Determination of activation energy of cement hydration by electrical resistivity measurement

Title: Determination of activation energy of cement hydration by electrical resistivity measurement
Author(s): Xiaosheng Wei, Lianzhen Xiao
Paper category : conference
Book title: 2nd International Symposium on Service Life Design for Infrastructures
Editor(s): K. van Breugel, Guang Ye, Yong Yuan
Print-ISBN: 978-2-35158-096-7
e-ISBN: 978-2-35158-097-4
Publisher: RILEM Publications SARL
Publication year: 2010
Pages: 883 - 890
Total Pages: 8
Nb references: 12
Language: English

Abstract: This study investigates the influence of temperature on the electrical resistivity of Portland cement pastes during first 72 hours. The experiments were conducted on the cement pastes with water-cement ratios of 0.3, 0.35, 0.45, 0.55 and different curing temperatures of 15 °C, 20 °C and 30 °C. The hyperbolic equation for each sample is established to estimate the ultimate resistivity value which can probably be reached. The electrical resistivity results at the temperatures are used to determinate the activation energy for liquid solution in pores (EaS) and the activation energy for hydration reaction (EaR). The electrical resistivity curves obtained at 15 °C and 30 °C are corrected to 20 °C for deleting the effect of temperature on the ionic mobility in the liquid solutions. EaS is increased with the decrease of W/C due to a higher ion concentration in lower W/C paste solution, and EaS ranges from 16 to 26 kJ/mol.
The activation energy of cement hydration is determined to be 39 kJ/mol, which is close to the value recommended by the ASTM 1074 standard method.

Online publication: 2011-04-20
Publication type : full_text
Public price (Euros): 0.00