Towards a fundamental evaluation of water retention tests for curing compounds

Title: Towards a fundamental evaluation of water retention tests for curing compounds
Author(s): K. Audenaert, G. De Schutter
Paper category : journal
Serial title: Materials and Structures
Abreviated Serial title: Mater. Struct.
ISSN: 1359-5997
Publisher: RILEM Publications SARL
Volume: 35
Issue: 251
Issue date: 2002-08-01
Publication year: 2002
Pages: 408 - 414
Total Pages: 7
Nb references: 6
Language: English

Abstract: Instrumentation was developed to perform calorimetric tests on concrete in isothermal conditions using 0.
11 x 0.
22 m cylindrical samples.
The purpose of this article is to study the validity of Arrhenius’ law and determine the changes occurring in the apparent activation energy of concrete as a function of temperature,by using this technique.
Heat of hydration measurements were made for various isothermal curing conditions (10,20,30 and 40 °C),enabling the apparent activation energy to be determined over this rang of temperature using two different methods:the method of "superposition" and the method of "rates" .
This parameter was calculated over a range of heat varying from 10 J/g to 140 J/g (corresponding to about 50%of the final value).
The two methods give relatively similar results (with deviations of the order of 3 kJ/mol).
However,it is noted that the apparent activation energy varies as a function of the temperature rang considered,which limits the use of this technique to thin elements (of less than 0.
2 m)subjected to slight temperature rises.
In the case of the concrete studied here,it seems however possible to use a single apparent activation energy value over the entire temperature range.

Online publication: 2002-06-27
Classification: Technical Reports
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/13767