FACTORS AFFECTING NEAR SURFACE TESTS OF IN-SITU CONCRETE STRUCTURES FOR CARBONATION-INDUCED CORROSION

Abstract

Corrosion in RC members leads to reduction in strength and serviceability
of the structures. Several non-destructive testing techniques can be
employed to evaluate the possibility of reinforcement corrosion relatively
quickly and cost-effectively. However, due to uncontrollable variations of
structures conditions in the field, the reliability and validity of the test
results are in doubt. This paper examines the effects of surface conditions,
concrete moisture content, ambient conditions, and carbonation depth on
the rebound number, half-cell potential, two and four-probe resistivities,
and linear polarization resistance. Eighteen reinforced concrete buildings
located in Bangkok metropolitan areas which are ten years or older were
sampled. Statistical analyses were performed to determine the
significance of each effect on the non-destructive test values. The effects
and relationship of each factor were shown on this paper.