Caracterização tecnológica dos granitóides do fácies Serra Branca, Quixeramobim – Ce

Abstract

The current work presents the mineralogical and technological characterization of granitoid of Serra Branca facies, which is part of the geological context of the Quixeramobim batholith, this one is in contact with the migmatitic gneiss of Juatama Unit. This batholith is located at the south of the Quixeramobim town, in Ceará. Aiming to assess the application of Serra Branca granite for use as a dimension stone, technological tests were performed, as: Physical Indexes, Uniaxial Compression, Modulus of Rupture (Flexural loading by 3 points), Ultrasonic Pulse Velocity and Abrasive Wear (Waste) by. AMSLER method, all of them based in ABNT and ASTM standards. Adding the other goals of this work was performed macroscopic and microscopic analysis that can classified the Serra Branca granite as a syenogranite composed by K-feldspar + biotite + plagioclase + quartz + Amphibole ± titanite apatite ± epidote, which is colored light gray, with the matrix granulating ranging between 0,5 to 13,0 mm and still presenting phenocrysts of K-feldspar with 20 cm of size. The syenogranite also shows a degree of microcracking equal to 3.17 microcracks/mm2, being 87.13% of these microcracks intragrain and 12.87% intergrain. The technological characterization showed results for apparent porosity, water absorption and apparent density, equal to 0.80%, 0.30% and 2696.95 kg/m3, respectively, those values are acceptable by the ABNT standard. The uniaxial compression test proved unsatisfactory due to errors in cutting the body of evidence, showing average score of 66.6 MPa, suggested by ABNT standard. However, the Modulus of Rupture assay (Flexural loading by 3 points) showed satisfactory results with average value of 11.6 MPa, higher than suggested by the ABNT standard. The test of Ultrasonic Pulse Velocity proved satisfactory for the two dimensions of the specimens in which the test was submitted with results of 4893.42 m/s and 4222.92 m/s to sample with 7x7x7 cm and 20x10x5 cm, respectively. The samples submitted to the test of abrasive wear by AMSLER method, exhibit wear of 0.93 to 1000 m, showing value below than the standard value. Thus, we conclude that the Serra Branca sample showed satisfactory results for the use of ornamental flooring, countertops, flooring and similar applications, with the exception of Uniaxial Compression test, which causes restrictions on its use in building structures and similar applications. Within these parameters the syenogranite of facies Serra Branca proved to be useful to ornamental market. This was justified by the results obtained for the tests.