Application of sodium silicate solution as self-healing agent in cementitious materials

Title: Application of sodium silicate solution as self-healing agent in cementitious materials
Author(s): Haoliang Huang and Guang Ye
Paper category : conference
Book title: International RILEM Conference on Advances in Construction Materials Through Science and Engineering
Editor(s): Christopher Leung and K.T. WAN
ISBN: 978-2-35158-116-2
e-ISBN: 978-2-35158-117-9
Publisher: RILEM Publications SARL
Publication year: 2011
Pages: 530 - 536
Total Pages: 7
Nb references: 9
Language: English

Abstract: The application of sodium silicate solution as self-healing agent was investigated in this paper. The sodium silicate solution was stored in capsules that were embedded in the engineering cementitious composites (ECC). Three-point bending tests were carried out to precrack the ECC specimens at the age of 14 days. The healing agent was released into the cracks to promote self-healing. The self-healing phenomenon was observed by environmental scanning electron microscopy (ESEM). The X-ray microanalysis (EDS) was also applied to determine the chemical elements of the healing products. From the EDS results, the main chemical elements of the healing products are Si, O, Ca and Na. Based on the analysis of the Ca/Si and Na/Si ratio, it can be concluded that the healing products formed in the cracks are the composites of CSH and sodium silicate. Thus the main mechanism of self-healing by sodium silicate solution is the reaction of calcium cations with the dissolved sodium silicate and the crystallization of the sodium silicate. The pre-cracked specimens after self-healing were bent again to evaluate the strength recovery efficiency. The results demonstrate that the concentration of the sodium silicate solution is the main influence factor which determines the self-healing efficiency.

Online publication: 2011-10-31
Publication type : full_text
Public price (Euros): 0.00