Cement and Concrete Research最新文献

英文中文

Understanding hydration reactions, mechanical properties, thermal expansion, and organic interfacial interactions of calcium sulfate hydrates from the atomic scale 从原子尺度上理解水化反应、机械性能、热膨胀和有机界面相互作用的硫酸钙水合物

IF 10.9 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement and Concrete Research

Pub Date : 2024-12-08 DOI: 10.1016/j.cemconres.2024.107740

Ratan K. Mishra , Samir Darouich , Pieter J. in 't Veld , Robert J. Flatt , Hendrik Heinz

Calcium sulfates such as anhydrite, hemihydrate, and gypsum are used extensively in building materials, wall board, and biomaterials. The correlation between nanoscale structure and macroscopic properties, however, remains incompletely understood. We employed molecular dynamics simulations with the Interface Force Field (IFF) to examine sensitive hydration reactions, anisotropic thermal and mechanical properties, as well as (hkl) specific adsorption of organic modifiers. Computed thermal transitions between calcium sulfate phases, directional coefficients of thermal expansion, and directional mechanical properties agree exceptionally well with partially known experimental measurements, provide missing data and mechanistic understanding at the atomic scale. Polymeric naphthalene sulfonate-formaldehyde condensates exhibit strong, selective adsorption to the hemihydrate (001) surface. The polymer conformations and facet-specific binding affinities explain the delayed hydration of calcium sulfate hemihydrate to gypsum. The simulation methods can be applied to predict crystal growth and properties of sulfate-containing multiphase materials from atoms to the micrometer scale.

硫酸钙如硬石膏、半水合钙和石膏广泛用于建筑材料、墙板和生物材料。然而，纳米级结构与宏观性质之间的关系仍不完全清楚。利用界面力场（IFF）进行分子动力学模拟，研究了有机改性剂的敏感水化反应、各向异性热学和力学性能以及（hkl）特异性吸附。计算出的硫酸钙相之间的热跃迁、热膨胀的定向系数和定向力学性能与部分已知的实验测量结果非常吻合，提供了缺失的数据和原子尺度上的力学理解。聚合萘磺酸甲醛缩合物对半水合物（001）表面表现出很强的选择性吸附。聚合物构象和面特异性结合亲和解释了半水合硫酸钙与石膏延迟水化的原因。模拟方法可用于从原子到微米尺度预测含硫酸盐多相材料的晶体生长和性能。

{"title":"Understanding hydration reactions, mechanical properties, thermal expansion, and organic interfacial interactions of calcium sulfate hydrates from the atomic scale","authors":"Ratan K. Mishra , Samir Darouich , Pieter J. in 't Veld , Robert J. Flatt , Hendrik Heinz","doi":"10.1016/j.cemconres.2024.107740","DOIUrl":"10.1016/j.cemconres.2024.107740","url":null,"abstract":"<div><div>Calcium sulfates such as anhydrite, hemihydrate, and gypsum are used extensively in building materials, wall board, and biomaterials. The correlation between nanoscale structure and macroscopic properties, however, remains incompletely understood. We employed molecular dynamics simulations with the Interface Force Field (IFF) to examine sensitive hydration reactions, anisotropic thermal and mechanical properties, as well as (hkl) specific adsorption of organic modifiers. Computed thermal transitions between calcium sulfate phases, directional coefficients of thermal expansion, and directional mechanical properties agree exceptionally well with partially known experimental measurements, provide missing data and mechanistic understanding at the atomic scale. Polymeric naphthalene sulfonate-formaldehyde condensates exhibit strong, selective adsorption to the hemihydrate (001) surface. The polymer conformations and facet-specific binding affinities explain the delayed hydration of calcium sulfate hemihydrate to gypsum. The simulation methods can be applied to predict crystal growth and properties of sulfate-containing multiphase materials from atoms to the micrometer scale.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"189 ","pages":"Article 107740"},"PeriodicalIF":10.9,"publicationDate":"2024-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142789811","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}

引用次数: 0

Reaction kinetics of calcined smectite in a clinker-free model and a synthetic cement system in comparison with selected calcined phyllosilicates 煅烧蒙脱石在无熟料模型和合成水泥体系中的反应动力学与煅烧层状硅酸盐的比较

IF 10.9 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement and Concrete Research

Pub Date : 2024-12-08 DOI: 10.1016/j.cemconres.2024.107766

Sebastian Scherb , Matthias Maier , Köberl Mathias , Nancy Beuntner , Karl-Christian Thienel

