Title: New Additive to Enhance the Slump Retention

Author(s): David Platel; Jean-Marc Suau; Clement Chosson; and Yves Matter

Publication: Symposium Paper

Volume: 302

Issue:

Appears on pages(s): 53-62

Keywords: polymer; slump; slump retention; water reduction; fluidity; cement; polycarboxylate ether; segregation

DOI: 10.14359/51688084

Date: 6/1/2015

Abstract:
For the Ready Mix Concrete mix design, the initial workability depends on the chemical composition of the Polycarboxylate Ether (PCE). Up to now the use of best PCE can achieve 2 hours of slump retention. However, a tendency to segregate is observed when over-dosage is made, due to water reduction capability of PCEs. An approach is to use also a combination of a water-reducing agent and a retarding agent which has the main disadvantage to delay the setting time and consequently the early strength of the concrete. This paper demonstrates the possibility to boost the performance of currently used PCEs. The new slump retention additive that we developed allows a significant increase of the slump retention while maintaining the initial fluidity without impacting the water reduction ability. The homogeneity of the concrete is also controlled by using this additive. On top of that, the combination between this new product and a standard water-reducting PCE is made at commonly used dosage.