The effect of long term weathering on hemp and rapeseed straw concrete

Abstract

In recent decades sustainability, carbon footprint and pollution have become significant issues on a global scale. It is widely recognised that the carbon footprint of the construction industry is something that can be reduced and this has led to sustainable materials being used more and more widely to meet emissions targets. The most widely researched bio-aggregate to date is hemp shiv; which is used in this study as well as chopped rapeseed straw which is an alternative bio-aggregate widely available in the UK. Bio-concretes are made of, in this case, hemp or rapeseed straw as well as water and a binder. The binder used in this study is Vicat prompt natural cement as well as a viscosity modifying agent (VMA) as a mixture additive. Most of the research into this area has revolved around the material properties in the relative short term and considerably less research has been conducted into the long term durability of these materials. This study investigates the effect of long term weathering and carbonation on rapeseed and hemp concrete with and without a VMA as an additive.