Case Studies in Construction Materials最新文献_第5页

Effect of specimen geometry on the dynamic direct tensile responses of ultra-high-performance fiber-reinforced concrete 试件几何形状对高性能纤维增强混凝土动态直接拉伸响应的影响

IF 6.6 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Case Studies in Construction Materials

Pub Date : 2025-12-25 DOI: 10.1016/j.cscm.2025.e05732

Hyeon Woo Noh , Van Doan Truong , Dong Joo Kim

Direct tensile responses of ultra-high-performance fiber-reinforced concrete (UHPFRC) at high strain rates were investigated using a high-rate hydraulic universal testing machine (HR-UTM) with modified cylindrical specimens. The modified cylindrical UHPFRC specimens containing 2 vol% steel fibers exhibited tensile strain-softening behavior even at static strain rates, in contrast to the tensile strain-hardening responses commonly reported in previous studies. The modified cylindrical UHPFRC specimens containing 0.5 and 2 vol% steel fibers exhibited average tensile strengths of 8.8 and 10.0 MPa, respectively, at static strain rate (

\dot{ε}

=5.55 ×10⁻⁴ s⁻¹). As the strain rate increased from 5.55 × 10⁻⁴ to 162.96 s⁻¹, the tensile strength of the specimen with 2 vol% steel fibers increased from 10.0 to 17.1 MPa. Moreover, the elastic modulus of UHPFRC in direct tension increased from 59.4 to 124.7 GPa as the strain rate increased from 5.55 × 10⁻⁴ to 99.53 s⁻¹. However, at strain rates exceeding 162.45 s⁻¹, accurately determining the tensile elastic modulus became difficult because of vibrations and early damage to strain gauges. Overall, the results demonstrate that specimen geometry plays a critical role in governing the dynamic tensile response of UHPFRC, emphasizing the need to consider geometric effects in material design and structural applications subjected to high strain rates.

采用高速率液压万能试验机（HR-UTM）对超高性能纤维增强混凝土（UHPFRC）在高应变率下的直接拉伸响应进行了研究。含有2 vol%钢纤维的改性圆柱形UHPFRC试样即使在静态应变率下也表现出拉伸应变软化行为，与以往研究中普遍报道的拉伸应变硬化反应形成对比。在静态应变率（ε ε =5.55 ×10−4 s−1）下，含0.5和2 vol%钢纤维的改性柱状UHPFRC试样的平均抗拉强度分别为8.8和10.0 MPa。当应变速率从5.55 × 10−4增加到162.96 s−1时，含2 vol%钢纤维试样的抗拉强度从10.0增加到17.1 MPa。当应变速率从5.55 × 10−4增加到99.53 s−1时，UHPFRC在直接拉伸下的弹性模量从59.4增加到124.7 GPa。然而，当应变率超过162.45 s−1时，由于振动和应变片的早期损坏，准确测定拉伸弹性模量变得困难。总体而言，研究结果表明，试样的几何形状在控制UHPFRC的动态拉伸响应中起着关键作用，强调在材料设计和结构应用中需要考虑高应变率下的几何效应。

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引用次数: 0

Research on the practical application of self-healing calcium alginate capsules in asphalt pavements in Fujian province 自愈海藻酸钙胶囊在福建省沥青路面中的实际应用研究

IF 6.6 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Case Studies in Construction Materials

Pub Date : 2025-12-24 DOI: 10.1016/j.cscm.2025.e05730

Hang Chen , Peixin Zhong , Jiazhu Wang , Zirong Ma , Shaopeng Wu , Quantao Liu , Yilun Shen , Xiaobin Zou , Aimin Sha , Pei Wan , Niecheng Lin , Zhiming Lin , Xinling Feng , Qiuyuan Luo , Pengjuan Zhang , Jixin Zhang , Jinqing Wang , Lei Zhang , Huan Wang , Xing Gong

Asphalt pavement maintenance faces challenges from crack propagation and material aging, prompting the exploration of innovative self-healing technologies. Traditional maintenance methods such as grouting and patching, are reactive and short-term. This study investigates the practical application of self-healing calcium alginate capsules in asphalt pavements to address performance degradation caused by traffic loads and environmental factors. The research team have developed an integrated production device for large-scale manufacturing of calcium alginate capsules. These capsules containing low-viscosity asphalt rejuvenator are incorporated into AC-13 asphalt mixtures and applied to test road section in Yongtai S213 Line, Fujian Province. Field tests demonstrate that the capsule-modified pavement met construction specifications, with compaction (97.8 %), texture depth (0.80 mm), and permeability (242 ml/min) within acceptable ranges. Although the capsules slightly reduced mixture density, marshal stability and dynamic stability compared to conventional asphalt, all parameters complied with Chinese standards. The study validates the feasibility of calcium alginate capsules for self-healing asphalt pavements, highlighting their potential to extend service life through crack repair and aged asphalt regeneration. Challenges remain in optimizing production scalability and long-term durability for broader engineering applications.

