PROPERTIES OF LIGHTWEIGHT CONCRETE MANUFACTURED WITH FLY ASH, FURNACE BOTTOM ASH, AND LYTAG

摘要

Fly ash (FA), furnace bottom ash (FBA) and Lytag (LG) were used in the current study to replace ordinary portland cement (OPC), natural sand (NS) and coarse aggregate (CA), respectively, and thereby to manufacture lightweight concrete (LWC). Two control mixes containing no replacement materials were designed with a 28-day compressive strength of 20 N/mm2 and 40 N/mm2. For each compressive strength, three different mixes, viz. (a) 100%OPC+100%NS + 100%CA, (b) 100%OPC + 100%FBA + 100%LG and （c）70%OPC + 30%FA + 100%FBA + 100%LG, were manufactured with slump in the range of 30～60 mm. The density, compressive strength, pull-off surface tensile strength, air permeability, sorptivity and porosity of the concretes were investigated. The results indicated that it is possible to manufacture lightweight concrete with density in the range of 1560-1960 kg/m3 and 28-day compressive strength in the range of 20-40 N/mm2 with various waste materials from thermal power plants. However, the introduction of FBA into concrete would cause detrimental effect on the permeation properties of concrete. With part of OPC replaced with FA, the strength decreased, but the permeability of the resulting concrete improved.