High-performance concrete is generally produced using carefully selected high quality
materials. These materials increase significantly the initial costs, hence, limiting its use. In this research
work the performance of concrete was enhanced through incorporating low cost untreated materials
like fly ash and crushed aggregates. Thus, it can be produced enhanced or even high performance low
cost concrete and, also, decrease significantly the use of cement and non-renewable natural resources
(river/sea sand), contributing to the necessary sustainability of construction. From experimental
program, the effect of replacing cement by fly ash (up to 60%) in the flexural tensile behaviour was
evaluated, using control compositions without the addition of fly ash as a base of comparison. The
results obtained demonstrate that it is possible to produce enhanced performance concrete with the
selected materials replacing up to 40% of the cement by fly ash. In specimens of such mixtures, cured
at least 56 days, the values of the compressive strength and the flexural tensile parameters were similar
to the ones of the control mixtures