The investigations of clinker-free model and synthetic cement systems reveal deeper insight into the behavior of metasmectite during early hydration. The use of metasmectite accelerates the aluminate clinker reaction and influences the degree of hydration of alite. Its chemical reactivity can be demonstrated in clinker-free as well as model cement systems by direct quantification of the metasmectite, its portlandite consumption and C-S-H formation. The influence on sulfate balance reveals an interaction of metasmectite's negatively charged surfaces with ions from the pore solution and demonstrates that sulfate adsorption does not solely take place on surfaces of C-S-H. Overall, it can be concluded that the impediment of the alite hydration during early hydration due to metasmectite is rather insignificant compared to metakaolinite and is within the range of metaillite. These findings provide a significant contribution to the expected widespread use of calcined clays with a low metakaolinite content in cementitious systems.

通过对无熟料模型和合成水泥体系的研究，可以更深入地了解偏铝云母在早期水化过程中的行为。偏铝赤铁矿的使用加速了铝酸盐熟料反应，影响了铝酸盐的水化程度。它的化学反应性可以在无熟料水泥体系和模型水泥体系中通过直接量化偏辉石，其硅酸盐消耗和C-S-H形成来证明。对硫酸盐平衡的影响揭示了偏辉石带负电表面与孔溶液离子的相互作用，并表明硫酸盐的吸附不仅仅发生在C-S-H表面。综上所述，与偏高岭石相比，变质铝石在早期水化过程中对阿利石水化的阻碍作用微不足道，属于变质铝石的范围。这些发现为低偏高岭石含量的煅烧粘土在胶结体系中的广泛应用提供了重要的贡献。

{"title":"Reaction kinetics of calcined smectite in a clinker-free model and a synthetic cement system in comparison with selected calcined phyllosilicates","authors":"Sebastian Scherb , Matthias Maier , Köberl Mathias , Nancy Beuntner , Karl-Christian Thienel","doi":"10.1016/j.cemconres.2024.107766","DOIUrl":"10.1016/j.cemconres.2024.107766","url":null,"abstract":"<div><div>The investigations of clinker-free model and synthetic cement systems reveal deeper insight into the behavior of metasmectite during early hydration. The use of metasmectite accelerates the aluminate clinker reaction and influences the degree of hydration of alite. Its chemical reactivity can be demonstrated in clinker-free as well as model cement systems by direct quantification of the metasmectite, its portlandite consumption and C-S-H formation. The influence on sulfate balance reveals an interaction of metasmectite's negatively charged surfaces with ions from the pore solution and demonstrates that sulfate adsorption does not solely take place on surfaces of C-S-H. Overall, it can be concluded that the impediment of the alite hydration during early hydration due to metasmectite is rather insignificant compared to metakaolinite and is within the range of metaillite. These findings provide a significant contribution to the expected widespread use of calcined clays with a low metakaolinite content in cementitious systems.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"189 ","pages":"Article 107766"},"PeriodicalIF":10.9,"publicationDate":"2024-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142789810","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Drying shrinkage and carbonation of steel slag-metakaolin alkali-activated composites: Effect of vegetable oil addition and slag aggregates 钢渣-偏高岭土碱活化复合材料的干燥收缩和碳化：植物油和矿渣集料的影响

IF 10.9 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement and Concrete Research

Pub Date : 2024-12-06 DOI: 10.1016/j.cemconres.2024.107764

O. Rudić , C. Grengg , Y. Seyrek , F. Steindl , B. Müller , I. Zögl , D. Wohlmuth , N. Ukrainczyk , F. Mittermayr

The influence of vegetable oil and steel slag aggregates on the drying shrinkage and carbonation performance of steel slag-based alkali activated materials was investigated. Decrease in carbonation rates by up to 19% attributed to the formation of metal soap phases which strongly reduced the gel and small capillary porosity as well as the specific surface area of the materials. When combined with steel slag aggregates, an additional reduction in carbonation rate of up to 50% could be achieved. Furthermore, the strain induced by shrinkage and rewetting was highly influenced by the type of aggregate used, with a reduction of 40 to 50% observed due to presence of soap phases resulting from the hydrolysis of oil in the metal-alkaline conditions. The observed improvement in durability properties may enable new application possibilities for alkali activated materials, overcoming well-known technical limitations such as high drying shrinkage and high carbonation rates.

