Análises de dosagens de concreto asfáltico do tipo Pré Misturado a Frio (PMF) utilizando Resíduos da Construção e Demolição de obras (RCD)

Abstract

Considering the great growth of the civil construction sector in Brazil until 2013/2014, some companies, and the economy in general, were highlighted by the high rate of urban development. Such events were directly responsible for the market development that stimulated various sectors of the economy, one of which is the construction sector. With these events, as a consequence, some negative aspects occur in a damaging and irreparable way. For example, researchers say that concrete using Portland cement today is the second most-consumed product in the world, with a prospect of increasing its consumption over the next few years. Based on these aspects, this work addresses points related to the reuse of Construction and Demolition Waste (RCD), which guides the theme of this work, stressing the importance and benefits of some sustainable actions for the environment and society. In a regional context, in the state of Rio Grande do Norte, there are four RCD recycling plants which maintain significant production and are responsible for collecting, processing and marketing all waste material. These companies generate income for the local population and contributes to the reduction of the mineral extraction (raw material exhaustible). In view of these facts, the present study evaluated the technical feasibility of waste from civil construction, using them as aggregates, after beneficiation at the plant, in the composition of asphaltic concretes in partial or total replacement of natural materials. The work method employed is based on the characterization tests, both with the aggregates and with the Asphalt Emulsion of Petroleum; in mineralogical characterization tests (SEM, EDS, XRD and FRX) with the RCD powdery material; and in the application of the Marshall method of cold premixed dosages which vary in asphalt emulsion contents between 6%, 7%, 8% and 9% in every four combinations of mixtures of the aggregates. As a research, and for a better analysis of technical feasibility of the aggregates, the four combinations of mixtures of the aggregates were used: fully natural materials, RCD's and RCD-Naturais, and three specimens were prepared for each binder content. Four pre-determined asphalt binder contents were applied to each mixing design of the aggregates, totalizing forty-eight specimens. As for the results obtained, it was possible to compare, through Marshall analysis parameters and physical and mineralogical characterization tests of the material used, the expressive potential of use of RCD aggregates in the composition of cold asphalt concretes. After analysis of Marshall parameter interactions (Vv, RBV, Gmb, Stability and Fluency) the optimum binder contents (% EAP) for the D1 - BNAN, D2 - BNAR, D3 - BRAR and D4 - BRAN dosages were respectively 7.75%, 7.25%, 7.75% and 7.50%. Therefore, the technical and environmental feasibility of using RCD when used in certain road pavements was evidenced.