Propuesta de modificación de la ecuación para la estimación del módulo de elasticidad del concreto en función de la resistencia a la compresión para Bogotá

With the modulus of elasticity of concrete (E) and the geometry
of the structural elements the designers assess the displacements
of reinforced concrete structures. Taking in mind that the quality
assurance of the concrete is established by strength tests and
that isn’t common that the buildings were design by its elasticity
modulus, the designers must have equations to calculate E. The
expression 3.900 ´E f c= (f´c is the compressive strength; f´c
and E in MPa) is proposed in the reference AIS (1998) to calculate
the modulus of elasticity of the concrete (average value for all
the national experimental information without distinguishing by
the type of aggregate) must not to be used in Bogotá since this
expression overestimate the modulus of elasticity of the concretes
of the city. The proposed expression in the same reference for
concretes made with sedimentary aggregate ( 3.600 ´f c ) already
overestimate the real elasticity modulus made in Bogotá. The
authors compiled experimental information of concrete strength
tests with measurement of elasticity modulus (more than 1.300
tests according to the standard NTC 4025) for the Colombian
capital and found that the coefficient that multiplies ´f c must be
inferior to 3.000 (units in MPa) to be consistent with the variability
of the modulus of elasticity and to have security levels according
to the reference AIS (1998). Additionally the authors propose to
revalue the expression 3.900 ´E f c= since it was calculated using
statistical data with a high variability.