沥青路面养护面临着裂缝扩展和材料老化的挑战，促使人们探索创新的自愈技术。传统的维修方法，如灌浆和修补，是反应性和短期的。本研究探讨自愈海藻酸钙胶囊在沥青路面上的实际应用，以解决交通负荷和环境因素造成的路面性能下降问题。研究小组开发了大规模生产海藻酸钙胶囊的集成生产装置。这些含有低粘度沥青再生剂的胶囊被掺入AC-13沥青混合料中，用于福建省永泰S213线试验路段。现场试验表明，胶囊改性路面的压实度（97.8% %）、纹理深度（0.80 mm）和渗透性（242 ml/min）均在可接受范围内，满足施工要求。虽然与常规沥青相比，胶囊的混合料密度、marshal稳定性和动力稳定性略有降低，但所有参数均符合中国标准。该研究验证了海藻酸钙胶囊用于自愈沥青路面的可行性，强调了其通过裂缝修复和老化沥青再生来延长使用寿命的潜力。为更广泛的工程应用优化生产可扩展性和长期耐用性仍然存在挑战。

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引用次数: 0

Coupled effects of polymer-to-cement ratio and resting time on cold-joint degradation and interfacial mechanism of PAE cement-based coatings 胶灰比和静置时间对PAE水泥基涂料冷缝降解及界面机理的耦合影响

IF 6.6 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Case Studies in Construction Materials

Pub Date : 2025-12-24 DOI: 10.1016/j.cscm.2025.e05731

Jinyu Ge , Qingan Li , Wenxun Qian , Xuesong Han , Pengfei Zhu , Fei Xu

Polyacrylic ester (PAE) latex cement-based coatings were prepared using P·O 42.5 ordinary Portland cement with polymer-to-cement (P/C) ratios ranging from 10 % to 50 %. The effects of P/C ratio and resting time before mortar overlay on the coatings’ crosslinking degree, adhesion strength, bonding performance, and corrosion resistance were systematically investigated. The P/C ratio significantly affected coating compactness and interfacial compatibility, with optimal performance achieved at a P/C ratio of 25 %, where the bonding strength increased by 11 % and the corrosion current density decreased from 9.31 to 0.35 μA·cm⁻², representing a reduction of nearly two orders of magnitude compared with bare rebar. Resting time was identified as a key factor governing interfacial evolution. At 3 h, sufficient migration of water and Ca²⁺ ions from the subsequently cast mortar promoted continuous hydration, yielding a hydration degree of 45.8 % and a dense C–S–H structure. Extending the resting time to 24 h resulted in excessive polymer crosslinking and densification, which restricted hydration-medium transport. Consequently, the hydration degree on the coating side decreased to 40.5 %, the C–S–H fraction dropped to 29 %, while CH content increased to 20 %, leading to an approximately 50 % reduction in bonding strength. This study elucidates the “polymer densification–hydration medium shielding” mechanism responsible for the interfacial cold-joint effect and provides quantitative insight into the coupled influence of P/C ratio and resting time. The findings offer a theoretical basis for optimizing polymer-modified cement-based coatings and controlling on-site construction timing.

采用P·O 42.5普通硅酸盐水泥制备聚丙烯酸酯（PAE）乳胶水泥基涂料，聚合物与水泥（P/C）比为10 % ~ 50 %。系统研究了P/C比和砂浆加铺前静置时间对涂料交联度、粘结强度、粘结性能和耐蚀性的影响。P/C比显著影响涂层致密性和界面相容性，P/C比为25 %时达到最佳性能，结合强度提高了11 %，腐蚀电流密度从9.31 μA·cm−2下降到0.35 μA·cm−2，比裸钢筋降低了近2个数量级。静息时间是控制界面演化的关键因素。在3 h时，水和Ca2+离子从随后浇注的砂浆中充分迁移，促进了连续水化，水化度为45.8% %，形成致密的C-S-H结构。将静置时间延长至24 h会导致聚合物交联过度和致密化，从而限制了水化介质的输送。结果表明，涂层侧水化程度下降到40.5 %，C-S-H含量下降到29 %，而CH含量增加到20 %，导致结合强度降低约50 %。本研究阐明了“聚合物致密化-水化介质屏蔽”机制对界面冷接头效应的影响，并定量分析了P/C比和静置时间的耦合影响。研究结果为优化聚合物改性水泥基涂料和控制现场施工时间提供了理论依据。

