Effect of Iron Ore Tailing on Compressive Strength of Manufactured Laterite Bricks and Its Reliability Estimate

Abstract

In recent years there is a significant demand of building materials in Nigeria. It is therefore imperative to use mining and mineral wastes in the production of bricks, paving blocks and other value added products since some of these waste materials possess potential characteristics, which can be tapped for various uses. Varying grams of IOT were mixed with constant measured portion of laterite sample and cast into lateritic brick cubes, which were later subjected to compressive strength test at 7 days interval for 21 days. The result of the compressive strength test revealed that the lateritic mix containing varying grams of IOT had higher strength value of 27 N/mm² when compared with laterite having compressive strength of 14 N/mm² both for 7 days curing. Reliability of estimates of the compressive strength values from laboratory results for specimens was developed by incorporating data obtained from compressive strength to produce a predictive model. Data obtained were incorporated into a FORTRAN-based first-order reliability program to obtain reliability index values. Variable factors such as water quantity, hydraulic modulus, iron ore tailing, water cement ratio produced acceptable safety index value of 1.0 at the energy levels of all curing period i.e. 7 days, 14 days and 21 days respectively and they were achieved at COV ranges of 10-100 %. The use of iron ore tailing which is a waste material will serve as an alternative source of building material when used as an admixture or replacement of fine aggregate ratio and also possible reduction in quantity of cement. It will also help reduce environmental problems associated with iron ore tailing disposal problems.

Keywords: Building Bricks, Compressive Strength, Reliability Analysis, Reliability Index, Iron Ore Tailing, Pozzolana, Utilization