Cement with Pozzolana

Pozzolana are defined as substances of siliceous or silico-aluminous composition. Finely ground pozzolanic materials react in the presence of water at normal ambient temperature with dissolved calcium hydroxide (Ca(OH)2) to form strength-developing calcium silicate and calcium aluminate compounds. In general, the use of a pozzolana as a main constituent of cement is possible if the content of reactive silicon dioxide amounts not less than 25% by mass. Often a differentiation is made between natural pozzolana and natural calcined pozzolana. The production of cements with pozzolana as a main constituent involves the pre-treatment of the pozzolana like crushing, drying and grinding and the intergrinding or mixing of the cement clinker with the pozzolanic material. The use of pozzolana as a main constituent can lead to better workability of the concrete due to a better grain size distribution as well as to higher long term strength and improved chemical resistance.

Conformance of this alternative with Indian standards needs to be established. 

Development Status Products
Commercial
Cement

Cement with PozzolanaCosts & Benefits

Parent Process: Blended Cement Alternatives
Energy Savings Potential

Thermal energy use decreases by 0 - 600 MJ/t cement; electricity use decreases by 0 - 25 KWh/t cement.

CO2 Emission Reduction Potential

The process-related emission reduction in the range of 0.52 tonne CO2 per every tonne of clinker replaced by pozzolana is possible. 

Costs

EU Flag Investment cost for retrofit is estimated to be € 8 to 12 millions. Capital costs are due to extra storage capacity for the pozzolana and the cements as well as the technical equipment for handling and drying of the pozzolana. 

Cement with Pozzolana Publications

Development of State of the Art Techniques in Cement Manufacturing: Trying to Look Ahead

The report represents the independent research efforts of the European Cement Research Academy (ECRA) to identify, describe and evaluate technologies which may contribute to increase energy efficiency and to reduce greenhouse gas emissions from global cement production today as well as in the medium and long-term future. 

Page Number: 

76-78