Characterization of Manganese Dioxide nanoparticles for reuse as a partial replacement of cement in concrete

In this research, we characterized nanoparticle residues of Anodic Manganese Dioxide with the aim of exploring its potential as a partial replacement for cement. Manganese Dioxide nanoparticles (MDN) is a by-product generated during the electrochemical process of Zinc refining and is specifically adhered to the anode. Microscopic studies revealed that this material is composed of 94.4% Manganese Dioxide and 5.6% Anglesite; and that the MDN particles have nanometric sizes, its density was determined; the pH of Portland cement type I was also measured with combinations of different replacement percentages of MDN, obtaining in all cases alkaline pH; in addition, the thermal reactivity of the cement with combinations of MDN was determined, obtaining temperatures of up to $31^{\circ}\mathrm{C}$; and with all this information, we proceeded to the experimental phase of concrete batching with the addition of MDN, applying the Bolomey’s design method; the concrete mixes with partial replacement of 5% cement by MDN and the control concrete were batched; for both cases the water-cement ratio used was 0.40; cylinders were manufactured according to ASTM C39 procedure, the compressive strength test was carried out at 7 and 14 days, showing that in all cases there were increases in compressive strength in the samples with MDN of 7% for 7 days and 8% for 14 days respect to the control concrete, in the tensile test, an increase of 12% was observed in the concrete with MDN respect to the control concrete.