Construction and Building Materials最新文献_第7页

Hybrid machine learning models and simplified design formulations for predicting punching shear strength in internal SFRC slab-column connections

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

Construction and Building Materials

Pub Date : 2025-04-21 DOI: 10.1016/j.conbuildmat.2025.141383

Yassir M. Abbas, Abdulaziz Alsaif

This study aims to develop and validate advanced machine learning models for predicting the punching shear strength of steel fiber-reinforced concrete (SFRC) slab-column connections. Using a curated dataset of 377 experimental results, 36 outliers were identified and removed using Cook's distance approach, which resulted in a refined dataset of 341 samples. Predictive frameworks were constructed employing artificial neural networks (ANN), Categorical Boosting (CatBoost), and a hybrid Auto search optimization (ATOM)-ANN approach. The performance of these models was rigorously evaluated against established design formulas to assess their predictive accuracy and robustness. The CatBoost model outperformed its counterparts, achieving a mean absolute error (MAE) of 0.007 and a coefficient of determination of 0.921 on the validation set, demonstrating its superior ability to handle highly nonlinear relationships. SHAP analysis identified critical factors influencing punching shear strength, including concrete strength, fiber volume content, reinforcement ratio, slab thickness, and column dimensions. Results highlighted optimal reinforcement ratios between 1.5 % and 1.7 %, beyond which fiber congestion compromises strength. Additionally, four nonlinear design models were introduced, with Model-2 providing the best performance among the proposed formulations. Benchmarking against existing design methods revealed moderate predictive capabilities, but their limitations in addressing nonlinear behaviors underscore the need for advanced approaches.

本研究旨在开发和验证先进的机器学习模型，用于预测钢纤维增强混凝土（SFRC）板柱连接的冲剪强度。通过使用包含 377 项实验结果的数据集，使用库克距离法识别并移除了 36 个异常值，从而得到了包含 341 个样本的精炼数据集。利用人工神经网络 (ANN)、分类提升 (CatBoost) 和自动搜索优化 (ATOM) -ANN 混合方法构建了预测框架。根据既定的设计公式对这些模型的性能进行了严格评估，以评估其预测准确性和稳健性。CatBoost 模型的性能优于同类模型，在验证集上的平均绝对误差 (MAE) 为 0.007，决定系数为 0.921，这表明该模型具有处理高度非线性关系的卓越能力。SHAP 分析确定了影响冲切剪切强度的关键因素，包括混凝土强度、纤维体积含量、配筋率、板厚度和柱尺寸。结果表明，最佳配筋率介于 1.5 % 和 1.7 % 之间，超过这一比例，纤维拥塞会影响强度。此外，还引入了四个非线性设计模型，其中模型-2 在所提出的方案中性能最佳。对现有设计方法进行基准测试后发现，这些方法具有适度的预测能力，但在处理非线性行为方面存在局限性，因此需要采用先进的方法。

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引用次数: 0

Performance comparison of polypropylene and elastic fibers in enhancing the flexural behavior of lime-stabilized kaolinite clay

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

Construction and Building Materials

Pub Date : 2025-04-21 DOI: 10.1016/j.conbuildmat.2025.141422

Mahmood Reza Abdi , Elham Abbasi , Mahdi Safdari Seh Gonbad

The use of fiber reinforcement to improve soil characteristics is widely accepted in geotechnical engineering. Current research introduces a novel elastic fiber (E fiber) aimed at enhancing the flexural characteristics of untreated and stabilized kaolinite clay, comparing its performance with that of the more well-known polypropylene fiber (PP fiber). The E fiber features a composite structure consisting of a core made of a larger spandex fiber, known for its high elasticity, surrounded by numerous finer polyester fibers. As a byproduct of the textile industry, E fiber is cost-effective, environmentally sustainable, and its larger dimensions facilitate mixing with soil compared to PP fibers. Kaolinite samples were treated with 1 %, 3 %, and 5 % lime (L) and reinforced with 0.15 %, 0.25 %, and 0.35 % PP fibers or 1.5 %, 2.5 %, and 3.5 % E fibers, with consistent lengths of 6 mm and 12 mm. All samples were cured at 20–25 °C for 7 and 28 days. For quantitative and qualitative assessment of fiber performance, three-point bending (TPB) tests and Scanning Electron Microscopy (SEM) analyses were conducted. Results indicated that reinforcement and stabilization, whether independently or concurrently applied, significantly increased the peak force (P) and deflection at peak load (Δ) of the samples. A direct relationship between P and Δ with the fiber content, fiber length, lime dosage, and curing duration was observed. Importantly, at the same lime content and curing periods, both E and PP fibers exhibited similar ranges and averages for load (α) and ductility (β) improvement coefficients. Thus, it is concluded that the performance of PP and E fibers is approximately similar in enhancing flexural strength and ductility. Consequently, E fiber can be considered a promising candidate for reinforcing untreated and lime-treated clay. However, it is recommended that before using E fiber in field projects, its performance in reinforcing other soils stabilized with different binders and subjected to varying environmental and loading conditions be investigated.

