Performance and Leaching Assessment of Flowable Slurry

Abstract

This project was conducted to evaluate the performance and leaching of controlled low strength materials (CLSM) incorporating fly ash and foundry sand. Two different CLSM (or flowable slurry) reference mixtures (equivalent to available production CLSM mixtures) were proportioned for unconfined compressive strength levels in the range of 0.3-0.7 MPa (50-100 psi), at 28 days, using two sources of ASTM Class F fly ash. For each reference mixture, other mixtures were proportioned using two sources of foundry sand (molten metal-casting mold sand) as a replacement for fly ash in the range of 30-85%. The ingredients of the slurry mixtures-fly ash, clean foundry sand, and used foundry sand-were tested for their physical and chemical properties and their leachate characteristics. Portland cement used as the primary binder was also tested for its properties. All CLSM mixtures made with and without foundry sand were evaluated for settlement, setting and hardening characteristics, compressive strength, permeability, and leachate characteristics. The leachate results of these CLSM-making materials were below the enforcement standards (ES) of the Wisconsin Department of Natural Resources (WDNR) groundwater quality standards (GWQS). They also met practically all the parameters of the drinking water standards. A number of CLSM mixtures incorporating fly ash and foundry sand are recommended for construction applications.

Effect of two different sources and washing treatment on the properties of UFS by-products for mortar and concrete production

“…The leachates, alkaline throughout the testing period with pH values greater than 11, indicate that the interstitial pore fluid in contact with hydrated cementitious materials is buffered by the presence of alkaline ions. So far as the local condition of the leachant remain unchanged, the heavy metals leaching remains very low, as found in previous works [30,36]. The resistance to the leaching is the most important factor for the evaluation of the immobilised matrices, because water would be the primary liquid available for the potential dispersion for the heavy-metal ions.…”

Permeability and Tensile Strength of Concrete with Arabic Gum Biopolymer

“…The permeability of concrete is affected by the replacement of fly ash with foundry sand [6]. The minimum of permeability was found at 30% of fly ash.…”

Used Foundry Sand in Cement Mortars and Concrete Production~!2010-03-27~!2010-05-03~!2010-07-07~!

“…Moreover, the environmental aspects and compatibility have been investigated in order to point out the prerequisites for the USF utilisation [20,21].…”