Investigation of strength and water permeability of sustainable high-performance concrete containing high-volume ground bottom ash blended with fly ash and nano-silica

Abstract

This investigation focussed on minimizing the Portland cement usage in developing sustainable high-performance concrete (HPC) as low-carbon concrete. High-volume ground bottom ash (GBA) was utilized as cement substitution in combination with fly ash (FA) and nano-silica (NS) for producing HPC with compressive strength of 100 MPa, and various concrete mixes were examined to assess its workability, mechanical performance, water permeability, and carbon emissions. The microstructure of the materials and pastes were also analyzed with X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA), and Mercury Intrusion Porosimetry (MIP). GBA was used to replace Ordinary Portland Cement (OPC) at very high levels of cement replacement, ranging from 60 to 80 % by weight of binder. As ternary binders, 10 % fly ash and 2 % nano-silica (NS) by weight of binder were also used to replace GBA. The early-age compressive strength of HPC containing high-volume GBA increased by using 2 % of NS. Incorporating 10 % of FA into HPC reduced the superplasticizer requirement, enhanced workability, and exhibited slightly lower early strength. The compressive strength of HPC containing 58 % GBA, 10 % FA, and 2 % NS could be developed at 90 days was more than 110 MPa. Moreover, the investigation indicated that employing GBA in the mix represents environmental sustainability for the development of high-performance concrete.