EMC - Introduction

Introduction

Introducing EMC

EMC cements and pozzolans are produced through a process of high activation grinding of Portland cement together with pozzolans.In the process, the particles are exposed to high energy impacts that create sub-micro cracks/dislocations on the particle surfaces, deform the particles, activate the surfaces, expand particle surface, and significantly increase the reactivity of the materials (see photo bellow).

The photo shows a processed powder consisting of 50 % quartz filler ground together with 50% Portland cement. It is taken with a Transmission Electron Microscope (TEM). The image demonstrates sub micro cracks and dislocations (see arrows) on the surface of a quartz particle, which could explain its significantly improved chemical reactivity in comparison with untreated powder.

In addition to traditional pozzolans like coal combustion fly ash, and blast furnace slag, EMC has also managed to activate materials traditionally considered inert, like fine quartz
(silica sand) and granite.

Depending on the pozzolanic materials used in the process, it is possible to replace between 50% (in the case of fine quartz sand and granite sand) and 85% (in the case of blast furnace slag) of the Portland cement content typically used in concrete structures.
EMC today focuses on five principal products:

Cement with about 70% fly ash content, a product that is marketed as EMC70f.
Cement with about 50% fine quartz sand content and 50% Ordinary Portland cement, a product that is marketed as EMC50q.
A highly reactive pozzolan consisting of 90-95% fly ash and 5-10% Portland cement, a product that is marketed as EMC CemPozz^®. This product is blended directly in the concrete mixer in the ratio of 60% CemPozz^® and 40% Portland cement.
EMC cement containing up to 85% blast furnace slag which competes with traditional recipes using 45-50% blast furnace slag.
EMC cement containing volcanic pozzolans.While this is the product on which the least work has been done to date, initial testing shows that similar results can be achieved to those described for the other products and chemical compositions similarities support this.