研究了植物油和钢渣骨料对钢渣基碱活化材料干燥收缩和碳化性能的影响。由于金属皂相的形成，碳化率降低了19%，这大大降低了凝胶和小毛细管孔隙率以及材料的比表面积。当与钢渣骨料结合使用时，碳化率可进一步降低50%。此外，收缩和再润湿引起的应变受到所使用的骨料类型的高度影响，由于在金属碱性条件下油水解产生的肥皂相的存在，观察到减少了40 - 50%。观察到的耐久性性能的改善可能为碱活性材料提供新的应用可能性，克服众所周知的技术限制，如高干燥收缩率和高碳化率。

{"title":"Drying shrinkage and carbonation of steel slag-metakaolin alkali-activated composites: Effect of vegetable oil addition and slag aggregates","authors":"O. Rudić , C. Grengg , Y. Seyrek , F. Steindl , B. Müller , I. Zögl , D. Wohlmuth , N. Ukrainczyk , F. Mittermayr","doi":"10.1016/j.cemconres.2024.107764","DOIUrl":"10.1016/j.cemconres.2024.107764","url":null,"abstract":"<div><div>The influence of vegetable oil and steel slag aggregates on the drying shrinkage and carbonation performance of steel slag-based alkali activated materials was investigated. Decrease in carbonation rates by up to 19% attributed to the formation of metal soap phases which strongly reduced the gel and small capillary porosity as well as the specific surface area of the materials. When combined with steel slag aggregates, an additional reduction in carbonation rate of up to 50% could be achieved. Furthermore, the strain induced by shrinkage and rewetting was highly influenced by the type of aggregate used, with a reduction of 40 to 50% observed due to presence of soap phases resulting from the hydrolysis of oil in the metal-alkaline conditions. The observed improvement in durability properties may enable new application possibilities for alkali activated materials, overcoming well-known technical limitations such as high drying shrinkage and high carbonation rates.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"189 ","pages":"Article 107764"},"PeriodicalIF":10.9,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142782498","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}

引用次数: 0

Revealing the tricalcium silicate formation behaviors in modified EAF slag at high temperatures for the production of electric recycled cement 揭示改性电炉炉渣在高温下的硅酸三钙形成行为，用于生产电再生水泥

IF 10.9 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement and Concrete Research

Pub Date : 2024-12-06 DOI: 10.1016/j.cemconres.2024.107756

Mingrui Yang, Zhiming Yan, Zushu Li

The formation behaviors of tricalcium silicate (C₃S) in modified EAF slag were investigated to assess the feasibility of using EAF slag for cement clinker production. For the formation conditions of C₃S, the C₃S content in slag exhibits a notable increase with elevating slag basicity and reaction time, while only a slight enhancement with temperature rising from 1400 °C to 1500 °C. The C₃S formation mechanism depends on the local conditions in the slag. In the lime-rich region it primarily takes place through the direct formation, i.e. 3CaO(s) + SiO₂(l) = 3CaO·SiO₂(s), controlled by the diffusion of SiO₄⁴⁻ in liquid phase. Conversely, in the dicalcium silicate (C₂S) rich region, C₃S formation primarily occurs via the indirect formation: 2CaO·SiO₂(s) + CaO(l) = 3CaO·SiO₂(s), with the reaction being controlled by the diffusion of Ca²⁺ in the liquid slag.

研究了改性电炉炉渣中硅酸三钙（C3S）的形成行为，以评价电炉炉渣用于水泥熟料生产的可行性。对于C3S的形成条件，随着矿渣碱度和反应时间的升高，矿渣中C3S含量显著增加，而在1400 ~ 1500℃温度范围内，随着温度的升高，C3S含量仅略有增加。C3S的形成机理取决于炉渣中的局部条件。富石灰区主要通过直接生成，即3CaO(s) + SiO2(l) = 3CaO·SiO2(s)，受液相SiO44−的扩散控制。相反，在硅酸二钙（C2S）富集区，C3S的生成主要通过间接生成：2CaO·SiO2(s) + CaO(l) = 3CaO·SiO2(s)，反应受Ca2+在液渣中的扩散控制。

引用次数: 0

Basic creep properties of hydrates in mature slag-based CEM II concretes: A micromechanical analysis 成熟渣基CEM II混凝土中水合物的基本蠕变特性：微观力学分析

IF 10.9 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement and Concrete Research

Pub Date : 2024-12-05 DOI: 10.1016/j.cemconres.2024.107735

Maximilian Sorgner , Rodrigo Díaz Flores , Bernhard Pichler , Thomas Pilgerstorfer , Bernd Moritz , Christian Hellmich

The demand for accurate characterization of slag-based CEM II concretes is becoming increasingly important as the construction sector shifts towards eco-efficient materials. Here, the basic creep behavior of slag-based CEM II concretes is traced back to mixture-invariant hydrate properties. Therefore, an experimentally validated three-step micro-viscoelastic model for CEM I/OPC-concretes is complemented by a Powers-Acker-type hydration model for CEM II and extended towards long-term creep, temperature activation, and moisture sensitivity. This model is used for a strain rate-based, aging viscoelastic analysis of two creep tests on distinctively different CEM II concretes; revealing that the shear creep modulus of CEM II hydrates is half as large as the one of ordinary Portland cement hydrates. This makes slag-based CEM II concretes especially suitable for applications such as precast segmental tunnel linings, where a faster stress relaxation under displacement-controlled conditions is beneficial.

