat.2025.141365","DOIUrl":"10.1016/j.conbuildmat.2025.141365","url":null,"abstract":"<div><div>This study investigates the uniaxial compression behavior of recycled sand concrete (RSC) prism and cube with different recycled sand contents and strength grades. The characteristic parameters of the stress-strain curves are analyzed, and a constitutive model is developed based on the energy evolution relationship of RSC during loading. The microfracture toughness of the interfacial transition zone (ITZ) in RSC is evaluated using the nanoscratch method. Classical size effect theory is used to characterise the strength of RSC with different height to thickness ratios in combination with finite element simulation and experiment. The results show that the peak stress and modulus of the C20 RSC increase with the RS content. Conversely, the C40 and C60 RSCs are observed to be highest when the RS content is 50 %. The Poisson's ratio of RSC exhibits a range of 0.192–0.388, which exceeds the typical value of 0.2 for ordinary concrete. This highlights the significant transverse deformation characteristic of RSC. The microfracture toughness of ITZ shows a consistent trend in accordance with the variation of the peak stress. It can be observed that an increased microfracture toughness serves to improve the macromechanical properties of RSC. The total strain energy and dissipation energy can be increased by the addition of RS in a manner dependent on the water/binder ratio, which in turn leads to improved ductility and toughness. The compressive constitutive relationship of RSC, established by combining dissipation energy with statistical damage theory, shows a high degree of correlation with experimental values, thus allowing the description of the constitutive behaviour of RSC. The strength of RSC is consistent with size effect laws, including Weibull size effect law (WSEL), Bazant size effect law (BSEL) and Carpinteri size effect law (CSEL). In particular, CSEL has a correlation coefficient of more than 0.95 when compared with experimental values.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"477 ","pages":"Article 141365"},"PeriodicalIF":7.4,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143847687","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}

引用次数: 0

A combination technique to improve natural low-grade illite as supplementary cementitious material for concrete 改进天然低级伊利石作为混凝土胶凝补充材料的组合技术

IF 7.4 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Construction and Building Materials

Pub Date : 2025-04-19 DOI: 10.1016/j.conbuildmat.2025.141334

Roshan Jayathilakage, Chamila Gunasekara, David Law, Sujeeva Setunge

Kaolinite-rich clays are the most utilized clay type as a supplementary cementitious material (SCM) due to their higher pozzolanic reactivity. However, these higher-grade clays may not be available due to widespread usage in other industries and geographical locations. Hence, this study investigates the potential of combining low-grade illite clays, characterized by low clay mineral content (<30 %) and reactivity, with higher-grade kaolinite clays to enhance pozzolanic properties and mechanical performance in clay-cement blended cementitious mixes. An optimal clay mixing ratio of 1:1 was found to yield improved strength (3 % higher than the control mix) and reactivity particularly when clays were co-calcined(13 % higher bound water content). Analysis indicated that the co-calcination process increased amorphous content by around 18 %. The high Si/Ca ratio (24 % higher than separately calcined and mixed) in the C-A-S-H component of the co-calcined mix is also visible with more amorphous Si. A separate Fe phase was formed, which improved the pore structure of the co-calcined mix (reduced porosity by 41 %). This contributed to an 8 % increase in compressive strength compared to the clays separately calcined and subsequently mixed. The findings suggest that the combination technique effectively enhances the utility of low-grade clays, providing a viable strategy for mitigating reliance on high-grade resources.

由于富含高岭石的粘土具有较高的水合反应活性，因此是最常用的胶凝补充材料（SCM）粘土类型。然而，由于在其他行业和地理位置的广泛使用，这些高等级粘土可能无法获得。因此，本研究探讨了将粘土矿物含量（30%）和反应活性较低的低级伊利石粘土与高级高岭石粘土结合使用的可能性，以提高粘土-水泥混合胶凝材料的水胶结性能和机械性能。研究发现，1:1 的最佳粘土混合比例可提高强度（比对照混合料高出 3%）和反应性，尤其是当粘土经过共煅烧时（结合水含量高出 13%）。分析表明，共煅烧过程使无定形含量增加了约 18%。在共煅烧混合物中，C-A-S-H 组分的硅/钙比率较高（比单独煅烧和混合高出 24%），无定形的硅也较多。形成的独立铁相改善了共煅烧混合物的孔隙结构（孔隙率降低了 41%）。与单独煅烧并随后混合的粘土相比，抗压强度提高了 8%。研究结果表明，这种组合技术有效地提高了低品位粘土的效用，为减轻对高品位资源的依赖提供了一种可行的策略。

