CEMENT最新文献

{"title":"Physicochemical kinetics of rapid soil stabilization using calcium sulfoaluminate-based cements","authors":"Nicholas Benjamin Petersen ,&nbsp;Ashish Bastola ,&nbsp;Pavan Akula ,&nbsp;John Rushing","doi":"10.1016/j.cement.2025.100134","DOIUrl":"10.1016/j.cement.2025.100134","url":null,"abstract":"<div><div>Rapid stabilization of weak soil offers a promising option for quick infrastructure development and soil repair. The interaction between the rapid stabilizer and the soil is critical in defining its strength and durability. This study investigates the physicochemical effects of using Calcium Sulfoaluminate (CSA) cement-based stabilizers for rapid stabilization of weak clays, focusing on early age (&lt;1 day) reaction kinetics and its effect on the short-term and long-term engineering characteristics. Geochemical modeling is proposed to model the chemical kinetics and predict the formation of strength-enhancing products in the stabilized soil mixtures. The study investigates the unconfined compression strength and durability (cyclic wetting and drying) of stabilized soil. Results showed stabilizers with a higher proportion (50 wt. percentage or more) of CSA (CSA-rich) achieved up to 80 % of the 28–day strength in 60 min after stabilization. Mineralogical characterization using X-Ray Diffraction, Thermogravimetric Analysis, and Scanning Electron Microscopy, identified Ettringite in CSA-rich stabilizers and Calcium-Silicate-Hydrates (C-S-H) in stabilizers with a higher (50 wt. percentage or more) proportion of Portland Cement (PC-rich) stabilizers as key strength-enhancing products. Integrating the modeling results with the engineering and mineralogical characterization provided valuable insights into the rapid stabilization mechanisms of CSA cement.</div></div>","PeriodicalId":100225,"journal":{"name":"CEMENT","volume":"19 ","pages":"Article 100134"},"PeriodicalIF":0.0,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143348518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessing the reliability of laboratory test procedures for predicting concrete field performance against alkali-aggregate reaction (AAR)","authors":"Ana Bergmann ,&nbsp;Leandro F.M. Sanchez","doi":"10.1016/j.cement.2025.100133","DOIUrl":"10.1016/j.cement.2025.100133","url":null,"abstract":"<div><div>Alkali aggregate reaction (AAR) affected structures show reduced serviceability and premature distress in over 50 countries worldwide. Several laboratory test protocols have been proposed to evaluate the potential reactivity of aggregates by varying the conditions known to trigger and sustain the reaction. Among them, the most popular methods are the accelerated mortar bar test (AMBT) and the concrete prism test (CPT). Nevertheless, exposure site data, displaying the behaviour of concrete blocks exposed to real environmental conditions, has increased considerably recently, showing significant discrepancies between laboratory and concrete field performance. This study explores the reliability of laboratory tests, indicating moderate accuracy in predicting field performance for the AMBT and the CPT. The findings highlight an opportunity for recalibration of these methods through advanced analytical models that account for environmental conditions, alkali content, and the presence of SCMs to improve predictive accuracy. These measures will enhance concrete infrastructure safety by identifying risks associated with incorporating AAR-prone aggregates into new structures.</div></div>","PeriodicalId":100225,"journal":{"name":"CEMENT","volume":"19 ","pages":"Article 100133"},"PeriodicalIF":0.0,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143152063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization of microprobe analysis of cementitious materials incorporating glass powder under electron beam to avoid alkali migration","authors":"Wena de Nazaré do Rosário Martel,&nbsp;Josée Duchesne,&nbsp;Benoît Fournier","doi":"10.1016/j.cement.2025.100132","DOIUrl":"10.1016/j.cement.2025.100132","url":null,"abstract":"<div><div>The growing use of alkali-rich glass powder (GP) as a supplementary cementitious material (SCM) in concrete has led to a rising number of studies focused on the microstructure of cementitious matrices incorporating GP. Electron probe microanalyzer (EPMA) is commonly used to characterize cementitious materials. However, alkali migration induced by electron irradiation - a well-known phenomenon in inorganic materials - remains underexplored in this context. This migration often leads to underestimation of Na and K and overestimation of Si and Ca, thus compromising the analysis of key elements in cementitious hydrates, such as C-S-H. Due to the lack of a tailored protocol for EPMA analysis of alkali-rich SCMs, this study established analytical conditions to minimize errors in quantifying pozzolanic GP. Mixed glass culets and GP particles embedded in 7-year-old ternary concrete made with GP and silica fume were analyzed using ten different current densities by varying beam size, current, and the sub-counting method. The results show that alkali migration is highly sensitive to material composition and irradiation conditions. Na losses exceeded 70% as Ca and Si overestimation reached approximately 13% at current densities above 0.354 nA/μm². Literature-reported densities often surpass this threshold. At those conditions, the implementation of a sub-counting method effectively reduces the Na loss to 3%. However, it introduced a tendency for Na overestimation at lower current densities. Among all conditions, a beam diameter of 6 µm and a current of 10 nA, was the most accurate, reducing losses to under 2% and closely matching the reference glass analysis.