Many authors have measured internal strains in concrete under compress
ion. Recently, Klink's results showed that sections did not remain pla
ne in such tests. These results call into question the method used to
determine the Young's modulus of concrete. We tested a concrete sample
with internal and on-surface gauges. Our results, taking into account
the inclusion effect of gauges, show that sections remain plane when
concrete is loaded under compression. So there is no need to change th
e method used to determine the Young's modulus of concrete.