Mechanical and hygric properties of lime plasters modified by biomass fly ash

Abstract

Utilisation of waste industrial products together with the modification and replacement of tradition binders represent an important discipline within the new material design. Since lime plasters are not suitable for many applications due to the poor durability and resistance against environmental deterioration and cement sometimes cannot be used because of its incompatibility with the historical buildings, the application of pozzolan admixtures poses an efficient way for plaster improvements. Moreover, in terms of the sustainable development, the utilisation of various environmentally friendly materials as a lime replacement represents an important advance for the low-carbon industry. On this account, the fly ash generated during wood combustion in a biomass power plant is employed as a promising pozzolanic material for the modification of lime plasters. Within the experimental investigations of the composed plasters with lime replacement up to 50 mass% the influence of waste wood fly ash (WWFA) on the basic material characteristics, mechanical and hygric properties is analysed. Experimental results show that WWFA dosage up to 50 mass% significantly improved the compressive and flexural strength while liquid transport properties were maintained on the same level. Therefore, the modified lime-pozzolan plasters reveal a good potential for the application in surface layer of buildings.