Tag Archives: Blended cement

EcoSmart Concrete in the Quebec Context: Mountain Equipment Co-op, Montreal

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The Mountain Equipment Co-op Montreal store is the Co-op s 8th retail store and the third -after the Ottawa and Winnipeg stores- to comply with Natural Resources Canada s C2000 Green Building Standard. It is the first C2000 compliant retail building in Quebec.

The decision to use EcoSmart concrete was based on the project s environmental objectives. The team initially hoped to use a 50% SCM concrete mix and was surprised to discover that the use of EcoSmart concrete in the MEC Montreal store would be a challenge both in terms of SCM percentage and in terms of cost. The cost premium for HVSCM -high volume supplementary cementing material- concrete in Quebec is related to the limited availability of SCMs in that province other than silica fume. Because most concrete plants do not have an extra silo for storing SCMs most SCM concrete in Quebec is made from preblended SCM cement based on an unvarying formula.

The goal of using a 50% mix was abandoned for budget reasons but MEC agreed to invest the extra money for the 27% mix. When the concrete bids were in the decision was made to use concrete made with Lafarge s Tercem 3000TM blended cement -a blend of 20-25% blast furnace slag 4-6% silica fume and 69-76% Portland cement- . The premium cost for this concrete was $20 / m3 which represents 11.3% of the total concrete cost.

Construction on the MEC store started in October 2002 and was completed in May 2003. The scheduling of the project suffered significant delays due to abnormally cold winter conditions. There was no perceived difference in curing time or workability. The quality of finishing was somewhat disappointing although this was mainly attributed to quality control of the finishing sub-trade rather than the concrete used.

Case Study Report Author: Studio MMA, Atelier d architecture

Mechanical Properties and Durability of Concrete Made With High Volume Fly Ash Blended Cements Using a Coarse Fly Ash

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This paper presents a study on the mechanical properties and durability of concrete made with a high-volume fly ash blended cement using a coarse fly ash that does not meet the fineness requirement of ASTM C 618. The results were compared with those of the HVFA concrete in which unground fly ash had been added at the concrete mixer. The properties of the fresh concrete determined included the slump air content slump loss stability of air content bleeding and setting time; those of the hardened concrete investigated included the compressive strength flexural- and splitting-tensile strengths Young’s modulus of elasticity drying shrinkage resistance to abrasion chloride-ion penetration freezing and thawing cycling and to de-icing salt scaling. The results show that except for the resistance of the concrete to the de-icing salt scaling the mechanical properties and the durability of concrete made with this blended cement were superior to the concrete in which the unground fly ash and the cement had been added separately at the mixer. The production of HVFA blended cements therefore offers an effective way for the utilization of coarse fly ashes that do not otherwise meet the fineness requirements of ASTM C 618.

This paper was originally published in Cement and Concrete Research Vol. 31 No. 3 Oct. 2001. It includes a list of tables and figures detailing the results of the studies.

Technical Report Author: M.H. Zhang, Nabil Bouzoubaa, V.M. Malhotra, CANMET Energy Technology Centre, Natural Resources Canada,

Development of Ternary Blends for High-Performance Concrete

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The purpose of this study was to develop ternary blends with optimum amounts of fly ash and silica fume to be used in high-performance concrete. Two series of air-entrained concrete mixtures were investigated in the study: series 1 included concretes with a total cementitious materials content -CM- of 350 kg/m 3 and a water-to-cementitious materials ratio -W/CM- of 0.40 and series 2 included concretes with a total CM of 450 kg/m 3 and a W/CM of 0.34. In each series one silica fume and three fly ashes were used; these consisted of two ASTM Class F and one ASTM Class C fly ashes. Properties of the fresh and hardened concrete such as slump air content bleeding setting time autogenous temperature rise plastic shrinkage compressive strength drying shrinkage and the resistance to chloride-ion penetration were determined. The results show that the combined use of fly ash and silica fume in concrete are more advantageous in terms of the following parameters: the dosage of superplasticizer plastic shrinkage chloride-ion penetrability and the drying shrinkage. The report includes various tables and figures detailing the results of the study.

Technical Report Author: Nabil Bouzoubaa, Alain Bilodeau, Benoit Fournier, V. Sivasundaram, D.M. Golden, CANMET Energy Technology Centre, Natural Resources Canada,

GLOBE 2002 Technical Presentation

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This presentation from GLOBE 2002 provides an overview of the issues and concerns associated with the use of fly ash and other supplementary cementing materials in concrete including ground slag cement -GS-Cem- natural pozzolans and metakaolin. Also introduces the EcoSmart project and the EcoSmart case studies. This presentation was part of Session 6: Innovative Technology Applications: Partnerships and Networks.

Presentation Author: Michel de Spot, P.Eng.

Production and Performance of Laboratory Produced High-Volume Fly Ash Blended Cements in Concrete

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This paper reports on CANMET s development of high volume fly ash -HVFA- blended cements and their performance in concrete. The blended cements are made by intergrinding approximately 55% of fly ash and 45% of ASTM Type I or Type III cement clinker together with small amounts of gypsum and a dry superplasticizer. The concrete made with the HVFA blended cements has adequate early-age and excellent later-age mechanical properties and demonstrates satisfactory performance in durability aspects such as resistance to freezing and thawing cycling and chloride ion penetration.

Technical Report Author: Nabil Bouzoubaa, M.H. Zhang, V.M. Malhotra, CANMET Energy Technology Centre, Natural Resources Canada,