RESUMO Este trabalho tem por objetivo caracterizar o desempenho de resistência mecânica e absorção de água de blocos solo-cimento para alvenaria, após 28 dias de cura, com a incorporação limite dos seguintes coprodutos siderúrgicos em substituição parcial ao solo: adições de até 20 % em massa do pó de balão coletado em alto-forno, até 10 % de poeiras de despoeiramento de aciaria elétrica, e até 20 % de escória granulada de forno elétrico a arco. As formulações propostas incluem adições simultâneas de pós obtidos do descarte da produção de blocos solo-cimento, onde a substituição parcial ao solo foi de até 20 % em massa. Os resultados obtidos sugerem a potencialidade de uso dos resíduos siderúrgicos em blocos intertravados de solo-cimento para alvenaria sustentável, como alternativa de aplicação para esses resíduos. Verificou-se a possibilidade de bons resultados confrontando os valores exigidos por norma (absorção de água < 20% e resistência mecânica > 2,0 MPa) com destaque quando se utilizou 20% pó de balão juntamente com 10% de reuso do bloco solo-cimento; 10% de escória de aciaria ou 20% de escória de aciaria juntamente com 10% de reuso do bloco solo-cimento; e 2,5% de pó de despoeiramento juntamente com 20% de reuso do bloco solo-cimento.

ABSTRACT This work aims to characterize the mechanical resistance performance and water absorption of soil-cement blocks for masonry, after 28 days of moist curing, with the incorporation limit of the following steel co-products to partial replacement of soil: up to 20% by weight of balloon blast furnace dust powder additions, 10% of dedusting dust secondary from electric arc furnace, and 20% of granulated slag of electric arc furnace. The proposed formulations also evaluated simultaneous additions of soil-cement blocks discarded, after granulated by crushing, with partial replacement of soil in up to 20% by mass. The results suggest the potential use of steel residues in soil-cement interlocked blocks for sustainable masonry, as applying alternative to this waste. It was found that the results that stood out, comparing standard specification (water absorption < 20% and strength > 2.0 MPa), the results that stood out were using 20% powder flask along with a 10% reuse of the soil-cement block; 10% of steel slag or 20% of steel slag with 10% reuse of soil-cement block; and 2.5% dusting powder with 20% reuse of the soil-cement block.

The constant heating rate method employed in sintering studies offers several advantages over the isothermal method, particularly the fact that all the parameters that describe the sintering phenomena can be obtained from a single sample. The purpose of this work is to determine the parameters of sintering kinetics of nanosized Ni-Zn ferrite powders synthesized by combustion reaction. The nonisothermal sintering method was studied using a constant heating rate (CHR). The Ni-Zn ferrite powders, with average particle size varying from 18 nm to 29 nm, were uniaxially pressed and sintered in an horizontal dilatometer at a constant heating rate of 5.0 °C/min from 600 °C up to complete densification, which was reached at 1200 °C. The compacts were characterized by scanning electron microscopy (SEM). Experimental results revealed three different sintering stages, which were identified through the Bannister Theory. The shrinkage and the shrinkage rate analyzed showed a viscous contribution in the initial sintering stage, which was attributed to the mechanism of structural nanoparticle rearrangement.