FCanadian Masonry Symposium, Banff, Alberta, June I - 12,2005 MOVEMENT COEFFICIENTSOF COMPRESSEDEARTH MASONRY UNITS C. W. Grahaml, M.L. Coody2oR. Burt3 and D. Beniwala lArchitect,Mitchell EndowedProfessor of ResidentialConstruction and Visualization, Departrnent of Construction Science,College of Architecture,Texas A&M University,College Station, Texas, USA, 2StructuralEngineer and Associat" tr"*ril:#ffi:fin"Hffi,:tln Science,college of Architecture,Texas A&M University, College Station, Texas, USA,
[email protected] 3Assistant Professor,Department of Construction Science,College of Architecture, Texas A&M University, College aGraduateStudent inconstructi.i,iTi?l;1ffiJ;l;"*H91Tl:xffilio",lt,,.n"", coregeof Architecture, TexasA&M University,College Station, Texas, USA,
[email protected] ABSTRACT Coefficients exist for the physical movementsclay brick and concretemasonry units undergo in service. Less well known, however, are the movements of masonry units made of compressed earth. The standard laboratory tests for certification of quality and strength standardsfor fired clay brick and concrete masonry units, for example, include test procedures that must be modified for earth masonry. The hot and cold water baths used for absorption determination would causeunmodified earth bricks to dissolve. While masonry units modified with Portland cement, lime, or fly ash will have increaseddurability to dissolving in the water baths, very few ASTM or other standard procedures have been developed to determine the movement coefficients for compressedearth block units. A review of the literature and preliminary testing of compressedearth bricks has found that standardtests in the laboratory must be adapted to determinethe physical characteristicsof earth masonry. Among the coefficients neededare those for thermal expansion(fr); moisture expansion(k"); shrinkage(k^); elasticshortening (ES); creep (k"); and, deflection (A).