随着建筑行业转向生态高效材料，对渣基CEM II混凝土的准确表征的需求变得越来越重要。在这里，渣基CEM II混凝土的基本蠕变行为可以追溯到混合物不变的水合物特性。因此，实验验证的CEM I/ opc混凝土的三步微粘弹性模型与CEM II的power - acker型水化模型相补充，并扩展到长期蠕变，温度活化和水分敏感性。该模型用于基于应变率的老化粘弹性分析，对两种不同的CEM II混凝土进行蠕变试验；CEMⅱ水合物的剪切蠕变模量是普通硅酸盐水泥水合物的一半。这使得渣基CEM II混凝土特别适用于预制分段隧道衬砌等应用，在位移控制条件下，更快的应力松弛是有益的。

{"title":"Basic creep properties of hydrates in mature slag-based CEM II concretes: A micromechanical analysis","authors":"Maximilian Sorgner , Rodrigo Díaz Flores , Bernhard Pichler , Thomas Pilgerstorfer , Bernd Moritz , Christian Hellmich","doi":"10.1016/j.cemconres.2024.107735","DOIUrl":"10.1016/j.cemconres.2024.107735","url":null,"abstract":"<div><div>The demand for accurate characterization of slag-based CEM II concretes is becoming increasingly important as the construction sector shifts towards eco-efficient materials. Here, the basic creep behavior of slag-based CEM II concretes is traced back to mixture-invariant hydrate properties. Therefore, an experimentally validated three-step micro-viscoelastic model for CEM I/OPC-concretes is complemented by a Powers-Acker-type hydration model for CEM II and extended towards long-term creep, temperature activation, and moisture sensitivity. This model is used for a strain rate-based, aging viscoelastic analysis of two creep tests on distinctively different CEM II concretes; revealing that the shear creep modulus of CEM II hydrates is half as large as the one of ordinary Portland cement hydrates. This makes slag-based CEM II concretes especially suitable for applications such as precast segmental tunnel linings, where a faster stress relaxation under displacement-controlled conditions is beneficial.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"189 ","pages":"Article 107735"},"PeriodicalIF":10.9,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142776560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Pyroaurite-like phases (Mg-Fe3+ LDH) synthesis and solubility 类辉钼矿相（Mg-Fe3+ LDH）的合成及溶解度

IF 10.9 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement and Concrete Research

Pub Date : 2024-12-05 DOI: 10.1016/j.cemconres.2024.107739

Ellina Bernard , Barbara Lothenbach , Rupert J. Myers , Marcus H.N. Yio

This study explores different methods for precipitating carbonated Mg-Fe³⁺ layered double hydroxides (LDHs) with Mg/Fe³⁺ ratios ranging from 2 to 2.5. Two synthesis approaches were investigated: a) CO₃-Mg-Fe³⁺-LDH co-precipitated directly from MgO, Fe(NO₃)₃ and Na₂CO₃ and b) NO₃-Mg-Fe³⁺-LDH precipitated by adding NaOH to Mg(NO₃)₂-Fe(NO₃)₃ solutions, followed by ion exchange with Na₂CO₃ to form CO₃-Mg-Fe³⁺-LDH. The solids were characterised using TGA, XRD and FTIR. For the co-precipitated samples in the presence of Na₂CO₃, the formation of carbonate-LDH was accompanied by ~10–30 wt% of hydromagnesite, while CO₃-Mg-Fe³⁺-LDH modified from the NO₃-Mg-Fe³⁺-LDH did not show any other Mg‑carbonates but contained Fe hydroxides, as evidenced by their brown coloration. All samples were re-equilibrated at 7, 20 and 50 °C. The solubility product (log Kso) was calculated from solution analysis, and preliminary thermodynamic data are presented. The findings provide insights into the stability and formation conditions of carbonated Mg-Fe³⁺ LDH phases in carbonate-rich environments.

