Geotechnical properties of flowable fill from excess foundry sand and cement kiln bypassdust

This study developed different mix proportions for flowable fill containingEFS and CBPD. Both fluid-state properties (flow consistency, setting time,bleeding and settlement) and hardened properties (unconfined compression test, splitting tension test, hydraulic conductivity, fresh and wet unit weight development and shear strength) were used with different ratio of CBPD/EFS and cement content, and the behavior was studied for curing time up to 28 days. At the suitable flow consistency ranging from 20 cm to 28 cm, the FF has a compressive strength between 583 kPa and 2285 kPa. Initial setting of studied mixtures ranging from 6.4 hrs to 11.9 hrs. The cohesion and the shear strength at 100 kPa normal strength increased with time, while the friction angle remains unchanged during the same curing time. The unconfined compressive strength of the proposed mixtures ranged between 583 and 2285 kPa at (5-15) % of water cement ratio. The indirect tensile strength of the mixtures without cement ranging between 81.55 kPa and 110 kPa. The hydraulic conductivity of flowable fill materials is typically in the range of 2.0* 10-6 to 4.0* 10-7 cm/sec. A different models between the FF properties developed in this study, the tensile strength can beconfidently estimated as a fraction (1/7.5) of the compressive strength.