Longitudinal forces in concrete structures. An ignored phenomenon which severely changes the structure behavior

Tension forces are practically present in each concrete element. The phenomenon is due to the loss of hydration heat, concrete shrinkage and temperature drop which produces shortening of the components. As soon as such actions are constraint by stiff adjacent building cores, longitudinal walls etc. large tension forces are activated and through cracks produced. Such cracks frequently affect structure behavior due to the phenomena: water intrusion due to the loss of compression zones, large deflections due to the decrease of stiffness and low shear bearing capacity due to the crack yielding to the vertical displacement. These facts indicate that longitudinal forces should not be ignored in modern design of concrete structures. The following investigations are based on generally accepted design methods by the author which found entrance into research work, standards and engineering practice.