本研究探索了沉淀Mg/Fe3+比为2 ~ 2.5的Mg-Fe3+层状双氢氧化物（LDHs）的不同方法。研究了两种合成方法：a)由MgO、Fe(NO3)3和Na2CO3直接共沉淀法合成CO3-Mg-Fe3+-LDH； b)在Mg(NO3)2-Fe(NO3)3溶液中加入NaOH，与Na2CO3离子交换生成CO3-Mg-Fe3+-LDH。采用TGA、XRD和FTIR对固体进行了表征。对于Na2CO3存在下的共沉淀样品，碳酸盐-LDH的形成伴随着~ 10-30 wt%的氢菱镁矿，而由NO3-Mg-Fe3+-LDH修饰的CO3-Mg-Fe3+-LDH不显示任何其他碳酸盐，但含有铁氢氧化物，其颜色为棕色。所有样品在7、20和50°C下重新平衡。通过溶液分析计算了溶解度积（log Kso），并给出了初步的热力学数据。这一发现为富碳酸盐环境中碳化Mg-Fe3+ LDH相的稳定性和形成条件提供了新的见解。

{"title":"Pyroaurite-like phases (Mg-Fe3+ LDH) synthesis and solubility","authors":"Ellina Bernard , Barbara Lothenbach , Rupert J. Myers , Marcus H.N. Yio","doi":"10.1016/j.cemconres.2024.107739","DOIUrl":"10.1016/j.cemconres.2024.107739","url":null,"abstract":"<div><div>This study explores different methods for precipitating carbonated Mg-Fe<sup>3+</sup> layered double hydroxides (LDHs) with Mg/Fe<sup>3+</sup> ratios ranging from 2 to 2.5. Two synthesis approaches were investigated: a) CO<sub>3</sub>-Mg-Fe<sup>3+</sup>-LDH co-precipitated directly from MgO, Fe(NO<sub>3</sub>)<sub>3</sub> and Na<sub>2</sub>CO<sub>3</sub> and b) NO<sub>3</sub>-Mg-Fe<sup>3+</sup>-LDH precipitated by adding NaOH to Mg(NO<sub>3</sub>)<sub>2</sub>-Fe(NO<sub>3</sub>)<sub>3</sub> solutions, followed by ion exchange with Na<sub>2</sub>CO<sub>3</sub> to form CO<sub>3</sub>-Mg-Fe<sup>3+</sup>-LDH. The solids were characterised using TGA, XRD and FTIR. For the co-precipitated samples in the presence of Na<sub>2</sub>CO<sub>3</sub>, the formation of carbonate-LDH was accompanied by ~10–30 wt% of hydromagnesite, while CO<sub>3</sub>-Mg-Fe<sup>3+</sup>-LDH modified from the NO<sub>3</sub>-Mg-Fe<sup>3+</sup>-LDH did not show any other Mg‑carbonates but contained Fe hydroxides, as evidenced by their brown coloration. All samples were re-equilibrated at 7, 20 and 50 °C. The solubility product (log Kso) was calculated from solution analysis, and preliminary thermodynamic data are presented. The findings provide insights into the stability and formation conditions of carbonated Mg-Fe<sup>3+</sup> LDH phases in carbonate-rich environments.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"189 ","pages":"Article 107739"},"PeriodicalIF":10.9,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142776419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Estimation of cement content in concrete by spatially resolved laser induced breakdown spectroscopy 空间分辨激光诱导击穿光谱法估算混凝土中水泥含量

IF 10.9 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement and Concrete Research

Pub Date : 2024-12-05 DOI: 10.1016/j.cemconres.2024.107714

Tobias Völker , Friedrich M. Mensing , Sabine Kruschwitz

The cement content in concrete significantly influences critical properties such as durability, permeability, strength, and workability. Traditional methods for estimating the cement content face limitations. These include the need for comprehensive chemical and solubility knowledge, extensive sample preparation, and their time-consuming and destructive nature. This study investigates the application of laser-induced breakdown spectroscopy (LIBS) as an alternative method. It involves probing concrete samples with high spatial resolution and analyzing the resultant spectra. The methodology is first tested on mesoscale concrete models to assess limitations and inherent errors. Subsequently, the methodology is applied to actual concrete samples with varying cement content and aggregate size distributions. The results demonstrate a promising accuracy, with an average relative error of approximately 8%. This paper offers a comprehensive evaluation of the method’s advantages, limitations, and factors influencing its practical applicability in field conditions.

