Potenciais materiais para construção civil à base de sedimentos marítimos e resíduos da produção de cal

Abstract

The application of the concept of sustainability is a reality in the most diverse productive sectors, not being different in the civil construction industry. The implementation of recycling systems is fundamental to give competitiveness to companies. The objective of this work is to study the properties of composites from the sediment mixture from the dredged sediment (DS) from the Seaport of Paranaguá, wood ashes (WA) of Bracatinga (Mimosa scabrella) and lime production wastes (LPW). With the selected residues, fifteen compositions were developed, the contents of dredged sediment varied between 30 and 70%, the contents of ashes varied between 5 and 40% and the amount of residual lime varied between 15 and 30%. The composites were submitted to tests of mechanical resistance to uniaxial compression, water absorption, water resistance, apparent density, XRD, MEV, EDS, mapping, DTA and TG. By studying the component interactions during the curing period, it was possible to verify that the uniaxial compression strength increases with increasing binder content and with curing time. The materials exhibited values of resistance to the maximum uniaxial compression in the 3rd day of 2.39 MPa, in the 28th day of 2.44 MPa, in the 90th day 5.45 MPa, in the 180th day 8.77 MPa, with 1 year of cure 12.55 MPa, with 2 years 13.01MPa and at 7 years 13.25 MPa. The water absorption values at 28 days of cure ranged from 9.5% to 17.2%, and on the 90th day there was a decrease, obtaining values that ranged from 8.3% to 16.6%, as well as at 7 years, ranging from 6.2% to 14.2%. All these changes of test sample mechanical properties took place due to chemical interaction of the initial components in the moist alkaline outdoors condition with partial chemical destruction of DS and WA particles and with synthesis of new crystalline and amorphous minerals, mainly of carbonates. As a conclusion, DS appeared to be a very interesting constituent for partially up to 50%, WA up to 40% and LPW up to 30%.