Utilização de cinza de resíduo hospitalar em mistura com solo em pavimentos flexíveis

Abstract

In paving engineering, one of the most used materials in the composition of its layers is the soil, however, in many cases, the available soil does not have appropriate properties. With the purpose of using the soil as a base for the sidewalk, it is possible to improve its properties through the stabilization process. Based on this, this study aimed to evaluate the implications of the partial replacement of a natural soil by ashes from hospital waste, aiming at its subsequent application in the layers of flexible sidewalks. In the present research, the soil under analysis was stabilized chemically and granulometrically, through the substitution of the natural soil by levels of 10, 15, and 20, % of ash from hospital waste. The soil used in the study is composed predominantly of clay, material of fine granulometry (less than 02 mm). From the chemical point of view, the treatments did not present a contaminant potential for the environment, and can be used in sidewalk layers. With regard to the California Support Index values, significant improvements in soil strength were found after the stabilization process, when compared to natural soil. In this test it was found that the soil mixtures with 10 and 15% addition have the highest expansions, and the natural soil and natural soil + 20% ash have the lowest expansions. However, all treatments have expansion less than the minimum required in the standard for use in sidewalk layers. The values of California Support Index, significantly increased the treatment Natural Soil + 20%, being considered as the most efficient treatment, which can be used in layers of sidewalk sub-base and with expansion less than 1%. Thus, it was confirmed that the natural soil present in the region of Frederico Westphalen/RS can be applied directly in the subbase layer of flexible sidewalks, provided that stabilized chemically and granulometrically with replacement levels of 20% hospital waste ash.