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引用次数: 0

Axial compressive behavior of concrete columns strengthened with BFRP grids 使用 BFRP 网格加固的混凝土柱的轴向抗压行为

IF 7.4 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Construction and Building Materials

Pub Date : 2025-04-19 DOI: 10.1016/j.conbuildmat.2025.141305

Peng Liu , Xin Wang , Weidong He , Dengfeng Lu , Zhishen Wu , Xiaofei Zhang , Yongbo Shao

The aim of this study is to evaluate the axial compressive behavior of concrete columns strengthened with basalt fiber-reinforced polymer (BFRP) grids. A total of 27 concrete cylinders were tested, including 18 strengthened specimens and 9 control specimens. The study parameters included specimen size and grids quantity, and comparisons were made with specimens strengthened using BFRP sheets. The results indicate that the control specimens exhibited brittle failure, while the strengthened specimens demonstrated ductile failure, with significantly improved compressive carrying capacity and deformation ability. The strength effectiveness of the grids gradually weakened as the specimen size increased. When the number of grids layers was less than two, the strength effect significantly improved with an increase in grids quantity. However, when the number of grids layers exceeded two, delamination between the grids and concrete occurred, and the strength effect became less significant. Compared to BFRP sheets, BFRP grids demonstrated higher strength efficiency. Several existing theoretical models were utilized to predict the peak stress of BFRP grid-strengthened concrete, and the predicted results agreed well with the experimental results.

{"title":"Axial compressive behavior of concrete columns strengthened with BFRP grids","authors":"Peng Liu , Xin Wang , Weidong He , Dengfeng Lu , Zhishen Wu , Xiaofei Zhang , Yongbo Shao","doi":"10.1016/j.conbuildmat.2025.141305","DOIUrl":"10.1016/j.conbuildmat.2025.141305","url":null,"abstract":"<div><div>The aim of this study is to evaluate the axial compressive behavior of concrete columns strengthened with basalt fiber-reinforced polymer (BFRP) grids. A total of 27 concrete cylinders were tested, including 18 strengthened specimens and 9 control specimens. The study parameters included specimen size and grids quantity, and comparisons were made with specimens strengthened using BFRP sheets. The results indicate that the control specimens exhibited brittle failure, while the strengthened specimens demonstrated ductile failure, with significantly improved compressive carrying capacity and deformation ability. The strength effectiveness of the grids gradually weakened as the specimen size increased. When the number of grids layers was less than two, the strength effect significantly improved with an increase in grids quantity. However, when the number of grids layers exceeded two, delamination between the grids and concrete occurred, and the strength effect became less significant. Compared to BFRP sheets, BFRP grids demonstrated higher strength efficiency. Several existing theoretical models were utilized to predict the peak stress of BFRP grid-strengthened concrete, and the predicted results agreed well with the experimental results.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"477 ","pages":"Article 141305"},"PeriodicalIF":7.4,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143847379","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}

引用次数: 0

Assessment of radioactivity in concrete grades M300 and M400 with fly ash addition and dose evaluation using the CEN room model 使用 CEN 室内模型评估添加粉煤灰的 M300 和 M400 级混凝土中的放射性和剂量

IF 7.4 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Construction and Building Materials

Pub Date : 2025-04-19 DOI: 10.1016/j.conbuildmat.2025.141350

Huynh Truc Van , Vu Ngoc Ba , Truong Thi Hong Loan , Huynh Van Tran Sang , Nguyen Ba Doan Trinh , Nguyen Quang Dao , Le Cong Hao , Huynh Truc Phuong

When fly ash is used in construction materials, it can increase exposure to gamma radiation and radon. This study aimed to evaluate the radioactive concentrations and exposure doses in concrete samples of grades M300 and M400 with added fly ash. We utilized an HPGe spectrometer and the RESRAD-BUILD simulation program for this purpose. The results indicated that the average activities of ²²⁶Ra and ²³²Th were below the reference values, while the average activity of ⁴⁰K exceeded the UNSCEAR limit. The findings for M300 and M400 were 1.5 and 1.6 times higher, respectively, than the global average for indoor absorbed gamma dose. However, the annual effective dose in residential and office spaces for both concrete grades remained below the 1.0 mSv y⁻¹ limit for the population. Multivariate analysis showed that radon and total dose were affected by the activities of ²²⁶Ra and ²³²Th, but not by ⁴⁰K. Additionally, the radon dose was impacted by the air exchange rate, with an increase in air circulation leading to a reduction in the radon dose. Overall, the results indicate that living and working in houses constructed with concrete samples of grades M300 and M400, mixed with fly ash content ranging from 0 % to 50 %, was safe for individuals.