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引用次数: 0

Influence of basalt fiber and flexural load on carbonation resistance of shotcrete: Experimental study and predictive model 玄武岩纤维和抗弯荷载对喷射混凝土抗碳化性能的影响：实验研究和预测模型

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

Construction and Building Materials

Pub Date : 2025-04-21 DOI: 10.1016/j.conbuildmat.2025.141421

Ximeng Wu , Huimin Pan , Kun Song , Shaokang Xie , Qingxin Zhao

The interior of tunnels presents a high-temperature, high-humidity, and high-concentration CO₂ environment, which makes the surface of shotcrete highly susceptible to carbonation. Additionally, shotcrete endures substantial surrounding rock stress during service. This study focuses on the service environment of tunnel structures to investigate the carbonation resistance of shotcrete, analyzing the effects of flexural load and basalt fiber content on carbonation depth. The results show that incorporating an appropriate amount of basalt fiber can reduce the carbonation depth of shotcrete, with the optimal carbonation resistance achieved at a basalt fiber content of 0.2 %. However, excessive basalt fiber content negatively impacts carbonation resistance. Flexural tensile stress consistently accelerates the carbonation process. When the basalt fiber content is within 0.2 %, compressive stress shows an inhibitory effect on carbonation. At a basalt fiber content of 0.3 %, both tensile and compressive stress adversely affect the carbonation resistance of shotcrete. Microstructural analysis reveals that a moderate amount of basalt fiber reduces large pore sizes in the concrete and increases the number of smaller pores, while excessive fiber content diminishes this effect. Tensile stress increases the total pore volume, reducing the density of the specimen. Conversely, compressive stress compresses existing cracks and large pores, causing medium-sized pores to collapse into smaller ones, thereby enhancing the density of the concrete. A prediction model for the carbonation depth of shotcrete under flexural load was established based on basalt fiber content, with fitting correlation coefficients exceeding 0.95. In conclusion, the findings of this study provide theoretical support for evaluating the durability of shotcrete and predicting the service life of tunnel linings.

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引用次数: 0

Highly efficient resistance to chloride ion penetration and enhanced compressive strength in cement coupled with cationic polymer grafted nano-silica

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

Construction and Building Materials

Pub Date : 2025-04-21 DOI: 10.1016/j.conbuildmat.2025.141420

Yangyang Xiang , Yasen Li , Zuhua Xu , Jinni Deng , Honghai Cui , Guoxing Sun

The degradation and loss of structural integrity in concrete due to chloride ion-induced corrosion of steel reinforcement represent significant challenges that limit the service life of concrete structures. To combat this, cationic polymer (polydimethylaminoethyl methacrylate quaternary ammonium, PDEMAQA) grafted nano-silica (SiO₂-g-PDEMAQA) was prepared by atom-transfer radical-polymerization (ATRP) reaction to enhance the chloride ion penetration resistance of cement. On one hand, cationic polymer provides the ability to facilitate the dispersion of nano-SiO₂ within cement, thereby promoting cement hydration. On the other hand, the substantial presence of quaternary amine groups in cationic polymer enhances the capacity to effectively bind free chloride ions in cement. Consequently, the incorporation of a modest quantity of organic polymer-modified nano-silica could lead to marked improvements in both the resistance to chloride ion penetration and the compressive strength of cement. The experimental results demonstrate that cement doped with just 1.0 wt% SiO₂-g-PDEMAQA could not only significantly improve early resistance to chloride ion penetration by 66.91 %, but also increase the compressive strength by 9.79 % after 28 days of curing. Benefiting from the synergistic effect of cationic polymer and nano-SiO₂, SiO₂-g-PDEMAQA exhibits highly efficient chloride ion penetration resistance and enhanced compressive strength. This work will develop a strategy of improving resistance to chloride corrosion in cement with high efficiency, and will contribute to the sustainable advancement of concrete technology.

