CEMENT最新文献

{"title":"Stabilization characteristics of cemented lateritic soil produced with selected cement types","authors":"A.A. Amadi ,&nbsp;S.S. Kolo ,&nbsp;A. Yusuf ,&nbsp;F.E. Eze ,&nbsp;U. Salihu","doi":"10.1016/j.cement.2025.100136","DOIUrl":"10.1016/j.cement.2025.100136","url":null,"abstract":"<div><div>It is recognized that different cements have different properties and stabilization effectiveness for different applications. The challenge of using the right type of cement should be a concern for practitioners in civil engineering construction. In this study, an experimental testing programme was conducted to evaluate and compare the stabilizing effects of CEM I 42.5 N, CEM II/B-L 42.5 N and CEM III/A 42.5 N types of cement on some physical and mechanical properties of lateritic soil. Laboratory tests performed on soil mixtures containing the selected cements added to constitute 0, 3, 6, 9 and 12 % of the dry weight of the composite materials include the consistency and compaction tests determined on the basis of fresh mixtures. In addition, unconfined compressive strength (UCS) test on specimens compacted at optimum moisture conditions with the British Standard Light (BSL) compaction effort and cured for 7, 28 and 90 days was performed. In equal proportions, soil mixtures prepared with the different types of cements yielded comparable results in terms of reducing the plasticity index (PI) from values as high as 60 % in untreated state to 5.05 %, 7.05 % and 8.2 % respectively for CEM I, CEM II and CEM III at 12 % cement content. Addition of cement also increased both the maximum dry unit weight (γ_dmax) and optimum moisture content (OMC) of the soil with CEM I cement having the greatest effect while CEM III cement affected the γ_dmax of the soil the least. For example, when compacted with BSH effort, CEM I achieved γ_dmax = 1.95 kN/m³ and OMC = 25 %, while for CEM III, γ_dmax = 1.63 kN/m³ and OMC = 22.6 % compared to γ_dmax of 1.53 kN/m³ and OMC of 21.1 % for the untreated soil. Regardless of the cement type, there was an overall improvement in the strength properties of the lateritic soil represented by a range of 11 – 14 times for UCS and 31 - 62 folds for E₅₀ at 12 % cement after 90 days curing duration in comparison with the untreated soil. While strength gain was higher in CEM I based mixtures at early (7 day) age (1635.44, 1622.85 and 1599.55 kN/m2 for CEM I, CEM II and CEM III respectively at 12 % cement content), CEM III provided superior strength improvement at the long term (90 day) curing period (2566.25 compared to 2444.58 and 2465.77 kN/m² respectively for CEM I and CEM II at 12 % cement content). Using the variance analysis (ANOVA) at a significance level (α) of 0.05, the influence of cement type was statistically confirmed for the liquid limit, optimum moisture content and UCS at 28 and 90 days curing ages.</div></div>","PeriodicalId":100225,"journal":{"name":"CEMENT","volume":"19 ","pages":"Article 100136"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510299","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":"2025-03-01","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":"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":"2025-03-01","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":"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":"2025-03-01","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":"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":"2025-03-01","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}

{"title":"Significance of fineness of pozzolans in determining pozzolanic reactivity","authors":"Mahipal Kasaniya,&nbsp;Michael DA Thomas,&nbsp;Ted Moffatt,&nbsp;Ashlee Hossack","doi":"10.1016/j.cement.2025.100137","DOIUrl":"10.1016/j.cement.2025.100137","url":null,"abstract":"<div><div>This paper presents the quantification of the pozzolanic reactivity of pozzolans examined in terms of compressive strength, bound water and electrical resistivity. The pozzolans studied included natural pozzolans, glass pozzolans and fly ash that were ground to four fineness levels or median particle sizes (d₅₀) of approximately 3, 5, 10 and 15 µm. Quantitative X-ray diffraction was employed to determine the amorphous content of pozzolans. The UNB lime-reactivity test and a modified ASTM <span><span>C311</span><svg><path></path></svg></span> activity with portland cement test were performed in mortars. In these two tests, bulk electrical resistivity measurements were conducted before measuring compressive strength. Additionally, pastes were prepared for bound water in accordance with the R³ test or ASTM <span><span>C1897</span><svg><path></path></svg></span>. While the pozzolanic reactivity for all materials tested generally improves with the fineness, one pozzolan could demonstrate a very different rate of pozzolanicity improvements compared to that of others. Bulk electrical resistivity provides a reliable assessment of pozzolanic reactivity and can help differentiate pozzolanic and pozzolanic-hydraulic materials when used in conjunction with compressive strength. The modified ASTM <span><span>C311</span><svg><path></path></svg></span> test is also found to be suitable and effective in rapidly distinguishing pozzolans, especially slow reactive ones, from inert materials at 7 days. A novel amorphous-fineness index derived by combining the amorphous content and fineness of pozzolans to reasonably predict the pozzolanic reactivity and limitations of the index are discussed.</div></div>","PeriodicalId":100225,"journal":{"name":"CEMENT","volume":"19 ","pages":"Article 100137"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143526710","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":"Influence of metakaolin content on the microstructure and strength in hardened LC3 paste","authors":"Qi Luo ,&nbsp;Xinyu Zhang ,&nbsp;Junchao Yu ,&nbsp;Guoqing Geng","doi":"10.1016/j.cement.2025.100138","DOIUrl":"10.1016/j.cement.2025.100138","url":null,"abstract":"<div><div>This study systematically investigates the impact of varying metakaolin contents on the compressive strength and microstructure of hardened limestone calcined clay cement (LC³) paste. The findings reveal that increasing metakaolin content intensifies the aluminum sulfate reaction peak and accelerates its onset, while decreasing metakaolin leads to higher total calcium hydroxide (Ca(OH)₂) and calcium carbonate (CaCO₃) levels in the system. A specific threshold of 70 % metakaolin content is identified as optimal for pozzolanic activity; excess metakaolin remains unreacted. The addition of metakaolin refines the pore structure, reduces harmful large pores, and promotes the formation of ettringite and other hydration products, enhancing mechanical properties. Notably, a sample with 70 % metakaolin content exhibits higher compressive strength than one with 100 % metakaolin, indicating that metakaolin containing 30 % impurities (referred to as sand powder) demonstrates superior mechanical performance. These results support the development of LC³ as a commercially viable and eco-friendly alternative to Ordinary Portland Cement (OPC).