CONSTRUCTION AND BUILDING MATERIALS
·
2024
·
IF 7.4
Xuan Hou,Shuhua Ma,Xiaohui Wang,Yanjun Ou,Ruiping Liu
Industrial waste fly ash was transformed into a fluffy C-S-H (hydrated calcium silicate) material with thermal activation process . The textural property of the material makes it easily integrated and well dispersed in cement using 2% addition. Characterization techniques such as hydration heat, XRD , thermogravimetric analysis , were carried out to elucidate the effect of this C-S-H on cement hydration : the compressive strength of cement mortar was improved beyond 25%; and the viscosity of cement paste was reduced by 22%; the volume of solidified cement expand by 10%. This advances the overall utilization of cement and improve the properties as well.
研究领域:
材料科学
·
水泥化学
✓ 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
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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
·
2022
·
IF 7.693
Chunyu Wang,Wenrui Xiang,Jiapei Du,Xiao Yao
A cement paste with low hydration heat flow is in high demand in hydrate layers cementing at low temperature to inhibit the hydrate decomposition. This paper prepared a heat flow inhibitor (HFI), which was compounded of disodium hydrogen phosphate dodecahydrate (DHPD), sodium silicate (SS) and nano calcium carbonate (NCC). DHPD was employed to reduce the heat flow of cement pastes. Porous ceramic particles were applied to carry DHPD to achieve slow-release. SS and NCC were employed to encapsulate and disperse the particles. The components were released in multi-stage into the cement paste to avoid their being blended into the cement paste at the same time. Setting time, thickening time , compressive strength , isothermal calorimetry , X-ray diffraction, mercury intrusion porosimetry and scanning electron microscopy were used to investigate the effects of HFI on cement hydration . The results showed that HFI reduced the hydration heat flow of cement pastes effectively, while displaying no negative impact on the compressive strength, setting time and thickening time. The maximum temperature of the cement paste dropped by 14.0 °C, and the maximum hydration heat flow was reduced by 28.75% at 8% HFI dosage . HFI is promising to be used in hydrate layers cementing.
研究领域:
材料科学
·
石油工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Shuai Li,Yaowu Wei,Bingrong Li,Xiujuan Wang,Junfeng Chen
The phase composition, microstructure, and hydration process of C 3 A with different MgO content were compared to elucidate the mechanism of hydration resistance of CaO improved by MgO–C 3 A solid solution . The process of hydration heat release was detected by isothermal calorimetry and the hydration products were analyzed by X-ray diffraction and scanning electron microscope. The results showed that the addition of MgO resulted in lattice distortion of C 3 A. In the middle and late stages of the hydration process, Mg(OH) 2 and amorphous gel-like substances covered the surface of the unreacted C 3 A and reduced the hydration reaction rate. The addition of MgO effectively reduced the hydration activity of the MgO–C 3 A solid solution that indicated the addition of MgO can improve the hydration resistance of CaO materials.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2021
·
IF 6.141
Jingxuan Cai,Chunmei Zhang,Li Zeng,Hao Xu,Jia Wang,Kaiqiang Liu,Xiaowei Cheng
Encountering natural gas hydrate (NGH) is inevitable in the process of drilling and the production of oil and gas wells in deep-sea and shallow formations. The heat released by the cement slurry during the hydration process will cause the decomposition of gas hydrates, which will lead to annular channelling. Our purpose is to improve the cementing quality and ensure the safety of oil and gas production. In this paper, temperature control phase change microcapsules (PCMCs) with dodecanol (DA)/n-decanoic acid (CA) composite phase change materials (PCMs) as the core and active silica as the shell were prepared by a chemical precipitation method to store and release heat reversibly, to reduce the hydration heat of cement and improve the early strength. Fourier infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy spectrometry (EDS) were used to test and analyse the chemical structure and microscopic morphology of the synthesized temperature-controlled phase change microcapsules. Differential scanning calorimetry (DSC) was used to determine the phase change characteristics of the phase change microcapsules. The thermal stability of the phase change microcapsules was measured by a thermogravimetric analyser (TG). The application of PCMCs in a low-temperature cement slurry was also investigated. The results showed that the synthesized microcapsules had good thermal stability with a phase transformation temperature of 12.4 ℃ and enthalpy of 1.65 J/g. PCMCs can effectively control the hydration heat of cement and reduce the rise of hydration temperature by 6.06% to 11.79%. In addition, PCMCs can slowly release heat to promote the hydration of cement in the later strength development, and improve the early compressive strength of cement in the range of 5 ℃ to 10 ℃.