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引用次数: 0

Improving the self-healing properties of bitumen mastic under microwave irradiation by heated oil-ground steel slag 加热油磨钢渣提高微波辐照下沥青胶泥的自愈性能

IF 6.6 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Case Studies in Construction Materials

Pub Date : 2025-12-23 DOI: 10.1016/j.cscm.2025.e05729

Qiao Liu , Jingyi Zeng , Xingyang He , Huahui Qi , Ying Su , Wei Chen , Chao Yang , Jin Yang , Chuang Zhou

Steel slag (SS) is a solid waste rich in iron elements with the potential for microwave heating. However, the low ferrite content and the barrier of the silicate layer limit the efficiency of microwave heating of SS. This study employs soybean oil as the grinding environment and utilizes heated oil milling technology to functionalize steel slag. This process facilitates the separation and purification of the iron phase from the SS, enabling the generation of additional Fe₃O₄ through reduction reactions. The synergistic effect of heating and grinding promotes the conversion of Fe^3 + to Fe²⁺, which results in a 31 % increase in Fe²⁺ content and a 34 % increase in saturation magnetization of heated oil grinding steel slag (HGSS). Through the targeted design of particle size and oleophilic surfaces, HGSS is uniformly and compactly dispersed in the bitumen, constructing a network structure with multi-refraction properties, which reduces the reflection loss by 26 %. Under the combined effect of phase and structural changes, compared to SS bitumen mastic, HGSS bitumen mastic showed a 20 % increase in temperature rise at 60 s of microwave heating, in addition to an 11 % increase in healing index. This study aims to enhance the microwave absorption performance of SS by optimizing its microstructure and composition, thereby improving the self-healing efficiency of steel slag-bitumen composite materials under microwave heating conditions and providing new insights into the high-value utilization of SS.

钢渣是一种富含铁元素的固体废物，具有微波加热的潜力。然而，铁素体含量低，硅酸盐层的阻隔性限制了微波加热SS的效率。本研究以大豆油为研磨环境，利用加热油磨技术对钢渣进行功能化处理。这个过程有利于从SS中分离和纯化铁相，使通过还原反应产生额外的Fe3O4成为可能。加热和磨矿的协同作用促进了Fe3 +向Fe2+的转化，使加热后的油磨钢渣中Fe2+含量提高了31 %，饱和磁化强度提高了34 %。通过对粒径和亲油表面的针对性设计，使HGSS均匀致密地分散在沥青中，形成具有多重折射特性的网状结构，使反射损失降低26% %。在相与结构变化的共同作用下，微波加热60 s时，HGSS沥青与SS沥青相比，温升提高了20 %，愈合指数提高了11 %。本研究旨在通过优化钢渣-沥青复合材料的微观结构和组成，增强其微波吸收性能，从而提高钢渣-沥青复合材料在微波加热条件下的自愈效率，为钢渣-沥青复合材料的高价值利用提供新的见解。

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引用次数: 0

Prediction of ultrasonic pulse velocity and physicochemical properties of rice husk ash concrete exposed to elevated temperatures and post-fire curing 高温及火后养护稻壳灰混凝土的超声脉冲速度及理化性能预测

IF 6.6 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Case Studies in Construction Materials

