NEW SUPERPLASTICIZERS FOR THE TOTAL CONTROL OF PERFORMANCES OF FRESH AND HARDENED CONCRETE

Admixtures for concrete and mortars are considered as additions that modify their properties in the fresh and the hardened state. Often, modifying one property may alter another equally important one, in an adverse manner. This behaviour is highlighted by the reduction of the water cement ratio with the help of the superplasticizers to improve the compressive strengths. Reduction of the water content may lead to a rapid slump loss. The ready mixed concrete industry is asked to provide concrete as per EN 206–1. It has to meet the requirements for the class of consistence, strength and exposure conditions. This is a concrete with long workability retention at a low water cement ratio; two properties in conflict with each other. New admixtures, using nanotechnology, address these demands of extreme performances through the understanding of admixture-cement interaction. Tailor made superplasticizers, meeting the market requirements, where different types of cements (Portland, slag, fly ash, limestone blends) are utilised, are now available. The characteristics and mechanism of action of these new superplasticizers and significant International field applications are presented.

• INTRODUCTION

• DURABILITY OF CONCRETE STRUCTURES

• THE NEW FRONTIERS OF ADMIXTURE SCIENCE

• MECHANISM OF ACTION OF PCE SKY SUPERPLASTICISERS

• ADVANTAGES OF PCE SKY SUPERPLASTICISERS

• CONCLUSIONS

• REFERENCES