Influence of Lightweight Aggregate’s Coatings on Poured Earth Strength

Abstract

The aim of the thesis is to predict the influence of di↵erent coatings on lightweight poured earth. Such building material does not exist yet but would benefit from the advantages of lightweight aggregates combined with poured earth and is therefore an interesting direction to place some focus of research. The procedure was based on literature research where techniques from the cement industry were analyzed on their presumable influence on the compressive strength of lightweight poured earth.

The highest potential was found in coatings that lower moisture wicking since lightweight aggregates absorb water in early stages and capillary forces will later attract the water back into the matrix dispersing the clay particles. Those coatings bring also disadvantages with them such as a lower overall density and a weaker interfacial connection. An additional layer of adhesive materials can compensate or even surpass the disadvantages through increasing the adhesive forces. Clay pow- der increases the van der Waals forces, sand would increase the friction forces and magnesium oxide the chemical bond.

The results can be used as a frame for practical experiments with the help of a guideline to find an optimized mix design.