Effect of Curing Regimes on Microstructure of Ultra High Performance Concrete Cement Pastes

Author(s): Qingjun Ding, Xiaoqing Liu, Yongqiang Liu, Shuguang Hu
Paper category: Proceedings
Book title: 1st International Conference on UHPC Materials and Structures
Editor(s): Caijun Shi and Dehui Wang
ISBN: 978-2-35158-164-3
e-ISBN: 978-2-35158-165-O
Publisher: RILEM Publications SARL
Publication year: 2016
Pages: 371-379
Total Pages: 09
Language: English

Abstract: By using the 29Si and 27Al Magic Angle Spinning Nuclear Magnetic Resonance (MAS NMR), XRD and SEM, effect of curing regimes (standard curing, high temperature steam curing and autoclave curing) on the mean chain length (MCL), degree of polymerization and degree of Al3+ substituting for Si4+ of C-S-H and composition of aluminum-containing phases (such as
AFt, AFm) in ultra-high-performance concrete (UHPC) cement paste was quantitatively studied. The results indicated that the hydration products were mainly C-S-H, CH, AFt, AFm and TAH in standard curing and high-temperature steam curing. After 210ć, 2MPa autoclave curing for 8h, the main hydration products were “Level A” tobermorite with low Ca/Si, CH and TAH. And TAH united with SO4 2- to form AFt and AFm with the prolongation of age. When UHPC reached the same strength under different curing regimes, the MCL of C-S-H was that autoclave curing > 80ć steam curing > standard curing.

Online publication: 2016
Publication type : full_text
Public price (Euros): 0.00

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