Mechanical Properties and Durability of Concrete made with HVFA Blended Cement Produced in a Cement Plant

This paper presents the results of a study on the mechanical properties and durability of concrete made with high volume fly ash -HVFA- blended cement produced in a cement plant. The test results obtained were compared with those of a control concrete made with a commercially available ASTM Type I cement; the control concrete had a 28-day compressive strength comparable to that of the concrete made with the HVFA blended cement.

The results showed that in order to obtain similar slump and air content to those of the control concrete the use of HVFA blended cement required increased dosages of the superplasticizer and the air-entraining admixture. This resulted in some delay in the initial and final setting times of concrete.

The use of HVFA blended cement resulted in lower compressive and flexural strengths at early ages -before 28 days- and higher mechanical properties after 28 days as compared with those of the control concrete made with ASTM Type I cement. The concrete made with the HVFA blended cement developed a 1-day compressive strength of 13 MPa -compared to 19 MPa for the control concrete- which is considered more than satisfactory for formwork removal.

The use of the HVFA blended cement improved significantly the durability characteristics of the concrete; the only exception was the resistance to the de-icing salt scaling as determined in ASTM C 672 test.

Technical Report Author: Nabil Bouzoubaa, Benoit Fournier, V.M. Malhotra, D.M. Golden