Physical Properties of Cement Paste and Concrete Containing Peat Fly Ash

Abstract

This paper presents data on selected properties of cement pastes and concretes that contain peat fly ash as a supplementary cementing material. Reference concretes and cement pastes with pure portland cement and with coal fly ash were used in the study. The tests were performed as comparison tests on pastes and concretes with or without an air-entraining agent. In addition, a superplasticizer and a water reducer were used in the pastes and concretes containing fly ashes. The fly ash contents used varied between 20 and 60 percent by mass of the total amount of binder. Tests on cement pastes showed that using peat fly ash or coal fly ash decreases the cracking tendency of a portland cement paste as measured by a shrinkage ring test method. No differences were observed between the pastes with peat fly ash or coal fly ash in this experiment. Drying shrinkage results show that concretes containing peat fly ash developed somewhat lower shrinkage values than the control mixtures containing coal fly ash. The strength, impermeability, and frost-resistance properties of concretes with peat fly ash did not essentially differ from those of coal fly ash concretes. The test data indicate that with proper mix design and choice of admixtures, peat fly ash could be used as a supplementary cementing material to produce a high-quality, frost-resistant concrete.