Compacted Non Cement Concrete Utilizing Fluidized Bed And Pulverized Coal Combustion By-Products

Abstract

The engineering characteristics and long-term durability of laboratory-made compacted non-cement composites made with fluidized bed combustion (FBC) spent bed and pulverized coal combustion (PCC) fly ash, by-products of fluidized bed and pulverized coal combustion processes, respectively, natural siliceous fine aggregate, and crushed limestone coarse aggregate, were investigated. The concrete constituents were combined and fabricated, at their optimum moisture content, in accordance with the requirements of ASTM D 1557. Once cured, the engineering characteristics of hardened specimens were assessed at different curing ages, up to 18 months, under both sealed and saturated conditions. The PCC:FBC impact compacted non-cement concretes were studied for unconfined compressive and indirect tensile strengths; static modulus of elasticity; and resistance to internal sulfate attack, abrasion wear, and freezing and thawing. Laboratory test results conclude that higher strength and expansion properties, and an increased performance in long-term durability are attained with increases in PCC fly ash to FBC spent bed ratio of the matrix. The inclusion of natural fine aggregate improves paste quality and properties of PCC:FBC compacted concretes. Under saturated conditions, the engineering and long-term characteristics of the selected mixtures are inferior to those obtained under sealed conditions.