水泥在混凝土中的含量显著影响关键性能，如耐久性、渗透性、强度和和易性。传统的水泥掺量估算方法存在局限性。这些包括需要全面的化学和溶解度知识，广泛的样品制备，以及它们的耗时和破坏性。本研究探讨了激光诱导击穿光谱（LIBS）作为替代方法的应用。它涉及以高空间分辨率探测混凝土样品并分析所得光谱。该方法首先在中尺度具体模型上进行测试，以评估局限性和固有误差。随后，将该方法应用于具有不同水泥含量和骨料尺寸分布的实际混凝土样品。结果表明，该方法具有较高的精度，平均相对误差约为8%。本文综合评价了该方法的优点、局限性以及影响其在野外实际应用的因素。

{"title":"Estimation of cement content in concrete by spatially resolved laser induced breakdown spectroscopy","authors":"Tobias Völker , Friedrich M. Mensing , Sabine Kruschwitz","doi":"10.1016/j.cemconres.2024.107714","DOIUrl":"10.1016/j.cemconres.2024.107714","url":null,"abstract":"<div><div>The cement content in concrete significantly influences critical properties such as durability, permeability, strength, and workability. Traditional methods for estimating the cement content face limitations. These include the need for comprehensive chemical and solubility knowledge, extensive sample preparation, and their time-consuming and destructive nature. This study investigates the application of laser-induced breakdown spectroscopy (LIBS) as an alternative method. It involves probing concrete samples with high spatial resolution and analyzing the resultant spectra. The methodology is first tested on mesoscale concrete models to assess limitations and inherent errors. Subsequently, the methodology is applied to actual concrete samples with varying cement content and aggregate size distributions. The results demonstrate a promising accuracy, with an average relative error of approximately 8%. This paper offers a comprehensive evaluation of the method’s advantages, limitations, and factors influencing its practical applicability in field conditions.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"189 ","pages":"Article 107714"},"PeriodicalIF":10.9,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142776422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Comparative evaluation of laboratory methods for performance assessment of cementitious materials in wastewater networks: Biological and chemical tests versus field exposure 污水管网中胶凝材料性能评估的实验室方法的比较评价：生物和化学试验与现场暴露

IF 10.9 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement and Concrete Research

Pub Date : 2024-11-30 DOI: 10.1016/j.cemconres.2024.107741

Alexandra Bertron , Cyrill Grengg , Matthieu Peyre Lavigne , Holger Wack , Gregor J.G. Gluth , Amr Aboulela , Vanessa Sonois , Tilman Gehrke , Florian Mittermayr

The biodeterioration of concrete elements in sewer systems and their repair is of significant economic and societal concern. However, the available test methods to assess the performance of cementitious materials under the relevant conditions are insufficiently validated. In the present study, two biological test methods and a standardised chemical test were applied to two sewer repair mortars and a reference mortar, and the performances of these materials were compared in a severely deteriorating sewer environment. In both biological tests, the induction period was considerably shorter than that of the field, and time-resolved recording of durability indicators enabled to determine deterioration rates in the steady-state regime, which compared reasonably well with each other and with the behaviour in the sewer environment. The chemical test does not allow to obtain a deterioration rate, and the observed relative performance differences of the mortars deviated from the results of the biological tests.

下水道系统中混凝土元素的生物降解及其修复是一个重大的经济和社会问题。然而，在相关条件下评估胶凝材料性能的现有测试方法尚未得到充分验证。本研究采用两种生物测试方法和标准化化学测试方法对两种下水道修复砂浆和一种参考砂浆进行测试，并在严重恶化的下水道环境中对这些材料的性能进行了比较。在这两项生物试验中，诱导期都比田间试验短得多，耐久性指标的时间分辨记录能够确定稳定状态下的劣化率，这两项指标相互比较并与下水道环境中的行为相比较都相当好。化学试验不能得到劣化率，而且所观察到的砂浆的相对性能差异与生物试验的结果有偏差。

{"title":"Comparative evaluation of laboratory methods for performance assessment of cementitious materials in wastewater networks: Biological and chemical tests versus field exposure","authors":"Alexandra Bertron , Cyrill Grengg , Matthieu Peyre Lavigne , Holger Wack , Gregor J.G. Gluth , Amr Aboulela , Vanessa Sonois , Tilman Gehrke , Florian Mittermayr","doi":"10.1016/j.cemconres.2024.107741","DOIUrl":"10.1016/j.cemconres.2024.107741","url":null,"abstract":"<div><div>The biodeterioration of concrete elements in sewer systems and their repair is of significant economic and societal concern. However, the available test methods to assess the performance of cementitious materials under the relevant conditions are insufficiently validated. In the present study, two biological test methods and a standardised chemical test were applied to two sewer repair mortars and a reference mortar, and the performances of these materials were compared in a severely deteriorating sewer environment. In both biological tests, the induction period was considerably shorter than that of the field, and time-resolved recording of durability indicators enabled to determine deterioration rates in the steady-state regime, which compared reasonably well with each other and with the behaviour in the sewer environment. The chemical test does not allow to obtain a deterioration rate, and the observed relative performance differences of the mortars deviated from the results of the biological tests.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"188 ","pages":"Article 107741"},"PeriodicalIF":10.9,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142753009","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}

