HYDRATION MODELLING OF FILLER RICH SELF-COMPACTING CONCRETE

摘要

For the realisation of self-compacting concrete,high filler contents are generally added to the cementitious system.In order to avoid problems with excessive heat of hydration during hardening,inert filler materials can be used.Within this research two different filler types are considered: limestone filler and quartzite filler,and this in combination with different types of Portland cement.Although the mentioned filler material is considered to be inert with respect to cement hydration,experimental research shows that it is interfering with the hydration processes.On the one hand the reaction speed is influenced due to a modified nucleation possibility.On the other hand,the reaction mechanism is also altered due to the presence of the large filler content,with a new hydration peak occuring,especially in the case of limestone filler.Based on isothermal conduction calorimetry on different cement filler systems,an existing hydration model for blended cement is modified for the situation of cement filler systems.Within the degree of hydration based hydration model for the filler rich cementitious systems,the cement powder ratio is an important parameter.The model results in an accurate prediction of the heat of hydration during the hardening process.This was also verified by means of adiabatic hydration tests on concrete.