Restrained shrinkage of massive reinforced concrete structures: results of the project CEOS.fr

Abstract

International audienc

Three-dimensional simulations of ageing concrete structures using a multiphase model formulation

“…Also, the force in the reinforcement and the restraining struts are monitored throughout the test program. Buffo-Lacarriére et al [21] gives a more detailed description of the installed sensors.…”

“…Measurements are available both from laboratory experiments on the concrete that can be used to calibrate the material model and for the actual test where environmental conditions, as well as mechanical and thermal data from the beam, were recorded. Buffo-Lacarriére et al [21] summarizes the entire experimental set-up, procedure and results from the research project. Furthermore, the experiment has been investigated theoretically to validate different models for early-age concrete, both as part of the CEOS.fr project and presented in the literature, see for example [43][44][45][46]…”

“…3, which includes the concrete beam and the two restraining steel struts. The central part of the concrete beam is 5.1 m long, 0.5 m wide and 0.8 m high with 2% longitudinal reinforcement content and stirrups of 16 mm bars with a spacing of 200 mm; more details are given by Buffo-Lacarriére et al [21]. The casting of the RG8 beam started at 10:30 h on the 7th of April in 2010, and the test ended 60 days later with a static bending test.…”

“…The ambient gas pressure is assumed The effect of the insulated formwork is modelled by modifying the heat transfer coefficient f T accordingly. According to Buffo-Lacarriére et al [21], two different zones regarding thermal properties of the formwork can be identified. Here it is assumed that for all lateral faces the formwork corresponds to surface coefficient equal to 1 W/m 2 K and for the upper and lower faces equal to 4 W/m 2 K, which approximately corresponds to average values calculated from the formwork drawings.…”

“…Furthermore, a new solution algorithm is presented to replace the fully-coupled solution method employed in [11], in order to arrive at a model that is more computationally efficient and thus more suitable for large-scale applications. To analyse the applicability of the proposed model to describe cracking due to restrained deformations in a structural scale application, one of the end-restrained beams tested within the French research project CEOS.fr [21] is modelled. This example includes both the early-age behaviour with cement hydration, self-desiccation and self-heating, as well as actual environmental conditions including hourly variations in temperature, relative humidity and solar radiation.…”