Performance investigation and environmental application of basic oxygen furnace slag – Rice husk ash based composite cementitious materials

• Basic oxygen furnace slag and rice husk ash based composite cementitious materials.
• Investigation on strength and durable properties.
• Preparation of cement mortar and concrete.
• Stabilization and solidification in contaminated soils and TCLP experiments for evaluation of environmental application.

In this present work, a novel composite cementitious material was prepared by mechanical activation of basic oxygen furnace slag (BOFs) – rice husk ash (RHA) and admixtures composite system. The basic, mechanical and durable properties of this cementitious blend mortars and concrete were investigated. Then a solidification/stabilization (S/S) process and toxicity characteristic leaching procedure (TCLP) for simulated contaminated soils was utilized to show the engineering and environment application of this cementitious material. Test results showed that ground BOFs and RHA can be used as the supplementary materials for Portland cement. The workability, strength, sulphate attack resistance, dry shrinkage resistance and freezing-thawing resistance performance of this composite cementitious was close or partly superior to those of Portland cement. The maximum compressive strength of concrete at 28 days by using this composite cementitious material was 52.51 MPa. S/S and TCLP test results indicated that BOFs and RHA based composite cementitious materials can be used as stabilizers as cement in fix of Pb, Cd and Cr contaminated soils. 28 days unconfined compressive strength of stabilized soils ranged from 6.65 MPa to 7.45 MPa at 8% of stabilizer content level. Concentration of leached Pb, Cd and total Cr was below the standard level limitation.