</div></div>","PeriodicalId":100225,"journal":{"name":"CEMENT","volume":"19 ","pages":"Article 100138"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143610612","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":"Phase evolution and performance of sodium sulfate-activated slag cement pastes","authors":"Zengliang Yue ,&nbsp;Yuvaraj Dhandapani ,&nbsp;Samuel Adu-Amankwah ,&nbsp;Susan A. Bernal","doi":"10.1016/j.cement.2024.100117","DOIUrl":"10.1016/j.cement.2024.100117","url":null,"abstract":"<div><div>This study evaluates the reaction kinetics, phase assemblage, and microstructure evolution of Na₂SO₄-activated slag cements produced with three commercial slags. The main reaction products identified are ettringite and calcium aluminosilicate hydrates, alongside a poorly crystalline SO₄^2- intercalated Mg-Al-layered double hydroxide (LDH) phase. Results revealed that the Al₂O₃ slag content alone does not correlate with the cement performance. While pastes made with a higher Al₂O₃ content slag exhibit faster reaction kinetics, those made with a slag with a higher Mg/Al ratio developed superior compressive strength and reduced porosity over extended curing periods. Thermodynamic modelling simulations indicate that sulfate consumption occurs via ettringite and LDH phase formation, influencing the slag reaction degree, pH value, and porosity reduction in these cements. This research highlights the critical role of slag composition in controlling microstructure and, consequently, performance of sodium sulfate activated slag cement pastes.</div></div>","PeriodicalId":100225,"journal":{"name":"CEMENT","volume":"18 ","pages":"Article 100117"},"PeriodicalIF":0.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142326499","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":"Multi-year cementitious hydrate product formation in non-Portland high performance concretes","authors":"Daniel A. Geddes ,&nbsp;Brant Walkley ,&nbsp;Taku Matsuda ,&nbsp;John L. Provis","doi":"10.1016/j.cement.2024.100111","DOIUrl":"10.1016/j.cement.2024.100111","url":null,"abstract":"<div><p>This paper describes the hydration products and microstructural formation processes that yield excellent mechanical properties in “zero-cement concretes” (ZCC) produced by chemical activation of a blend of silica fume, blast furnace slag, and fly ash, using a CaO-rich additive (commercially supplied as an expansive agent but taking a chemical activation role here), a high superplasticizer dose, and a very low water content. These concretes reach 70 MPa at 28 days and then continue to gain strength beyond 150 MPa after 5 years, either under sealed conditions or exposed on a rooftop in the climate of Tokyo, Japan. The reaction products of ZCC are dominated by C-A-S-H gel, accompanied by aluminate hydrates of different layered double hydroxide forms; this unconventional cementitious blend yields reaction products that are familiar from Portland cement and blended binder systems. The ferronickel slag used as fine aggregate in these mixes makes an important contribution to the balance of fresh-state and hardened-state properties by modifying hydration chemistry.</p></div>","PeriodicalId":100225,"journal":{"name":"CEMENT","volume":"18 ","pages":"Article 100111"},"PeriodicalIF":0.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666549224000203/pdfft?md5=2d8fb3d1eb36b0b453eef4161dfc40f2&pid=1-s2.0-S2666549224000203-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142230073","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":"Prediction of strength activity index using chemical and physical properties of pozzolans","authors":"Farzaneh Elyasigorji,&nbsp;Habib Tabatabai","doi":"10.1016/j.cement.2024.100116","DOIUrl":"10.1016/j.cement.2024.100116","url":null,"abstract":"<div><div>Reductions in cement use have essential benefits in reducing the embodied energy in concrete and CO₂ emissions. Hence, effective assessment of potential pozzolanic materials is highly desirable to facilitate usage as sustainable supplementary cementitious materials (SCMs). However, assessment of pozzolanic reactivity using conventional experimental tests is typically time-consuming and expensive. Pozzolanic reactivity is mainly related to the chemical and physical characteristics of various pozzolans, such as amorphous silica and alumina contents and specific surface area. This study develops and presents an equation that can predict the strength activity index (SAI) as an indirect method for the assessment of potential pozzolans and their strength outcome using their chemical and physical properties. The development of a prediction equation not only saves time and resources but also helps with designing optimized and improved pozzolanic SCMs. The strength activity index (SAI) of seven different materials with varying pozzolanic properties was measured at an age of 90 days. The powdered test materials included pottery cull, brick powder, lightweight aggregate fines, glass powder, silica fume, dolostone, and Class C fly ash. In the second stage, correlation analyses were performed to find parameters (based on chemical and physical properties) that were highly correlated with SAI. An equation was then developed as a function of the chemical and physical properties of raw pozzolanic materials using an optimization tool. Consequently, an equation predicting SAI was derived which had a high degree of correlation (<em>R</em> = 0.972) with measured SAI.</div></div>","PeriodicalId":100225,"journal":{"name":"CEMENT","volume":"18 ","pages":"Article 100116"},"PeriodicalIF":0.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666549224000252/pdfft?md5=dc7fd71feb2a2f82cde2b54621e27a7c&pid=1-s2.0-S2666549224000252-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142311850","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}