This study presents the characteristics of Municipal Solid Waste (MSW) incineration ash obtained from electric energy generation place, to evaluate the MSW ash applicability road base as a pavement layer through the ash mixture with a non.lateritic regional clay soil. Chemical, physical, mechanical tests and the mechanistic.empirical design for a typical pavement structure were carried out on the pure soil and also in the soil mixture with the addition of different ash content (20 and 40%). The addition of MSW ash had a consistent mechanical behavior to be used on low traffic volume road pavements. Fly ash reduced the expansion of the material, showing a substantial increase in the CBR value. The results show that the resilient modulus of soil is dependent on the deviator stress and the fly ash addition with a mixture cure increase the value of resilient modulus, which is revealed by the decrease in thickness of the base layer, compared to pure soil for the same level of loading and the same design requirements. The results were satisfactory, being dependent on the content and type of ash used, highlighting the positive work of MSW fly ash for use in base road pavement layers, minimizing the current problems of waste disposal in landfills, giving a noble use for this material. It is noteworthy that studies on the use of such waste in pavements are rare and this research adds to an exploratory knowledge of its potential applicability.