CEMENT最新文献

{"title":"Ability of a one-part granite-based geopolymer sealant to withstand exposure to CO2 with H2S or H2SO4 in the presence of H2O","authors":"Seyed Hasan Hajiabadi ,&nbsp;Reinier van Noort ,&nbsp;Mahmoud Khalifeh","doi":"10.1016/j.cement.2026.100169","DOIUrl":"10.1016/j.cement.2026.100169","url":null,"abstract":"<div><div>The long-term integrity of wellbore sealants is critical for successful CO₂ storage in geological reservoirs. This paper addresses the durability of a one-part, granite-based geopolymer (GP) sealant batch-exposed to CO₂ and H₂O, with or without H₂S or H₂SO₄ for up to 16 weeks. Microstructural and mineralogical changes were then characterized using a wide range of analytical techniques. Results show that exposure led to an increase in the material’s crystalline content. Vaterite was the dominant early carbonate in all cases. This then transformed primarily into aragonite in samples exposed to clean CO₂, while calcite was more prominent in samples exposed to CO₂ with H₂S or H₂SO₄. The matrix's crystallinity was further enhanced through consecutive reactions of aluminosilicate gels. Even though exposure resulted in elevated sulfur contents, no sulfur-bearing minerals were detected. Despite these alterations, the GP maintained its integrity during exposure to chemically aggressive conditions, demonstrating its durability as a sealant.</div></div>","PeriodicalId":100225,"journal":{"name":"CEMENT","volume":"23 ","pages":"Article 100169"},"PeriodicalIF":0.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146037749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"X-ray computed tomography to investigate steel corrosion in cementitious media: Experimental guidance, challenges and opportunities","authors":"S. Governo ,&nbsp;E. Rossi ,&nbsp;S. Azad ,&nbsp;A. Kaestner ,&nbsp;U. Angst","doi":"10.1016/j.cement.2025.100166","DOIUrl":"10.1016/j.cement.2025.100166","url":null,"abstract":"<div><div>X-ray computed tomography (XCT) provides unique opportunities to investigate steel corrosion in reinforced concrete, the primary degradation mechanism compromising infrastructure durability and safety. Its non-destructive nature, combined with high-resolution three-dimensional imaging and time-lapse capabilities, allows for detailed insights into corrosion processes without altering the specimen. However, applying XCT to reinforced concrete remains challenging due to recurring methodological issues, such as selecting appropriate tube voltage and current, defining pre-filtering combinations, mitigating imaging artefacts, and balancing image resolution with sufficient X-ray transmission. These challenges are particularly pronounced when imaging systems with components of widely differing X-ray attenuation, such as steel, concrete, air, and water.</div><div>This paper proposes a systematic guideline for designing XCT acquisitions tailored to the study of corrosion in reinforced concrete specimens, integrating theoretical considerations with practical examples. The guideline is supported by dedicated charts and design criteria, which guide researchers in selecting acquisition parameters, specimen configurations, and imaging strategies to achieve high-quality and reproducible results. This approach is built upon a critical review of previous studies, highlighting past limitations and identifying future research opportunities for the application of XCT to study corrosion in steel-concrete systems.</div><div>By providing a coherent framework for experimental design, this paper allows researchers to fully exploit the potential of XCT for studying in-situ steel corrosion and to advance understanding of reinforced concrete degradation, thereby addressing an important challenge in engineering.</div></div>","PeriodicalId":100225,"journal":{"name":"CEMENT","volume":"23 ","pages":"Article 100166"},"PeriodicalIF":0.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145926164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance of a granite-based two-part geopolymer in hydrogen sulfide-rich environments: Implications for sour wells","authors":"Seyed Hasan Hajiabadi ,&nbsp;Mahmoud Khalifeh ,&nbsp;Anna Magdalena Stroisz ,&nbsp;Marcin Ireneusz Duda ,&nbsp;Gunnar Vistnes ,&nbsp;Torstein Lange ,&nbsp;Jelena Todorovic","doi":"10.1016/j.cement.2026.100170","DOIUrl":"10.1016/j.cement.2026.100170","url":null,"abstract":"<div><div>The long-term stability of wellbore sealants is crucial for the success of oil and gas operations. This study evaluates the performance of a low-calcium, granite-based two-part geopolymer (GP) system under hydrogen sulfide (H₂S)-rich brine exposure. GP samples were immersed in H₂S-saturated seawater at 100 °C and 11 bar for up to 12 months. Their mechanical, mineralogical, and microstructural integrity was assessed using unconfined compressive strength (UCS) testing, computed tomography (CT) scanning, X-ray diffraction (XRD), scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS), and Fourier-transform infrared spectroscopy (FTIR). Results showed a progressive increase in UCS and Young’s modulus during exposure, coinciding with changes in mass, density, and microstructural features. CT scanning revealed surface-localized density reduction and preserved interior