Construction and Building Materials最新文献

{"title":"Investigation of fracture performance of top-down cracks and bottom-up cracks for nano-silica modified stone matrix asphalt using semi-circular bending test","authors":"Bin Li ,&nbsp;Jie Chen ,&nbsp;Alireza Naseri ,&nbsp;Mohammad Zarei","doi":"10.1016/j.conbuildmat.2025.142812","DOIUrl":"10.1016/j.conbuildmat.2025.142812","url":null,"abstract":"<div><div>Stone matrix asphalt (SMA) is a gap-graded asphalt mixture with a higher percentage of filler, designed for roads with high-volume and heavier axle loads. Top-down cracks (TDC) and bottom-up cracks (BUC) are two types of cracks occurring in SMA, which are caused by fatigue of the surface layer and construction factors, respectively. Despite the good performance of SMA mixes against BUC, the TDCs are as challenging as BUCs, especially in mountainous areas where SMA experiences severe temperature changes and frost heave. To address this concern, this study used low doses of nano-silica to improve the fracture properties of TDCs and BUCs in SMA mixtures. SMA and SMA reinforced with 0.3 % and 0.6 % nano-silica were subjected to freeze-thaw (F-T) damage to study the time-dependent properties of these two types of pavements compared to the base SMA. In addition to the laboratory studies, a numerical analysis was conducted to model the cracking performance of specimens containing angle cracks under tensile-shear loading state; hence, the short- and long-term fracture behavior of vertical and angular cracks was studied to prioritize the critical crack type. Finally, the fracture performance of specimens with and without nano-silica was compared at different temperatures and conditions. The short-term results showed that nano-silica improved the fracture properties of TDCs and BUCs at −15 °C and +15 °C. At −15 °C and under 0 F-T cycles, the fracture energy (FE) values for the mixes modified with 0.3 % and 0.6 % nano-silica increased by 5 % and 16 %, 7 % and 6 %, and 9 % and 13 % under modes II, I+II, and I, respectively. These increases were 13 % and 19 %, 15 % and 25 %, and 23 % and 35 %, respectively, based on the fracture toughness (K_iC). At +15 °C and under 0 F-T cycle, the FE values for the mixes modified with 0.3 % and 0.6 % nano-silica increased by 18 % and 30 %, 7 % and 17 %, and 7 % and 18 % under modes II, III, and III, respectively. These increases were 12 % and 25 %, 11 % and 21 %, and 17 % and 40 %, respectively, based on the K_iC. Also, the long-term results showed that imposing F-T failure caused a decline in the fracture specification of TDCs and BUCs (both temperatures); however, nano-silica improved the results, as confirmed by the functional groups obtained from the Fourier Transform Infrared Spectrometer (FTIR) test. Regarding critical crack, it was documented that cracks of tensile, tensile-shear, and shear origin were the most essential conditions, respectively. Finally, increasing the temperature resulted in an increase in FE, a decrease in K_iC, a boost in flexibility, and a reduction in stiffness under various conditions. Based on this study's findings, SMA mixes reinforced with 0.3 % and 0.6 % nano-silica can be used in cold-temperate and tropical regions, respectively.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"492 ","pages":"Article 142812"},"PeriodicalIF":7.4,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144704393","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}

