COMPUTER SIMULATION OF PORTLAND CEMENT HYDRATION BASED ON ELECTRICAL RESISTIVITY

Author(s): Yibing Zuo, Xiaosheng Wei
Paper category: Proceedings
Book title: Proceedings of CONSEC13 Seventh International Conference on Concrete under Severe Conditions - Environment and Loading Volume I
Editor(s): Z.J. Li, W. Sun, C.W. Miao, K.Sakai, O.E. Gjørv, N.Banthia
ISBN: 978-2-35158-124-7
e-ISBN: 978-2-35158-134-6
Publisher: RILEM Publications SARL
Publication year: 2013
Pages: 140-152
Total Pages: 961
Language : English

Abstract: Electrical resistivities were measured by a non-contacting electrical resistivity measurement device for Portland cement pastes with water cement (w/c) ratios of 0.35, 0.4 and 0.45. The critical time between phase-boundary period and diffusion-controlled period during cement hydration was obtained from the rate of electrical resistivity curve. This study conducts a computer simulation with the critical time as the input datum for the cement hydration, which considered the influence of interparticle contacts, particle size distribution, w/c ratio etc. The visualization of the microstructure evolution in the paste can well interpret the hydration process, which is consistent with the theoretical analysis. The microstructure evolutions show that a lower w/c ratio makes the hydration products cluster more quickly; consequently, it is easier and hence takes less time to form clusters. The formation of net-structure hydration products blocks the electrical conductive channels, thus increasing electrical resistivity, and makes the porosity decrease rapidly, offering reasonable explanation of the characteristics of the 24h compressive strengths of the pastes. The porosity obtained can well explain the development of the electrical resistivities of cement pastes with different w/c ratios after the dissolution period.

Online publication : 2013
Publication type : full_text
Public price (Euros) : 0.00