引用次数: 0

Effect of flow rate on spatio-temporal deterioration of concrete under flowing sulfate attack 流速对流动硫酸盐侵蚀下混凝土时空劣化的影响

IF 10.9 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement and Concrete Research

Pub Date : 2024-11-28 DOI: 10.1016/j.cemconres.2024.107734

Fujian Yang , Zhihao Zhao , Yuan Liu , Man Li , Jinliang Song , Dawei Hu , Hui Zhou

Flowing effect on concrete deterioration caused by sulfate attack at varying flow rates was studied. It was found that an increased flow rate can expedite the weakening of the concrete's elastic modulus in the short term, thus causing an earlier onset of this weakening. However, the long-term deterioration of the elastic modulus remains unaffected by the flow rate due to the limited amount of products responsible for concrete deterioration. Notably, the deterioration depth or rate of the elastic modulus increases with higher flow rates due to the scouring effect of sulfate flow. To quantify this acceleration effect, an acceleration coefficient was defined, representing the impact of flow rate on the weakening process of concrete. It is approximately 1.20 for every 0.5 m/s increase in flow rate within the tested range. This coefficient provides a useful metric to assess the durability of concrete to sulfate attack under varying flow conditions.

研究了不同流速下硫酸盐侵蚀对混凝土劣化的影响。研究发现，流速的增加会在短期内加速混凝土弹性模量的减弱，从而使这种减弱提前开始。然而，由于造成混凝土劣化的产物数量有限，弹性模量的长期劣化不受流速的影响。值得注意的是，由于硫酸盐流的冲刷效应，弹性模量的劣化深度或速度会随着流速的增加而增加。为了量化这种加速效应，我们定义了一个加速系数，表示流速对混凝土弱化过程的影响。在测试范围内，流速每增加 0.5 米/秒，加速系数约为 1.20。该系数为评估混凝土在不同流量条件下受硫酸盐侵蚀的耐久性提供了一个有用的指标。

引用次数: 0

Penetration test of sheet-like indenter for yield stress assessment of 3D-printed concrete 用于评估 3D 打印混凝土屈服应力的片状压头渗透试验

IF 10.9 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement and Concrete Research

Pub Date : 2024-11-26 DOI: 10.1016/j.cemconres.2024.107728

Haoyu Lu, Lizhi Zhang, Junkai Wang, Zhaoxin Shi, Wei She, Wenqiang Zuo

The evolution of early mechanical properties of 3D-printed concrete (3DPC) plays a crucial role in early constructability, while current methods face challenges on the tradeoff between the accuracy and feasibility of mechanical properties characterization. In this paper, we designed a sheet-like indenter configuration to quantitatively obtain the yield stress of fresh 3DPC. First, we show the typical force-depth curve of sheet-like indenters obtained during the penetration test and analyze the main factors affecting the penetration resistance at various regimes. Then, we derive the quantitative correlation between the yield stress and the force-depth curve based on numerical simulation. Our results show that the slipping phenomenon between the indenter side and the material leads to an underestimation of the yield stress compared to the standard compression test and cone-shaped indenter. We moreover propose a sheet-like indenter with surface roughness modification to obtain the accurate yield stress value, together with a formula for the yield stress calculation based on the force-depth curve. Finally, we assess the feasibility of the proposed approach, which can robustly predict fresh 3DPC with yield stresses in the range of 1–100 kPa.

三维打印混凝土（3DPC）早期力学性能的变化对早期施工性能起着至关重要的作用，而目前的方法在力学性能表征的准确性和可行性之间面临着权衡的挑战。在本文中，我们设计了一种片状压头配置来定量获得新拌 3DPC 的屈服应力。首先，我们展示了片状压头在穿透测试过程中获得的典型力-深度曲线，并分析了在不同状态下影响穿透阻力的主要因素。然后，我们基于数值模拟推导出屈服应力与力-深度曲线之间的定量相关性。结果表明，与标准压缩试验和锥形压头相比，压头侧面与材料之间的滑动现象导致屈服应力被低估。此外，我们还提出了一种表面粗糙度改良的片状压头，以获得准确的屈服应力值，并提出了基于力-深度曲线的屈服应力计算公式。最后，我们评估了所提方法的可行性，该方法可以稳健地预测屈服应力在 1-100 kPa 范围内的新鲜 3DPC。

