An international team of geologists and engineers, in an effort to make concrete more sustainable and durable, will take advantage of the experience of the ancient Romans, whose massive concrete buildings have stood the test of time, standing for more than 2000 years.
The University of California at Berkeley research team has examined a sample of a Roman concrete structure.
The chemical secrets of Roman concrete (also called opus caementicium), which has been submerged in the Mediterranean for the past 2,000 years, have been discovered by an international team of researchers led by Paulo Monteiro of the University of California at Berkeley.
Sample analysis, performed by Mary Jackson, has allowed to understand the reasons why Roman concrete is superior in quality to modern concrete, and to answer the question of how the Romans managed to make the creating concrete process so environmentally friendly, as well as to develop ways to implement the acquired knowledge in the modern world.
“In the middle of the 20th century, cement structures were designed to last 50 years, and many of them have already gone beyond that limit,” Monteiro said. “Today we create buildings that are designed to last 100-120 years, while Roman buildings withstood 2,000 years of chemical attack and undercurrents.”
The Romans created cement by mixing effusive rocks with lime
The lime reacted with aluminum-rich volcanic tuff, pozzolana (pulvis puteolanus in Latin), and seawater to provide strength and durability. Both the materials and the method of production used by the Romans contain invaluable experience.
“Pozzolan is important for us, first of all, in practical terms,” Monteiro said. “The new material could replace a total of 40% of the world’s demand for Portland cement. Pozzolana deposits can be found all over the world.”