Chemical Properties and Performance Results of Sustainable Solidia Cement Detailed in White Paper Series

In the first of a two-part white paper series, Solidia Technologies® details the chemical properties, manufacture and performance qualities of a sustainable cement that, combined with its concrete counterpart, can reduce the carbon footprint of cement and concrete products up to 70%. Made from the same raw materials and equipment as traditional Portland cement, Solidia Cement™ is adaptable to a wide variety of cement formulations and production methods, offering Portland cement manufacturers the world over a sustainable and performance-enhancing alternative.

Abstract

Solidia Cement™ is a non-hydraulic cement composed primarily of low-lime containing calcium silicate phases such as wollastonite / pseudowollastonite (CaO·SiO2), and rankinite (3CaO·2SiO2). This contrasts the high-lime alite (3CaO·SiO2), belite (2CaO·SiO2), tricalcium aluminate (3CaO·Al2O3), tetracalcium aluminum ferrite (4CaO·Al2O3·Fe2O3), and gypsum (CaSO4·2H2O) phases that comprise ordinary Portland cement (OPC). The setting and hardening characteristics of Solidia Cement are derived from a reaction between carbon dioxide (CO2) and the calcium silicates. During the carbonation process, calcite (CaCO3) and silica (SiO2) form and are responsible for the strength development in concrete.

The technological process used to produce Solidia Cement is adaptable and flexible, allowing a wide variety of cement raw meal formulations and production methods. Solidia Cement is made from the same calcareous and siliceous raw materials as Portland cement. Its manufacture needs neither specialized equipment nor additional unit operations, and existing Portland cement plants can be used without modification. Solidia Cement can be manufactured in any part of the world, wherever Portland cement is produced. The clinker of Solidia Cement is produced at a temperature of about 1200OC, which is roughly 250OC lower than the sintering temperature used in Portland cement clinker manufacturing. Production of Solidia Cement reduces the emission of greenhouse gas-CO2 by 30%.

Concrete products made with Solidia Cement are manufactured using the same, basic mixing and forming processes as Portland cement-based concrete. Concrete products made using Solidia Cement sequester up to 300 kg of CO2 per tonne1 of cement used and have similar or better performance compared to traditional concrete products. When the reduced CO2 emissions associated with Solidia Cement production are considered along with the ability of that cement to sequester CO2 during concrete curing, the CO2 footprint associated with the manufacturing and use of cement can be reduced by up to 70%.

“For over 50 years, scientists have tried to cure concrete with CO2 knowing the resulting product would be stronger and more stable. Solidia Technologies is the first to make this commercially viable. Our current focus is testing additional applications with an even wider variety of concrete formulations and manufacture methods to facilitate adoption across the globe,” said Solidia Chief Technology Officer Nicholas DeCristofaro, Ph.D., who co-authored the paper with Principal Scientist Sada Sahu, Ph.D.

Collaborations include research in concrete applications with Lafarge and a CRADA with the U.S. Federal Highway Administration to examine transportation infrastructure applications. The original generation of the technology was developed at Rutgers University.

Solidia Concrete™ will be explored in a companion paper to be released January 2014.

A winner of the 2013 R&D Top 100 Award and shortlisted for the 2013 Cleantech 100, Solidia’s investors include Kleiner Perkins Caufield & Byers, Bright Capital, BASF, and BP. Follow Solidia Technologies at www.solidiatech.com and on LinkedIn and Twitter: @SolidiaCO2.

1 All calculations are based on the tonne, also known as the metric ton, equaling 1,000 kilograms.