Materials Research Express
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2024
·Vol. 11
·期 8
·085310
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IF 1.8
Yunhai Shi,Kai Lu,Zejian He,Yulong Chen,Mi Zhou
Water reducing agent as an important admixture. It is used to decrease the initial water content in cement paste, improving its fluidity. Polycarboxylic acid water reducing agent (PCE) is a high-performance type with advantages such as low dosage, high water reduction rate, environmental friendliness, and a simple synthesis process. In this study, the third monomer (TPEG-SAA-SHES) was synthesized by modifying isopentenol polyoxyethylene ether (TPEG) with sodium hydroxyethyl sulfonate (SHES). Subsequently, a modified ether polycarboxylic acid-based water reducing agent (PCE-S) was synthesized with TPEG and acrylic acid (AA). The experimental conditions for the synthesis of PCE-S were optimized through orthogonal tests. The synthesized PCE-S showed a certain degree of improvement in the initial net slurry flow compared to PCE, with a maximum enhancement of 19.64%. The adsorption increased by 18.25% when the TSS dosage was 5%. PCE-S enhances the hydration products of cement, increasing the compactness of the structure. The product is environmentally friendly, safe, and durable, effectively reducing the dosage of additives and helping to cut costs. It lays the foundation for the next industrialized mass production.
研究领域:
建筑材料化学
·
高分子材料合成
✓ 已验证
产品关联
DOI
高影响因子
CEMENT AND CONCRETE RESEARCH
·
2025
·
IF 13.1
Hui Xie,Xin Liu,Haochuan Wang,Zhenqi Yu,Lijing Shao,Wei Wang,Jinxiang Hong,Chong Wang,Pan Feng
The use of aluminum sulfate (Al 2 (SO 4 ) 3 )-based alkali-free accelerators in shotcrete often impeded tricalcium silicate (C 3 S) hydration, leading to poor ultra-early strength development. To address this, a novel stage-wise kinetic control strategy was proposed to regulate the sequential formation of ettringite and C-S-H gel through the delayed addition of C-S-H nano seeds. The dosage of C-S-H nano seeds, delayed time, addition sequence of Al 2 (SO 4 ) 3 and C-S-H nano seeds were carefully examined in this study, and the effects of addition sequence on the hydration kinetic, hydration products, and pore structure of cement pastes were systematically investigated. Results demonstrated a significant enhancement in 6 h compressive strength, achieving a 35% increase when C-S-H nano seeds (4% dosage) were added 1 h after initial mixing compared to simultaneous addition. Hydration heat, XRD, TG, SEM, and BSE-EDS analyses revealed that the delayed addition promoted C 3 S hydration at later stages by staggering intensive ettringite formation and C-S-H gel precipitation, mitigating competition for calcium ions. This stage-wise approach facilitated C-S-H gel integration into the pre-constructed porous ettringite skeleton, refining the pore structure and enhancing ultra-early mechanical performance. These findings highlight an effective strategy to optimize hydration kinetics and strength development in shotcrete applications.
研究领域:
土木工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2026
·
IF 8
Tingmin Zhu,Xiaoyang Chen,Yan Guan,Tian Zeng,Jun Chang,Zhiqi Hu,Kai Cui
Magnesium oxysulfate (MOS) cement is a cementitious material formed through the hydration reaction of light-burnt magnesia and magnesium sulfate solutions as the primary raw materials. During the construction process, harmful anions are easily introduced into MOS cement, affecting the formation of the main hydration product 517 phase. Therefore, to improve the adaptability of MOS cement to harmful anions and complex environmental changes, this study investigated the effects of adding magnesium salts containing various anions (Mg(OH) 2 , Mg(HCO 3 ) 2 , MgCl 2 ·6 H 2 O, Mg(NO 3 ) 2 ·6 H 2 O and MgHPO 4 ·3 H 2 O) on the properties of a hardened paste of magnesium oxysulfate (MOS) cement. Research has shown that the introduction of low levels of exogenous anions does not significantly disrupt the structure of the main hydration product 517 phase in MOS cement but rather promotes the formation of amorphous phases within the system. In the specific doping-modified MOS system, the grain size of the 517 phase changes, the stability of the material is enhanced, ion leaching is reduced, and the material has excellent compressive strength. X - (Cl - , HCO 3 - , NO 3 - , HPO 4 2- , OH - ) can partially replace SO 4 2- in the original structure of the 517 phase to form a phase similar to ‘X-517.’ The microstructure is reconstructed. In summary, the type and dosage of magnesium salt containing different anions have been demonstrated to have a significant effect on the hydration behavior, phase structure evolution and macroproperties of MOS cement systems.
