Aproveitamento de resíduo de trefilação de fio máquina como substituto do agregado miúdo no concreto de cimento Portland.

Abstract

In recent years, approximately 30 billion tonnes of concrete are produced annually, making it one of the most widely used materials in the world and essential for the construction industry. Concrete is composed of binder, aggregates, and water, and its production generally has a negative impact on the environment. One widely adopted practice to mitigate this impact is the incorporation of by-products from various industrial processes into concrete production, aiming to reduce both environmental impact and the costs associated with raw material acquisition. These residues are often used as partial replacements for sand in the concrete mix. Accordingly, the present study aimed to assess the feasibility, in terms of compressive strength, of using scale waste derived from the wire rod drawing process in the production of Portland cement concrete. Initially, the scale was characterized using X-ray Fluorescence (XRF) and X-ray Diffraction (XRD) techniques. Concrete specimens for compressive strength testing were produced with partial sand replacement by drawing scale at proportions of 5%, 10%, 15%, and 20%. Control specimens with no scale addition were also fabricated to allow for comparative analysis. The specimens were subjected to four curing durations: 7, 14, 21, and 28 days. Compressive strength tests were conducted to comparatively assess the effects of both the scale addition and curing time. The characterization of the scale revealed that it is primarily composed of hematite (Fe2O3) and magnetite (Fe3O4). With respect to the amount of scale added, it was observed that using 5% and 10% of drawing scale as fine aggregate led to a decrease in compressive strength, with the reduction being more pronounced in specimens with 10% scale than those with 5%. For a 15% addition, an increase in compressive strength was observed at 7, 21, and 28 days of curing. An improvement in compressive strength was also recorded in specimens containing 20% scale. Overall, the increase in curing time generally resulted in a significant gain in compressive strength, except in specimens with 10% scale addition. Furthermore, it was concluded that from a scale addition range between 10% and 15% relative to sand mass, favorable results were achieved regarding the reuse of drawing process waste, considering compressive strength performance.