PROPERTIES OF DEVELOPED SYNTHETIC LIGHTWEIGHT AGGREGATE (COMPOSITE) BASED ON HYDRAULIC BINDERS AND WASTE
Marcin Głodniok, Jerzy Korol, Paweł Zawartka
Quarterly No. 4, 2022 pages 191-195
DOI:
keywords: sewage sludge, synthetic lightweight aggregate, granulates
abstract Lightweight aggregates developed on the basis of hydraulic binders and mining waste were investigated in the study. Original technology was utilized to obtain the aggregates. The synthetic aggregate materials obtained in the work satisfy the basic requirements for materials used in construction. Granulates were obtained by granulating raw materials with a counter-current high intensity mixer having a nominal capacity of 30 litres. A rotary tube furnace was selected as the most appropriate to sinter the produced granulates. The process combined two operations: burning the combustible fractions (sewage sludge) responsible for porosity, and sintering (consolidating) the granulate. The sintering process was conducted at the temperature of 950°C in the presence of air. The working reactor tilt was about 2°. Initially the rotational speed for the quick tests was 4.28 rpm, which yielded a granule residence time of about 7.3 minutes in the heating zone (a variant was applied for the tests). The obtained aggregates were subjected to strength testing, and their crushing resistance was determined based on standard PN-EN 13055-1. Depending on the proportions of the individual raw materials, the aggregates are characterised by high crushing resistance from 4.1 to 6.5 MPa, which confirms the potential for their industrial application. These aggregates may be used for purposes such as lightweight building and pavement concrete production due to their relatively low bulk density.