Blended Cements

Development and implementation of  high performance concrete (HPC) materials using blended cements is a major area in the development of sustainable constructions materials.  The knowledge of using blended cement systems allows cost-effective solutions and a greater flexibility in meeting the design requirements.  In the area of blended cements mour team has specialized in teh use of blended Class C, F, and N flyash, copper slag, Matakaolin, and Wollastonite.  It is imperative that new research, guidelines, and laboratory evaluation of these supplementary cementitious systems be developed for proper utilization.   The economic benefits of blended cements are in several main areas which include:

environmental aspects of converting waste materials into value added components,  improved microstructural properties of the end product.

The main role of the mineral admixtures in the development of strength is through the formation of pozzolanic reactions.  In these reactions, the calcium-silicate rich materials such as silica fume and fly ash react with the calcium hydroxide which is a by-product of the reaction of hydration products of Portland cement and water.   The improved microstructure, and enhanced strength are some of the main attributes of this process.

This project is aimed at using industrial by-products such as flyash and slag materials in order to manufacture blended cements for use in concrete. Emphasis is placed on the hydration characteristics, durability, strength, and fracture properties.   We use  X-ray diffraction, scanning electron microscopy, and thermogravimetric methods in addition to closed loop mechanical testing of concrete containing various blended cement compositions. Various durability tests are conducted in order to evaluate the performance. Results are compared with fly ash and silica fume based concrete. For recent research publications in the area of blended cements please see the following:

2-D Mud Cracking Phenomenon

Arino, A., Tixier, R., and Mobasher, B., ” Effect of Copper Slag on the Hydration and Mechanical Properties  of Blended Cementitious Mixtures” MRS 1996 Fall Meeting, Symposium HH: Structure-Property Relationships in Hardened Cement pastes and Composites, Boston, Mass. [view] 
B. Mobasher, V. Devaguptapu, and A.M. Arino, “Effect of Copper Slag on the Hydration of Blended Cementitious Mixtures,”ASCE, Materials Engineering Conference, Materials for the New Millennium, ed. K. Chong, pp. 1677-86, 1996. [PDF] 
Tixier, R. and Mobasher, B., “Blended Cements,” Chapter 5, Cements Research Progress,1997. Editor: L. Struble.  American Ceramic Society, 1999.  pp. 153-212. [PDF] 
Economical Concrete Mix Designs For Highway Applications With High Dosage Flyash R. V. Shah and B. Mobasher, Report to SRP, 2003. PDF 
Tixier, R. and Mobasher, B., ” Blended Cements,” Chapter 5, Cements Research Progress,1998. Editor: L. Struble.  American Ceramic Society,  2000. [PDF
Mobasher, B. , Peled, A., and Pahilajani, “Pultrusion of Fabric Reinforced High Flyash Blended Cement Composites,”  Proceedings, RILEM Technical Meeting, BEFIB, 2004. pp.1473-1482. [pdf]