Properties of controlled low-strength material containing foundry sand

This research study was performed to document and evaluate engineering properties of controlled low-strength materials containing by-product foundry sand (FS-CLSM). Mixtures containing clay-bonded and chemically bonded sand were compared in the plastic and hardened states to CLSM mixtures containing uniformly graded crushed limestone sand. The data presented show that by product foundry sand can be successfully used in CLSM and it provides similar or better properties to that of CLSM containing crushed limestone sand. The foundry sand assisted in keeping the strength from exceeding the desired upper limit of 700 kPa. Claybonded sand retarded the setting time, and chemically bonded sands required a reduction in water to control bleeding. CLSM containing a combination of fly ash and chemically bonded sands was shown to have excellent characteristics for flowable backfill and excavatable base material.