Rheology and Build-Up of Fresh SCC Pastes Evaluated with the Mini-slump Cone Test

SCC are composed by a larger amount of paste than conventional concrete in order to achieve larger flowability without segregation. SCC pastes are typically very fluid, showing large spread diameters in consistency tests, while exhibiting high viscosity values.

In this study, a mini-slump cone test is used to evaluate the fresh properties of SCC pastes with different supplementary cementitious materials (SCM), as limestone filler (LF), colloidal nanosilica (NS) and metakaolin (MK). Two amounts of NS were studied and different amounts of Superplasticizer (SP) were considered to achieve self-compacting ability. The mini-slump test has been implemented with a video acquisition setup that records the spread diameter and allows to follow the velocity of deformation of the fresh paste. The basic rheological parameters were calculated using simple analytical models obtained from the literature. The effects of the type and amount of SCM and the level of SP were analyzed. Several cones were filled in each batch and tested at different times after cast, comparing samples at rest with other stirred before testing. The comparison of both results allowed to identify the structural build-up and the reversible/irreversible processes that take place in the fresh SCC pastes and the effect of SCM and SP.