structure, highlighting spatial zonation rather than temporal densification. XRD analysis indicated increased relative crystallinity in H₂S-exposed samples compared to the initial cured state, while SEM-EDS revealed elemental redistribution and an increase in bulk sulfur content with exposure time, although no crystalline sulfur-bearing phases were detected within the resolution of XRD. The chemical form and binding state of sulfur could not be resolved with the applied techniques. Overall, the results indicate that the low-calcium, granite-based GP can retain mechanical integrity under prolonged H₂S-rich brine exposure, with degradation largely confined to surface regions, suggesting its potential as an alternative wellbore sealant in sour environments while recognizing that further studies with chemically equivalent controls are required to fully resolve underlying mechanisms.</div></div>","PeriodicalId":100225,"journal":{"name":"CEMENT","volume":"23 ","pages":"Article 100170"},"PeriodicalIF":0.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147396536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recalcification of carbonated cement paste","authors":"Thinh Nguyen ,&nbsp;Quoc Tri Phung ,&nbsp;Norbert Maes ,&nbsp;Lander Frederickx ,&nbsp;Rodrigo de Oliveira Silva ,&nbsp;Dimitrios Sakellariou ,&nbsp;Geert De Schutter ,&nbsp;Özlem Cizer","doi":"10.1016/j.cement.2025.100167","DOIUrl":"10.1016/j.cement.2025.100167","url":null,"abstract":"<div><div>Carbonation lowers the pH, leading to decalcification, shrinkage, and densification of the pore structure. Recalcification, the process of reintroducing calcium ions into decalcified cementitious materials, is a promising approach for restoring carbonated cement pastes. However, its impact on carbonated cementitious materials remains unelucidated. This study demonstrates, for the first time, how recalcification not only restores the Ca/Si ratio of calcium–(aluminum)-silicate-hydrate (C–(A)-S-H) to levels comparable with intact gel but also fundamentally alters its nanostructure. Using solid-state ²⁹Si NMR, we show that recalcification turned silica gel into cross-linked Q^3(1Al) sites, introducing small capillary pores and reducing the surface area. The extent of microstructural changes depended on the initial degree of carbonation. Importantly, ²⁹Si NMR suggested that recalcification is a diffusion-controlled process, similar to calcium leaching and carbonation. These findings highlight the potential of recalcification to restore the binding phase and improve the durability of carbonated cement pastes, with implications for the development of targeted repair techniques in the construction industry.</div></div>","PeriodicalId":100225,"journal":{"name":"CEMENT","volume":"23 ","pages":"Article 100167"},"PeriodicalIF":0.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145926162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Production and properties of amorphous silica extracted from olivine for use as a supplementary cementitious material","authors":"Pei B. Ong,&nbsp;Yixiu Zhuge,&nbsp;Christopher Cheeseman,&nbsp;Hong S. Wong","doi":"10.1016/j.cement.2025.100168","DOIUrl":"10.1016/j.cement.2025.100168","url":null,"abstract":"<div><div>Amorphous precipitated silica (APS) produced by acid leaching of olivine has been characterised and assessed for use as a supplementary cementitious material (SCM). The APS was thermally treated between 400 and 1000°C to modify its pore structure, surface area, composition and reactivity. Pastes and mortars containing APS were cast with CEM I replacement levels from 0 to 30 wt.% and water-to-binder ratio of 0.5. TGA-MS, Q-XRD, FTIR and R³ tests show that APS has moderate to high pozzolanic reactivity. Mortars with 10 wt.% as-produced APS showed 30% increase in 28-day compressive strength compared to the control (50 MPa). Mortars with 20 wt.% replacement had comparable strengths to the control. Thermal treatment moderately reduced APS specific surface area and water demand, and improved mix workability, with mortars retaining comparable strengths to samples containing as-produced APS. The research demonstrates that silica derived from olivine has potential to be used as an SCM.</div></div>","PeriodicalId":100225,"journal":{"name":"CEMENT","volume":"23 ","pages":"Article 100168"},"PeriodicalIF":0.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145926163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of ASR-induced development in concrete with natural and recycled reactive aggregates via resonant ultrasound spectroscopy coupled with imaging techniques","authors":"L.F.M. Sanchez ,&nbsp;M. Griffa ,&nbsp;A. Leemann","doi":"10.1016/j.cement.2025.100161","DOIUrl":"10.1016/j.cement.2025.100161","url":null,"abstract":"<div><div>Numerous characterization techniques have been used to assess ASR-induced development (<em>i.e.</em>, the formation of ASR products and cracks during expansion). Amongst those, scanning electron microscopy (SEM), coupled with energy dispersive X-ray spectroscopy (EDS), is a well-recognized technique enabling assessing the presence, morphology, and composition of ASR products. However, the correlation between ASR products' amounts and physicochemical features with induced damage (<em>i.e.