Simulation of corrosion field measurement on reinforced concrete using BEM

Reinforced concrete (RC) corrosion is a leading of structural deterioration and premature degradation for the infrasturctures, with significant affected for safety, durability and reability. Therefore, early assessment of RC corrosion is important to prevent deterioration of the structure. The objective of this paper is to apply Boundary Element Method (BEM) for improving reinforced concrete (RC) corrosion assessment using field measurement data. In this study, the potential on whole domain of concrete structures was modeled by Laplace equation. The Laplace equation was solved by BEM, hence the potential on the concrete structure can be determined. The field data were measured by using half-cell potential technique and collected from an existing house in Aceh region that struck by the 2004 Sumatra tsunami. The simulation results show the use of BEM can improve the RC corrosion assessment. According to ASTM C876, the distribution of potential values on the concrete surface above the corroded area were in range -200 mV to -350 mV that indicated active corrosion was occurred. It can be inferred, the method can improve the field measurement data since it has capability to predict the corrosion profiles of reinforcing steel in more precise.

The Propagation of Tsunami-Generated Acoustic–Gravity Waves in the Atmosphere

Tsunami-generated acoustic–gravity waves have been observed to propagate in the atmosphere up to the ionosphere, where they have an impact on the total electron content. The authors simulate numerically the propagation of two-dimensional linear acoustic–gravity waves in an atmosphere with vertically varying stratification and horizontal background winds. The authors’ goal is to compare the difference in how much energy reaches the lower ionosphere up to an altitude of 180 km, where the atmosphere is assumed to be anelastic or fully compressible. The authors consider three specific atmospheric cases: a uniformly stratified atmosphere without winds, an idealized case with a wind jet, and a realistic case with an atmospheric profile corresponding to the 2004 Sumatra tsunami. Results show that for the last two cases, the number and height of turning points are different for the anelastic and compressible assumptions, and the net result is that compressibility enhances the total transmission of energy through the whole atmosphere.