Cement Mortars with Addition of Fly Ash from Thermal Transformation of Sewage Sludge and Zeolite

Abstract

The aim of research was an influence evaluation of fly ash and zeolite on selected parameters of cement mortar. The scope of the research includes studies of composition and properties of fly ash itself from the thermal transformation of sewage sludge and natural zeolite (clinoptilolite). The research also included the determination of selected mechanical properties of designed mortars, both under normal conditions and after initial thermal loads. A mortar was designed based on CEM I 42.5 R Portland cement with different content of the applied additive in the amount of 5, 10 and 15% of the cement weight. In the course of experimental work, the bending strength of mortars heated at 20, 300, 500, 700 °C were tested. The resulting beam halves (40 × 40 × 160 mm) were used to test the compressive strength. The collected results made it possible to compare the properties of the mortars. The experiment confirmed the possibility of producing cement mortars modified with fly ash from thermal transformation of sewage sludge and zeolite from tuff deposits. The average compressive strength for the mortar containing 5% fly ash and zeolite was set at 28.7 and 27.1 MPa, respectively.