Influência da adição de RAP no comportamento mecânico de misturas com solo laterítico de alta plasticidade para uso em pavimentação

Abstract

The exploration of deposits, damage resulting from the emission of greenhouse gases, and scarcity of materials in certain regions, in addition to transport costs, were factors that boosted the civil engineering sector, especially the paving industry. The initiative to reuse waste, such as materials arising from the milling of the asphalt coating, known as Reclaimed Asphalt Pavement (RAP), is formed by the mixture of aged Petroleum Asphalt Cement (PAC) and aggregates of different sizes. This process is considered one of the largest generators of construction waste. When discarded inappropriately, it becomes harmful to the environment, making its reuse necessary. The present study aims to evaluate the influence of RAP content on the mechanical behavior of a high plasticity laterite soil for application in paving, with the following percentages of RAP content 0%, 50%, 60%, 70%, 80% and 100%. In mixtures with soil, laboratory tests were conducted for geotechnical characterization, mini-MCV, mass loss by immersion (PI), California Support Compaction Index (ICS), as well as Resilience Modulus (RM) and Permanent Deformation (PD). Chemical analysis of the soil, along with stress-strain analysis using the Elastic Analysis of Multiple Layers (AEMC) software, was performed to determine the mechanical behavior of Soil-RAP mixtures. The results indicated that only Soil-RAP mixtures of 70% and 80% fell within the particle size ranges specified in ES DNIT 141 (DNIT, 2022). The addition of RAP to the soil caused improvements in the mechanical behavior of the mixtures starting from 70% RAP. However, a tendency for PD growth was observed with increasing RAP content in Soil-RAP mixtures in relation to values in the lowest tension pairs. From the stress-strain analysis, it was observed that in the analysis of the unbonded layer interface, none of the pavement configurations met the Nadm ≥ NAASHTO requirement. However, in the adhered condition, the structure that exhibited the greatest useful life for the soil was the B70SB70 configuration, which achieved a Nadm of approximately 1.73 x 10^6. Therefore, this structure demonstrated greater resistance compared to the others studied in the adhered condition of the soil layer.