Utilization of Granite and Limestone Wastes as Aggregates in Concrete

Document Type : Original Article

Authors

1 Chemist at Egyptian Mineral Resources Authority

2 Professor at Ain Shams University

3 Professor at Geology Department, National Research Center, Cairo

Abstract

The feasibility study of utilizing granite and limestone waste materials as alternatives to aggregates in various grain sizes in concrete is carried out in this work.
The granite and limestone wastes are pelletized into different grain sizes and then dried for 48 hours in open air at room temperature to remove the excess water and enhance workability. Subsequently, the pellets are fired in a rotary kiln at a very high temperature, with a heating rate of 20°C per minute, for 2 hours at 1100°C.
The chemical and mineralogical composition of the waste materials is analyzed using techniques such as petrography, X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). These analyses show the composition and structure of the first material which is granite with a high iron content (6.66%) is called “Ferriferous granite”, the second material is granite with normal iron content (3.15%) is called “Normal granite” and the third material is “Limestone”, and aid in the selection of suitable materials for concrete production.
In conclusion, this research aims to investigate the potential use of granite and limestone waste materials as replacements for traditional aggregates in concrete production. Through a series of shaping, burning, and mixing processes. The important results obtained is that as the percentage of granite waste increases, the pellets become more friable. Therefore, based on this research, we recommend mixing the granite and limestone to enhance the durability of the aggregates, enabling their utilization in the production of high-strength concrete.

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