A new mix design concept for earth-moist concrete: A theoretical and experimental study

Abstract

This paper addresses experiments on earth-moist concrete (EMC) based on the ideas of a new mix design concept. First, a brief introduction into particle packing and relevant packing theories is given. Based on packing theories for geometric packing, a new concept for the mix design of earth-moist concrete will be introduced and discussed in detail. Within the new mix design concept, the original grading line of Andreasen and Andersen [Andreasen, A.H.M. and Andersen, J., 1930, Ueber die Beziehungen zwischen Kornabstufungen und Zwischenraum in Produkten aus losen Körnern (mit einigen Experimenten). Kolloid-Zeitschrift 50, p. 217–228 (in German).], modified by Funk and Dinger [Funk, J.E. and Dinger, D.R., 1994, Predictive Process Control of Crowded Particulate Suspensions, Applied to Ceramic Manufacturing. Kluwer Academic Press, Boston.], will be used for the mix proportioning of the concrete mixtures. Mixes consisting of a blend of slag cement and Portland cement, gravel (4–16), granite (2–8), three types of sand (0–1, 0–2 and 0–4) and a polycarboxylic ether type superplasticizer are designed using the new mix design concept. The designed concrete mixes are tested in the lab, both in fresh and hardened states, to show the suitability of the ideas of the new mix design concept. The tested concrete mixes meet the requirements on the mechanical and durability properties. Furthermore, the application of fine stone waste materials in the form of premixed sand (Premix 0–4) is presented. By means of an optimized particle packing, stone waste materials can be used to reduce the amount of the most cost intensive materials in earth-moist concrete mixes, viz. binder and filler. The results of tests carried out on mortar samples as well as on paving blocks produced on a laboratory paving stone machine will be discussed. The application of fine stone waste materials in earth-moist concrete mixes does not only meet the current trends in raw materials use, but also fulfill the technical requirements of the concrete in fresh and hardened state.