Influence of triethanolamine on reactivity of hydrated matrix in sodium silicate self-healing system and the mechanism. (10th October 2018)

• Record Type: Journal Article
• Authors: Hu, Miaomiao; Guo, Jintang; Xu, Yang; Fan, Jinjie; Cao, Lei; Wang, Meiyu; Feng, Yakai
• Is Part Of: Construction & building materials. Volume 185(2018)
• Page Start: 445
• Page End: 452
• Publication Date: 2018-10-10
• Subjects: Self-healing -- Triethanolamine -- Calcium silicate hydrate (C-S-H) -- Complexation -- Cement matrix; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2018.07.040
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: TEA was incorporated to increase the reactivity of hydrated cement. The self-healing efficiency of sodium silicate system was improved by the complex between TEA and Ca 2+ . TEA enhanced the micromechanical properties of self-healing product. Abstract: A suitable binding agent proposed in literatures or patents is sodium silicate, which achieves self-healing by formation of calcium silicate hydrate (C-S-H) in cracks. We systematically investigated the influences of triethanolamine (TEA) on the stimulated C-S-H, sodium silicate/hydrated cement and real self-healing system. Results suggest that TEA addition induces the C-S-H to arrange in order and forms sponge-like structure. In sodium silicate/hydrated cement sample, the morphology of C-S-H is simultaneously affected by the heterogeneous nucleation and restriction effect of hydrated cement particles, and the reticulate structure is observed. It is believed that the formation of TEA-Ca 2+ facilitated the dissolution of solid Ca from hydration products, hence increases the chemical reactivity of hydrated cement matrix and the actual binding ability is improved due to the increment of high density C-S-H. Finally, the improved performance of self-healed area was demonstrated by optical microscope, SEM and Raman analysis, meanwhile the promotion in micromechanical properties of C-S-H was studied by AFM.