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引用次数: 0

Effect of admixture on compressive fatigue properties of lightweight concrete underwater

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

Construction and Building Materials

Pub Date : 2025-04-21 DOI: 10.1016/j.conbuildmat.2025.140859

Atsushi Shibayama , Takumi Sakata , Ziping Zhu , Yuan Liu , Naoto Kihara , Minehiro Nishiyama

Using lightweight concrete, rather than ordinary concrete, for floating structures is expected to reduce costs, mainly due to the reduction of external mooring forces. However, previous studies point out that lightweight concrete has lower fatigue strength than ordinary concrete and that the fatigue strength of concrete decreases when underwater. To investigate whether the admixture helped improve fatigue performance, this study conducted compressive fatigue tests on concretes with several kinds of compositions in air and underwater. It was observed that the underwater fatigue life of lightweight concrete mixed with silica fume and reinforced with steel fiber is about 20–30 times larger than that of ordinary concrete, which has almost the same static compressive strength. Consequently, silica fume and fiber reinforcement effectively improved the underwater compressive fatigue strength of lightweight concrete.

引用次数: 0

Intrinsic rheological behavior of limestone calcined clay cementitious (LC3) binders for automated construction: Effect of calcium sulfate varieties

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.2025.141314

Mirza Abdul Basit Beigh , Cesare Signorini , Asim Rauf , Christof Schröfl , Thomas Köberle , Konrad Grahl , Thomas Matschei , Viktor Mechtcherine

As the concrete industry moves toward sustainable, automated construction, understanding the rheological behavior of alternative binders is essential. In particular, the rheology of limestone calcined clay cement (LC³) is extremely sensitive to the type of calcium sulfate used. This study systematically investigates the impact of anhydrite (CaSO₄), bassanite (CaSO₄·0.5 H₂O), and gypsum (CaSO₄·2 H₂O) on hydration kinetics, structural build-up, and workability of LC³ pastes. Isothermal calorimetry, rotational and oscillatory rheometry (Large-Amplitude Oscillatory Shear (LAOS) tests) were used to decouple the interplays between sulfate dissolution, hydration and thixotropic behavior. The results indicate that bassanite accelerates early-age structuration due to its rapid dissolution and ettringite formation, yielding a high structuration rate (A_thix = 0.5 Pa/min) and optimal shear stress evolution (up to 102 Pa). Conversely, gypsum retards structuration and extends workability beyond 140 minutes, but compromises early stiffening. Anhydrite, despite its coarser morphology, exhibited intermediate behavior with rapid workability reduction. LAOS analysis also identified distinct viscoelastic thresholds. Pastes with bassanite reached critical strain (10⁻³) and crossover strain (10⁻²) at minimal deformation, ideal for automated construction, while gypsum formulations showed delayed stiffening. This study demonstrates that sulfate selection directly controls open time, with bassanite formulations requiring a 90-minute operational time frame to balance extrudability and layer stability. These findings underscore the need to tailor calcium sulfate type to application-specific rheological demands and offer a pathway to optimize LC³ binders for automated processes such as robotic shotcreting and 3D concrete printing.

