In case the A380 movements are twice as many as predicted the
CDF is increasing to 1.55, causing structural failure of the CTB base layer. For this reason the
alternative structure has been recalculated based on the development of cracks, reducing the Emodulus to a value of 5,000 MPa, resulting in an AC CDF of 0.92. To avoid random cracking
and control the possible reduction in E-modulus the CTB subbase, dummy joints are sawed into
the surface at a grid of 3.5 x 3.5 meter. Aggregate interlock in the dummy joints, together with
the controlled cracking procedure, will keep the E-modulus at an acceptable high level during its service life.