{"title":"Penetration test of sheet-like indenter for yield stress assessment of 3D-printed concrete","authors":"Haoyu Lu, Lizhi Zhang, Junkai Wang, Zhaoxin Shi, Wei She, Wenqiang Zuo","doi":"10.1016/j.cemconres.2024.107728","DOIUrl":"10.1016/j.cemconres.2024.107728","url":null,"abstract":"<div><div>The evolution of early mechanical properties of 3D-printed concrete (3DPC) plays a crucial role in early constructability, while current methods face challenges on the tradeoff between the accuracy and feasibility of mechanical properties characterization. In this paper, we designed a sheet-like indenter configuration to quantitatively obtain the yield stress of fresh 3DPC. First, we show the typical force-depth curve of sheet-like indenters obtained during the penetration test and analyze the main factors affecting the penetration resistance at various regimes. Then, we derive the quantitative correlation between the yield stress and the force-depth curve based on numerical simulation. Our results show that the slipping phenomenon between the indenter side and the material leads to an underestimation of the yield stress compared to the standard compression test and cone-shaped indenter. We moreover propose a sheet-like indenter with surface roughness modification to obtain the accurate yield stress value, together with a formula for the yield stress calculation based on the force-depth curve. Finally, we assess the feasibility of the proposed approach, which can robustly predict fresh 3DPC with yield stresses in the range of 1–100 kPa.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"188 ","pages":"Article 107728"},"PeriodicalIF":10.9,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142706203","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}

引用次数: 0

首页上一页

下一页尾页

类型

全部化学•材料生命科学医学物理工程技术环境•农林材料科学地球科学法学管理学化学环境科学与生态学计算机科学教育学经济学农林科学人文科学生物学数学物理与天体物理心理学综合性期刊其他工业工程理学历史学农学文学信息工程

数据库

全部 ACS Publications Elsevier ieeexplore Springer The Royal Society of Chemistry Wiley

期刊

Cement and Concrete Research

全部 Acc. Chem. Res. ACS Applied Bio Materials ACS Appl. Electron. Mater. ACS Appl. Energy Mater. ACS Appl. Mater. Interfaces ACS Appl. Nano Mater. ACS Appl. Polym. Mater. ACS BIOMATER-SCI ENG ACS Catal. ACS Cent. Sci. ACS Chem. Biol. ACS Chemical Health & Safety ACS Chem. Neurosci. ACS Comb. Sci. ACS Earth Space Chem. ACS Energy Lett. ACS Infect. Dis. ACS Macro Lett. ACS Mater. Lett. ACS Med. Chem. Lett. ACS Nano ACS Omega ACS Photonics ACS Sens. ACS Sustainable Chem. Eng. ACS Synth. Biol. Anal. Chem. BIOCHEMISTRY-US Bioconjugate Chem. BIOMACROMOLECULES Chem. Res. Toxicol. Chem. Rev. Chem. Mater. CRYST GROWTH DES ENERG FUEL Environ. Sci. Technol. Environ. Sci. Technol. Lett. Eur. J. Inorg. Chem. IND ENG CHEM RES Inorg. Chem. J. Agric. Food. Chem. J. Chem. Eng. Data J. Chem. Educ. J. Chem. Inf. Model. J. Chem. Theory Comput. J. Med. Chem. J. Nat. Prod. J PROTEOME RES J. Am. Chem. Soc. LANGMUIR MACROMOLECULES Mol. Pharmaceutics Nano Lett. Org. Lett. ORG PROCESS RES DEV ORGANOMETALLICS J. Org. Chem. J. Phys. Chem. J. Phys. Chem. A J. Phys. Chem. B J. Phys. Chem. C J. Phys. Chem. Lett. Analyst Anal. Methods Biomater. Sci. Catal. Sci. Technol. Chem. Commun. Chem. Soc. Rev. CHEM EDUC RES PRACT CRYSTENGCOMM Dalton Trans. Energy Environ. Sci. ENVIRON SCI-NANO ENVIRON SCI-PROC IMP ENVIRON SCI-WAT RES Faraday Discuss. Food Funct. Green Chem. Inorg. Chem. Front. Integr. Biol. J. Anal. At. Spectrom. J. Mater. Chem. A J. Mater. Chem. B J. Mater. Chem. C Lab Chip Mater. Chem. Front. Mater. Horiz. MEDCHEMCOMM Metallomics Mol. Biosyst. Mol. Syst. Des. Eng. Nanoscale Nanoscale Horiz. Nat. Prod. Rep. New J. Chem. Org. Biomol. Chem. Org. Chem. Front. PHOTOCH PHOTOBIO SCI PCCP Polym. Chem.

﹀