Estimation of compressive strength at early age using electric conductivity

The techniques using electrical conductivity to estimate compressive Strength of concrete is effective in tunnel construction as concrete structures are greatly affected by demolding time. The study presents a methodology for estimating compressive strength at early age using electric conductivity by carrying out two main tests; compressive strength of different concrete mixes, using ordinary Portland cement (OPC), blast furnace slag type (B) and chemical admixture (A) as an accelerator, water cement ratio 50% (W/C) and monitoring the performance at temperature 5°C–35°C. Electric conductivity test to measure the phenomena of increase in conductivity ratio was conducted. The analysis revealed a model for predicting the compressive strength of concrete mixes at early age (24 hours). From the analysis and the results, there is a relationship between electrical conductivity and liquid water content in the pore in other words, the conductivity ratio and the compressive strength. Therefore using these techniques will provide indispensable techniques for efficient constructions of concrete structures.