Materials Today Communications
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2025
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IF 4.5
Shixuan Zhang,Xuesong Lu,Jie Wang,Xiufeng Deng,Hongbo Tan
Excess-sulphate phosphogypsum slag cement (ESC) is a clinker-free binder with low carbon footprint, low embodied energy and good corrosion resistance, but slow strength development, known as one of the most serious issues, limits its application in practical engineering. In this regard, in-situ precipitation of ettringite by adding NaAlO 2 (NA) to act as nucleation seeds was proposed in this study. ESC consisting of 45% granulated blast-furnace slag (GBFS), 45% phosphogypsum, and 10% steel slag was designed, and 0.1~4% NA was added as chemical admixture to produce ettringite. Effects of NA on compressive strength, hydration process, microstructure and shrinkage were discussed. Results suggested that 0.1~4% NA significantly improved the compressive strength of ESC paste after 7 d, and 1% NA enhanced the strength by 87.6% at 28 d and 77.5% at 56 d. The reason was that NA could supply Al(OH) 4 - to react with the ions in pore solution of ESC to quickly precipitate ettringite seeds, thus inducing the hydration of ESC and formation of hydrates, and especially the formation of ettringite was greatly promoted. However, NA hardly affected early strength of ESC, since NA reduced liquid alkalinity during ettringite seeds formation, and this is not conducive to early precursor dissolution and hydrate formation.
研究领域:
材料科学
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环境工程
✓ 已验证
产品关联
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2024
·
IF 7.4
Penghao Xin,Hui Liu,Jianfeng Wang,Yali Wang,Hui Wang,Suping Cui
In this study, the impacts of CO 2 -absorbed triethanolamine solutions (TEA-CO 2 ) on the mechanical property, phase composition and micro-structure of cement mortars were investigated. The results showed that TEA-CO 2 addition increased the 1d, 3d, and 28d compressive strength by 47%, 19%, and 4%, respectively, which suggests a synergistic effect of triethanolamine and absorbed CO 2 on strength development of cement mortars. The enhancement is due to TEA-CO 2 accelerates hydration of aluminate and silicate phases in early age. TEA-CO 2 facilitated CaCO 3 formation to increase cement hydration degree and modify the pore structures . However, the hydration of silicate phases was delayed slightly by TEA-CO 2 at 28d. The above results provide theoretical support for further utilization of CO 2 in cementitious materials .
研究领域:
土木工程
·
材料科学
✓ 已验证
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2024
·
IF 7.4
Bin Zeng,Wenjin Han,Shaojie Jia,Liwu Mo
Grinding aids and hydration accelerators (GA-HAs) are important admixtures for reducing energy consumption and enhancing cement performance, however, widely used alkanolamine GA-HAs have the drawback of only enhancing early strength while contributing little to the later strength development. In this study, a new amide-alcohol bearing admixture named Diethanolamine-Citrate (DC) was synthesized by using diethanolamine (DEA) and citric acid (CA). The addition of DC improved the particle size distribution of cement, delayed the initial setting time and shortened the final setting time of cement, and enhanced the fluidity of cement. The 28d compressive strengths of cement mortar added with DC were 16.4 % and 11.4 % higher than that of control group and cement mortar added with TEA, respectively. The incorporation of DC promoted the dissolution of cement, accelerated the overall hydration process of cement, increased the production of C-S-H and AFm, reduced the pore size and porosity, produced smaller (Sub-micron grains and nano-grains), tightly accumulated and partially amorphous CH. Moreover, CA is cheap and readily available industrial product that can reduce the cost of GA-HAs as synthetic feedstock . This study represents a breakthrough in preparing organic cement GA-HAs and provides a new approach to developing a novel type of amide-alcohol cement admixtures .
研究领域:
建筑材料学
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材料化学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS LETTERS
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2022
·
IF 3.574
Feifei Zhou,Ganghua Pan,Haining Meng,Hailong Sun
For preparing finer and well-dispersed calcium-silicate-hydrate (C-S-H) seeds at a lower cost, the waste solution of acid treatment of recycled concrete aggregates (RCAs) and black liquor from pulping were used for the synthesis of C-S-H seeds. The results show that C-S-H seeds can be successfully fabricated by chemical co-precipitation reaction using the two waste solutions. Interestingly, it was globular rather than traditional foil-like. Furthermore, C-S-H seeds synthesized using the two waste solutions had smaller particle size and better dispersibility. More importantly, it had a more prominent accelerating effect to the strength development of mortar, significantly enhancing the early and long-term compressive strength of mortar.
研究领域:
材料科学
·
土木工程
·
环境科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）