{"title":"From surface to core: Exploring bulk hydrophobicity in geopolymer tiles","authors":"Gurkan Akarken ,&nbsp;Ugur Cengiz","doi":"10.1016/j.conbuildmat.2025.142863","DOIUrl":"10.1016/j.conbuildmat.2025.142863","url":null,"abstract":"<div><div>This study presents a pioneering approach to produce superhydrophobic bulk geopolymer tiles (SBGT) using a novel concurrent polymerization and cold-press technique. Unlike traditional hydrophobic coatings that degrade over time, this method achieves bulk hydrophobicity by integrating fluoroalkyl silane (FAS) modification directly into the geopolymerization process. The exothermic heat released during geopolymerization was utilized to trigger a sol-gel reaction, enabling chemical grafting of the hydrophobic agent within the geopolymer matrix. The resulting SBGT materials exhibited exceptional hydrophobic properties, with water contact angles (WCA) exceeding 150°, demonstrating complete superhydrophobicity based on both static and dynamic criteria. Self-cleaning tests confirmed the high dust-repelling capability, and liquid resistance tests demonstrated strong non-wettability against common household liquids (coffee, tea, wine, and milk). Furthermore, sandpaper abrasion and water dripping tests revealed that SBGTs maintain their hydrophobicity even under mechanical stress, highlighting their long-term durability. Additionally, mechanical strength analyses showed that while moderate FAS concentrations enhanced flexural strength, excessive amounts led to a decline due to microstructural disruptions. X-ray diffraction (XRD) and scanning electron microscopy (SEM/EDX) analyses confirmed the transformation of the geopolymer into an amorphous aluminosilicate gel, reinforcing its mechanical integrity and water resistance. This is the first study to successfully implement simultaneous concurrent polymerization and hydrophobic modification in cold press geopolymer synthesis, producing a fully hydrophobic bulk material without post-processing treatments. These findings demonstrate the commercial potential of SBGTs for self-cleaning, moisture-resistant, and energy-efficient building applications.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"492 ","pages":"Article 142863"},"PeriodicalIF":7.4,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144704389","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}

{"title":"Performance evolution of high ductility cementitious composites under different curing regimes: Hydration kinetics, microstructure development, and mechanical behavior","authors":"Fei Xiang-peng ,&nbsp;Guo Li-ping ,&nbsp;Du Hongjian ,&nbsp;Li Jia-yi ,&nbsp;Shen Hao-ran ,&nbsp;Chen Hai-tao","doi":"10.1016/j.conbuildmat.2025.142728","DOIUrl":"10.1016/j.conbuildmat.2025.142728","url":null,"abstract":"<div><div>High ductility cementitious composites (HDCC) exhibit exceptional strain-hardening behavior and multiple cracking capabilities, making them highly promising for engineering applications. However, the high mineral admixture content leads to slow early-age strength development under standard curing. Steam curing effectively accelerates hydration and pozzolanic reactions, enhancing mechanical properties, refining microstructure, and increasing production efficiency. Despite these advantages, the absence of standardized steam curing regimes results in inconsistent performance outcomes. This study systematically examined the performance evolution of HDCC under steam curing and standard curing conditions through a multi-scale approach, encompassing microscopic hydration processes to macroscopic mechanical properties. The findings revealed that: (1) Increasing steam curing temperature accelerates hydration kinetics by shortening the nucleation and growth phase while prolonging the diffusion-controlled stage. Rapid FA dissolution releases Al^3 + , destabilizing AFt and promoting its transformation into AFm. Excessive temperatures further induce AFt decomposition, SO₄^2- desorption, and DEF formation, resulting in microstructural damage and compromised long-term durability. (2) Steam curing significantly influences fiber-matrix interfacial properties. High-temperature exposure weakens fiber bridging by increasing interfacial friction and reducing chemical bonding, thereby compromising tensile ductility and multiple-cracking behavior. (3) A curing regime of 60 °C for 5 days achieves comparable strength and ductility to 60–90 days of standard curing, meeting engineering demands while considerably shortening construction timelines. This research deepens our understanding of the mechanisms underlying HDCC performance evolution under different curing conditions, providing a robust theoretical foundation for material design. Furthermore, it offers scientific guidance for optimizing HDCC steam curing regimes, balancing performance and time efficiency, and fostering broader adoption in engineering applications.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"492 ","pages":"Article 142728"},"PeriodicalIF":7.4,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144704296","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}

