Uniquely Shaped Concrete Beam Passes Strength Test

Brief 

A “Zip-Form” concrete beam with a flat top and curved base cracked after being subjected to a 12,000-pound load, far exceeding its design strength of 8,500 pounds. The uniquely shaped beam, designed by MIT doctoral student Mohamed Ismail with help from graduate students at the University of Arkansas, contains 40% less embodied carbon than conventional beams.

Insight

On a scorching day in July, representatives from multiple colleges at the U of A, as well as the Massachusetts Institute of Technology, gathered at the Harvell Civil Engineering Research and Education Center to conduct a stress test on a concrete beam. Typically, a beam testing doesn’t draw a crowd, but this test was a showcase for a collaborative new approach to beam design and optimization.

The man most responsible for the beam’s design was Mohamed Ismail, a Ph.D. student in building technology at MIT, a discipline residing at the intersection of architecture and engineering. Ismail had flown in to witness the test in person and seemed vaguely nervous that the beam might not perform as expected — a feeling perhaps heightened by the unusual degree of attention the stress test was receiving.

The fruits of research are not always immediately evident, but the nature of the test — hydraulic press versus concrete beam — brought out the various colleges’ social media staff, who recognized strong visual content when they saw it.

Perhaps a dozen people were assembled to see how Ismail’s beam performed.

Among Ismail’s research interests is increasing the structural efficiency of building materials. In the case of concrete beams, that means reducing the amount of concrete and steel used to a minimum — removing concrete from where it isn’t needed, retaining it where it is.

This resulted in his beam having a flat top but a base that curved in unanticipated ways. He estimates that the beam in question contained 40 percent less embodied carbon — the amount of carbon burned to produce the concrete and steel used in the beam — than standard rectangular beams.