Properties and Durability of a Pre-Columbian Lightweight Concrete
J. G. Cabrera, R. Rivera-Villarreal
and R. Sri Ravindrarajah
Appears on pages(s):
History; lightweight concrete; lime; pozzolans; pumice.
Lightweight concrete was designed and used for the construction of structural elements by the pre-Columbian builders who lived in a very advanced civilisation in El Tajin near Mexico City, in Mexico. This investigations present data on the engineering and performance properties of this lightweight concrete obtained from the slab of a floor of one of the buildings discovered in El Tajin. Detailed drawings made during the exploration show that the unreinforced thick slabs were supported by columns placed four metre apart and that they probably behaved structurally as arches. Data obtained includes strength, porosity and permeability. A detailed study of the composition of the aggregate and binder show that the aggregate was pumice and the binder was a pozzolanic cement made with volcanic ash and lime. Microstructural features obtained by electron microscopy reveal interesting features of this lightweight concrete which as far as the authors know was the oldest lightweight concrete found in the world. The concrete has survived for more than 2000 years in a very good condition providing an outstanding example of a concrete of low strength and very long-term performance.