Scholars Challenge Ancient And Modern Masonry Myths

Drexel University Department of Materials Science and Engineering Professor M.W. Barsoum made headlines late last year from a Journal of the American


Drexel University Department of Materials Science and Engineering Professor M.W. Barsoum made headlines late last year from a Journal of the American Ceramic Society article, Microstructural Evidence of Reconstituted Limestone Block in the Great Pyramids of Egypt. Through micrographic observation, he suggested that some blocks from the 5,000-year-old structures are precast concrete instead of carved limestone. If other researchers can confirm certain blocks’ lime binder and companion mix constituents, the professor noted that his findings clearly show the Ancient Egyptians were exceptional civil and architectural engineers [and] superb chemists and material scientists. They would have to be credited with the invention of concrete, thousands of years before the Romans.

Dr. Barsoum is not the Philadelphia school’s only faculty member examining concrete block, although colleagues are involved with product of more conventional scale than the 2.5-ton units from which pyramid specimens were taken. Thanks to a National Concrete Masonry Association Education and Research Foundation (NCMA Foundation) grant, the Drexel Department of Civil, Architectural and Environmental Engineering has acquired precision machinery that molds concrete masonry units at one-third scale to standard 8_8_16 product (report, page 10). It equips students to make their own ASTM C90 block, then build wall specimens or scale-model buildings for testing applicable to full-sized CMU.

The NCMA Foundation funds activities under Workforce Development, Codes and Standard Research, and Architectural and Engineering Student Curriculum headings. Scale-model block production and testing conform to the third activity, as the machinery enables Drexel to resume an architecture and engineering student masonry design competition. (Its predecessor was sidetracked for five years when the school retired an original miniature block machine because of high maintenance, low output, and inability to yield ASTM-grade product researchers could consider for test measurements.)

The NCMA Foundation has awarded grants to Drexel and the University of Arizona for student design competitions involving block or landscaping units, and is reviewing applications to fund similar projects at five other schools. The miniature block machinery positions Drexel to create a template for other schools, since product is readily available for scale-model execution of student designs.

Toward the NCMA Foundation’s Codes and Standards grant criteria, the new machine will be used to make product for scale-model building tests to demonstrate how restrictive International Building Code provisions could diminish concrete masonry walls’ competitiveness by mandating heavy grouting and reinforcement regardless of a state or locale’s seismic exposure. Should a concrete masonry building in a low-seismic, IBC-covered East Coast market really be built to the same robustness as a comparable structure in Los Angeles or San Francisco?

Drexel’s small-scale block production and scale-model tests are progressing under Professor Ahmad Hamid and Assistant Professor Frank Moon. In their initial NCMA Foundation proposal, they noted how the lack of masonry research at universities has hampered building code development. Slow advances in code provisions, they contend, have fueled the misconception that masonry is a material of the past and thus well understood. While masonry is perhaps the oldest building material, it is also one of the most complicated and least understood from a behavior standpoint ÷ [resulting] in grossly conservative [code] design provisions that unduly penalize masonry buildings.

The NCMA Foundation is right on track helping the school take the lead in scale-model block building and design competitions Û not to mention research that promotes logical masonry building code provisions versus designs that might keep a block wall standing as long as an Egyptian pyramid.

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