Durability of Concrete with Fly Ash from the Dam Orlík after 55 Years

Abstract

The paper focuses on some properties of concrete with fly ash after 55 years in operation. Among other things this topic refers to still current issue of sustainable development. In this case, it is saving of cement by using of substitution of fly ash. Another researched topic in the paper is the durability of structures and building materials. For obtaining important data, samples of concrete were extracted from the body of the dam Orlík, which has been in operation since 1961 and fly ash was used in a mixture. The results of the measurement of carbonation and frost resistance of concrete with fly ash addition are presented and analyzed in this paper.

The Influence of High Temperatures and Time on the Material and Mechanical Properties of Cement Binder with Fly Ash

“…If more than 40% of the cement is replaced by the fly ash in the mixture, the increase strength is slowed, but in the following time the strength same like the reference mixture [12,13,14,15]. This fact was also previously verified on concrete from the Orlík reservoir body where the 28-day compressive strength was 10 MPa and after 50 years of operation the concrete had a characteristic strength of 38.7 MPa [16]. However, it is not possible to say whether the right way is to use fly ash in combination with a cement matrix as a protection against high temperatures, further measurements and research is needed.…”

Long-Term Development of Strength of Cement Paste with Fly Ash

“…The concrete from the Orlík dam corresponds to class C8/10 and fly ash replaced in the mixture of 28.8% by weight of cement. The characteristic compressive strength was 10 MPa after 28 days and 38.7 MPa after 50 years in operation [16]. The strength development of the Orlík dam in time is shown in Fig.…”

“…The problem may occur with the durability, specifically with frost resistance, resistance to deicing salts or carbonation [7,13,14,15]. A separate chapter is increase the strength of concrete and its development [7,13,16], which this paper is devoted.…”

Durabilidad de mezclas de concreto con diferentes contenidos de ceniza volante activada

“…(Lizarazo et al, 2015). Up until now, the use of FA is considered an effective solution (Zobal et al, 2017). Considering the background use of FA, positive effects on concrete properties, low cost and current availability of FA in Mexico (stored), this article focuses on determining durability properties, which were: quality concrete through ultrasonic pulse velocity (UPV), apparent electrical resistivity (ρ), rapid chloride permeability, mechanical resistance to compression and mixtures with FA with different contents of Portland cement (CPC).…”