A possibilidade de utilização de areias marinhas como agregado na construção civil na Região Metropolitana de Fortaleza, Estado do Ceará

Abstract

The exploration of dunes, channels and floodplains of rivers, seeking the extraction of sands for use as aggregates in the production of the concrete, it comes being implemented there is plenty of time in the metropolitan areas of the country, causing the exhaustion of those mineral goods so much in the proximities of the great urban centers as serious related environmental problems the mining activity. Objectifying to facilitate the creation of a new alternative for the problem of the extraction of sand in the coastal metropolitan areas, an area was selected in the continental platform to northwest of the point of Mucuripe, in Fortaleza City for accomplishment of the study of characterization of the sands for use as aggregates in the production of the concrete. With relationship the granulometry, the potential alkali reactivity and the presence of materials finer than 75µm, clay lumps and friable particles, organic impurities and mica, the samples of marine sands presented quite satisfactory results. The largest problems for use of the marine sands in the civil construction can be the contents in salts and in carbonate of calcium. In relation to the contents of CaCO3, less than 20% of the analyzed samples presented inferior values at 30%, being necessary a bolting to 4 mm of the samples and tests on mortars to be proven those sands is adapted for use as aggregates in the production of the concrete. As the presence of salts in the marine sands, more than 90% of the studied marine sands were classified as not saline, for hydraulic descharge, could be used for the production of mortars and of any type of armed concrete or not.