UC Davis

Earthen masonry has been used since prehistoric times to build structures primarily made from soil. In the modern era of concrete and steel, earthen structures have seen a significantly reduced usage, because of their relatively low strength and lack of standardization. However, they are once again getting attention because of their low cost, low carbon footprint, energy efficiency, use of indigenous materials, and inherent simplicity. In particular, compressed and stabilized earth block (CSEB) construction is appealing as a viable response to the lack of affordable housing in the US and worldwide, as over two billion new houses will be needed in the next 80 years.

Currently, only few building codes in the US allow the use of CSEB construction through a prescriptive approach adapted from ordinary masonry. As a result, earthen buildings represent only a small fraction of the building inventory in the US, even in places where this type of construction is historically established and culturally appreciated. The CSEB construction is even rarer in locations with humid and rainy climates such as the US Gulf Coast, because of the poor resistance to degradation experienced by traditional earthen construction and its widespread perception as a substandard structural choice under extreme wind loads. Therefore, the present research aims to engineer modern earthen construction by: (1) demonstrating the feasibility of CSEB masonry housing in the US Gulf Coast region; (2) enhancing the properties of CSEBs using sugarcane bagasse fibers, an agricultural by-product; (3) developing a computationally efficient and robust interface element’s constitutive model for simulating the mechanical behavior of masonry; (4) investigating the capabilities and limitations of finite element (FE) simplified micro-modeling techniques that are frequently used for simulating the behavior of ordinary masonry; and (5) developing an FE detailed micro-model specifically tailored for earth block masonry systems. The results of this research represent an advancement in the engineering knowledge necessary for (1) promoting CSEB construction that can endure humid climate and hurricane wind, and (2) understanding the structural behavior of CSEB masonry, which is ultimately required for developing material-specific design standards of CSEB masonry systems.