Pub Date : 2025-12-23 DOI: 10.1016/j.cscm.2025.e05715

Ali Nazari, Vahab Toufigh

The novelty of this study is its evaluation of the physicochemical properties and non-destructive testing performance of concrete containing rice husk ash (RA) subjected to post-heating curing. The study examines temperatures of 300°C, 500°C, and 700°C. Post-heating curing was performed in water and in air for 28 and 56 days. Ultrasonic pulse velocity (UPV), X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetric (TG)/differential thermogravimetric (DTG) analysis were determined to evaluate thermal damage and recovery mechanisms. Predictive relationships between UPV and the outcomes of destructive tests were established, allowing the condition of the concrete to be estimated without relying solely on destructive methods. The high R-squared values, ranging from 0.83 to 0.98, confirm that UPV is a reliable indicator of thermal damage and recovery. Physicochemical analyses highlighted the rehydration and pozzolanic activity of RA, with 8 % RA recovering 36.7 % compressive strength after 56 days of water re-curing. A statistical optimization using the Taguchi method and ANOVA was additionally performed to identify the most effective parameters influencing strength recovery. Post hoc Tukey HSB was used to compare RA levels and temperatures. Optimization results highlighted that 8 % RA content provided the most significant improvement in recovery behavior, particularly under water re-curing conditions. Finally, a life cycle assessment (LCA) was conducted to evaluate the environmental impacts of the studied concrete mixtures. This assessment showed that incorporating RA significantly lowered environmental impacts, reducing global warming potential by 21.3 % and resource depletion by 24.8 %.

本研究的新颖之处在于对稻壳灰后加热养护混凝土的理化性能和无损检测性能进行了评价。该研究检测了300°C、500°C和700°C的温度。在水中和空气中进行28天和56天的后加热固化。通过超声脉冲速度（UPV）、x射线衍射（XRD）、扫描电镜（SEM）和热重(TG)/差热重（DTG）分析来评估热损伤和恢复机制。建立了UPV与破坏试验结果之间的预测关系，从而可以在不完全依赖破坏方法的情况下估计混凝土的状况。高r平方值，范围从0.83到0.98，证实UPV是热损伤和恢复的可靠指标。理化分析强调了RA的再水化和火山灰活性，8 % RA在水再固化56天后恢复了36.7 %的抗压强度。此外，采用田口法和方差分析进行统计优化，以确定影响强度恢复的最有效参数。事后Tukey HSB用于比较RA水平和温度。优化结果表明，8 % RA含量对采收率的改善最为显著，特别是在水再固化条件下。最后，进行了生命周期评价（LCA）来评价所研究的混凝土混合料的环境影响。该评价结果表明，纳入RA可显著降低环境影响，使全球变暖潜势降低21.3% %，资源耗竭降低24.8% %。

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引用次数: 0

Effect of Hybrid Surface Treatment of Tire Rubber Aggregates on the microstructure and mechanical properties of Standardized Mortars 轮胎橡胶集料复合表面处理对标准砂浆微观结构和力学性能的影响

IF 6.6 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Case Studies in Construction Materials

Pub Date : 2025-12-23 DOI: 10.1016/j.cscm.2025.e05721

Achouak Yousfi , Habib Abdelhak Mesbah , Mohamed Saadi

The incorporation of tire rubber aggregates in cement-based mortars reduces the consumption of natural sand but typically leads to substantial strength losses because of the weak and porous interfacial transition zone (ITZ) formed around untreated rubber. This study develops a hybrid mineral-epoxy surface treatment designed to overcome this limitation by forming a continuous composite shell composed of sand, cement, silica fume and epoxy resin. Microstructural analyses show that the treatment yields a uniformly coated rubber surface, a denser particle morphology and a markedly refined ITZ: the interfacial layer around untreated rubber is wide and highly porous (≈14–15 µm), whereas the hybrid coating reduces it to a compact band of about 1–2 µm. These refinements translate into consistent mechanical gains across all curing ages, with flexural strength increasing by 11–27 % and compressive strength by 23–76 %, depending on substitution level and age. In parallel with these mechanical and microstructural improvements, the method offers a favourable cost-performance balance, particularly thanks to the possibility of reducing resin consumption through optimisation of the adhesive film. The hybrid coating concept significantly strengthens the feasibility of producing high-performance and economically viable rubberized mortars and, ultimately, rubberized concretes.

