Compaction voids formation on concrete surfaces: influence of rheological properties

Title: Compaction voids formation on concrete surfaces: influence of rheological properties
Author(s): M. Martin, R. Pleau, J. L. Gallias
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
Language: English

Abstract: Concrete surfaces may present surface defects such as compaction voids. Mechanisms and parameters conditioning the concrete surface’s texture have been very little investigated in the scientific literature. This experimental study aims to assess the influence of the paste volume, the water/cement ratio (W/C), and the rheological properties of concrete on the compaction voids. Five series of concrete mixtures were tested in order to study the formation and the behaviour of compaction voids. All the concrete mixtures were based on an identical optimized granular skeleton made of 50% of sand and 50% of coarse aggregate. In the first two series of mixtures, all the parameters were kept constant except the paste volume and the W/C ratio. In the third and fourth series of mixtures, all the parameters were kept constant except the dosage of the superplasticizer. In the fifth series, all the parameters were kept constant except the dosage of the viscosity modifying agent. The rheological properties and surface area of compaction voids were measured for all concrete mixtures. The results obtained show that the amount of compaction voids decreases with an increase of the mortar volume. They also point out the existence of a threshold value of slump and yield stress below or beyond which, the amount of compaction voids becomes significant.

Keywords: compaction voids, yield stress, paste volume

Online publication: 2006-08-02
Classification: 3.2 Theme 2: From Fresh to Hardened Concrete
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/2351580028.070