Title: Two Limiting Lines Technique to Obtain Minimum Paste Demand of Self-Consolidating Concrete
Author(s): Maciej Urban
Publication: Materials Journal
Appears on pages(s): 131-138
Keywords: minimum paste content; self-consolidating concrete (SCC) composition design; SCC; thickness of excess paste on aggregate grains
Today, one of the most important challenges of self-consolidating concrete (SCC) technology is minimization of cement paste content. Unfortunately, there are no methods that include this important criterion. The author aimed to fill this gap by determining the relative thickness of excess paste on aggregate grains parameter (trel). This parameter is linearly correlated to minimal paste content needed to obtain a given SCC consistency level (Vpaste min). Two such lines were recognized: minimum paste demand line and minimum relative thickness of excess paste line. The main parameters influencing obtaining these lines are: sand to total aggregate ratio (s/a), void content in a loose state (νl), the coarsest fraction content, water-binder ratio (w/b), superplasticizer content, and aggregate fines content (or, alternatively, stone powder content). The proposed design procedure begins with assessment of both lines (using only four to six trial batches of extreme compositions in consideration). Next, the lines are used to predict the Vpaste min level by simple calculation of trel for a given SCC composition.