在水泥基砂浆中掺入轮胎橡胶骨料可以减少天然砂的消耗，但由于在未经处理的橡胶周围形成了弱而多孔的界面过渡区（ITZ），因此通常会导致大量强度损失。本研究开发了一种混合矿物-环氧树脂表面处理方法，旨在通过形成由砂、水泥、硅灰和环氧树脂组成的连续复合外壳来克服这一限制。微观结构分析表明，处理后的橡胶表面涂覆均匀，颗粒形态致密，ITZ明显细化：未处理橡胶周围的界面层宽且多孔（≈14-15 µm），而杂化涂层将其缩小到约1-2 µm的致密带。这些改进转化为所有龄期的一致力学增益，根据替代水平和龄期的不同，抗弯强度提高11-27 %，抗压强度提高23-76 %。与这些机械和微观结构的改进并行，该方法提供了有利的成本-性能平衡，特别是由于通过优化胶膜减少树脂消耗的可能性。混合涂层概念大大加强了生产高性能和经济可行的橡胶砂浆的可行性，并最终生产橡胶混凝土。

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引用次数: 0

Erosion resistance of basalt fiber-aeolian sand concrete under wind-sand erosion: Experimental analysis and mechanisms 玄武岩纤维-风积砂混凝土风沙侵蚀抗侵蚀性能试验分析及机理研究

IF 6.6 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Case Studies in Construction Materials

Pub Date : 2025-12-23 DOI: 10.1016/j.cscm.2025.e05728

Yu Ye , Tianyu Xie , Tong Guo , Biqin Dong , Jianye Zhao , Jiajia Feng

The study explores the deterioration mechanism of basalt fiber-aeolian sand concrete (BF-ASC) under wind-sand erosion (WSE) and compares its performance with ordinary concrete. Experimental analysis was conducted to examine the effects of factors such as attack angle, average wind velocity, sand carrying capacity, sand erosion time, and sand particle size on the erosion of BF-ASC. Three-dimensional blue-light scanning was used to observe surface morphological changes, revealing the distribution of damage during erosion. Scanning electron microscopy (SEM) was employed to examine the effects of microstructural changes on corrosion resistance. The results show that BF-ASC exhibits stronger erosion resistance than ordinary concrete under different attack angles, particularly at a 45° angle, where the mass loss and degree of erosion were significantly lower for BF-ASC than for ordinary concrete. However, under other WSE parameters, the erosion resistance of both concretes was similar, with BF-ASC showing slightly better resistance. The study also reveals multiple mechanisms of WSE. The impact of sand particles causes localized stress concentration, leading to the detachment of surface material and the expansion of microcracks. Shallow angle impacts primarily induce shear, leading to surface deterioration and crack propagation, while larger angle impacts create deep pits, further increasing local material removal. Increased wind velocity and sand particle size significantly exacerbate the erosion process. Erosion rate is strongly influenced by erosion time, with rapid erosion occurring in the early stages (0–8 min), followed by stabilization in the later stages (8–16 min). The findings provide valuable insights into optimizing the durability of concrete structures in wind-sand environments, suggest strategies to enhance concrete erosion resistance, and offer a theoretical basis for the design and maintenance of concrete structures in extreme conditions.

研究了玄武岩纤维-风成砂混凝土在风沙侵蚀作用下的劣化机理，并与普通混凝土进行了性能比较。实验分析了攻角、平均风速、携沙量、冲沙时间、沙粒粒径等因素对BF-ASC侵蚀的影响。利用三维蓝光扫描观察表面形态变化，揭示侵蚀过程中损伤的分布。采用扫描电镜（SEM）研究了显微组织变化对耐蚀性的影响。结果表明：在不同攻角下，BF-ASC均表现出比普通混凝土更强的抗冲蚀性能，特别是在45°攻角时，其质量损失和冲蚀程度均明显低于普通混凝土；但在其他WSE参数下，两种混凝土的抗冲蚀性能相似，BF-ASC的抗冲蚀性能略好。研究还揭示了WSE的多种机制。砂粒的冲击引起局部应力集中，导致表面材料的剥离和微裂纹的扩展。浅角度冲击主要引起剪切，导致表面劣化和裂纹扩展，而大角度冲击产生深坑，进一步增加局部材料去除。风速和沙粒大小的增加显著加剧了侵蚀过程。侵蚀速率受侵蚀时间的影响较大，前期快速侵蚀（0 ~ 8 min），后期稳定（8 ~ 16 min）。研究结果为优化风沙环境下混凝土结构的耐久性提供了有价值的见解，提出了增强混凝土抗侵蚀能力的策略，并为极端条件下混凝土结构的设计和维护提供了理论依据。

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引用次数: 0

Impact of fiber-induced tensile strain hardening on the bearing performance of ECC and UHPC pipes: Experimental study and strength modeling 纤维诱导拉伸应变硬化对ECC和UHPC管道承载性能的影响：实验研究和强度建模

