MICROSTRUCTURAL INVESTIGATIONS ON EARLY HYDRATION PRODUCTS OFCEMENTITIOUS SYSTEMS IN COMBINATION WITH MODERN PCE-TYPESUPERPLASTICIZERS BY ADVANCED CRYO-TRANSFER SEM

摘要

Fundamental investigations on the influence of modern PCE-type superplasticizers onthe morphology of the early hydration products of cementitious systems are a crucialelement for understanding the basic mechanisms of action of this class of admixtures. Itis believed that a more profound knowledge on the early stages of cement hydration ingeneral and in the presence of high performance superplasticizers in particular can laythe foundation for development of tailor-made products of a new generation.The cryo-SEM technique is well established for the investigation of biological systems. Ithas also already been applied successfully to cementitious systems in the past.However in recent years most research groups were focused on the ESEM techniquesince it provides the possibility to study hydrating systems in situ. Advanced cryotransferSEM allows detailed examination of the microstructure at very high resolutioneven at very early hydration times almost free of any artefacts.The present paper deals with time-resolved cryo-transfer SEM of cement paste andconcrete in the presence and absence of selected PCE-type superplasticizers.