</em>, crack formation and impact on the mechanical performance of the affected concrete) via SEM is purely qualitative. Preliminary results showed that resonant ultrasound spectroscopy (RUS) could be a suitable technique to evaluate ASR-induced damage because it allows assessing the corresponding changes in the linear viscoelastic properties. Nonetheless, a systematic study fully demonstrating its potential to appraise ASR-induced expansion and deterioration, especially from ASR originating both from natural and from recycled aggregates, is still lacking in literature. This work aims to quantitatively appraise ASR-induced products and associated deterioration by the coupling of SEM-EDS and RUS, particularly a version thereof called SIngle MOde RUS (SIMORUS). Concrete mixtures incorporating highly reactive natural and recycled fine and coarse aggregates were cast and stored in conditions accelerating ASR development. At 4, 11, 16, 24 and 36 weeks, the samples were characterized by the abovementioned techniques. Quantifications of ASR-induced damage proxy parameters (<em>i.e.</em>, Young’s, <em>E</em>, and shear, <em>G</em>, moduli), and the respective quality (Q-)factor, were performed over time. The results reported here suggest that SIMORUS is a promising technique to describe the impact of the ASR-induced development on the linear viscoelastic properties of an affected concrete. However, as shown, such an impact depends on the reactive aggregate type used in the mixture.</div></div>","PeriodicalId":100225,"journal":{"name":"CEMENT","volume":"23 ","pages":"Article 100161"},"PeriodicalIF":0.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145705872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sustainable mortar production using volcanic ash and crushed laterite as partial cement replacements","authors":"Bahiru Bewket Mitikie ,&nbsp;Demelash Leyekun Kebede ,&nbsp;Walied A. Elsaigh","doi":"10.1016/j.cement.2025.100162","DOIUrl":"10.1016/j.cement.2025.100162","url":null,"abstract":"<div><div>Cement is a critical construction material globally and particularly in Ethiopia, where its production is energy-intensive, costly, and a major source of greenhouse gas emissions. This study explores the partial replacement of Portland cement with volcanic ash and crushed laterite powder in cement mortar as a sustainable and cost-effective alternative. Preliminary mix designs were prepared with varying proportions of volcanic ash and laterite powder to determine optimal combinations which is equal percentage of volcanic ash and laterite powder as selected based the compressive strength result. Subsequent experimental mixes replaced cement with equal proportion of volcanic ash and laterite soil at 0%, 5%, 10%, 15%, 20%, 25%, and 30% by weight, following ASTM C109 standards. The study assessed characterization, mechanical (compressive strength and ultrasonic pulse velocity), durability (sulfate resistance, porosity, and water absorption), and microstructural properties using Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), and differential thermal analysis (DTA) analyses. Characterization results showed that volcanic ash and crushed laterite are finer than cement and are predominantly pozzolanic. Bernauer-Emmett-Teller (BET) analysis confirmed their fine particle sizes, contributing to the dense packing of the mortar. At 10% of replacement of cement by equal amount of volcanic ash and laterite soil, the highest compressive strength was recorded 33.1 MPa at 28 days and 46.2 MPa at 56 days. Water absorption decreased with increasing the replacement percentage up to 15%, indicating improved durability. Microstructural analysis revealed a denser morphology due to secondary C-S-H formation and filler effects. Overall, volcanic ash and laterite powder improved both mechanical and durability properties of mortar up to 15% replacement, with optimal performance at 10%. This shows the potential of those pozzolanic as a viable partial cement substitute, promoting sustainable construction practices in Ethiopia.</div></div>","PeriodicalId":100225,"journal":{"name":"CEMENT","volume":"23 ","pages":"Article 100162"},"PeriodicalIF":0.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145798979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Alkali dissolution from aggregates and its effect on ASR expansion simulated by the use of alkali rock powder","authors":"Kannosuke Shiraishi ,&nbsp;Kazuo Yamada ,&nbsp;Takashi Kawakami ,&nbsp;Yasutaka Sagawa ,&nbsp;Soshiro Miyama","doi":"10.1016/j.cement.2025.100160","DOIUrl":"10.1016/j.cement.2025.100160","url":null,"abstract":"<div><div>Concrete expansion due to an alkali-silica reaction (ASR) occurs when alkali ions (OH⁻) in the pore water react with silica minerals in reactive aggregates. To mitigate ASR expansion, the concentration of alkali ions determined primarily by the amount of alkali metals derived from cement has to be controlled. In addition to silica minerals, minerals in the aggregates containing alkali metals may also undergo reactions, resulting in the dissolution of alkali metals. It is considered that this release increases the OH⁻ concentration. This alkali metal dissolution reaction is referred to as alkali release. This