Opposite effects of ground granulated blast-furnace slag and silica fume on the fracture behavior of self-compacting lightweight concrete

Temporal flowability evolution of slag-based self-compacting concrete with recycled concrete aggregate

“…The viscosity of the SCC mixes with CEM I was higher than that of the mixes with CEM III for the same fine RCA content and the same type of aggregate powder. This result validates the use of GGBFS for producing SCC of acceptable initial viscosity, as observed in SCC with 100% NA (Salehi and Mazloom, 2019). However, this alternative binder induced higher relative increases in viscosity over time: 63.6 and 218.2% at 30 and 60 min, respectively, for mix I-0/F, and 75.0 and 325.0% for mix III-0/F.…”

“…The worst temporal results were for the R mixes, as the largest percentage decreases in the CEM I mixtures (Fig. 5) were observed following the addition of RCA 0/0.5 mm The highest percentage increase in viscosity was observed in the F mixes with CEM III, due perhaps to the poor interaction between those two materials (Salehi and Mazloom, 2019).…”

“…Their air content was therefore lower (for example, the air content of mixes I-100/L and III-100/L was 5.3 and 4.4%, respectively). So, the increased air content of the mixes after adding 45% GGBFS (Salehi and Mazloom, 2019) was compensated by the increased flowability of the SCC.…”

“…However, the crushing of rejected concrete elements mainly from the precast concrete industry yields the highest quality RCA (Fiol et al, 2018). If the mix design of SCC is adjusted to the particular characteristics of this residue, mainly to its high water absorption levels (Sainz-Aja et al, 2019), then RCA is a valid alternative by-product for the manufacturing of SCC (Salesa et al, 2017). If coarse RCA is used, the higher its content, the worse the temporal retention of flowability.…”

Models for compressive strength estimation through non-destructive testing of highly self-compacting concrete containing recycled concrete aggregate and slag-based binder

“…However, the mixes with CEM III/A had a greater temporal increase in viscosity than mixes with CEM I. This fact is due to the properties of GGBFS that usually hinder the temporary preservation of viscosity [59]. The addition of fine RCA increased the viscosity both initially and at 30-minutes.…”