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引用次数: 0

High-efficient hydrothermal synthesis of α-hemihydrate gypsum: A comparison of innovative microwave heating versus traditional electric heating

IF 7.4 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Construction and Building Materials

Pub Date : 2025-04-19 DOI: 10.1016/j.conbuildmat.2025.141346

Yawen Du , Xianbo Li , Weiping Yang

Heating method plays a crucial role in determining the conversion efficiency of phosphogypsum (PG) into α-hemihydrate gypsum (α-HH), traditional electric heating is bedeviled by a long preparation time and elevated reaction temperature. To address the issue, microwave heating is employed for high-efficient hydrothermal synthesis of α-HH in salt solution, the process parameters, such as reaction temperature, solid-liquid ratio, salt concentration and modifier concentration were systematically investigated and compared with the electric heating. Additionally, the enhanced mechanism of microwave heating was clarified by the measurements of solution conductivity and microwave absorption performance. The results demonstrate that microwave heating has a significant advantage in reducing the lower limit of reaction conditions and shortening the reaction time. Specifically, using electric heating, the initial reaction temperature, MgCl₂ concentration and solid-liquid ratio are 90 ℃, 25 % and 1:4, respectively. However, the initial reaction temperature and MgCl₂ concentration are decreased to 87 ℃ and 22.5 %, respectively, meanwhile the solid-liquid ratio is improved to 1:3 by microwave heating. In the presence of potassium hydrogen phthalate, short columnar α-HH crystals with an aspect ratio of 1:1 can be obtained within 120 min by microwave heating, whereas the reaction time is significantly delayed to 240 min by electric heating. This can be attributed to that MgCl₂ solution with a high conductivity and PG with a low reflection loss have a strong absorption ability for microwaves. Consequently, microwave heating is proven to be highly efficient for hydrothermal synthesis of α-HH.

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引用次数: 0

Study on the characteristics of pressure relief spread and pressure reconstruction in pumped concrete

IF 7.4 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Construction and Building Materials

Pub Date : 2025-04-19 DOI: 10.1016/j.conbuildmat.2025.141348

Kang Gao , Lianjun Chen , Guanguo Ma , Zhenjiao Sun , Hui Ma , Huamou Liu , Yongjing Deng

The pressure relief and backflow of concrete during the swing of the distribution valve are major causes of pumping pulses in dual-plunger concrete pumping systems, which significantly disrupt the continuity of concrete delivery. In this study, we independently developed an experimental platform for concrete pulse pumping and a platform for pressure relief spread experiments. Using concretes with different rheological properties, pulse pumping and pressure relief spread experiments were conducted. The results indicate that: (1) Pumping pulses lead to the alternation of "pressure relief spread (PRS)" and "pressure reconstruction (PCR)" within the pipeline. (2) PRS mainly occurs in the middle and later sections of the pipeline, where large pipe diameters and high water-cement ratios enhance concrete flowability and spread capability, while higher pressure inhibits spread by increasing cohesion and compressibility. (3) At the start of each pumping cycle, pipeline pressure must be re-established to overcome the maximum static friction between the concrete and the inner wall, after which steady pumping is achieved with a slight pressure drop. As the water-cement ratio increases, the maximum pressure values at different points in the pipeline become less pronounced. (4) The PCR near the pipeline outlet is slightly slower, but this time difference is minimal, and nearly all points reach the maximum pressure simultaneously. Through experimental research, this study clearly demonstrates the behavior and characteristics of concrete within pipelines during pulse pumping in traditional dual-plunger systems. This study demonstrates that optimizing the water-cement ratio and pipeline diameter configuration reduces the pressure required to overcome static friction, thereby lowering peak pumping pressure. This mitigation diminishes pipeline impact, equipment vibration, and structural fatigue. The findings provide a critical theoretical foundation for eliminating pulsating pumping effects, achieving continuous concrete delivery, prolonging equipment longevity, and facilitating intelligent upgrades in concrete pumping systems.

