为解决普通喷射混凝土凝结时间长、早期强度低和抗渗性能差等问题,通过外掺纳米水化硅酸钙(calcium-silicate-hydrate,C-S-H)凝胶的方式对其进行性能提升。研究纳米C-S-H凝胶对喷射混凝土凝结时间、抗压强度及抗渗等性能的影响,并采用...为解决普通喷射混凝土凝结时间长、早期强度低和抗渗性能差等问题,通过外掺纳米水化硅酸钙(calcium-silicate-hydrate,C-S-H)凝胶的方式对其进行性能提升。研究纳米C-S-H凝胶对喷射混凝土凝结时间、抗压强度及抗渗等性能的影响,并采用水化热测试、X射线衍射(X-ray diffraction,XRD)和扫描电子显微镜(scanning electron microscope,SEM)等技术探究纳米C-S-H凝胶提升喷射混凝土性能的机理。结果表明:纳米C-S-H凝胶可明显缩短掺速凝剂水泥净浆的凝结时间,与基准组相比,掺2%纳米C-S-H凝胶的喷射混凝土1 d抗压强度可提高19.0%,渗水深度降低31.4%。机理分析表明,纳米C-S-H凝胶的晶核和填充效应能够促进水泥水化且可以致密混凝土内部结构,从而提升喷射混凝土的各项性能。展开更多
The novel calcium-silicate-hydrate(C-S-H)/paraffin composite phase change materials were synthesized using a discontinuous two-step nucleation method.Initially,the C-S-H precursor is separated and dried,followed by im...The novel calcium-silicate-hydrate(C-S-H)/paraffin composite phase change materials were synthesized using a discontinuous two-step nucleation method.Initially,the C-S-H precursor is separated and dried,followed by immersion in an aqueous environment to transform it into C-S-H.This two-step nucleation approach results in C-S-H with a specific surface area of 497.2 m^(2)/g,achieved by preventing C-S-H foil overlapping and refining its pore structure.When impregnated with paraffin,the novel C-S-H/paraffin composite exhibits superior thermal properties,such as a higher potential heat value of 148.3 J/g and an encapsulation efficiency of 81.6%,outperforming conventional C-S-H.Moreover,the composite material demonstrates excellent cyclic performance,indicating its potential for building thermal storage compared to other paraffin-based composites.Compared with the conventional method,this simple technology,which only adds conversion and centrifugation steps,does not negatively impact preparation costs,the environment,and resource consumption.This study provides valuable theoretical insights for designing thermal storage concrete materials and advancing building heat management.展开更多
文摘为解决普通喷射混凝土凝结时间长、早期强度低和抗渗性能差等问题,通过外掺纳米水化硅酸钙(calcium-silicate-hydrate,C-S-H)凝胶的方式对其进行性能提升。研究纳米C-S-H凝胶对喷射混凝土凝结时间、抗压强度及抗渗等性能的影响,并采用水化热测试、X射线衍射(X-ray diffraction,XRD)和扫描电子显微镜(scanning electron microscope,SEM)等技术探究纳米C-S-H凝胶提升喷射混凝土性能的机理。结果表明:纳米C-S-H凝胶可明显缩短掺速凝剂水泥净浆的凝结时间,与基准组相比,掺2%纳米C-S-H凝胶的喷射混凝土1 d抗压强度可提高19.0%,渗水深度降低31.4%。机理分析表明,纳米C-S-H凝胶的晶核和填充效应能够促进水泥水化且可以致密混凝土内部结构,从而提升喷射混凝土的各项性能。
基金The National Natural Science Foundation of China(No.52122802,52078126)Jiangsu Provincial Department of Science and Technology Innovation Support Program(No.BK20222004,BZ2022036).
文摘The novel calcium-silicate-hydrate(C-S-H)/paraffin composite phase change materials were synthesized using a discontinuous two-step nucleation method.Initially,the C-S-H precursor is separated and dried,followed by immersion in an aqueous environment to transform it into C-S-H.This two-step nucleation approach results in C-S-H with a specific surface area of 497.2 m^(2)/g,achieved by preventing C-S-H foil overlapping and refining its pore structure.When impregnated with paraffin,the novel C-S-H/paraffin composite exhibits superior thermal properties,such as a higher potential heat value of 148.3 J/g and an encapsulation efficiency of 81.6%,outperforming conventional C-S-H.Moreover,the composite material demonstrates excellent cyclic performance,indicating its potential for building thermal storage compared to other paraffin-based composites.Compared with the conventional method,this simple technology,which only adds conversion and centrifugation steps,does not negatively impact preparation costs,the environment,and resource consumption.This study provides valuable theoretical insights for designing thermal storage concrete materials and advancing building heat management.
