EVALUATION OF HIGH PERFORMANCE CONCRETE USING
ELECTRICAL RESISTIVITY TECHNIQUE
36th Our World in Concrete and Structures (OWICs) - 2011
Darren T.Y. Lim*, B. Sabet Divsholi, Da Xu and Susanto Teng
rapid chloride migration test, high performance, concrete, electrical resistivity
Using the coefficient of chloride diffusivity to evaluate the quality of the concrete in terms of the durability aspects is a commonly used method. With the inclusion of supplementary cementitious materials (SCM) and a lower water/cementitious ratio, the permeability of high performance concrete (HPC) is reduced significantly. Therefore the testing for chloride diffusivity using the rapid chloride migration test (RCMT) becomes an elaborate affair requiring at least 4 to 5 days of testing instead of the usual 24 hours duration or less. At the early stage of construction, a fast and convenient technique to provide quality checks is required. Electrical resistivity technique is fast and convenient, and is proven to be able to establish a relationship with the chloride diffusivity results for lower grades concrete. In this work, the effectiveness of electrical resistivity technique for HPC to establish a relationship with chloride diffusivity in order to evaluate the quality of the concrete is studied. Six mixes of three different grades of concrete with different SCM such as 30% ultra-fine granulated ground blast-furnace slag replacement and 10% undensified silica fume were cast. Compressive strength, RCMT, and electrical resistivity test results are presented. The correlation of the measurements from electrical resistivity and the chloride diffusivity tests were conducted to study the possibility of establishing a relationship between the results. High correlation coefficients (R>0.94) for all the mixes were achieved, representing the feasibility of using electrical resistivity test on HPC. The measurements will be used to determine the quality of the concrete and the corrosion rate of the concrete.