{"title":"Underwater dam crack image enhancement and crack detection based on improved diffusion model and SDI-ASF-YOLO11","authors":"Chuan Lin ,&nbsp;Rongfeng Liu ,&nbsp;Weiwei Lin ,&nbsp;Yun Zou ,&nbsp;Xuqi Wei ,&nbsp;Yan Su","doi":"10.1016/j.conbuildmat.2025.142861","DOIUrl":"10.1016/j.conbuildmat.2025.142861","url":null,"abstract":"<div><div>Underwater cracks are a prevalent and hazardous structural issue during dam operations. The early identification and mitigation of cracks are enabled by the effective capture and analysis of underwater structural surface images. However, complex underwater environments and imaging mechanisms often degrade crack image quality, causing blurring, color distortion, and low contrast. These factors significantly hinder the performance of existing visual detection methods. To address these challenges, this study proposed a method for underwater crack image enhancement and detection in dams by integrating an improved diffusion model and SDI-ASF-YOLO11 architecture. First, a generative diffusion model for underwater crack image enhancement (Underwater Diffusion Model, UWDM) was developed by incorporating prior knowledge of marine underwater images through transfer learning, enabling cross-domain enhancement of crack images in dam environments. An underwater imaging platform was also constructed to generate a benchmark dataset of underwater cracks. The effectiveness of the UWDM method was validated through both qualitative and quantitative analyses. Subsequently, an improved crack detection model, SDI-ASF-YOLO11, featuring with an optimized feature fusion network, was proposed to enhance the detection accuracy and segmentation quality. Case studies showed that UWDM substantially improved the visual quality of degraded crack images. The performance metrics improved by 12.41 % in IE, 9.91 % in UCIQE, and 218.45 % in UIQM, compared to the original images. The combined utilization of UWDM and SDI-ASF-YOLO11 further boosted the detection accuracy by 51.6 % and segmentation accuracy by 45.9 %. This integration of image enhancement and model optimization enables accurate dam crack detection. The proposed approach demonstrated effectiveness in crack detection, applicability in engineering environments, and superiority in terms of methodological design.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"492 ","pages":"Article 142861"},"PeriodicalIF":7.4,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144704392","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}

{"title":"Plastic damage assessment of Q690 high strength structural steel derived from the eddy current array technique","authors":"Enlai Wen ,&nbsp;Xiao Wang ,&nbsp;Ziqiong Xu ,&nbsp;Lan Zhou ,&nbsp;Fubao Zhang ,&nbsp;Houyao Liu ,&nbsp;Na Risu","doi":"10.1016/j.conbuildmat.2025.142792","DOIUrl":"10.1016/j.conbuildmat.2025.142792","url":null,"abstract":"<div><div>This paper reports a novel use of eddy current array technique to assess the plastic damage of a high strength Q690 steel. The eddy current array parameters can not only effectively judge the severe damage area but also can characterize the early plastic damage of specimens. Under a detection frequency of 375KHz, the mean axial voltage increased from begin-stretch (0.01 V) to fracture (1.83 V). Meanwhile, the digital image correlation tests showed that the strain value increased from 0 % to 14.785 % at this process. Coherently, it was found that the eddy current array parameters had a certain linear relationship with the strain degree. Besides, the microstructure observation revealed that the voids generation/growth as well as the dislocation structure/density change in Q690 steel aggravated with the strain degree. In the early plastic deformation stage, the void defect could be the influence factor to the change of eddy current array parameters, since the axial voltage exhibited a significant increase in relation to both void area fraction and number density, ranging from 0 % to 1.519 % and 11.636 × 10⁴/mm², respectively. In later stage, the change of voltage could be due to the joint effect of void factor and dislocation factor, since its growth from the void defect slowed down, while it increased steadily with the increase of GND density, ranging from 2.12 to 6.31 × 10⁴/m². In summary, the current array eddy technique could be an effective detecting method, which can characterize the plastic damage degree of Q690 steel even at the early stage.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"492 ","pages":"Article 142792"},"PeriodicalIF":7.4,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144704394","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}

