Estabilização de solo tropical argiloso com cimento e zeólito sintético como solução em pavimentação no Amazonas

Abstract

Atypical situations in Amazonas State, which contribute to the accelerated deterioration of conventional pavements, raise the need to develop specific paving solutions. This work aims to identify changes of the mechanical and microstructural properties of tropical soil with cement (8.20%) and chemical additive based on synthetic zeolite, called Roadcem® (RC) at different rates (0%, 0.087% and 0.174%). Changing its moisture condition during compaction (0%, 30% and 60% of optimum moisture) and different curing conditions (wet, submerged and under cycles of durability), in order to represent the expected conditions of the execution. After extensive characterization of the materials used, non-confined compression tests and diametral compression stress, mass loss through the durability test and investigation of microscopic changes were performed. Systematic procedures for soil stabilization work with cement and RC are also proposed. An experimental stretch was built, structural design developed and its mechanical performance evaluated. A regression model considering the results of compressive strength of the material for condition of curing under cycles of durability (R² = 0.85) indicated maximum resistance predicted for 0.174 % RC and 0% increase of moisture, in the value of 5, 97 MPa. With excess water, the chemical reactions that promote the greatest interaction between the grains do not occur at the same intensity. Rates of 0.174% RC reduced the mass loss to 0.6% for samples molded at optimal moisture in the durability test. Ettringite crystals and lower occurrence of fractures was observed only in samples with RC additive in microstructural analysis. The proposed work procedures describe in a broad way the steps to be successful in the execution of subgrade soil stabilization with cement and RC additive. The resistance of the samples extracted from the experimental section reach 3,01 MPa after 28 days curing and the track presented with no surface cracks evolution. Thus, the results indicated that RC additive contributed with mechanical properties conservation under studied conditions.