01664171

Component

Replacing Portland cement with alternative sources of coal bottom ash can help supplement fly ash supply, have substantial benefits to the environment, and enhance the physical and mechanical concrete properties. The effectiveness and reactivity of the supplemental bottom ash powder will, however, depend largely on the ash particle fineness and dispersion within the cement matrix. In this study, a raw sub-bituminous coal bottom ash was pulverized using a vibratory ball mill, dispersed in solution with a poly-carboxylate ether superplasticizer and homogenized with an ultrasonication treatment. The ultra-fine dispersed solution was then blended within a cement mortar mix to study the impacts on compressive strength activity, matrix microstructure, sedimentation, and rheological stability. Two different sonication energies and dispersed bottom ash solid:liquid solutions were studied. The results indicate that there is a significant increase in strength activity and a reduction in calcium hydroxide content in the mixes containing dispersed bottom-ash solution. ANOVA was then conducted using 190 data points from both the current experimental program and previously published studies empirically quantify the effects of fineness, cement replacement, sonication, bottom ash solution concentration, and age on strength activity. Overall, the sonicated pulverized bottom ash blended cement mortar yielded approximately 6 – 17% greater strength activity than the non-sonicated control cement mortar mix and 2-13% greater strength activity than the non-sonicated blended cement-bottom ash mortar mix.

This paper was sponsored by TRB committee AFN10 Standing Committee on Basic Research and Emerging Technologies Related to Concrete. Alternate title: Dispersed Ultrafine Bottom Ash Blended Cement Mortar

18-03617

English

15p

2018

Transportation Research Board 97th Annual Meeting

Digital/other

Figures; Photos; References; Tables

Analysis of variance; Bottom ash; Cement mortars; Compressive strength; Concentration (Chemistry); Dispersions (Chemistry); Fineness; Mechanical properties; Microstructure; Physical properties; Rheology; Sedimentation; Solutions (Chemistry); Subbituminous coal; Ultrasonic radiation

Highways; Materials; I30: Materials

Transportation Research Board Annual Meeting 2018 Paper #18-03617

TRIS, TRB, ATRI

Jan 8 2018 10:54AM