Study of the Potential of Adhesion to the Substrate of Masonry and Tensile in the Flexion in Mortars of Coating with Gray of the Sewage Sludge

Abstract

This work evaluates mortars using sewage sludge calcined at temperatures of 600°C and 700°C as a hydraulic binder replacing the cement. The percentages incorporated by mass to replace the Portland cement were 10%, 20% and 30%, using the 1:3:0,60 (cement: sand: factor a/c) trace. Sludge ash was characterized and tensile strength at flexion as well as tensile strength (pullout test) were evaluated. As a way of performing a comparison with conventional mortars, the same tests were carried out using reference mortar. The results of the flexural tensile strength tests indicated that results were higher than the reference traces of the mortars with the calcined sludge at a temperature of 700°C, a factor related to the increase of the calcination temperature and the incorporated percentage. With respect to the tests on the determination of tensile strength, it was observed that the specimens submitted to the test suffered rupture in the mortar, and that the calcination temperature of the sewage sludge was not influenced. The results obtained with the mortars using sewage sludge ash with partial replacement of the cement are shown within the normative standards and approximate to the results obtained with the tests executed with the reference mortar.

Potentialities in the performance of coating mortars through the addition of sewage sludge ash

“…Ingunza, Camarini & Costa (2018), when incorporating the sewage sludge ash (SSA), calcined at a temperature of 850°C for 3 hours, in mortar as a mineral addition, realized that the percentage of 20% is ideal for application to from a conjunctural analysis of all the parameters analyzed, corroborating even more satisfactory results when comparing the mortar without adding the SSA for axial compression tests (Figures 4 and 5). Cunha Oliveira, Chagas, Meira, Carneiro & Melo Neto (2020), evaluated the use of calcined SSA at 600°C and 700°C, incorporated in coating mortar in percentages of 10%, 20% and 30%, and evaluating the mixtures in terms of flexural strength (Figure 6), and adhesion to the masonry substrate (Table 1). The authors concluded that both temperatures contribute to the SSA becoming reactive enough to be pozzolanic, a factor directly reflected in the increase in the flexural strengths and the adhesion of mortars, with emphasis on 700°C, which produces more dehydroxylated amorphous structure, that is, more reactive, so the resistance values are higher for the temperature of 700°C.…”

“…Table 1 -Results of the studies concerning the adhesion resistance of the control mortar and of the additives with calcined sludge at 600°C and 700°C, both with a 1:3 formulation. Source: Cunha Oliveira, Chagas, Meira, Carneiro & Melo Neto (2020).…”

“…A proposal to alleviate the problem regarding sewage sludge would, according to Cunha Oliveira, Chagas, Meira, Carneiro & Melo Neto (2020), through its insertion in Portland cement mortar, where the use of cement would be reduced through the insertion of the calcined by-product, and when evaluating the performance and potential of adherence to the masonry substrate and flexion traction, which are some of the parameters of fundamental importance to ratify the final viability of the residue with large-scale application for masonry coatings, it was noted if it is possible to carry out such an application. Data from the Sindicato Nacional da Indústria do Cimento -SNIC (2012), point out that in Brazil the consumption of cement exceeded the mark of 69 million tons.…”

Highlights on the properties of the soda-lime-silicate glass residue that enable its use as filler in ultra-high performance concrete

“…Verifying the presence of pozzolanic behavior in industrial by-products makes it possible to classify whether supplementary cementitious materials (SCM) are inert (filler) or reactive (pozzolan). The pozzolanic potential of a material is configured to detonate cementing properties when it reacts in the presence of calcium hydroxide (CH), which originates from the hydrated phases of Portland cement, producing low-density calcium silicate hydrated (C-S-H) (Cunha Oliveira, Chagas, Meira, Carneiro & Melo Neto, 2020;Cunha Oliveira, Meira & Lucena, 2021), similar to that produced by C3S and C2S (tricalcium and dicalcium silicates), and which increases the durability of the cement matrix in the hardened state.…”

Ultra-high performance concrete made from the insertion of glass residues as supplementary cement material

“…Verifying the presence of pozzolanic behavior in industrial by-products makes it possible to classify whether SCM are inert (filler) or reactive (pozzolan) (Cunha Oliveira, Meira & Lucena, 2021b). The pozzolanic potential of a material is configured by detonating cementing properties when it reacts in the presence of calcium hydroxide (C-H), which originates from the hydrated phases of Portland cement, producing low-density calcium silicate hydrated (C-S-H) (Cunha Oliveira, Chagas, Meira, Carneiro & Melo Neto, 2020;Cunha Oliveira, Meira & Lucena, 2021a), similar to that produced by C3S and C2S (tricalcium and dicalcium silicates), and which increases the durability of the cement matrix in the hardened state.…”