Mechanical Properties and Durability of High‐Performance Concretes Blended with Circulating Fluidized Bed Combustion Ash and Slag as Replacement for Ordinary Portland Cement

Abstract

This study investigates the mechanical properties and durability of three families of high-performance concrete (HPC), in which the first was blended with fly ash, the second with circulating fluidized bed combustion (CFBC) ash, and the third with CFBC slag. In addition to each of the three mineral additives, silica fume and a superplasticizer were also incorporated into the HPC. Hence, three families of HPC, containing 10%, 20%, and 30% mineral admixtures and 9% silica fume of the binder mass, respectively, were produced. The microstructure and hydration products of the HPC families were examined by scanning electron microscopy (SEM) and X-ray diffraction (XRD) to explore the influence of fly ash, CFBC ash, and CFBC slag on the compressive strength and frost resistance of HPC. The experimental results show that the compressive strength of HPC could reach 60 MPa at 28 d age. When the fly ash content was 30%, the compressive strength of HPC was 70.2 MPa at 28 d age; after the freeze-thaw cycle, the mass loss and strength loss of HPC were 0.63% and 8.9%, respectively. When the CFBC ash content was 20%, the compressive strength of HPC was 75 MPa at 28 d age. After the freeze-thaw cycle, the mass loss and strength loss of HPC were 0.17% and 0.81%, respectively.

Strength Tests and Numerical Simulations of Loess Modified by Desulfurization Ash and Fly Ash

“…Meanwhile, the desulfurization ash has anhydrite, which does not exist in the fly ash. The chemical reaction of the desulfurization ash needs more water [18,27].…”

“…It has a good effect to link the modified loess as a whole. In general, desulfurization ash is better than fly ash to modify the loess [18,22,23].…”

“…The solid wastes discharged from CFB boiler can be divided into two kinds, which are desulfurization ash and desulfurization slag. Among them, desulfurization ash is collected in the gas flue, and desulfurization slag is discharged from the bottom of the furnace [18]. At present, the utilization rate of desulphurization ash and slag is less than 10%, and most of them are in the state of stockpiling.…”

Study of the Frost Resistance of HDFC Based on a Response Surface Model and GM (1,1) Model

“…Bin Chen and Jun Wang [24] studied the freeze-thaw damage amount and freeze-thaw damage model with sodium chlorate and sodium silicate as compound alkali activators. Cheng [25] studied the mechanical properties and durability of three types of high performance concrete (HPC). e tests showed that when the CFBC ash content is 20%, the compressive strength of HPC at the curing period of 28 d is the highest at 75 MPa and the strength loss after freeze-thaw cycling is the lowest of 0.17% and 0.81%.…”

Use of Fluidized Bed Combustion Fly Ash as a Partial Substitute for Cement in Underwater Concrete Mixes

“…These structural changes are significant enough to lead to amorphic phase formation, which significantly improves the pozzolanic activity of the fluidized bed combustion fly ashes [ 12 , 13 ]. FBC fly ashes contain no glass phase [ 14 ], in contrast to siliceous fly ashes.…”