{"title":"Study on the characteristics of pressure relief spread and pressure reconstruction in pumped concrete","authors":"Kang Gao , Lianjun Chen , Guanguo Ma , Zhenjiao Sun , Hui Ma , Huamou Liu , Yongjing Deng","doi":"10.1016/j.conbuildmat.2025.141348","DOIUrl":"10.1016/j.conbuildmat.2025.141348","url":null,"abstract":"<div><div>The pressure relief and backflow of concrete during the swing of the distribution valve are major causes of pumping pulses in dual-plunger concrete pumping systems, which significantly disrupt the continuity of concrete delivery. In this study, we independently developed an experimental platform for concrete pulse pumping and a platform for pressure relief spread experiments. Using concretes with different rheological properties, pulse pumping and pressure relief spread experiments were conducted. The results indicate that: (1) Pumping pulses lead to the alternation of \"pressure relief spread (PRS)\" and \"pressure reconstruction (PCR)\" within the pipeline. (2) PRS mainly occurs in the middle and later sections of the pipeline, where large pipe diameters and high water-cement ratios enhance concrete flowability and spread capability, while higher pressure inhibits spread by increasing cohesion and compressibility. (3) At the start of each pumping cycle, pipeline pressure must be re-established to overcome the maximum static friction between the concrete and the inner wall, after which steady pumping is achieved with a slight pressure drop. As the water-cement ratio increases, the maximum pressure values at different points in the pipeline become less pronounced. (4) The PCR near the pipeline outlet is slightly slower, but this time difference is minimal, and nearly all points reach the maximum pressure simultaneously. Through experimental research, this study clearly demonstrates the behavior and characteristics of concrete within pipelines during pulse pumping in traditional dual-plunger systems. This study demonstrates that optimizing the water-cement ratio and pipeline diameter configuration reduces the pressure required to overcome static friction, thereby lowering peak pumping pressure. This mitigation diminishes pipeline impact, equipment vibration, and structural fatigue. The findings provide a critical theoretical foundation for eliminating pulsating pumping effects, achieving continuous concrete delivery, prolonging equipment longevity, and facilitating intelligent upgrades in concrete pumping systems.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"477 ","pages":"Article 141348"},"PeriodicalIF":7.4,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143850087","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}

引用次数: 0

An investigation on the use of coal gangue and coal gasification slag as reducing agent in synergistic utilization of steel slag for higher-activity supplementary cementitious materials 将煤矸石和煤气化渣作为还原剂协同利用钢渣生产高活性辅助胶凝材料的研究

IF 7.4 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Construction and Building Materials

Pub Date : 2025-04-19 DOI: 10.1016/j.conbuildmat.2025.141094

Qiang Song , Tiantian Song , Jiao Nie , Hong Zhou , Yaru Hu , Yanxin Chen , Yang Deng , Qian He , Fuan Cheng

To explore the synergistic effect of iron recovery and the hydration reactivity of the residue, steel slag was heated and reduced at different temperatures using coal gangue and coal gasification slag as reducing agents. The resulting aluminosilicates were then quenched in water. The content of Fe in reduced ferroalloys and water quenching residues is determined. X-ray diffraction, infrared spectroscopy, microcalorimeter, etc. were used to analyze the phase changes and hydration activity of water quenching residues. The results show that the increase of reduction temperature can significantly improve the iron recovery rate, reaching a maximum of 98.5 %, and an iron grade of 98 %. When the reduction temperature is below 1450 ℃, the mineral phases in the water quenching residues are mainly merwinite and gehlenite. With the temperature increase to 1450 ℃ and 1500 ℃, the phases of merwinite and gehlenite disappeared. At this time, the water quenching residues is mainly composed of glass phase. The increase of reduction temperature leads to an increase of the glass content in the water quenching residues, enhancing the hydration activity. The cumulative heat release of cement hydration reaction is greater when high reduction temperature water quenching residues is added. The compressive strength development rate of water quenching residues cement is higher than that of reference cement. After 28 d, the compressive strength of cement prepared with 30 wt% water quenching residues (reduced at 1400 ℃) reaches 90 % of the reference cement strength.

