Measurement of reinforcement bar depths and diameters in concrete

Abstract

Ground Penetrating Radar is one of the methods usedl for the determination of depth and position of reinforcement bars in concrete. Recent work suggests that GPIl can also be used to estimate rebar diameters. This paper presents the results of GPRmax3D simulations for two centre frequencies of GPRs applied to a range of rebar sizes at different depths. This is compared with real measurements of different rebar sizes in air using a 4GHz GPR system. A further comparison is made with measurements of rebar depths and sizes obtained from a practical GPR survey of ceilings in a series of prefabricated blocks of flats originally erected in the late 1960s.