</div></div>","PeriodicalId":100225,"journal":{"name":"CEMENT","volume":"19 ","pages":"Article 100132"},"PeriodicalIF":0.0,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143152062","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Predicting sorption isotherms from thermodynamic calculations","authors":"Keshav Bharadwaj ,&nbsp;O. Burkan Isgor ,&nbsp;W. Jason Weiss","doi":"10.1016/j.cement.2025.100131","DOIUrl":"10.1016/j.cement.2025.100131","url":null,"abstract":"<div><div>Accurate sorption/desorption isotherms for cementitious materials are important in predicting drying shrinkage, moisture transport, ionic transport, freezable water content, and the service life of concrete. This paper develops a framework for constructing water sorption isotherms for hydrated cementitious pastes from the outputs of thermodynamic modeling and a pore partitioning model (PPM). Thermodynamic modeling helps quantify the solid phases and pore space in the hydrated matrix. The PPM provides the volume of evaporable water in crystalline hydrates, the total volume of gel water, the volume of capillary water, and volume of pores due to chemical shrinkage. The sorption isotherm is constructed from information on the evaporable water present in individual phases at each RH, water adsorbed on C-S-H, water in pores with kelvin radius of 2–5 nm, capillary water, and water in pores due to chemical shrinkage and air voids. The Brunauer-Skalny-Bodor (BSB) model is used to calculate the water adsorbed on the C-S-H. This model predicts the sorption isotherms from the literature to within an error of 2–19 %. The areas for future work and the challenges in predicting the desorption isotherms are discussed.</div></div>","PeriodicalId":100225,"journal":{"name":"CEMENT","volume":"19 ","pages":"Article 100131"},"PeriodicalIF":0.0,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143152061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Compressive strength and microstructural development of cement paste incorporating nanosilica with different particle sizes","authors":"Pegah Farjad ,&nbsp;Ahmed G. Mehairi ,&nbsp;Fereshteh Meshkani ,&nbsp;Roozbeh Mowlaei ,&nbsp;Rahil Khoshnazar ,&nbsp;Nashaat N. Nassar","doi":"10.1016/j.cement.2025.100128","DOIUrl":"10.1016/j.cement.2025.100128","url":null,"abstract":"<div><div>Nanosilica particles are among the most studied nanomaterials in cementitious mixtures. However, literature on the effect of nanosilica particle size on the performance of these mixtures is still limited, with sometimes inconsistent findings. This study aims to address this gap by including the synthesis and application of different-sized nanosilica particles in one study. A uniform synthesis method was used to achieve nanosilica with four distinct average particle sizes (10, 35, 65, and 90 nm), covering the whole nanoscale range. The nanosilica particles were then fully characterized and utilized in cement paste at 1, 2, and 3 wt% of the cement. The compressive strength, heat evolution, microstructure, and rheological behaviour of the resultant pastes were investigated. The results revealed that the smallest particle size of nanosilica (10 nm) provided the highest compressive strength enhancement (over 100 % enhancement when used at 2 wt% of cement). The high pozzolanic reactivity of such small nanosilica particles at 2 wt%, together with their acceleration effect on cement hydration and densification of the paste microstructure, all contributed to this strength improvement. Overall, the enhancing effects of the nanosilica particles on the compressive strength of the pastes were less substantial when their particle size increased from 10 to 90 nm at any given concentration. All the nanosilica particles also increased the viscosity of the paste. This increasing effect was higher for smaller-sized nanosilica particles and at higher concentrations.</div></div>","PeriodicalId":100225,"journal":{"name":"CEMENT","volume":"19 ","pages":"Article 100128"},"PeriodicalIF":0.0,"publicationDate":"2025-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143152662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chemical transformations during the preparation and rehydration of reactivated virgin cements","authors":"Neshable Noel,&nbsp;Tommy Mielke,&nbsp;Gustave Semugaza,&nbsp;Anne Zora Gierth,&nbsp;Susanne Helmich,&nbsp;Stefan Nawrath,&nbsp;Doru C. Lupascu","doi":"10.1016/j.cement.2025.100129","DOIUrl":"10.1016/j.cement.2025.100129","url":null,"abstract":"<div><div>This paper aims to provide a thorough comprehension of the chemical transformations occurring during the thermal preparation of reactivated virgin cements (RVCes). X-ray Diffraction (XRD) analysis