Research Proposal: Rammed Earth- Research and Application

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.

Travel to 100 mile area (5x)	$700.00
Salt Spring Island Seminar	$600.00
Total	$1400.00