IF 6.6 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Case Studies in Construction Materials

Pub Date : 2025-12-22 DOI: 10.1016/j.cscm.2025.e05726

Chung-Chan Hung, Shu-Er Chen, Ya-Jung Tsai, Cheng-Hao Yen

The mechanical and durability performance of concrete pipes is critical in modern infrastructure, particularly in regions with high load demands and stringent maintenance requirements. This study addresses these challenges by exploring the use of tensile strain-hardening cementitious materials—namely, Engineered Cementitious Composites (ECC) and Ultra-High-Performance Concrete (UHPC)—as advanced alternatives to conventional concrete. A total of seven specimens were evaluated under three-edge bearing tests in accordance with ASTM C497 to assess their damage pattern, cracking strength, ultimate strength, stiffness, and energy dissipation capacity. The effects of fiber type, fiber volume fraction, and the presence of a steel cage reinforcement were systematically explored. Experimental results demonstrated that both ECC and UHPC pipes offered significantly enhanced cracking and ultimate strengths. The inclusion of steel fibers in UHPC was particularly effective, allowing pipes with just 0.5 % fiber volume to achieve comparable or even superior stiffness and energy dissipation capacities compared to steel-reinforced conventional concrete counterparts. These findings suggest the feasibility of either reducing or completely replacing traditional steel reinforcement with high-performance fiber reinforcement. Furthermore, the study developed and validated analytical models that reasonably predict the cracking and ultimate strengths of the pipes, with an average underestimation of 5 % and 7 %, respectively.

混凝土管道的机械性能和耐久性在现代基础设施中至关重要，特别是在高负荷需求和严格维护要求的地区。本研究通过探索使用拉伸应变硬化胶凝材料（即工程胶凝复合材料（ECC）和超高性能混凝土（UHPC））作为传统混凝土的先进替代品来解决这些挑战。按照ASTM C497标准对7个试件进行了三边承载试验，评估了试件的损伤模式、开裂强度、极限强度、刚度和耗能能力。系统地探讨了纤维类型、纤维体积分数和钢笼增强物的存在的影响。实验结果表明，ECC和UHPC管道的抗裂强度和极限强度均有显著提高。在UHPC中加入钢纤维尤其有效，与钢增强的传统混凝土相比，纤维体积仅为0.5 %的管道可以获得相当甚至更好的刚度和耗能能力。这些发现表明，用高性能纤维增强材料减少或完全取代传统钢筋是可行的。此外，研究建立并验证了合理预测管道开裂和极限强度的分析模型，平均低估分别为5 %和7 %。

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引用次数: 0

Mechanical properties, durability, and life cycle assessment of recycled brick powder concrete reinforced with different fibers 不同纤维增强再生砖粉混凝土的力学性能、耐久性及生命周期评价

IF 6.6 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Case Studies in Construction Materials

Pub Date : 2025-12-22 DOI: 10.1016/j.cscm.2025.e05723

Yuanyuan Zhao , Huifang Tao , Dongze Xie , Min LV , Shiqi Sun

The recycling of construction and demolition waste containing clay bricks inevitably yields waste clay brick powder as a by-product. By optimizing the particle size and replacement level of waste clay brick powder, a composite cementitious material with high mechanical strength and enhanced durability can be developed. In this study, recycled brick powder (RBP) of varying particle sizes was produced from discarded clay bricks. RBP was then used to replace cement at different substitution rates to produce recycled brick powder concrete (RBPC). Then, five types of fibers, including 12 mm long polypropylene fiber (PPF-12), 19 mm long polypropylene fiber (PPF-19), copper-coated steel fiber (CF), glass fiber (GF), and basalt fiber (BF), were added to RBPC to further enhance the performance of RBPC. The mechanical properties, durability tests, and life cycle assessment of the fiber-reinforced RBPC were also carried out. The results show that the optimal particle size and substitution rate of RBP are 0.075 mm and 5 %, respectively. CF has the best effect on improving the mechanical properties of RBPC, while PPF-12 has a stronger impact on improving the mechanical properties of RBPC than PPF-19. Scanning electron microscopy analysis showed that CF and BF had the best binding effect with cement hydration products. In addition, the durability of RBPC was improved after adding fibers. Among them, BF had the best impact on improving the high temperature resistance and corrosion resistance of RBPC, and CF had the best effect on improving the freeze-thaw resistance of RBPC, followed by BF. Life cycle assessment shows that fiber-reinforced RBPC is more sustainable and economically friendly. Among them, RBPC doped with BF has the best sustainability, while RBPC doped with PPF-12 is the most economical.

