The answer to the question can petrographic measure the water/cement ratio in hardened concrete is not a seasy one to answer. Especially when the petrographer is examinaing the concrete with a scanning electron microscope (SEM) to do the work.
The argument for whether water/cement ratio in hardened concrete can be effectively measured is not a new argument. Using petrograhic means to determine the water to cement ratio of the orignal mix of hardened concrete is generally accepted for purposes of research.
The challenge to answer this question effectively is that there is no generally accepted standard of procedure to utilize microscopical methods for determing water to cement ratio in hardened concrete.
ASTM C856 acknowledges that estimation of the original water to cement ratio of hardened concrete by petrographic means is useful, such estimation cannot be reliable.
There is a project which Building Forensics International consulted in the 2005 where Judge David C. Velasquez made a ruling on this very issue. If you would like to read his detailed ruling on this subject click on his name and read futher regarding the argument whether Petrography can be used to determine water to cement ratio in hardened concrete
BFI Staff Writer -