Aloe vera Extract as a Natural Foaming Agent on the Density and Compressive Strength of Concrete

Abstract

This study aimed to evaluate the influence of Aloe vera extract as a natural foaming agent on the physical and mechanical properties of concrete. Mixtures were prepared with three dosages of additive (2%, 4%, and 6% by weight of cement) and without additive. Two concrete specimens were made from each of these mixtures, for a total of eight specimens. The method was experimental, applying slump tests (NTP 339.035), density tests (NTP 339.046), and compressive strength tests at 28 days (NTP 339.034). The results showed that Aloe vera progressively reduced workability, decreasing from a fluid slump of 16.5 cm (without additive) to 13.7 cm (2%), 13.9 cm (4%), and 9.6 cm (6%). Regarding density, it decreased from 2307.16 kg/m3 to 1988.36 kg/m3, 1974.00 kg/m3, and 1969.07 kg/m3, respectively. Compressive strength also decreased from 234.86 kg/cm2 (without additive) to 232.44 kg/cm2 (2%), 162.72 kg/cm2 (4%), and 136.73 kg/cm2 (6%). It is concluded that the Aloe vera extract entrains air in the mix, lightens the concrete, and maintains acceptable strengths up to a 4% addition, confirming its potential as a sustainable alternative to synthetic foaming agents.