phenomenon was investigated through the concrete prism test using a reactive chert aggregate and nepheline syenite (NS) powder, an alkali-rich rock. The results indicated that the addition of NS contributed to increased expansion over the storage period. At an NS addition of 5 % by mass of fine aggregate (NS5 %), the alkali dissolution from NS, estimated from the expansion, was 9.2 kg/m³, which closely matched the measured water-soluble alkali content of the concrete, 8.2 kg/m³. However, when the NS addition was increased to 10 % (NS10 %), the water-soluble alkali content increased to 11.2 kg/m³, yet the expansion rate remained unchanged compared to NS5 %. Thus, alkali dissolution beyond a certain threshold did not contribute further to expansion. Additionally, the alkali dissolution from NS, as evaluated using RILEM AAR-8, was considerably underestimated, with values of 0.13 kg/m³ for NS5 % and 0.25 kg/m³ for NS10 %.</div></div>","PeriodicalId":100225,"journal":{"name":"CEMENT","volume":"22 ","pages":"Article 100160"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145578884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dissolution behaviour and mechanism of fly ash in acid activators","authors":"Mengxin Bu ,&nbsp;Biqin Dong ,&nbsp;Muhammad Riaz Ahmad ,&nbsp;Yanshuai Wang","doi":"10.1016/j.cement.2025.100159","DOIUrl":"10.1016/j.cement.2025.100159","url":null,"abstract":"<div><div>Clarifying the dissolution behaviour and mechanism of fly ash in acid activators is essential to understand the properties of fly ash-based silico-aluminophosphate geopolymer. This paper investigated the <em>in-situ</em> dissolution behaviour of fly ash (FA) in aluminium dihydrogen phosphate (MAP), phosphoric acid (PA), citric acid (CA), oxalic acid (OA), and tartaric acid (TA) using optical microscopy and electron probe microscopic analysis (EPMA). The phase and elemental changes before and after dissolution were further investigated using quantitative X-ray Diffraction (QXRD) and 2D-Fourier transform infrared (FTIR) spectrometry. In addition, the changes in dissolved elements were elucidated from a liquid phase perspective. The results showed that the capacity of each acid to dissolve FA was CA&gt;MAP&gt;PA&gt;TA&gt;OA. Ca-containing phases in FA were preferentially dissolved in all acids. The main contributor to FA dissolution in acid was the amorphous phase, and the Si<img>O<img>Si bond in quartz was more sensitive than other chemical bonds to acid. When FA was dissolved in OA and TA, new crystalline phases—calcium oxalate and calcium citrate—formed on the FA surface, inhibiting further dissolution.</div></div>","PeriodicalId":100225,"journal":{"name":"CEMENT","volume":"22 ","pages":"Article 100159"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145417236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-strength self-compacting alkali-activated concrete produced with fly ash and steel slag: rheological behavior and mixing rheology comparisons with a Portland cement concrete","authors":"Lucas B.R. Araújo ,&nbsp;Madson L. de Souza ,&nbsp;Abcael R.S. Melo ,&nbsp;Heloina N. Costa ,&nbsp;Lucas F.A.L. Babadopulos ,&nbsp;Antonio E.B. Cabral ,&nbsp;Rafael G. Pileggi","doi":"10.1016/j.cement.2025.100156","DOIUrl":"10.1016/j.cement.2025.100156","url":null,"abstract":"<div><div>The construction industry has recently seen a growing demand for sustainable materials. Alkali-activated binders (AAB) have emerged as a viable alternative to Portland cement-based materials. This study investigates the influences of the composition and mixing methods on the rheological and mechanical properties of an alkali-activated concrete (AAC) based on fly ash (FA) and steel slag (SS), compared to a reference Portland cement concrete (PCC) with equivalent volume fractions of aggregate and paste. Two mixing methods were examined: a free fall mixer and a planetary mixer that also functions as a rheometer. In the fresh state, the performance of concretes was assessed, focusing on rheological parameters such as mixing energy, maximum torque, and equivalent apparent viscosity indicator. In the hardened state, compressive strength tests were conducted. Pseudoplastic rheological model effectively described AAC behavior, while the Bingham model better characterized PCC. AAC demonstrated high passing ability and extended flow time, with flow behavior significantly influenced by the mixing process. Rheological analysis revealed that AAC required five times more mixing energy and exhibited greater equivalent apparent viscosity indicator compared to PCC. Additionally, AAC achieved higher compressive strength than PCC, which presented values from 34 to 43 MPa (PCC) depending on curing conditions. Thermal curing increased compressive strength by nearly 60 % at 28 days for AAC, from 48.6 MPa to 76.8 MPa. Furthermore, the mixing procedure influenced the fresh and hardened properties of both AAC and PCC, though PCC exhibited only minor variations. Mixing methods with higher energy input led to improved compressive strength.</div></div>","PeriodicalId":100225,"journal":{"name":"CEMENT","volume":"22 ","pages":"Article 100156"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145107884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}