Computer Modeling of Concrete (IMAGE) Rice University Caption Rice University researchers analyzed more than 600 computer models of concrete's inner matrix to determine how voids (center) and portlandite particles (right) impart strength and toughness by preventing the spread of cracks (left). Credit Ning Zhang/Rice University Usage Restrictions For news reporting purposes only. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.