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产品关联
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2020
·
IF 4.419
Huiting Liu,Jianzhou Jin,Yongjin Yu,Huimin Liu,Shuoqiong Liu,Jiyun Shen,Xiujian Xia,Hongfei Ji
Excellent physical and chemical properties of halloysite nanotube make it potential to reinforce cement composites. In this study, effects of halloysite nanotube on mechanical properties of oil well cement were investigated. The results showed that the compressive and flexural strength of cement with 3% halloysite nanotube was increased by 40.8% and 49.2%, respectively and the elasticity modulus decreased by 20.01% after curing for 28 days, which demonstrated that halloysite nanotube cement had high strength and good toughness. TG-DTA, SEM, XRD, MIP tests were carried out to study the hydration products and microstructure changes in cement samples after adding halloysite nanotube. Optimized hydration products, lower permeability up to 38.82%, cross-linking and denser microstructure all contributed to excellent mechanical properties of oil well cement with halloysite nanotube.
研究领域:
材料科学
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石油工程
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水泥化学
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纳米复合材料
✓ 已验证
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2024
·
IF 7.1
Xiangshan Hou,Jingwei Li,Jianwei Xu,Xin Xiao,Jianyong Wang,Yanhui Liu,Mona Ossman,Fawei Lin,Xujiang Wang,Yuzhong Li,Wenlong Wang
Rapid repair mortar (RRM) is widely used to repair infrastructures, which must achieve high early strength and long-term service. This study investigated the influence of hot/wet harsh environmental conditions on RRM prepared using solid-waste-based sulfoaluminate cement (WSAC). Orthogonal experiments were conducted to obtain the optimized WSAC-based RRM. Then, the impact of simulated harsh conditions (cross-combination of 20/60 °C and 10/40/90%RH humidity) on RRM and synthetic ettringite was studied. High temperature and low humidity restrained the volume deformation and promoted the growth of the later-age compressive strength of the RRM, but reduced the flexural strength. In this case, ettringite lost some water molecules in the Ca–H2O groups and transformed into amorphous meta-ettringite, which retained its needle-rod morphology. A small amount of ettringite decomposed into gypsum, AH3, and Ca(OH)2 under high-humidity conditions, which caused a slight expansion and reduced the compressive strength of the RRM. Fortunately, most ettringite was well protected by the dense RRM matrix, and harsh temperature and humidity conditions could only slowly promote the transformation of ettringite in RRM over a long period. Therefore, short-term rain or hot weather has little effect on the mechanical properties of WSAC-based RRM. This study provides a theoretical basis and data support for the promotion of industrialization of WSAC-based RRM, which is in line with the concept of green and sustainable development.
研究领域:
土木工程
·
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2025
·
IF 8
Dandan Yan,Min Li,Chunxiang Qian
Phase change materials are used in cementitious materials to reduce the hydration temperature rise and thus inhibit the temperature cracks generation. However, the influence mechanism of phase change materials on the hydration properties of cementitious materials is still unclear. In this study, ZIF-8-based composite phase change materials (CPCM) were added to the Portland cement (PC) clinker-anhydrite (C$)-calcium sulfoaluminate (CSA) cement ternary system (PCCSA) in the form of admixtures. The effects of controlling the phase change temperatures, dosages of CPCM and hydration temperatures on the hydration exothermic characteristics, hydration products and the compressive strength development in the PCCSA composite system were investigated. CPCM addition reduced the hydration exothermic rate and cumulative heat release of the ternary system, especially when the phase change temperature of CPCM was 25.8 ℃, and the larger the dosage, the more obvious the reduction effect. In addition, CPCM did not participate in the hydration reaction of the system, but promoted the formation of CH and AFm. Simultaneously, the compressive strength of the PCCSA system paste containing CPCM decreased due to increased porosity in the paste. Furthermore, elevated hydration temperature significantly improved the hydration rate of the system, while reduced the hydration degree, and the hydration products types of the system were not affected by the hydration temperatures. This study results are fundamental for predicting the hydration behavior of cement systems containing CPCM and promoting the application of composite phase change materials in cementitious materials.
研究领域:
建筑材料学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）