为了探索铁回收和残渣水化反应性的协同效应，使用煤矸石和煤气化渣作为还原剂，在不同温度下对钢渣进行加热和还原。然后将生成的铝硅酸盐在水中淬火。测定了还原铁合金和水淬残渣中的铁含量。利用 X 射线衍射、红外光谱、微量热仪等分析了水淬残渣的相变和水化活性。结果表明，提高还原温度可显著提高铁回收率，最高可达 98.5%，铁品位为 98%。当还原温度低于 1450 ℃ 时，水淬残渣中的矿物相主要是梅花石和gehlenite。随着温度升高到 1450 ℃ 和 1500 ℃，梅花石和格氏石相消失。此时，水淬残留物主要由玻璃相组成。还原温度的升高导致水淬残留物中玻璃相含量的增加，从而提高了水化活性。加入高还原温度的水淬渣时，水泥水化反应的累积放热量更大。水淬渣水泥的抗压强度发展速度高于基准水泥。28 d 后，用 30 wt%的水淬渣配制的水泥（还原温度为 1400 ℃）的抗压强度达到基准水泥强度的 90%。

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引用次数: 0

Flexural behavior of reinforced high strength concrete slabs containing glass powder, flay ash, and rice husk ash as cement substitute

IF 7.4 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Construction and Building Materials

Pub Date : 2025-04-19 DOI: 10.1016/j.conbuildmat.2025.141393

Mahmoud Elsayed , Mustafa Hamada Saad , Mahmoud.A.M. Hassanean

This study supports a move toward greener construction methods by endorsing sustainable building materials, which can have long-term positive effects on the environment and public health. Utilizing waste materials makes concrete production more environmentally friendly by lowering emissions, landfill usage, and the need for natural resources. The purpose of this study is to evaluate the effect of using glass powder (GP), fly ash (FA), and rice husk ash (RHA) as cement substitutes on the flexural behavior of reinforced high-strength concrete (RHSC) slabs. Ten RHSC slabs with different proportions (0 %, 10 %, 15 %, and 20 %) of GP, FA, and RHA as cement substitutes were experimentally cast and tested under four-line loading conditions. Experimental results indicated that using FA and RHA as cement alternatives for HSC mixes reduced workability, whereas GP increased it. Test results showed that the HSC mixes containing 15 % GP, 15 % FA, and 10 % RHA had the highest increase in compressive, tensile, and flexural strengths. Incorporating 15 % GP, FA, or RHA enhanced the ultimate load, stiffness, and toughness of the tested RHSC slabs compared to the control slab. Conversely, increasing replacement levels of GP, FA, or RHA to 20 % of cement led to a reduction in ultimate load. The optimal replacement ratios for the RHSC slab are 15 % GP, 15 % FA, or 10 % RHA, which result in acceptable performance of RHSC slabs and protect the environment and natural resources. Finally, the predictions of two methodologies, ACI 318 and ECP 203, were compared with the experimental findings, revealing satisfactory concordance.

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引用次数: 0

Highly thermally stable MOF-based flame retardant system for fire-safe and toxicity-suppressing rigid polyurethane foam

IF 7.4 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Construction and Building Materials

Pub Date : 2025-04-19 DOI: 10.1016/j.conbuildmat.2025.141382

Gang Tang , Mengfan Guan , Sujie Yang , Yuan Fang , Xiuyu Liu , Kang Dai , Wei Wang

Metal-organic frameworks (MOF) as promising flame retardants are constrained in polymer applications due to their low thermal stability and mechanical strength. To tackle these challenges, biomass-modified steel slag (PSS) was utilized to develop a highly thermally stable MOF-based flame retardant system, designed to enhance the thermal stability, flame retardancy, and toxicity suppression properties of rigid polyurethane foam (RPUF). When combined with ammonium polyphosphate, the MOF flame retardant system significantly enhances the flame retardancy of RPUF, achieving the UL-94 V-0 rating. Cone calorimeter tests revealed that compared to pure RPUF, the total heat release values of RPUF/APP/MOF, RPUF/APP/PSS, and RPUF/APP/PSS@MOF decreased by 22.8 %, 25.1 %, and 24.5 %, respectively, highlighting their effectiveness in mitigating thermal hazards. Notably, RPUF/APP/PSS@MOF emitted the least CO during the later stages of combustion. The CO adsorption capabilities of MOF and PSS@MOF were analyzed and validated through molecular dynamics modeling and simulations. While MOF demonstrated good CO adsorption capacity due to its distinctive porous structure, PSS@MOF obviously outperformed MOF in toxic gas adsorption. This finding aligns with cone calorimeter test results, confirming its superior effectiveness in reducing toxic emissions during combustion. This study underscores the significant flame-retardant potential of combining biomass-modified steel slag with MOF materials, promoting efficient recycling of industrial waste and significantly enhancing the flame-retardant and toxicity-inhibiting capabilities of MOF. These findings pave new ways for developing sustainable, efficient, and high-value flame retardants, enhancing the fire resistance of polymer composites while addressing environmental sustainability challenges.

