ABSTRACT
This chapter gives general information related to sampling, grinding, homogenisation, and storage of anhydrous binders and preparation and curing of pastes and mortars as well as stoppage of hydration, focusing on the experimental work in a research laboratory devoted to studying cementitious systems. The content given in this chapter will be restricted mostly to general considerations, while the individual chapters will give more detailed information related to the respective analytical methods. The
CONTENTS
1.1 Introduction 1 1.2 Sampling 2 1.3 Grinding 4
1.3.1 Grinding of unhydrated binders 4 1.3.2 Grinding of hydrated pastes 7
1.4 Blending of dry binders and mortars 9 1.5 Storage and shelf life of unhydrated binders 12
1.5.1 Prehydration and shelf life of cementitious binders and mortars 12
1.5.2 Storing of unhydrated binders in the laboratory 15 1.6 Mixing, casting and curing of pastes and mortars 16
1.6.1 Mixing 16 1.6.2 Casting and curing 19
1.7 Hydration stoppage 21 1.7.1 Direct drying techniques 22 1.7.2 Solvent exchange 23 1.7.3 Sample storage 26 1.7.4 General points to consider 28
1.8 Conclusions 30 Acknowledgements 32 References 32
main purpose of this chapter is that the reader should be aware that reliable analytics is impossible when the sample preparation is inappropriate. When consulting scientific literature, not only in the field of cement science, it is highly recommended to check how sample preparation was performed. For example, many papers related to cement hydration and microstructure describe harsh methods for hydration stoppage, such as drying at 105°C, used prior to mercury intrusion porosimetry (MIP). Conclusions from data obtained under these conditions can be strongly biased.
