Bioinspired Concrete - Biotechnologies and Biomimetics for Civil Engineering - page 292

Chapter 13
Bioinspired Concrete

Brent R. Constantz, Mark A. Bewernitz, Christopher L. Camiré,
Seung-Hee Kang, Jacob Schneider and Richard R. Wade II

Abstract New bioinspired cement can be used to form artificial limestone
aggregate for concrete, as well as cement for the binding phase of concrete.
Amorphous calcium carbonate precursors were first used in combination with
unstable calcium phosphates to form high strength, rapid setting carbonated cal-
cium phosphate cements, similar to the mineral phase of bone. Later, these
amorphous calcium carbonate precursors and other unstable polymorphs of cal-
cium carbonate were used in combination to form calcium carbonate cements with
high strength and other advantageous properties. In the last decade, mechanisms to
use the carbon dioxide from the combustion of fossil fuels were developed,
allowing very large quantities of calcium carbonate cementing precursor materials
to be formed, making it a foreseeable reality that new concrete mixes comprising
calcium carbonate, both as the aggregate component and the cementing phase of
concrete can be establish broadly on a worldwide basis. Calcium carbonate con-
crete compositions enable a sustainable pathway for concrete as a construction
material.

13.1 Introduction

Earth's most massive biological structures are coral reefs that may extend for
hundreds of miles and are composed mainly of calcium carbonate minerals. The
biological formation of minerals, biomineralization, plays a dominant role as a
reservoir of carbon on Earth by converting carbon dioxide to carbonate minerals.
In fact, most of Earth's accessable carbon is in the form of carbonate rocks in
Earth's lithospheric crust as limestone, comprised of the fossil remains of ancient