Summary and Statement of Proposed Project
The technique of rammed earth is one of
the oldest building methods used dating back to the construction of the Great
Wall of China. The technique has had multiple revivals in its use, most
recently in the 1930’s. It was used by the government to encourage low income
families to develop outside of the city and to provide them with a low cost,
community style of living. The push from industry for sustainable building
practices has started a revival of rammed earth in this era. The objective of
this research project is to evaluate the process of building rammed earth homes
and applying it to the South Cariboo Region. The research will focus on the
building material that is suitable for use and the process of building that
will allow a non-professional to build their own home.
Purpose
The purpose of this research is to
examine the soil in the 100 Mile area and how well it can be used in the
building of rammed earth homes. The focus of the research will be to examine
various rammed earth building techniques and their ability to be built by the
amateur home builder. The durability of all the wall styles will be compared to
one another to determine the best method to use. This would provide the
regional district of South Cariboo as well as Thompson district with an example
of an alternative building method proven to succeed in the local region that
the amateur home builder could apply to their own project with the correct
engineering guidance.
Goals and Objectives
The goal of the research is to build a
mock-up wall on a client’s property where a proposed house would be built. The
mock-up wall would allow the chosen building technique to be tested. If
successful the technique will then be applied to build a full size house. The
main objective is to research the soil ratios and proctor value needed for
rammed earth and then apply the testing to a mock-up wall. Then the wall will
be monitored during seasonal changes to observe the durability. The final
research data would then be applied to a full scale project for a client that
is currently interested in building a home in the Cariboo Region.
Methodology and Analytical Approach
The first method of data collection will
be to use published books, peer reviewed articles on rammed earth, and local
case studies to analyse previous project data and to determine the optimal soil
ratios and technique used. This research will also identify any construction
issues that previous designers had which will reduce the building time of the mock-up
wall. The consultation with a building envelope specialist will also be done to
determine addition testing that would be useful to the industry.
The second method of data collection
will be to use a geotechnical consultant firm to test the soil on site to
determine the soil ratio. The soil report will also be used to find the proctor
value and moisture content of the site soil. The soil ratio will then be used
to determine if any type of soil, moisture or cement that will need to be added
to obtain the optimum mixture.
The third step of the research is to
build a mock-up wall, of the style that was proven best on other researched
projects, on a client’s site with the client and faculty advisor. This includes
leveling the proposed building area, forming and pouring a concrete foundation
able to support the wall, mixing a batch of soil based on the geotechnical
results, and manually build the wall using forms and different types of soil
compacting techniques to pack the soil. During the soil compaction density tests
will be conducted to observe the compaction of the soil based on the
geotechnical results.
The fourth method of data collection
will be to periodically examine the wall manually for any type of deterioration
through the season changes. Upon the evaluation of the wall the owner will then
decide if the performance is suitable for the home to be built. Moisture
sensors may be applied if the building envelope consultant determines this to
be useful.
Previous Studies
The previous studies observed on rammed
earth done in the province of British Columbia are of a variety of disciplines.
The look into projects found many examples of outdoor esthetic walls used in a
variety of settings such as walls, and entry gates. There are also many
examples of homes that have been built in the area of salt spring island and
some built in the Okanagan area. The main factor linking all the projects
together is that they are built by a professional company with engineers on
staff. On a local scale there are rammed earth homes built in Summerland, and Penticton.
Plans for Dissemination of Work
The research will be shared with others through a blog used
in class. This blog allows the research to be reviewed and commented on by
academic peers, professionals in the industry, and instructors at Thompson
Rivers University. Upon the completion of the research, a research report will
be produced for instructor marking. The research paper will also be uploaded to
the blog site. There is also some consideration to present the paper to
building envelope specialist as well as the undergraduate research presentation
held every year at Thompson Rivers University.
References
1)
Delgado, M. C. J., & Guerrero, I. C. (2006). Earth Building in Spain.
Construction and Building Materials, 20(9), 679-690. doi:
10.1016/j.conbuildmat.2005.02.006
2)
Easton, D. (2007). The rammed earth house. White River Junction, Vt:
Chelsea Green Pub.
3)
Hall, M., & Allinson, D. (2009). Assessing the effects of soil grading on
the moisture content-dependent thermal conductivity of stabilised rammed earth
materials. Applied Thermal Engineering, 29(4), 740-747. doi:
10.1016/j.applthermaleng.2008.03.051
4)
Hall, M., & Djerbib, Y. (2004). Moisture Ingress in Rammed Earth: Part
1—the effect of soil particle-size distribution on the rate of capillary
suction. Construction and Building Materials, 18(4), 269-280. doi:
10.1016/j.conbuildmat.2003.11.002
5)
Hall, M., & Djerbib, Y. (2006). Moisture Ingress in Rammed Earth: Part 3 –
sorptivity, surface receptiveness and surface inflow velocity. Construction
and Building Materials, 20(6), 384-395. doi:
10.1016/j.conbuildmat.2005.02.004
6)
Jiménez Delgado, M. C., & Guerrero, I. C. (2007). The selection of soils
for unstabilised earth building: A normative review. Construction and
Building Materials, 21(2), 237-251. doi: 10.1016/j.conbuildmat.2005.08.006
7)
King, B. (1996). Buildings of earth and straw: Structural design for rammed
earth and straw-bale architecture. Sausalito, Calif: Ecological Design
Press.
8)
Minke, G. (2006). Building with earth: Design and technology of a
sustainable architecture. Basel: Birkhauser-Publishers for Architecture.
9)
Pacheco-Torgal, F., & Jalali, S. (2012). Earth construction: Lessons from
the past for future eco-efficient construction. Construction and Building
Materials, 29(1), 512-519. doi: 10.1016/j.conbuildmat.2011.10.054
Personal
Contribution
The research that will be conducted will
help my understanding of research and development of processes in the industry.
The research will help me to better identify my personal and academic interests
to better define my career path. My role in the project will be to research methods
used in other countries and to implement it to this research. Once research is
complete I will personally work with the consultants and clients to test the
soil and build the rammed earth wall. The plan to begin construction of the
wall is for the summer of 2013 where I will be traveling to the site and
working with the client. After the completion of the wall I will be continually
monitoring the moisture content through the seasons on a periodical schedule
yet to be determined.
This research has sparked my interest in
sustainable development. Having the resources and opportunity to work with a
client to produce a potentially working product encourages me to apply my
current knowledge and to learn more.
Budget
The majority of the cost will be broken
down into soil testing, travel to the site, and the attendance of a rammed
earth construction seminar held in Salt Spring Island by SIREWall.