Water adsorption in concrete at low temperature

Title: Water adsorption in concrete at low temperature
Author(s): D. Conciatori, E. Brühwiler
Paper category : conference
Book title: 2nd International RILEM Symposium on Advances in Concrete through Science and Engineering
Editor(s): J. Marchand, B. Bissonnette, R. Gagné, M. Jolin and F. Paradis
Print-ISBN: 2-35158-003-6
e-ISBN: 2351580028
Publisher: RILEM Publications SARL
Publication year: 2006
Nb references: 22
Language: English

Abstract: The steel reinforcement corrosion in reinforced concrete elements is the primary cause of rehabilitation interventions on concrete structures. In the domain of highway structures, the majority of corrosion is initiated by the presence of chloride ions introduced by winter de-icing salts. The deterioration evolution of highway structures therefore depends on the structure’s exposure to liquid water or water vapour containing dissolved aggressive agents like chloride ions. It has been demonstrated, the deterioration evolution rate is quicker for zones in direct contact with liquid water containing aggressive agents than in other zones not in contact with water.
This paper presents laboratory tests to quantify the liquid water movement in cover concrete as a function of low temperature to determine the extent of water and chloride ion transport. The principle objective of this experimental campaign is to assess the durability of conventional structural concrete and to analyze the influence of the local microclimate conditions. Low temperature capillary tests have been conducted on various concrete test samples with different permeabilities.
The concrete mixtures tested can be separated into three distinct groups based on the water to cement ratio employed, respectively 0.42, 0.52 and 0.73. The permeability of the samples was measured by air permeability and electrical resistivity tests. Prior to conducting the capillarity tests, the samples were dried to three different humidity levels, specifically, 25%, 50% and 75% relative humidity. Following the drying process, the test elements were placed in a freezer until they reached the desired temperature. Finally the capillarity tests were conducted by submerging the specimen in a low-temperature high-concentration salt solution bath at four specific temperatures, -20°C, -10°C, 0°C and +10°C.

Keywords: low temperature, capillary tests, concrete, climate, concrete permeability

Online publication: 2006-08-02
Classification: 3.1 Theme 1: Numerical Models: from Microstructure to Transport Properties and Durability
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/2351580028.020