随着混凝土行业向可持续、自动化建筑方向发展，了解替代粘结剂的流变行为至关重要。尤其是石灰石煅烧粘土水泥（LC3）的流变性对所使用的硫酸钙类型极为敏感。本研究系统地探讨了无水石膏（CaSO4）、重晶石（CaSO4-0.5 H2O）和石膏（CaSO4-2 H2O）对 LC³ 浆料的水化动力学、结构形成和工作性的影响。研究人员使用等温量热法、旋转和振荡流变仪（大振幅振荡剪切（LAOS）试验）对硫酸盐溶解、水合和触变行为之间的相互作用进行了解耦。结果表明，贝闪石因其快速溶解和乙闪石的形成而加速了早期的结构化，产生了较高的结构化速率（Athix = 0.5 Pa/min）和最佳的剪应力演化（高达 102 Pa）。相反，石膏会延缓结构化，并将可加工性延长至 140 分钟以上，但会影响早期硬化。无水石膏尽管形态较粗，但表现出中间行为，可加工性迅速降低。LAOS 分析还确定了不同的粘弹性阈值。使用贝壳粉的浆料在变形最小的情况下达到临界应变（10-3）和交叉应变（10-2），非常适合自动化施工，而石膏配方则表现出延迟僵化。这项研究表明，硫酸盐的选择直接控制着开放时间，低闪石配方需要 90 分钟的操作时间来平衡挤出性和层稳定性。这些发现强调了根据特定应用的流变学要求定制硫酸钙类型的必要性，并提供了优化 LC3 粘合剂的途径，使其适用于机器人喷丸和 3D 混凝土打印等自动化工艺。

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引用次数: 0

Improvement of mineral admixtures on the properties of fluoroaluminic acid shotcrete and fluoride ion leaching behavior

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.2025.141384

Yike Lin , Tingshu He , Yongqi Da , Xiaodong Ma , Renhe Yang , Qiheng Qu

Fluoroaluminate accelerators have been widely adopted in engineering applications due to their excellent setting acceleration performance, cost-effectiveness, and satisfactory stability. However, their adverse effects on the mechanical properties of shotcrete and the potential risks associated with fluoride ion leaching remain unresolved, posing threats to structural durability and environmental safety. In this study, three mineral admixtures (fly ash, slag powder, and silica fume) were incorporated at different replacement levels (0 %, 5 %, 10 %, and 20 %) with fluoroaluminate accelerators to fabricate shotcrete. The investigation focused on evaluating the effects of mineral admixtures on enhancing the mechanical properties of shotcrete and reducing fluoride ion leaching concentration. Isothermal calorimetry was employed to analyze the influence of mineral admixtures on the hydration kinetics of shotcrete. Thermogravimetric analysis (TGA), X-ray diffraction (XRD), and mercury intrusion porosimetry (MIP) were utilized to characterize the hydration product composition and internal pore structure of the shotcrete. The results demonstrated that mineral admixtures synergistically interact with fluoroaluminate accelerators to further shorten the setting time and improve the 28 d compressive strength retention rate. Specifically, the incorporation of 20 % silica fume increased the 1 d compressive strength from 8.6 MPa to 9.3 MPa, while the addition of 10 % slag powder enhanced the 3 d compressive strength by 18.4 %. Mineral admixtures were found to effectively reduce the fluoride ion leaching concentration of shotcrete, with slag powder and silica fume demonstrating the most significant improvements in the environmental safety of shotcrete leachate. Furthermore, this study elucidated the mechanisms by which mineral admixtures enhance the mechanical performance and environmental safety of shotcrete through the integration of microscopic analysis results.