由于热稳定性和机械强度较低，金属有机框架（MOF）作为有前途的阻燃剂在聚合物应用中受到限制。为了应对这些挑战，我们利用生物质改性钢渣（PSS）开发了一种高热稳定性的 MOF 阻燃剂体系，旨在增强硬质聚氨酯泡沫（RPUF）的热稳定性、阻燃性和毒性抑制性能。当与聚磷酸铵结合使用时，MOF 阻燃剂系统可显著提高 RPUF 的阻燃性，达到 UL-94 V-0 等级。锥形量热仪测试表明，与纯 RPUF 相比，RPUF/APP/MOF、RPUF/APP/PSS 和 RPUF/APP/PSS@MOF 的总放热值分别降低了 22.8%、25.1% 和 24.5%，突出表明了它们在减轻热危害方面的功效。值得注意的是，RPUF/APP/PSS@MOF 在燃烧后期排放的二氧化碳最少。通过分子动力学建模和模拟，对 MOF 和 PSS@MOF 的 CO 吸附能力进行了分析和验证。虽然 MOF 因其独特的多孔结构而表现出良好的 CO 吸附能力，但 PSS@MOF 在有毒气体吸附方面明显优于 MOF。这一发现与锥形量热计测试结果相吻合，证实了 PSS@MOF 在减少燃烧过程中有毒气体排放方面的卓越功效。这项研究强调了将生物质改性钢渣与 MOF 材料相结合的巨大阻燃潜力，促进了工业废物的高效回收利用，并显著提高了 MOF 的阻燃和抑毒能力。这些发现为开发可持续、高效和高价值的阻燃剂铺平了新的道路，在提高聚合物复合材料阻燃性能的同时，也解决了环境可持续发展的挑战。

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引用次数: 0

Enhancing printability and mechanical performance of 3D printed magnesium phosphate cement through silica fume modification: Rheological, microstructural, and numerical insights 通过硅灰改性提高 3D 打印磷酸镁水泥的可打印性和机械性能：流变学、微观结构和数值见解

IF 7.4 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Construction and Building Materials

Pub Date : 2025-04-19 DOI: 10.1016/j.conbuildmat.2025.141302

Chaofan Wang , Bin Li , Bing Chen

This study explores the modification of 3D printed magnesium phosphate cement (MPC) using silica fume (SF) from rheological, microstructural and numerical perspectives, with the aim of enhancing its printability and mechanical performance. Results demonstrate that the incorporation of SF improved the yield stress and viscosity by forming compact flocculation structures. For hardened 3D printed MPC, SF reduced its mechanical anisotropy by enhancing its interlayer bonding. Microstructural analysis reveals that SF refined pores, suppressed dittmarite formation and promoted the formation of magnesium silicate hydrated (M-S-H) phase at interlayers, which is critical for the interlayer bonding enhancement. A discrete element method (DEM) model validates the critical influence of interlayer bonding on anisotropic behavior and reveals the failure mechanism of 3D printed MPC loaded in different loading directions. This work bridges the gap between rheology control and mechanical anisotropy in 3D printed MPC, offering valuable insights for advancing additive manufacturing in construction.

本研究从流变学、微观结构和数值角度探讨了使用硅灰（SF）对 3D 打印磷酸镁水泥（MPC）进行改性的问题，旨在提高其可打印性和机械性能。结果表明，硅灰的加入通过形成紧凑的絮凝结构提高了屈服应力和粘度。对于硬化的三维打印 MPC，SF 通过增强层间粘合力降低了其机械各向异性。微观结构分析表明，SF 可细化孔隙，抑制闪长岩的形成，促进层间水合硅酸镁（M-S-H）相的形成，这对增强层间结合力至关重要。离散元素法（DEM）模型验证了层间结合对各向异性行为的关键影响，并揭示了以不同加载方向加载的三维打印 MPC 的失效机理。这项研究填补了三维打印 MPC 中流变控制与机械各向异性之间的空白，为推进建筑增材制造提供了宝贵的见解。

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引用次数: 0