研究领域:
材料科学
·
石油工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2018
·Vol. 135
·期 32
·46550
·
IF 1.901
Hongwei Zhao,Bing Liao,Fuwei Nian,Yangyang Zhao,Kun Wang,Hao Pang
In this work, a polyamidoamine dendrimer-based polycarboxylic superplasticizer (DPC) with a crosslinked emanative structure was synthesized via simple free radical polymerization. 1 H-nuclear magnetic resonance and Fourier transform infrared spectroscopy measurements were used for structural characterization. The fluidity, rheology behavior, and compressive strength of the cement/DPC samples were investigated in detail. The DPCs performed better dispersion and dispersion maintaining capabilities, stronger water reduction capability, and higher adsorption amounts than the conventional comb-shaped superplasticizer. The dispersive capacity of the DPC increased with an increasing generation of polyamidoamine dendrimers. Besides, compared with conventional comb-shaped superplasticizer, the addition of DPC led to a delayed and lowered heat flow peak on the hydration of cement paste at early age of hydration process. Furthermore, compressive strength results showed that the cement/DPC samples performed higher compressive strength than blank cement samples. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135 , 46550.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Building Engineering
·
2021
·
IF 5.318
Ting Zhang,Baoguo Ma,Hongbo Tan,Huahui Qi,Tao Shi
Both sodium carbonate (NC) and sodium phosphate (NP) could immediately precipitate in the presence of calcium ions (Ca 2+ ), and these precipitates would deposit on the surface of cement as one layer in cement paste . However, these precipitates have different effects on the hydration of cement. In this study, effect of NC and NP on cement hydration was discussed, and the different effect between these two was investigated. Setting time, hydration heat, conductivity of cement suspension , and compressive strength of cement paste were examined, and the hydrates were analyzed with XRD and TG-DTG. The precipitates synthesized in saturated calcium hydroxide solution were characterized with XRD, TEM, and SEM. Then one model was proposed to illustrate the mechanism of the effect of NC and NP on cement hydration. The results indicated that NC accelerated cement hydration, but NP retarded it. And the results of TEM and SEM showed that calcium carbonate (the precipitate formed by NC and Ca 2+ )) could well crystalize with directional growth, there is a large amount of interspace in the calcium carbonate-based layer, which would benefit the transports of water molecules and dissolved ions. However, the calcium phosphate precipitate (the precipitate formed by NP and Ca 2+ )) seemed to have a large amount of amorphous structure with a much more compact layer structure than calcium carbonate. The difference in composition and structure of the layer was responsible for the effect of NC and NP on cement hydration. The mechanism behind accelerating effect of NC was due to the interspace in the calcium carbonate based layer which facilitated the ion dissolution of system, while that for retarding effect of NP was because the calcium phosphate-based layer formed on the surface of cement grains seemed compact enough to restrict the transports of water molecules and dissolved ions. Such consequences were expected to give deeper insight into the effect of the surficial structure of cement grains on early hydration of cement paste.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Energies
·
2022
·Vol. 15
·期 12
·4197
·
IF 3.252
Guokun Yang,Tianle Liu,Hai Zhu,Zihan Zhang,Yingtao Feng,Ekaterina Leusheva,Valentin Morenov
This study aims to develop a novel low-heat cement slurry using phase change microcapsule additives to reduce the decomposition of hydrate-bearing sediments during cementing. Microcapsules were prepared by coating mixed alkanes with polymethyl methacrylate, and lipophilic-modified graphite was incorporated to enhance the thermal conductivity of microcapsules. The effects of microcapsules upon the hydration heat, pore distribution, and compressive strength of the cement slurry/stone were studied through a variety of tests. The results showed that the phase-change temperature, thermal enthalpy, and encapsulation efficiency of the microcapsules were 8.99–16.74 °C, 153.58 Jg−1, and 47.2%, respectively. The introduction of lipophilic-modified graphite reduced the initial phase-change temperature of microcapsules by 0.49 °C, indicating an improvement in their temperature sensitivity. The maximum hydration heat of cement slurry decreased by 41.3% with 7% dosage of microcapsules; the proposed microcapsules outperformed comparable low-heat additives. Moreover, the presence of microcapsules could reduce the number of large pores in (and thereby improve the compressive strength of) cement stone. The innovation of this study is that it comprehensively and intuitively confirms the feasibility of the application of low-heat cement slurry with MPCM as the key in hydrate sediments rather than just focusing on the reduction of hydration heat; furthermore, a self-made cementing device was developed to simulate the cementing process of hydrate deposition. The results show that the thermal regulation of microcapsules inhibited the temperature increase rate of the cement slurry, significantly reducing the damage caused to the hydrate. These findings should improve the safety and quality of cement in offshore oil and gas well applications.Keywords:microencapsulated phase-change materials;heat control;temperature sensitivity;cementing;hydration heat;natural gas hydrate-bearing sediment
研究领域:
土木工程
·
材料科学
·
海洋工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Building Engineering
·
2025
·
IF 7.4
Dandan Yan,Min Li,Chunxiang Qian
The cement containing heavy metals for collaborative disposal (HMC) as a low-environmental-load cementitious material still encounters challenges related to temperature-induced cracking due to high hydration heat. In this paper, a paraffin (PA)/metal-organic framework (MOF) composite phase change material (CPCM) with excellent shape stability, thermal storage capacity, and thermal stability was creatively integrated into HMC, aiming to investigate the impacts of CPCM on the hydration heat release behavior. The compressive strength and hydration product evolution of HMC paste mixed with CPCM were also discussed. The experimental results demonstrated that CPCM notably reduced the initial hydration rate (especially the main exothermic peaks) and total hydration heat of HMC, regardless of the hydration temperature. Furthermore, the impact of CPCM on the hydration heat of HMC was found to be positively correlated with the dosage. Additionally, the compressive strength of composite paste decreased and chromium (Cr) leaching content increased due to the addition of CPCM, which can be attributed to the expansion of paste pores. But, the additional inclusion of minute quantities of ZIF-8 significantly ameliorated these negative effects. Moreover, CPCM, ZIF-8, and hydration temperatures did not change the type of hydration products in HMC, but they did affect the amount and microstructure of hydration products. CPCM indeed effectively reduced the hydration heat of HMC, this study offers new insights into the use of phase change materials to mitigate the thermal cracking issue in cementitious materials.