{"title":"Improvement of mineral admixtures on the properties of fluoroaluminic acid shotcrete and fluoride ion leaching behavior","authors":"Yike Lin , Tingshu He , Yongqi Da , Xiaodong Ma , Renhe Yang , Qiheng Qu","doi":"10.1016/j.conbuildmat.2025.141384","DOIUrl":"10.1016/j.conbuildmat.2025.141384","url":null,"abstract":"<div><div>Fluoroaluminate accelerators have been widely adopted in engineering applications due to their excellent setting acceleration performance, cost-effectiveness, and satisfactory stability. However, their adverse effects on the mechanical properties of shotcrete and the potential risks associated with fluoride ion leaching remain unresolved, posing threats to structural durability and environmental safety. In this study, three mineral admixtures (fly ash, slag powder, and silica fume) were incorporated at different replacement levels (0 %, 5 %, 10 %, and 20 %) with fluoroaluminate accelerators to fabricate shotcrete. The investigation focused on evaluating the effects of mineral admixtures on enhancing the mechanical properties of shotcrete and reducing fluoride ion leaching concentration. Isothermal calorimetry was employed to analyze the influence of mineral admixtures on the hydration kinetics of shotcrete. Thermogravimetric analysis (TGA), X-ray diffraction (XRD), and mercury intrusion porosimetry (MIP) were utilized to characterize the hydration product composition and internal pore structure of the shotcrete. The results demonstrated that mineral admixtures synergistically interact with fluoroaluminate accelerators to further shorten the setting time and improve the 28 d compressive strength retention rate. Specifically, the incorporation of 20 % silica fume increased the 1 d compressive strength from 8.6 MPa to 9.3 MPa, while the addition of 10 % slag powder enhanced the 3 d compressive strength by 18.4 %. Mineral admixtures were found to effectively reduce the fluoride ion leaching concentration of shotcrete, with slag powder and silica fume demonstrating the most significant improvements in the environmental safety of shotcrete leachate. Furthermore, this study elucidated the mechanisms by which mineral admixtures enhance the mechanical performance and environmental safety of shotcrete through the integration of microscopic analysis results.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"477 ","pages":"Article 141384"},"PeriodicalIF":7.4,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143847517","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

Atomic insights into corrosion of Fe-Cr alloy in chloride contaminated environment: Development of JAX-ReaxFF force field

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.2025.141351

Guojian Liu , Minhao Li , Adri C.T. van Duin , Yunsheng Zhang

This study provides atomic-level insights into the chloride-induced corrosion of Fe-Cr alloy, using the newly developed JAX-ReaxFF force field. Fe/Cr/Cl parameters were generated from density functional theory (DFT)-derived data on chromium-chloride and iron-chloride molecular clusters. These parameters were validated against DFT results, showing strong agreement in bond dissociation energies, angular distortions, atomic charges, and adsorption energies. Reactive molecular dynamics simulations revealed that chloride ions accumulate on the Fe-Cr alloy surface, destabilizing the passive film and leading to metal ion dissolution, forming soluble chlorides. As the process advances, metal oxides and hydroxides deposit, further accelerating corrosion. The charge transfer between Fe and Cr plays a critical role (Fe loses approximately 1 electron, while Cr loses only 0.5 electrons), with Fe exhibiting higher diffusivity (diffusion coefficient = 5.54 ×10⁻¹² m²/s) due to significant charge loss, while Cr forms a protective oxide layer that slows its dissolution. These findings provide valuable insights into the corrosion resistance of Fe-Cr alloy, particularly in chloride-contaminated environments.

{"title":"Atomic insights into corrosion of Fe-Cr alloy in chloride contaminated environment: Development of JAX-ReaxFF force field","authors":"Guojian Liu , Minhao Li , Adri C.T. van Duin , Yunsheng Zhang","doi":"10.1016/j.conbuildmat.2025.141351","DOIUrl":"10.1016/j.conbuildmat.2025.141351","url":null,"abstract":"<div><div>This study provides atomic-level insights into the chloride-induced corrosion of Fe-Cr alloy, using the newly developed JAX-ReaxFF force field. Fe/Cr/Cl parameters were generated from density functional theory (DFT)-derived data on chromium-chloride and iron-chloride molecular clusters. These parameters were validated against DFT results, showing strong agreement in bond dissociation energies, angular distortions, atomic charges, and adsorption energies. Reactive molecular dynamics simulations revealed that chloride ions accumulate on the Fe-Cr alloy surface, destabilizing the passive film and leading to metal ion dissolution, forming soluble chlorides. As the process advances, metal oxides and hydroxides deposit, further accelerating corrosion. The charge transfer between Fe and Cr plays a critical role (Fe loses approximately 1 electron, while Cr loses only 0.5 electrons), with Fe exhibiting higher diffusivity (diffusion coefficient = 5.54 ×10⁻¹² m²/s) due to significant charge loss, while Cr forms a protective oxide layer that slows its dissolution. These findings provide valuable insights into the corrosion resistance of Fe-Cr alloy, particularly in chloride-contaminated environments.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"477 ","pages":"Article 141351"},"PeriodicalIF":7.4,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143847680","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

