Title: Maturity Approach Applied to Concrete by Means of Vicat Tests

Author(s): Alvaro García, Daniel Castro-Fresno, and Juan Antonio Polanco

Publication: Materials Journal

Volume: 105

Issue: 5

Appears on pages(s): 445-450

Keywords: activation energy; cement paste; early age properties; maturity method; setting time; temperature; Vicat test

DOI: 10.14359/19973

Date: 9/1/2008

Abstract:
Better knowledge of the time of initial setting of concrete would aid contractors in planning the times of texturing and finishing a pavement. With this aim in mind, this paper presents a straightforward method for evaluating the temperature influence on setting time. This was accomplished using the Freiesleben-Hansen and Pedersen maturity function. To determine the apparent activation energy of the cement for use in this equation, a series of Vicat tests were carried out at different temperatures. To determine whether the activation energy found was correct, it was applied to the times to attain a specific penetration resistance of concrete made at different temperatures with various water-cement ratios (w/c) and three different types of cement. When equivalent ages of the setting times of concrete were calculated, linear relationships were obtained between w/c and setting time at the reference temperature. It was concluded that the apparent activation energy obtained by this method could be used to evaluate the temperature influence on setting times of concrete.