研究领域:
建筑材料学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Building Engineering
·
2024
·
IF 6.7
Yanchen Oinam,Mandip Dahal,Minwuye Mesfin,Solmoi Park,Hyeong-Ki Kim,Sukhoon Pyo
The study aimed to achieve high strength in slag-based cementless ultra-high performance concrete (UHPC) while investigating the role of calcium formate and calcium chloride as accelerators using advanced characterization and microstructural analysis . The UHPC specimens were evaluated using various techniques, including heat of hydration, thermogravimetric analysis , X-ray diffraction, nuclear magnetic resonance, scanning electron microscopy, and porosity measurements . The results showed that both accelerators improved the UHPC properties, with calcium formate being more effective than calcium chloride, as evidenced by higher heat of hydration, improved microstructure, and lower porosity. Furthermore, the thermodynamic modeling revealed insightful information on the reaction mechanisms with C-(N-)A-S-H and hydrotalcite as the primary hydration products formed in the matrix. Notably, the UHPC specimens with calcium chloride exhibited a very low pH value, which could increase the risk of corrosion in reinforced structures. Therefore, the use of calcium formate as an accelerator can lead to the development of cementless UHPC with superior properties.
研究领域:
材料科学
·
土木工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
·
2020
·
IF 1.701
Jingfei Zhang,Bing Liao,Yeyun Meng,Simin Li,Xiuju Lin,Jianheng Huang,Hao Pang
The synthesis, characterization and properties of novel amphoteric polycarboxylate superplasticizers (PCs) are highlighted in this work. Specifically, two classes of amphoteric PCs were prepared through the addition of isobutenyl polyethylene glycol, acrylic acid and synthesized amphoteric monomer. The fluidity and fluidity retention of cement pastes containing these PCs and their adsorption behavior were investigated. In addition the cement hydration heat was measured, while X-ray diffraction and thermogravimetric behavior were also characterized. Consequently, the results indicated that these amphoteric PCs exhibited good dispersion performance and enhanced adsorption onto the cement. Furthermore, the results revealed that the PCs exerted a retardation effect during the early stages of cement hydration and subsequently accelerated this process, without affecting the subsequent cement hydration. These findings highlight the potential applications of these amphoteric PCs in concrete engineering.
研究领域:
建筑材料
·
材料化学
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2020
·
IF 3.99
Xiuju Lin,Hao Pang,Daidong Wei,Mangeng Lu,Bing Liao
At present, several researchers mainly focus on the synthesis of new micro-cross-linking structure, or explore the effect of cross-linkers with different molecular weight and similar structure on the performance of cross-linked polycarboxylate superplasticizers . In order to explore the influence of the different molecular structure of the cross-linker on the performance of polycarboxylate superplasticizers , two kinds of cross-linked polycarboxylate superplasticizers were synthesized in this study. These two superplasticizers incorporated either a linear cross-linker triethylene glycol diethyl ether or a cyclic cross-linker 3,9-divinyl-2,4,8,10-tetroxyspiro[5,5] undecane as one of the monomers . Then the polymers were respectively coded as SPT and SPD. Furthermore, the dispersion performance of the cross-linked polymers was evaluated by cement slurry fluidity tests and scanning electron microscopy (SEM) characterization. Consequently, cementitious mixtures incorporating SPT had better dispersibility than those incorporating conventional comb-type polycarboxylate superplasticizers (SPC) and SPD. In addition, the XRD , thermogravimetric analysis (TGA), hydration heat, and setting time tests confirmed that SPT exhibited a stronger retardation effect on cement hydration than that was provided by SPD. It was also found that SPT enhanced the compressive strength of concrete, compared to SPC and SPD. This study provides a reference for the development of cross-linked polycarboxylate superplasticizer.
研究领域:
材料科学
·
土木工程
✓ 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）