Influence of the Aggregate Shape and Type on the Properties of Poured Earth

Abstract

The aim of this thesis is to predict the influence of the aggregate shape and type on the properties of poured earth. This is done by analysing the aggregates’ influence in concrete and in rammed earth and subsequently inferring what their influence in poured earth could be. It was found that crushed aggregates lead to a higher mechanical strength than gravel, but also to a lower workability. Smaller aggregates showed to impact a composite’s strength and workability negatively due to their high surface area, which yields a high volume fraction of the interfacial transition zone. On top of that, recycled concrete aggregates lead to a lower workability than regular ones and in concrete they also lead to a lower total strength. It is plausible that the use of recycled aggregates does not lead to a decreased strength of poured earth, due to the much lower strength of the clay binder than the aggregates. Testing is required to further examine the influence of aggregates on poured earth properties. In particular, it would be interesting to examine the influence of the stress concentration at the boundary of the aggregates and the binder. In addition, the general role of the interfacial transition zone in poured earth could be examined.