Effects of Copper (II) Nitrate Trihydrate Admixture on some Fresh and Hardened Properties of Concrete

Abstract

The use of admixtures to improve specific properties of concrete has gained popularity in the construction industry in recent years. Fungicidal admixtures are used to control bacterial and fungal growth on or in concrete. The effects of Copper (II) Nitrate Trihydrate [Cu(NO3)2.3H2O] admixture on the workability and strength of concrete was investigated in this research. Concrete cubes of 150 x 150 x 150mm were cast with different proportions, 0 - 4% of Cu(NO3)2.3H2O by mass of cement. Slump and compressive strength tests were conducted. The result shows that the slump value increases with increase in percentage of Cu(NO3)2.3H2O; the concrete workability is medium up to 2.5% of Cu(NO3)2.3H2O inclusion, beyond which the concrete is highly workable. Furthermore, the compressive strength reduces with increase in the percentage of Cu(NO3)2.3H2O; above 0.5% of Cu(NO3)2.3H2O inclusion, the value of the compressive strength obtained was below the target design value of 20 N/mm2. In essence, the improvements in the workability adversely affects the strength of the concrete.