{"title":"Experimental investigation on mechanical and aging properties of novel high durability NR/EPDM blended rubber bearings","authors":"Siqi Wang ,&nbsp;Qiaoyun Wu ,&nbsp;Yafeng Li ,&nbsp;Daoming Zi ,&nbsp;Lianglu Wei ,&nbsp;Yu Liang","doi":"10.1016/j.conbuildmat.2025.142832","DOIUrl":"10.1016/j.conbuildmat.2025.142832","url":null,"abstract":"<div><div>The durability of rubber materials is a critical factor influencing the long-term service performance of rubber bearings, and blending technology has been scientifically validated as an effective approach to significantly enhance the comprehensive performance characteristics of these materials. Plate rubber bearings are extensively utilized in bridge engineering, where durability issues are particularly prominent, leading to increased lifecycle costs of the bridge. To address this, the present study designed 10 distinct rubber blends by combining natural rubber (NR), known for its superior mechanical properties, with ethylene propylene diene monomer (EPDM) rubber, which exhibits excellent aging resistance. Through systematic testing of tensile strength, elongation, thermal aging resistance, and ozone aging resistance, three formulations—NR, NR/EPDM 8:2, and NR/EPDM 6:4—were selected for further evaluation. These formulations were used to fabricate 6 scaled and 15 full-scale rubber bearings, which subsequently underwent a series of rigorous experimental tests. The results demonstrate that the high-durability plate rubber bearings exhibit a shear modulus change rate less than 10 % after 72 h of accelerated aging at 100°C, and show no cracking after 336 h of exposure to high-concentration ozone (300 pphm). This study highlights the potential of blending technology to develop advanced rubber materials with enhanced performance for critical engineering applications.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"492 ","pages":"Article 142832"},"PeriodicalIF":7.4,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144704323","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}

{"title":"Multi-scale comparative evaluation and property-optimized method of laboratory-prepared shotcrete","authors":"Cheng Liu ,&nbsp;Wangxin Li ,&nbsp;Yunsheng Zhang ,&nbsp;Yuyang Ying ,&nbsp;Kun Tang ,&nbsp;Rusheng Qian ,&nbsp;Dafu Wang","doi":"10.1016/j.conbuildmat.2025.142880","DOIUrl":"10.1016/j.conbuildmat.2025.142880","url":null,"abstract":"<div><div>On-site adjustments and variable environmental conditions during the tunnel construction potentially affect the quality of shotcrete, resulting in inconsistent properties and durability concerns. The article investigates the feasibility of preparing shotcrete under laboratory conditions with the identical raw materials and mix proportions employed on-site. And the effects of sand ratio on shotcrete properties are also studied. Results demonstrate that laboratory-prepared shotcrete can match or exceed the properties of site-prepared shotcrete. Improving the sand content within a specific range can optimize the shotcrete properties. For surface roughness evaluation, lab specimens exhibited a lower surface deviation (SD = 50.49 vs. 56.56) and a 3.25 % higher uneven area ratio (UAR), indicating more uniform paste coverage. Increasing the sand ratio can improve surface smoothness and reduce the SD value. Both the early-age and 28-day compressive strengths of the lab specimens reached 35 MPa, exhibiting a faster strength gain compared to the on-site samples. However, a 62 % sand ratio slightly reduced the 28-day strength due to its high specific surface area. Porosity of laboratory-prepared shotcrete was marginally higher than site‑prepared shotcrete (11.63 % vs. 9.69 % by MIP) under the same mix proportion, with NMR T₂ spectra confirming similar pore‑size distributions and porosity rising from 10.61 % to 11.14 % as sand ratio increased. SEM images revealed equivalent hydration products and C–S–H networks up to a 60 % sand ratio, with microcracking observed at a 62 % sand ratio. This article can serve as a reference for researchers to prepare shotcrete in the laboratory flexibly.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"492 ","pages":"Article 142880"},"PeriodicalIF":7.4,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144704390","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}

{"title":"Recycling municipal solid waste incineration fly ash as a functional foaming agent in slag-based geopolymer","authors":"Junhyeok Lee,&nbsp;Minseok Nam,&nbsp;Dongcheon Park,&nbsp;Kwangwoo Wi","doi":"10.1016/j.conbuildmat.2025.142839","DOIUrl":"10.1016/j.conbuildmat.2025.142839","url":null,"abstract":"<div><div>Municipal solid waste incineration fly ash (MSWIFA), a hazardous byproduct containing heavy metals, chlorides, and metallic aluminum, presents significant challenges for reuse in construction materials. This study utilizes the reaction between metallic Al in MSWIFA and alkaline activators to develop self-expanding foamed geopolymers. The in-situ generation of hydrogen gas induces pore formation, while simultaneous polymerization of dissolved precursors into C–(A)–S–H and N–A–S–H gels increases paste viscosity, which plays a key role in foam stabilization. Low-viscosity pastes allow gas to escape or pores to coalesce, while high viscosity facilitates bubble merging and collapse, leading to foam instability. By varying the MSWIFA replacement level, NaOH concentration, and alkali activator ratio (NaOH:Na₂SiO₃), the interaction between foaming, polymerization, and pore morphology was systematically investigated. Key properties such as expansion, porosity, compressive strength, and thermal conductivity were evaluated. Microstructural analyses confirmed the formation of Friedel’s salt, calcite, halite, and aluminosilicate gels. All mixtures achieved over 80 % heavy metal immobilization, complying with USEPA leaching limits. These findings demonstrate the feasibility of using MSWIFA as both a precursor and foaming agent in low-carbon geopolymer systems and offer insights into the coupled mechanisms that govern pore formation and structural development.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"492 ","pages":"Article 142839"},"PeriodicalIF":7.4,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144704391","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}