Packing coupled post-fire behavior of ultra-heavy-weight 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.2025.141008

Z.C. Huang , B.X. Zhang , F.M. Ren , J.C.M. Ho , S. Kitipornchai , M.H. Lai

Heavy-weight concrete (HWC) made with heavy-weight aggregate (HWA) is recently widely used in the nuclear industry due to its superior radiation shielding capacity. A new-type HWC containing iron sand (IS) and steel slag coarse aggregate (SSCA) simultaneously, renamed as ultra-heavy-weight concrete (UHWC) due to its ultra-high unit weight, has been proposed in this paper. A total of 16 mixes were fabricated, in which IS and SSCA were selected to replace natural fine and coarse aggregates, respectively with volumetric replacement ratio of 50 % and 100 %. In the meanwhile, fly ash (FA) was adopted to replace 15 %, 25 % and 35 % cement. The heating test with target temperatures of 400–1000°C was conducted and the heating curve, mass loss, surface change, residual compressive strength and elastic modulus after fire were studied. Besides, the chemical phases were detected by X-ray diffraction (XRD) before and after exposure to elevated temperatures. Results revealed that the heat-insulation capacity of UHWC was greatly enhanced by adding SSCA due to its lower thermal conductivity. Satisfactory flowability and pre- and post-fire mechanical properties of UHWC could be achieved. Lastly, it is evident that the pre- and post-fire performance of UHWC could be explicable by the change of packing structure.

{"title":"Packing coupled post-fire behavior of ultra-heavy-weight concrete","authors":"Z.C. Huang , B.X. Zhang , F.M. Ren , J.C.M. Ho , S. Kitipornchai , M.H. Lai","doi":"10.1016/j.conbuildmat.2025.141008","DOIUrl":"10.1016/j.conbuildmat.2025.141008","url":null,"abstract":"<div><div>Heavy-weight concrete (HWC) made with heavy-weight aggregate (HWA) is recently widely used in the nuclear industry due to its superior radiation shielding capacity. A new-type HWC containing iron sand (IS) and steel slag coarse aggregate (SSCA) simultaneously, renamed as ultra-heavy-weight concrete (UHWC) due to its ultra-high unit weight, has been proposed in this paper. A total of 16 mixes were fabricated, in which IS and SSCA were selected to replace natural fine and coarse aggregates, respectively with volumetric replacement ratio of 50 % and 100 %. In the meanwhile, fly ash (FA) was adopted to replace 15 %, 25 % and 35 % cement. The heating test with target temperatures of 400–1000°C was conducted and the heating curve, mass loss, surface change, residual compressive strength and elastic modulus after fire were studied. Besides, the chemical phases were detected by X-ray diffraction (XRD) before and after exposure to elevated temperatures. Results revealed that the heat-insulation capacity of UHWC was greatly enhanced by adding SSCA due to its lower thermal conductivity. Satisfactory flowability and pre- and post-fire mechanical properties of UHWC could be achieved. Lastly, it is evident that the pre- and post-fire performance of UHWC could be explicable by the change of packing structure.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"477 ","pages":"Article 141008"},"PeriodicalIF":7.4,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143847683","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

Effect of slag on the hydration mechanism of limestone calcined clay cement (LC3)

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.2025.141357

Lingzhi Guo , Juanhong Liu , Yayun Xi , Huan Cheng , Deping Chen

To investigate the influence of slag on the hydration of limestone calcined clay cement (LC³) and expand the application potential of low-carbon cementitious materials. This study investigates the effects of slag contents on the hydration mechanism of LC³ binder, compared with ordinary Portland cement (OPC). The results show that the 3 days compressive strength of limestone calcined clay cement-slag (LC³-S) increased with the slag content; however, LC³-S5 (5 % slag) showed the highest compressive strengths at 28 days. Slag provides more reactive material to the LC³-S system, accelerates the aluminate reaction, increases the bound water content, improves the pore structure, and promotes the production of more AFt and C-(A)-S-H gels. However, excessive slag (>10 %) reduces LS content, suppressing carboaluminate phase formation while promoting AFt-to-AFm conversion, which reduces the cumulative heat release and the hydration of raw materials.

引用次数: 0