含粘土砖的建筑和拆迁垃圾的回收利用不可避免地产生废粘土砖粉作为副产品。通过优化废粘土砖粉的粒径和替代水平，可以开发出高机械强度和增强耐久性的复合胶凝材料。以废弃粘土砖为原料，制备了不同粒径的再生砖粉（RBP）。然后用RBP以不同取代率替代水泥生产再生砖粉混凝土（RBPC）。然后，在RBPC中添加12 mm长聚丙烯纤维（PPF-12）、19 mm长聚丙烯纤维（PPF-19）、镀铜钢纤维（CF）、玻璃纤维（GF）和玄武岩纤维（BF）等5种纤维，进一步提高RBPC的性能。进行了纤维增强RBPC的力学性能、耐久性试验和寿命周期评价。结果表明，RBP的最佳粒径为0.075 mm，取代率为5 %。CF对RBPC力学性能的改善效果最好，而PPF-12对RBPC力学性能的改善作用强于PPF-19。扫描电镜分析表明，CF和BF与水泥水化产物的结合效果最好。此外，添加纤维后，RBPC的耐久性得到了提高。其中，BF对提高RBPC的耐高温、耐腐蚀性能效果最好，CF对提高RBPC的抗冻融性能效果最好，BF次之。生命周期评价表明，纤维增强RBPC具有更强的可持续性和经济友好性。其中，掺BF的RBPC具有最佳的可持续性，而掺PPF-12的RBPC最具经济性。

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引用次数: 0

Experimental and theoretical study on the flexural behavior of NC-UHPC composite beams with embedded thin UHPC layers 嵌入超薄超高压混凝土层的NC-UHPC复合梁抗弯性能的实验与理论研究

IF 6.6 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Case Studies in Construction Materials

Pub Date : 2025-12-22 DOI: 10.1016/j.cscm.2025.e05725

Tianyu Cai , Zhi-Qi He , Wenjie Li

Placing a thin layer of ultra-high performance concrete (UHPC) locally in critical regions, particularly in negative-moment zones, provides an effective means to improve the flexural behavior and durability of concrete bridge girders while limiting UHPC usage. However, targeted experimental evidence on locally embedded UHPC-NC beams and systematic investigations of their flexural and interfacial responses remain limited. In this study, NC-UHPC composite beams with embedded thin UHPC layers (NC-UHPC-ETUL) with different section heights and reinforcement layouts were fabricated and tested under three-point bending to evaluate flexural behavior and interfacial performance. The results show that embedding a thin UHPC layer in the NC matrix increases flexural stiffness, delays crack initiation and propagation, and enhances ultimate load capacity. Specimens with through-reinforcement across the UHPC-NC interface exhibited more uniform crack patterns and greater ductility than those without. An analytical model was developed to predict stress distributions, interface-debonding loads, and flexural capacities, explicitly accounting for the mechanical interaction between the UHPC and NC layers; its predictions agreed well with the experimental results. The validated framework provides an effective and efficient tool for the preliminary design and assessment of NC-UHPC-ETUL beams.

在关键区域，特别是负弯矩区域局部铺设薄层超高性能混凝土（UHPC），是改善混凝土桥梁抗弯性能和耐久性的有效手段，同时限制了UHPC的使用。然而，针对局部嵌入UHPC-NC梁的有针对性的实验证据以及对其弯曲和界面响应的系统研究仍然有限。在本研究中，制作了具有不同截面高度和配筋布局的嵌入式UHPC薄层的NC-UHPC复合梁（NC-UHPC- etul），并进行了三点弯曲试验，以评估其抗弯性能和界面性能。结果表明：在NC基体中嵌入超高压混凝土薄层可以提高试件的抗弯刚度，延缓裂纹的萌生和扩展，提高试件的极限承载力；贯通加固试件在UHPC-NC界面上表现出更均匀的裂纹形态和更大的延性。建立了一个分析模型来预测应力分布、界面剥离载荷和弯曲能力，明确地考虑了UHPC层和NC层之间的力学相互作用；它的预测与实验结果非常吻合。验证的框架为NC-UHPC-ETUL梁的初步设计和评估提供了有效的工具。

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引用次数: 0