{"title":"Unveiling the performance evolution and reaction mechanisms of alkali-activated incineration bottom ash-cement composite systems","authors":"Zhennan Chen ,&nbsp;Songsong Lian ,&nbsp;Liya Zhang ,&nbsp;Wenbo Bian ,&nbsp;Xinyuan Xu ,&nbsp;Jiaxing Ma ,&nbsp;Ping Chen ,&nbsp;Jingge Ren ,&nbsp;Shaoqin Ruan","doi":"10.1016/j.conbuildmat.2025.142842","DOIUrl":"10.1016/j.conbuildmat.2025.142842","url":null,"abstract":"<div><div>To address the low resource utilization efficiency of incineration bottom ash (IBA) caused by its insufficient reactivity, this study systematically investigates the influence mechanisms of alkali activation modification on ash (IBA)–cement composite systems. IBA was activated using NaOH and Na₂SiO₃ as alkali activators, with particular emphasis on the enhancement of mechanical properties and the evolution of microstructure under different activator ratios. Results indicate that when the Na₂O content concentration in the alkali activator is 0.8 %, the latent reactivity of IBA can be effectively activated, promoting the formation of high-strength gel in the hydration products, resulting in a 25 % increase in 28-day compressive strength compared to the control group. Notably, when the Na₂O content increases to 1.6 %, excessive alkali not only disrupts the normal hydration process but also significantly intensifies the alkali-silica reaction (ASR), leading to severe degradation of specimen performance. In addition, it was observed that Na₂SiO₃ accelerates specimen hardening, necessitating strict control of its dosage within the range of 0.7–1.3 %. Excessive dosage may lead to overly rapid hardening, severely hindering the complete progression of hydration, while dosages below 0.7 % result in suboptimal performance improvement.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"492 ","pages":"Article 142842"},"PeriodicalIF":7.4,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144704322","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}

{"title":"Disclosing the mechanism behind rheological challenges in calcined clay-based cements","authors":"Lucia Ferrari ,&nbsp;Anastasiia Nagmutdinova ,&nbsp;Arnaud Müller ,&nbsp;Nikola Mikanovic ,&nbsp;Mohsen Ben-Haha ,&nbsp;Villiam Bortolotti ,&nbsp;Elisa Franzoni","doi":"10.1016/j.conbuildmat.2025.142837","DOIUrl":"10.1016/j.conbuildmat.2025.142837","url":null,"abstract":"<div><div>Calcined clay is gaining recognition as a viable cement substitute for producing low-carbon binders like limestone calcined clay cement (LC3). However, its impact on workability remains unclear. This study investigates the mechanisms causing rheological issues in calcined clay-based mixes. LC3 was formulated with two calcined clays of similar chemistry but differing specific surface areas. Differential Scanning Calorimetry (DSC) and Time-Domain Nuclear Magnetic Resonance (¹H TD‐NMR) measured free water at varying water-to-solid ratios, while paste and mortar rheology were evaluated and modeled. Results reveal significant differences in internal specific pore volume (0.108 cm³/g vs. 0.055 cm³/g), corresponding to varying water absorption (30 % vs. 15 % of mixing water), which increased yield stress from 106 Pa to 163 Pa and superplasticizer demand from 1.2 % to 1.3 %. A model to estimate the apparent yield tress (YODEL) clarified the role of water absorption in drastically increasing the yield stress of paste.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"492 ","pages":"Article 142837"},"PeriodicalIF":7.4,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144702184","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}