of RVCes reveals the reformation of the di-calcium mineral phases in two polymorphic forms: α^/_L-C₂S and β-C₂S, within the temperature range from 600 °C to 850 °C. We exactly quantify the two polymorphs α^/_L-C₂S and α^/_H-C₂S and distinguish their presence in the reactivation temperature range. This phase formation is corroborated by scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDX). We further investigated the chemical changes that, after re-activation, take place during the 28-day rehydration period using differential scanning calorimetry (DSC), thermogravimetry (TG), XRD, and SEM, confirming the reformation of the typical hydration mineral phases. Mercury intrusion porosimetry (MIP) and compressive strength tests verified the development of strength-enhancing mineral phases in RVCs, exhibiting a mechanical strength recovery ranging from 50 % to 75 % compared to industrially produced virgin cement (VCe).</div></div>","PeriodicalId":100225,"journal":{"name":"CEMENT","volume":"19 ","pages":"Article 100129"},"PeriodicalIF":0.0,"publicationDate":"2025-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143152060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A molecular formalism of the hydraulic cement deterioration stored at different temperatures and its impact on the mechanical behavior","authors":"H.C.B. Nascimento ,&nbsp;N.B. Lima ,&nbsp;S.D. Jesus ,&nbsp;D.G. Rocha ,&nbsp;H.S. Cavalcante ,&nbsp;B.S. Teti ,&nbsp;R. Manta ,&nbsp;L.B.T. Santos ,&nbsp;S. Campelo ,&nbsp;N.B.D. Lima","doi":"10.1016/j.cement.2025.100130","DOIUrl":"10.1016/j.cement.2025.100130","url":null,"abstract":"<div><div>The different temperatures associated with the climatic conditions of each continent and each biome directly influence the exposure properties of each material used in each region, including hydraulic cement, an important material widely employed in bridges, viaducts, and buildings worldwide. Despite being prepared at elevated temperatures, hydraulic cement is often stored and used under ambient conditions, posing challenges, particularly in tropical environments. The present work investigates the effects of different temperatures (10 °C, 30 °C, and 50 °C) on the deterioration of hydraulic cement and microstructural and mechanical behaviors. Kinect investigations were carried out to advance a chemical formalism of the deterioration of cement stored at different temperatures in a tropical climate. Signs of chemical deterioration of cement samples were investigated by XRD and SEM analyses, which revealed the presence of essential phases on the surface of the mortars, such as Portlandite, CSH, and Ettringite. The study incorporated gray residue into the mortar mixtures in two forms: addition (type B mortar) and substitution (type C mortar). For type B, 10 % of gray residue was added as an additive without reducing the cement content, while for type C, 10 % of the cement was replaced with gray residue to lower environmental impact. The presence of gray residue contributed to the hydration kinetics and microstructure, enhancing the formation of CSH phases, which are critical for mechanical strength. Mechanical performance revealed that type A (reference mortar) suffered a 6 % reduction in compressive strength after 90 days of storage at ambient conditions, while type B showed a 23 % increase due to the addition of ash residue, and type C, although with a 33 % reduction, balanced lower cement use with environmental benefits and mitigated losses related to chemical deterioration. Finally, sustainable mortars showed better mechanical performance than traditional ones, especially when the cement was stored at 50 °C, as predicted by the kinetic formalism (R² = 0.99 across storage conditions).</div></div>","PeriodicalId":100225,"journal":{"name":"CEMENT","volume":"19 ","pages":"Article 100130"},"PeriodicalIF":0.0,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143152663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of ultrasonication on sucrose structure and its influence on controlled retardation of earth-based alkali-activated materials","authors":"Pitabash Sahoo,&nbsp;Souradeep Gupta","doi":"10.1016/j.cement.2024.100127","DOIUrl":"10.1016/j.cement.2024.100127","url":null,"abstract":"<div><div>Excavated soil from construction and demolition activities can be stabilized by alkali-activated binders to manufacture low-carbon construction materials. This research attempts to investigate the efficacy of non-sonicated (S) and sonicated sucrose (USS) as a controlled retarder in alkali-activated materials containing excavated lateritic soil (EAAM) (clay content of 42.5 %). Influences of sucrose dosage and sonication on hydration kinetics, setting, and structural build-up of EAAM have been investigated. Findings from isothermal calorimetry show 30 – 65 % retardation in hydration kinetics leading to a 50 – 60 % delay in setting and slower structural build-up of EAAM during the initial 12 h. This results in higher flowability and superior flow retention for longer duration than the control (0 % sucrose). By decoupling the effect on hydration of GGBS and FA, it is found that sucrose has a more dominant retarding effect on GGBS compared to FA, attributed