Service life of combined mechanical and environmental loads

Title: Service life of combined mechanical and environmental loads
Author(s): F.H. Wittmann, Zhao Tie-jun, Jiang Fu-jiang, and Zhang Peng
Paper category : conference
Book title: International RILEM Conference on Advances in Construction Materials Through Science and Engineering
Editor(s): Christopher Leung and K.T. WAN
ISBN: 978-2-35158-116-2
e-ISBN: 978-2-35158-117-9
Publisher: RILEM Publications SARL
Publication year: 2011
Pages: 998 - 1004
Total Pages: 7
Nb references: 5
Language: English

Abstract: For prediction and design of service life of reinforced concrete structures single deteriorating mechanisms such as carbonation or chloride penetration are usually considered independently. If there are synergetic effects of combined actions, however, the usual prediction of service life of reinforced concrete structures is not necessarily conservative. Different processes may act simultaneously or consecutively in practice. In this contribution the influence of frost action on carbonation and the combination of frost action and carbonation on chloride penetration will be considered as an example of combined loads. Another selected example of combined loads is an applied tensile load followed by chloride penetration. Experimental results are presented and discussed in this contribution. They indicate that the rate of carbonation is significantly accelerated after 50 and even more so after 150 frost cycles. Chloride penetration is also significantly accelerated after frost damage and after prior carbonation. The rate of chloride penetration is considerably accelerated by an applied tensile load. It has been found that capillary absorption is a useful tool to quantify damage, induced to the composite structure of concrete, and its implications for durability in aggressive environment. It can be concluded that in general service life of reinforced concrete structures as determined on the basis of one selected dominating deteriorating mechanism is considerably overestimated. As a consequence it follows that combined mechanical and environmental loads must be taken into consideration if service life design is to be realistic and useful in practice.

Online publication: 2011-10-31
Publication type : full_text
Public price (Euros): 0.00