Early setting and hardening process of young concrete using the resistivity measurement

The process of hydrating young concrete was studied based on the critical points of electrical resistivity and its differential curves.The electrical resistivity curve was identified to divide the hydration process into four periods: dissolution,setting,initial hardening,and hardening deceleration.A method to obtain concrete setting time based on electrical resistivity results was introduced. The results show that the electrical resistivity and penetration methods have strong correlation in determining setting time.The electrical resistivity and strength development between the control concrete and fly ash concrete were compared.The results show that the strength and bulk resistivity of concrete at an early age decrease with the increase of(amount) of fly ash replacement.