Title: A New Superplasticizer for Early High-Strength Development in Cold Climates

Author(s): T. Cerulli, P. Clemente, M. Decio, G. Ferrari, M. Gamba, D. Salvioni, and F Surico

Publication: Symposium Paper

Volume: 217

Issue:

Appears on pages(s): 113-127

Keywords: cold climates; early strength development; polycarboxylate

DOI: 10.14359/12909

Date: 9/1/2003

Abstract:
Acrylic based superplasticizers are characterised by high water reducing ability and high retention of the workability in comparison to the traditional superplasticizers based on naphthalene sulfonate formaldehyde condensate (NSFC) and melamine sulfonate formaldehyde condensate (MSFC). On the other hand, polycarboxylate polymers may lead to a retardation of the cement hydration. This disadvantage can limit the use of these superplasticizers in cold climates, particularly in the cases where early strength development is required. In the present work, a new polycarboxylate superplasticizer based on high molecular weight polyoxyethylene side chains is presented. This new polymer allows the production of cement mixtures characterised by low water-cement ratio and high early age mechanical strength development, even at low temperature of curing. These results can greatly improve the productivity of precast concrete industry by reducing or even eliminating the steam curing cycle and the time for the moulds reuse. The polymer has been studied in comparison to a traditional acrylic based superplasticizer in terms of superplasticizing effect, development of mechanical strength, adsorption rate, heat development and morphological analysis of the cement hydration products by means of ESEM-FEG (Environmental Scanning Electron MicroscopeField Emision Gun).