PSI - Issue 70

Siddesh K N et al. / Procedia Structural Integrity 70 (2025) 231–238

233

Fig. 1 illustrates the use of aluminum dross and Conplast SP 430 in casting cubes and beams. The mix design for M20 grade concrete was carried out as per IS 10262:2019 – Guidelines for Concrete Mix Proportioning, and the material testing procedures followed the specifications in IS 456:2000 – Code of Practice for Plain and Reinforced Concrete. Cube compressive strength tests were conducted according to IS 516:2018 – Method of Tests for Strength of Concrete, while split tensile strength and flexural strength tests followed IS 5816:1999 and IS 516:2018, respectively. All specimens were cured in water as per standard procedures outlined in IS 9013:1978 – Method of Making, Curing and Determining Compressive Strength of Accelerated Cured Concrete Test Specimens. 1.2. Experiment details The specific gravity test was conducted on coarse aggregate, fine aggregate, cement, and aluminum dross, with the corresponding values noted as specified earlier. To determine the workability of concrete, the Marsh flow test, also known as the flow table test, was performed to assess the flow consistency and fluidity of the concrete mixture. A graph was plotted between time (sec) and dosage (%) to determine the optimal percentage of superplasticizers by the weight of cement for a fixed water-cement ratio. For the chemical characterization of aluminum dross, Energy Dispersive X-ray Analysis (EDX), also referred to as Energy Dispersive Spectroscopy (EDS), was employed to analyze the elemental composition of the sample, as shown in Fig. 2(a). The EDX analysis revealed the presence of aluminum as the dominant element, along with oxygen and minor constituents such as Si, Ca, and Fe, confirming the heterogeneous composition of the aluminum dross sample. Additionally, X-ray Diffraction (XRD), a non-destructive analytical technique, was used to determine the crystalline structure, phase composition, and other structural properties of aluminum dross, with the results illustrated in Fig. 2(b). The design mix for M20 grade concrete was derived and is presented in Table 1.

Table 1. Design mix for M20 grade concrete Cement

Water

M. Sand

20mm

Admixture

W/C

Quantity (kg/m 3 )

383.16

134.11

610.55

1293.29

4.78

0.35

Fig. 2. (a)EDX image (b) XRD image of Aluminum Dross The EDX elemental mapping in Figure 2(b) illustrates the distribution of key elements in the aluminum dross sample. The high concentration of aluminum and oxygen supports the presence of alumina (Al₂O₃), which is known for its pozzolanic reactivity. This composition suggests that aluminum dross may contribute to the strength development in concrete when used as a partial cement replacement. The trace elements such as silicon, calcium, and iron further indicate the potential for forming cementitious compounds during hydration. The chemical composition of aluminum dross, obtained through Energy Dispersive X-ray (EDX) analysis, is summarized in Table X. The primary component is aluminum (61.3%), followed by oxygen (25.6%), indicating the presence of alumina (Al₂O₃). Trace amounts of silicon, calcium, iron, and magnesium were also detected, which may contribute to minor pozzolanic or filler effects when the dross is used as a cement substitute. For each aluminum dross percentage, six cubes were