Analysis of the Mechanical Properties of Concrete Mix Added with Water Lily Ash (Eichornnia Crassipes)

Abstract

The pollution associated with construction materials production has led to searching for new or existing sustainable and efficient replacements. Some materials are not directly defined as construction materials, but they have properties applied in the field. The pursuit of sustainable materials to be used in the construction industry has been focused on organic materials such as extracts or fibers directly used in concrete mixtures and other construction elements like CEB (Compressed Earth Blocks). In this work, water lily ash (Eichornnia Crassipes) from Tamaulipas southern is proposed to replace cement in concrete mixtures and evaluate its effect on mechanical, thermal, and sound diffusion properties. The consumption of lily ash controls its exponential growth in aquatic environments and is presented as a solution to the adverse effects on aquatic flora and fauna developed by this invasive species. The water lily specimens were taken from the southern Tamaulipas and calcinated in a ground furnace to take advantage of traditional regional techniques with low energy consumption, obtaining 2,45 kg of ashes from approximately 18 kg of raw material (13,6% yield). Concrete mixtures were obtained with Portland cement, water, coarse gravel (19 mm, 2.7 ton/m³), and local river sand for 15,2; 8,8; 42,2; and 33,8% w/w, respectively. Lily ashes were dosed as cement replacement for 0,5; 1, 2, and 3% w/w. It was found that 1% of ashes substituting cement equals the compressive strength and reduces the thermal transmissive by 12.53%. Besides, sound diffusion velocity is increased, which indicates that ash promotes a better particle distribution without compromising mechanical properties. Therefore, lily ash is a good candidate as a cement substituent, and it would be double troubleshooting: reduction of cement consumption and elimination of lily ash as invasive species.