Optimization of Fly Ash in Concrete

This report outlines the preliminary results of a research project aimed at optimizing the fly ash content in concrete. Such fly ash concrete would develop an adequate 1-day compressive strength and would be less expensive than the normal Portland cement concrete with similar 28-day compressive strength.

The results show that in a normal portland-cement concrete having a 28-day compressive strength of 40 MPa. it is possible to replace 50% of cement by a fine fly ash -~3000 cm2/g- with a CaO content of ~ 13% yielding a concrete of similar 28-day compressive strength. This concrete air-entrained or not can be designed to yield an early-age strength of 10 MPa. and results in a cost reduction of about 20% in comparison to the control concrete. In a case of a coarser fly ash -~2000 cm2/g- with a CaO content of ~ 4% substitution levels of cement by this ash could be from 30 to 40%. This concrete yields a 1- day compressive strength of 10 MPa. and 28-day compressive strength similar to that of the control concrete. The total cost of this concrete is about 10% lower than that of the control concrete. The above fly ash concrete are made without the use of a superplasticizer and are found to have higher resistance to chloride-ion penetration than the control concrete.

Technical Report Author: Nabil Bouzoubaa, Benoit Fournier, CANMET Energy Technology Centre, Natural Resources Canada,

Use of EcoSmart Concrete in Multi-Unit Residential Construction – A Case Study: Cranberry Commons

The report analyzes the economical technical and business impacts of using EcoSmart concrete in Cranberry Commons a multi-unit residential construction project. The Cranberry Commons Cohousing Development Corporation chose to incorporate EcoSmart concrete because of their dedication to implementing environmentally sustainable building technologies throughout their building. Although the concrete took longer to set it did not effect the scheduling of the project. The use of EcoSmart concrete meant that the contractors were able to reduce cement content by 32%.

Case Study Report Author: Bob Mann, Artian Construction Ltd.,