Implementing Rapid Durability Measure for Concrete Using Resistivity and Formation Factor

Abstract

The durability of in-place concrete is a high priority issue for concrete pavements and bridges. Several studies have been conducted by INDOT to use electrical resistivity as a measure of fluid transport properties. Resistivity is dependent on the chemistry of the cement and supplementary cementitious system used, as such it has been recommended that rather than specifying resistivity it may be more general to specify the formation factor. Samples were tested to establish the current levels of performance for concrete pavements in the state of Indiana. Temperature and moisture corrections are presented and acceptable accelerated aging procedure is presented. A standardized testing procedure was developed (AASHTO TP 119–Option A) resulting in part from this study that provides specific sample conditioning approaches to address pore solution composition, moisture conditioning, and testing procedures. An accelerated aging procedure is discussed to obtain later age properties (91 days) after only 28 days.

Increasing the Reliability of Formation Factor-Based Transport Property Prediction for High Performance Concrete Mixtures Through Innovative Matching Pore Solution Curing

“…Prediction of D e -based on AFF and FF of HPC mixtures. D e for HPC mixtures are predicted using the 91-day AFF and FF from SPS and MPS curing regimen following Equation 3, proposed in previous studies (5,10,45)…”

“…Service life evaluation studies require determining the concrete mix's transport properties, such as chloride diffusion (ASTM C 1556) or rate of absorption (ASTM C 1585), which primarily control ion/fluid ingress into concrete structures (3,4). However, these performance tests require laborious sample conditioning, are timeconsuming and slow in implementation, and provide limited information on the measured properties in some cases, and, thus, are not ideal for implementation for quality control (5,6). However, the desire for rapid service life evaluation of concrete structures has led to the development of tests that rely on the electrical conduction of pore fluid to characterize the microstructure and transport properties of concrete mixtures (7).…”

“…Recently specifications for concrete BR tests (ASTM C 1876 and AASHTO TP 119) have recommended a submerged standard (simulated) pore solution (SPS) curing regimen (curing solution conductivity = 78.74 mS/cm) for sample curing (5). Accordingly, the ''bucket test'' (i.e., sample immersion in sealed buckets containing SPS curing solution) was proposed to resolve two primary issues of alkalis leaching and determination of the pore solution resistivity for calculating FF (18).…”