Abstract
Self-compacting concrete (SCC) is a concrete type that does not require vibration for placing and compacting. SCC possesses special technical features and properties that recommend its application in many jobs. Nevertheless, in some situations, it has been observed an inadequate behaviour of the material at early ages due to shrinkage. The existing shrinkage prediction models were developed for standard concrete. In this paper three SCC mixtures, with different compressive strength, are studied in terms of autogenous and total shrinkage. The results are compared with the Eurocode 2 model. For the studied mixtures it was found that this model underestimates the autogenous shrinkage, while the total shrinkage is generally overestimated.
Highlights
The estimation of time-dependent behaviour is still one of the most difficult aspects in designing a concrete structure
The following sections provide the results of shrinkage obtained on the three concrete mixtures (3 different strength levels) including the correspondent values obtained from the Eurocode 2 model (EC2)
Bermejo et al [56] measured the total shrinkage on 3 different self-compacting concrete (SCC) mixtures (30 MPa compressive strength), and refer that the EC2 overestimates the shrinkage strains, in accordance with the results presented in Figures 4c) and 4d)
Summary
The estimation of time-dependent behaviour is still one of the most difficult aspects in designing a concrete structure. Changes in the surface tension of the solid gel particles, disjoining pressure and tension in capillary water are parameters that have been discussed [16, 23, 36, 37] In addition to these main mechanisms, other phenomena may be involved in the early volume changes: swelling phase related to sulfate-to-alkali ratio of the clinker and the amount of free lime [19], influence of the type of hydration products [21, 24, 27, 32, 34, 38], creep in the C-S-H phases [30]. A better understanding of early and long-term shrinkage will promote good performance of the concrete structure during its service-life
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