养护制度对纳米改性水泥净浆自愈合性能的影响

The Influence of Curing Regimes in Self-Healing of Nano-Modified Cement Pastes.

作者信息

Stefanidou Maria, Tsardaka Eirini-Chrysanthi, Karozou Aspasia

机构信息

Laboratory of Building Materials, Aristotle University of Thessaloniki, 54635 Thessaloniki, Greece.

出版信息

Materials (Basel). 2020 Nov 23;13(22):5301. doi: 10.3390/ma13225301.

DOI:10.3390/ma13225301

PMID:33238635

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC7700502/

Abstract

The present study proposes nano-calcium oxide (NC) and nano-silica (NS) particles as healing agents in cement pastes, taking into account the curing conditions. Two series of specimens were treated in water and under wetting-drying cycles. The addition of NC (1.5%wt of binder) triggered early healing since cracks were healed within 14 days in underwater immersion and before 28 days at wetting-drying cycles. Attenuated Total Reflectance (ATR) spectroscopy and SEM analysis revealed that the healing products were mainly aragonite and calcite in water conditions and more amorphous carbonates under wetting-drying cycles. The combination of NS and NC (3.0%wt in total) offered healing under both curing conditions before 28 days. The presence of NS assisted toward porosity refinement and NC increased the carbonates' content. The newly formed material was dense, and its elemental analysis by SEM revealed the C-S-H compounds that were also verified by ATR.

摘要

本研究提出将纳米氧化钙（NC）和纳米二氧化硅（NS）颗粒作为水泥浆体中的愈合剂，并考虑了养护条件。制备了两个系列的试件，分别在水中和干湿循环条件下进行处理。添加NC（占粘结剂重量的1.5%）可引发早期愈合，因为在水下浸泡时，裂缝在14天内愈合，在干湿循环条件下，裂缝在28天前愈合。衰减全反射（ATR）光谱和扫描电子显微镜（SEM）分析表明，在水养护条件下，愈合产物主要为文石和方解石，在干湿循环条件下则为更多的无定形碳酸盐。NS和NC的组合（总量为3.0%wt）在28天前的两种养护条件下均能实现愈合。NS的存在有助于细化孔隙率，而NC则增加了碳酸盐的含量。新形成的材料致密，通过SEM进行的元素分析揭示了C-S-H化合物，ATR也证实了这一点。