Appraisal of the Sustainability of Compressed Stabilized Earthen Masonry

Authors

Elena Claire Hoff, University of Nebraska-LincolnFollow

First Advisor

Ece Erdogmus

Date of this Version

12-2016

Document Type

Thesis

Citation

A thesis presented to the faculty of the Graduate College at the University of Nebraska in partial fulfillment of requirements for the degree of Master of Science

Major: Architectural Engineering

Under the supervision of Professor Ece Erdogmus

Lincoln, Nebraska, December 2016

Comments

Copyright 2016, Elena Hoff. Used by permission

Abstract

Compressed stabilized earthen block (CSEB) masonry presents an environmentally and economically sustainable alternative to conventional residential construction materials such as clay brick masonry or concrete masonry (CMU). Earthen masonry is locally sourced and manufactured on site, thus minimizing costs associated with raw material extraction and transportation. Furthermore, CSEB requires very little use of electricity and water during both the manufacture and construction processes and it has excellent thermal resistivity while in use, allowing for additional cost and energy savings during most phases of its life cycle. Analyzing the life cycle trade-offs in a comparative study between CSEB and clay brick masonry supplements the existing recent research on earthen masonry and encourages a wider adoption of the technology around the world. In this study, a comparative Life Cycle Analysis (LCA) is conducted between an exterior residential wall constructed of CSEB and one of clay brick for a proposed single family dwelling on the Winnebago Native American Reservation in Nebraska, USA. The scope of this LCA is narrowed to the impacts associated with choosing one construction material over the other, and the system boundary includes the raw material extraction, manufacturing, and transportation phases of construction.

Thermal conductivity is an important aspect of the energy efficiency of a building envelope during the use phase of a building’s life cycle. As part of this study, an experimental program was conducted using a modified hotbox apparatus in order to obtain a thermal conductivity value for the CSEB blocks under investigation. After analysis, the thermal conductivity of the CSEB analyzed in this study is determined to be 0.361 W/(m·K) ± 20.0% compared to 1.024 W/(m·K) for clay brick.

The three indicators for measuring the environmental or economic impacts of each material in this study are: 1) Energy, measured in kWh, 2) Global Warming Potential (GWP), measured in kg CO2 eq., and 3) Cost, measured in US Dollars. The results of this Life Cycle analysis indicate that CSEB is the more economic and environmentally sustainable option, with the transportation phase of the life cycle of highest impact on cost.

Advisor: Ece Erdogmus