Contemporary stabilized rammed earth (SRE) draws upon traditional rammed earth (RE) methods and materials, often incorporating reinforcing steel and rigid insulation, enhancing the structural and energy performance of the walls while satisfying building codes. SRE structures are typically engineered by licensed Structural Engineers using the Concrete Building Code or the Masonry Building Code. The construction process of SRE creates structural walls of relatively high compressive strength appropriate for a broad range of heating and cooling climates. The incorporation of rigid insulation creates a high mass interior wythe that is thermally separated from the exterior, resulting in improved thermal performance. Modular aluminum reinforced formwork allows walls to be built without the use of through ties, common in concrete construction. The North American Rammed Earth Builders Association (NAREBA) collaborated with Unisol Engineering Ltd. and the British Columbia Institute of Technology (BCIT) on a battery of tests to obtain preliminary data to be used in support of engineering design. The tests included compressive strength comparisons, pull out rebar testing of both horizontally and vertically placed steel, simple beam tests, and the deflection of two composite wall columns with an insulation core and two types of reinforcing steel connections between the RE wythes.
References
[1]
The New Mexico Earthen Building Materials Code. Title 14, Chapter 7, Part 4. State of New Mexico, NM, USA, 2009.
[2]
1997 Uniform Administrative Code Amendment for Earthen Materials and Straw Bale Structures, Tucson/Pima County, Arizona. In Appendix Chapter 71, Earthen Materials Structures; City council of Tucson: AZ, USA, 1997.
[3]
ASTM E2392/E2392M-10. In Standard Guide for Design of Earthen Wall Building Systems; ASTM International: West Conshohocken, PA, USA, 2010.
[4]
Reddy, B.V.; Venkatarama, K.; Prasanna, P. Embodied energy in cement stabilized rammed earth walls. Energ. Build. 2010, 42, 380–385, doi:10.1016/j.enbuild.2009.10.005.
[5]
CSIRO Media Release (2000) Ref 2000/110. Available online: http://www.dab.uts.edu.au/ebrf/research/csiro.html (accessed on 27 April 2000).
[6]
Hall, M.A. Assessing the moisture-content-dependent parameters of stabilized earth materials using the cyclic-response admittance method. Energ. Build. 2008, 40, 2044–2051, doi:10.1016/j.enbuild.2008.05.009.
[7]
Dow Product Information—Cavity Mate Extruded Polystyrene Foam. The Dow Chemical Company Building Solutions. Midland, MI, USA. Available online: www.dowstyrofoam.com/architect (accessed on 24 January 2012).
[8]
Roxul Cavity Rock DD Technical Product Information. 2007. Roxul Inc.: Milton, Ontario, Canada. Available online: www.roxul.com (accessed on 24 January 2012).
[9]
Dow Building and Construction–socast R Insulation Application Information. The Dow Chemical Company Building Solutions. Midland, MI, USA. Available online: www.dowstyrofoam.com/architect (accessed on 24 January 2012).
[10]
E.composites Biofoam Product Description. 2009.
[11]
Schmidt, A. NAREBA Internal Report—Phase I and II; NAREBA Research and Development at BCIT: Vancouver, British Columbia, Canada, 2011.
[12]
BCIT, British Columbia Institute of Technology Department of Civil Engineering, Evaluation of Compressive, Pull Out, Flexural, and out of Plane Bending of Rammed Earth, Phase I and II; Report No. CERP-2009/06/15 and Report No. CERP-2009/11/09, Department of Civil Engineering, School of Construction and the Environment, BCIT, Burnaby British Columbia, Canada, 2009.
[13]
Tandy, T. Engineering Conclusions, R&D #1, BCIT; Unpublished Internal Report for NAREBA, Victoria, British Columbia, Canada, 2010.
