Sugarcane today plays a major role in the worldwide economy, and Brazil is the leading producer of sugar
and alcohol, which are important international commodities. The production process generates bagasse
as a waste, which is used as fuel to stoke boilers that produce steam for electricity cogeneration. The final
product of this burning is residual sugarcane bagasse ash (SBA), which is normally used as fertilizer in
sugarcane plantations. Ash stands out among agroindustrial wastes because it results from energy generating
processes. Many types of ash do not have hydraulic or pozzolanic reactivity, but can be used in
civil construction as inert materials. The present study used ash collected from four sugar mills in the
region of São Carlos, SP, Brazil, which is one of the world’s largest producers of sugarcane. The ash samples
were subjected to chemical characterization, sieve analysis, determination of specific gravity, X-ray
diffraction, scanning electron microscopy, and solubilization and leaching tests. Mortars and concretes
with SBA as sand replacement were produced and tests were carried out: compressive strength, tensile
strength and elastic modulus. The results indicated that the SBA samples presented physical properties
similar to those of natural sand. Several heavy metals were found in the SBA samples, indicating the need
to restrict its use as a fertilizer. The mortars produced with SBA in place of sand showed better mechanical
results than the reference samples. SBA can be used as a partial substitute of sand in concretes made
with cement slag-modified Portland cement.