X-ray diffraction study of carbonation rate of C-S-H(i) with different Ca/Si ratio

Author(s): Bei Wu, Guang Ye
Paper category: Proceedings
Book title: Proceedings of the International Conference on Sustainable Materials Systems and Structures (SMSS2019) Durability, Monitoring and Repair of Structures
Editor(s): Ana Baričević, Marija Jelčić Rukavina, Domagoj Damjanović, Maurizio Guadagnini
ISBN: 978-2-35158-217-6
e-ISBN: 978-2-35158-218-3
Publisher: RILEM Publications SARL
Publication year: 2019
Pages: 309-316
Total Pages: 813
Language: English

Abstract: As the major calcium-bearing phases in the hydration products of blended cement, the C-S-H has a relatively lower average Ca/Si ratio (C/S) than that found in the portland cement paste. Moreover, the Ca/Si ratio of C-S-H vary from supplementary cementitious materials (SCMs) or portion of SCMs to another. Therefore, it’s important to study the carbonation mechanism of C-S-H with different C/S when talking about the durability problem of blended cement concrete under the carbonation environment. In this paper, synthesized C-S-H(I) phases (Ca/Si ratio: 0.66 to 2.0) were exposed to the accelerated
carbonation to study the carbonation of C-S-H. C-S-H(I) phases were identified by X-ray diffraction, as well as the carbonation rate and products. The results show that relatively pure C-S-H(I) phases with different Ca/Si ratio (lower than 1.40) were synthesized successfully. C-S-H(I) with the lower Ca/Si ratio is decomposed in the faster way than that with a higher Ca/Si ratio.

Online publication :2019
Publication type : full_text
Public price (Euros) : 00