Title: Materials Technology Laboratory
Author: N. Bouzoubaâ, M.H. Zhang, and V.M. Malhotra
Abstract: This paper presents data on the performance of the concrete made with HVFA blended cements using fly ashes from Canada and the U.S.A. The parameters investigated included the compressive strength of concrete and its resistance to the chloride-ion penetration. Regardless of the type of the fly ash used, the concrete made with the HVFA blended cements developed higher compressive strength at all ages than that of the HVFA concrete in which unground fly ashes and laboratoryproduced portland cements had been added separately at the concrete mixer. The increase in the compressive strength was more significant for the HVFA blended cements produced with the cement without a superplasticizer and made with coarse fly ash. The use of the HVFA blended cements improved the resistance of the concrete to the chloride-ion penetration, and the improvement in the resistance increased with an increase in the intergrinding time of the fly ash and the cement..

Title: Air-entraining Admixtures for Use with Fly Ashes Having High Carbon Contents
Author: P.C. Nkinamubanzi, A. Bilodeau, C. Jolicoeur and D. M. Golden
Abstract: New air-entraining admixtures (AEA), suitable for use with
concrete containing fly ashes having levels of unburned carbon higher than the typical 2-4% allowed in the concrete industry, have been tested in this study.

Title: Some key cement factors that control the compatibility between naphthalene-based superplasticizers and ordinary Portland cements
Author: Pierre-Claver Nkinamubanzi, Byung-Gi Kim and Pierre-Claude Aïtcin
Abstract: Superplasticizers improve the workability of concrete at low water-cement ratios but this workability is sometimes lost rapidly in the first hour after contact between the cement and water. This is especially the case for naphthalene-based and melamine-based superplasticizers when used with the so-called incompatible cements. It is possible to reasonably predict the rheological behavior of a given Portland cement when used with a naphthalene-based superplasticizer once the physico-chemical composition and the properties of the clinker, of the cement, and of the superplasticizer are known.

Title: Production and Performance of Laboratory Produced High-Volume Fly Ash Blended Cements in Concrete
Author: N. Bouzoubaâ and V. M. Malhotra
Abstract: This paper reports the development at CANMET of high-volume fly ash blended cements, and their performance in concrete. The blended cements are made by inter-grinding 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.

Title: High-Volume fly Ash System: The Concrete Solution for Sustainable Development
Date: September 1998
Author: A. Bilodeau and V.M. Malhotra
Abstract: The challenge for the civil engineering community in the near future will be to realize projects in harmony with the concept of sustainable development, and this involves the use of high performance
materials produced at reasonable cost with the lowest possible environmental impact.

Title: Use of High-Volume Fly Ash Concrete at the LIU Centre
Date: January 2001
Author: A. Bilodeau, V.M. Malhotra, and P.T. Seabrook
Abstract: In view of the global sustainable development, it is imperative that supplementary cementing materials be used to replace large proportions of cement in the concrete industry, and the most available supplementary cementing material worldwide is fly ash, a by-product of
thermal power stations. In order to increase considerably the utilization of fly ash that otherwise is being wasted, and to have a significant impact on the production of cement, it is necessary to advocate the use of concrete that will incorporate large amounts of fly ash as replacement for
cement. However, such concrete will have to demonstrate performance comparable to that of conventional Portland cement concrete, and must be cost effective.

Title: Practical Uses of High-Volume Fly Ash Concrete Utilizing a Low Calcium Fly Ash
Date: February 2001
Author: Wilbert S. Langley, M.Eng., P.Eng., FACI, FCSCE
Abstract: Concrete containing fly ash has been used in many parts of the world for several decades. Various standards and codes have generally limited the use of ASTM Class F fly ash from 20 to 25 percent. Laboratory studies and field demostration projects sponsored by CANMET during the last 15 years have shown that concrete containing 55 to 60 percent fly ask has excellent structural and durability characteristics when proportioned with superplasticizers and at low water to cementing materials ratio.

Title: Mechanical Properties and Durability of Concrete made with HVFA Blended Cement Produced in a Cement Plant
Author: N. Bouzoubaâa, B. Fournierb, M.V. Malhotrac and D.M. Goldend
Abstract: 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 28-day compressive strength comparable to that of the concrete made with the HFA blended cement.

Title: Performance of Mortars Incorporating Finely-Ground Fly Ash
Author: N. Bouzoubaâ and V. M. Malhotra
Abstract: This paper presents results on the compressive strength of mortars in which 10 and 20% of ASTM Type I cement has been replaced by ground fly ash from two different sources. The results are compared with those of the mortars made with ASTM Type I cement, and with the mortar in which 10% of portland cement has been replaced by silica fume. The results show that the mortars made with 20% replacement of cement by the fine Sundance fly ash that had been ground for 2 hours achieved a 28-day compressive strength that was 90 to 93% of the strength of the mortars incorporating 10% silica fume as cement replacement. However, for the coarse fly ash, the results were not encouraging. Even increasing the grinding times of the fly ash up to 10 hours, did not yield the compressive strengths approaching that of the silica fume mortars.

Title: Leachability of Trace Metal Elements from Fly Ashes and Concrete Incorporating the Fly Ashes
Date: December 1999
Author: M.H. Zhang, M.Blanchette and V.M. Malhotra
Abstract: This paper presents information on the leachability of trace metal elements from fly ashes from canadian and the U.S. sources, and from the concrete incorporating the fly ashes. It provides data not reported previously, and deals with different leaching conditions such as column-leaching tests to simulate wetting, drying and batch-leaching tests using synhetic acid rain as a leachant.

Title: Optimization of Fly Ash Content in Concrete
Date: February 2002
Author: N. Bouzoubaâ and B. Fournier
Abstract: 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.

Title: Self Compacting Concrete Incorporating High-Volumes of Class F Fly Ash: Preliminary Results
Author: N. Bouzoubaâa and M. Lachemib
Abstract: In recent years, self-compacting concrete (SCC) has gained wide use for placement in congested reinforced concrete structures with difficult casting conditions. For such applications, the fresh concrete must possess high fluidity and good cohesiveness. The use of fine materials such as fly ash can ensure the required concrete properties. The initial results of an experimental program aimed at producing and evaluating SCC made with high-volumes of fly ash are presented and discussed. Nine SCC mixtures and one control concrete were investigated in this study. The content of the cementitious materials was maintained constant (400 kg/m3), while the water/ cementitious material ratios ranged from 0.35 to 0.45. The self-compacting mixtures had a cement replacement of 40, 50, and 60% by Class F fly ash. Tests were carried out on all mixtures to obtain the properties of fresh concrete in terms of viscosity and stability. The mechanical properties of hardened concretes such as compressive strength and drying shrinkage were also determined.
The self-compacting concretes developed a 28-day compressive strengths ranging from 26 to 48 MPa. The results show that an economical self-compacting concrete could be successfully developed by incorporating high-volumes of Class F fly ash.

Title: The Role of Fly Ash in Controlling Alkali-Silica Reaction in Concrete
Author: B. Fournier
Abstract: The alkali-silica reaction (ASR) is one of the various deterioration processes that can affect the serviceability and the service life of concrete structures. Past field experience and extensive
laboratory investigations have shown that an adequate amount of an effective fly ash can significantly reduce and even control deleterious expansion due to ASR in concrete. This paper deals with the role of fly ash in controlling alkali-silica reaction in concrete, and
discusses preventive mechanisms.