Modified Concretes Containing Peat Ash

The use of alternative materials, such as waste, as a replacement for ordinary Portland cement ensures economical and sustainable production of concrete with minimal hazardous impact on the environment. In this study, ash from peat combustion is used to replace some proportion of Portland cement in concrete. The properties of the fresh concrete modified with superplastisizer and the strength of concrete were studied when 5, 10, 15 and 20 wt.% of Portland cement was replaced by peat ash. It is shown that the introduction of ash instead of a part of cement into concrete in the amount of 5 and 10 wt.% does not affect the consistence class of fresh concrete. Adding of ash instead of a part of cement into concrete with a strength class C30/35 causes a decrease of the strength of concrete after 2 days of hardening by 7–18%, and a slight decrease of concrete strength with peat ash is observed after 28 days of hardening without changing the strength class.