Análise do comportamento à fadiga de solo laterítico fino estabilizado com cal e polímero.

Abstract

In recent years, a progressive deterioration in the quality of flexible pavements has been observed in Brazil. Among the main identified defects, rutting and fatigue cracking stand out. Although these issues are strongly associated with the asphalt layer, recent studies indicate that the pavement support layers also play a significant role, justifying the need for further investigation on the subject. Despite the scarcity of research in this area, the evaluation of fatigue behavior in base layers has gained academic relevance, driven by the search for solutions that combine durability and economic feasibility. In this context, the use of stabilized local soils emerges as a promising alternative, provided they meet the required performance criteria. This study aims to analyze the fatigue behavior of a fine lateritic soil stabilized with lime and polymer to assess its applicability in flexible pavement base layers. To this end, characterization and classification were conducted using the TRB, MCT, and the Universal Lateritic Soil Classification System (SUCSL). These analyses provided a deeper understanding of the material’s properties. Additionally, the lime and polymer used for stabilization were characterized, followed by the optimized lime dosage for the studied soil. Tests for unconfined compressive strength, tensile strength, California Bearing Ratio (CBR), resilient modulus, and diametral compression fatigue were performed to evaluate the mechanical performance of both natural and stabilized soil. Furthermore, the influence of curing time on the strength gain of stabilized soils was investigated.The results demonstrated that stabilization with lime and polymer was effective, with significant improvements in soil strength observed from seven days of curing. The mixture with 5% polymer stood out due to its superior performance in terms of durability and fatigue resistance, mainly attributed to the flexibility provided by the polymer in the composition. With increased tensile strength over the curing period, the material demonstrated the ability to withstand higher loads in the fatigue life test, highlighting its potential application in pavement structural layers. The mechanistic-empirical modeling conducted using the MeDiNa software indicated that the stabilized soil meets the performance criteria for light traffic in the proposed structure. However, in heavy traffic scenarios, limitations were observed, possibly related to the pavement layer configuration, suggesting the need for structural adjustments. These findings indicate that the stabilization of fine lateritic soils with lime and polymer can be a viable alternative for flexible pavement base layers, provided that specific traffic conditions are considered.