to its stronger interaction with calcium-rich sites than aluminates. The addition of 2 % USS to EAAM results in higher retardation compared to 2 %S. This is attributed to the formation of acidic byproducts due to sonication-induced breakdown of sucrose molecules, leading to reduced pH and electrostatic repulsion. The densified microstructure of EAAM with USS compared to that with S results in a noticeable improvement in strength retention under wet conditions, suggesting reduced moisture sensitivity. Due to enhanced hydration at later ages, sucrose-EAAM possesses 30 – 48 % higher wet compressive strength than the control EAAM at the 28-day mark. Overall, sucrose, which can be prepared from waste biomass through “green” processes, can be a potential chemical admixture for earth-based alkali-activated constructions.</div></div>","PeriodicalId":100225,"journal":{"name":"CEMENT","volume":"19 ","pages":"Article 100127"},"PeriodicalIF":0.0,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143152059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synergistic effects of silica fume, nanomaterials and inorganic salts on the hydration and compressive strength of low-density oil well cement slurry","authors":"Kenedy Geofrey Fikeni ,&nbsp;Xueyu Pang ,&nbsp;Yukun Zhao ,&nbsp;Shenglai Guo ,&nbsp;Jie Ren ,&nbsp;Kaihe Lv ,&nbsp;Jinsheng Sun","doi":"10.1016/j.cement.2024.100125","DOIUrl":"10.1016/j.cement.2024.100125","url":null,"abstract":"<div><div>During offshore cementing at shallow depth, the low-temperature environment at the bottom of the sea and the low-density requirement of the cement slurry significantly hinder the strength development of oil well cement systems. Hence there is always a strong need to take various measures to enhance the strength development of low-density oil well cement systems. During this study, potential synergistic effects of silica fume, nanomaterials (C-S-H nano-seeds, nano-silica, nano-alumina), and inorganic salts (CaCl₂, NaCl, Na₂SiO₃) to improve the strength of low-density well cement slurry were investigated. Water-to-cement ratio (w/c) was varied between 1.04 and 1.28 to obtain a constant slurry density of 1.5 g/cm³. Test results revealed that the addition of silica fume altered the rheology and flow behavior of low-density cement slurries, resulting in flat rheology profiles at high shear rates. The Bingham plastic model can describe the rheological behavior of cement slurries without silica fume, whereas the Power-law model is more suitable to cement slurries with silica fume. High-dosage silica fume (30 %) is shown to have similar acceleration capability as the strongest nanomaterial accelerator (i.e. C-S-H nano-seeds) at 2 % dosage. However, adding nanomaterials to silica-fume-enriched slurries cannot further increase the hydration rate of cement (i.e. no synergistic effect), possibly due to their similar acceleration mechanism. In contrast, adding chloride-based inorganic salts to silica-fume-enriched slurries further increased the hydration rate of cement significantly, exhibiting a strong synergistic effect. Based on the 7-day compressive strength test results at 15°C, the addition of silica fume or nanomaterials individually can increase the strength of neat cement by up to 92 %, while the combined addition of silica fume and NaCl can increase its strength by 306 %.</div></div>","PeriodicalId":100225,"journal":{"name":"CEMENT","volume":"19 ","pages":"Article 100125"},"PeriodicalIF":0.0,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143152665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sanitary ware waste in eco-friendly Portland blended cement: Potential use as supplementary cementitious material","authors":"Vitor Affonso Lopes Silveira,&nbsp;Domingos Sávio de Resende,&nbsp;Augusto Cesar da Silva Bezerra","doi":"10.1016/j.cement.2024.100126","DOIUrl":"10.1016/j.cement.2024.100126","url":null,"abstract":"<div><div>The sanitary ware industry led to significant waste generation with a long biodegradation period. To produce eco-friendly Portland blended cement, partial Portland cement (PC) substitution is proposed, reducing clinker consumption and mitigating adverse environmental impacts. This paper assessed the pozzolanic activity and the filler effect of clay-based sanitary ware waste (CSW) to study its feasibility of reutilization as a supplementary cementitious material (SCM). After being collected, the samples underwent a preparation process consisting of drying and sieving. The waste replaced 0 to 25 wt% PC. The CSW powder was characterized by laser diffraction granulometry, X-ray diffraction (XRD), X-ray fluorescence, and scanning electron microscopy (SEM). The pozzolanic activity was assessed by compressive strength test, isothermal calorimetry, and electrical conductivity. Durability was considered by acid attack, and the hardened mortar proprieties were shown. The utilization of CSW blended with PC is feasible for producing eco-friendly binders.</div></div>","PeriodicalId":100225,"journal":{"name":"CEMENT","volume":"19 ","pages":"Article 100126"},"PeriodicalIF":0.0,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143152666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}