Water Migration Phenomenon in Concrete in Prepeak Region

An experimental and analytical study on pore-water pressure occurring in the prepeak region of concrete due to the external load is performed to investigate the mechanism of water migration in concrete. In the experiment, an apparatus is developed that can measure the pore-water pressure in concrete under fixed lateral displacement. Concrete strain, stress, and pore-water pressure are measured; the experimental parameters are the loading age and water curing period. The effects of each parameter on pore-water pressure generation are discussed. The pore-water pressure occurring in the prepeak region of concrete can be measured due to the development of a cell that is imitated to be completely fixed for the lateral displacement and undrained condition for pore water. The ratio of pore-water pressure to concrete stress is very high. The existence of the inflection point means that negative pore-water pressure exists in the voids formed by the hydration reaction during a curing period.