Assessment of concrete produced by partial replacement of cement with waste clay brick powder

Abstract

ABSTRACT Cement production emits carbon dioxide (CO2) gas to the atmosphere, thereby contributing to global greenhouse gas emission. While Waste Clay Bricks are abundant in Minna and it is mostly used in landfills. This study focuses on the pozzolanic properties of the Waste Clay Bricks and their effect on the compressive strength of concrete. X-ray fluorescence (XRF) test was used to examine the oxide composition of Waste Clay Bricks powder. WCB was used as a partial replacement for cement in increasing percentages of 5, 10, 15 and 20% by weight for grade 25. Concrete specimens prepared target mean strength was 33.2N/mm2 and water/cement ratio of 0.5. Sieve Analysis, Natural Moisture Content, Specific Gravity and Bulk density test were also conducted on the aggregates with all tests done in accordance with relevant British Standards. The oxide composition of Waste Clay Bricks powder obtained for this research meets the ASTM C618 (ASTM, 2015) recommendation that for a suitable pozzolanic materials, the summation of the SiO2, Al2O3 and Fe2O3 was 94% which according to ASTM C618 must not be less than 70%. It was observed that waste clay brick increases the workability and consistency of fresh concrete. However, at 5% partial replacement of cement with Waste Clay Bricks powder, the compressive strength at 28 days curing is 25.41 N/mm2 which is above the targeted value at 28days. The 5% partial replacement of Waste Clay Bricks powder value is close to the compressive strength of the control concrete at 28days which is 26.07 N/mm2. Hence the use of Waste Clay Bricks powder to replace cement should be limited to 5% for plain concrete of grade 25.