PROPOSAL OF A NEW APPROACH FOR DETERMINATION OF PORE CONTINUITY AND SUITABLE INTRUSION PRESSURE BASED ON STEP-BY-STEP MERCURY INTRUSION POROSIMETERY TEST

摘要

Hardened cementitious materials consist of various kinds of pores, like gel pores, capillarypores, air voids and so on, whose size and shape distribution is often called pore structure.However, Ink-bottle relations are most characteristic pore structure of cementitious materialsand govern drying shrinkage or ion absorption. Mercury intrusion porosimetry (MIP) test isone of the most widely used methods to study the pore structure of cementitious materials.However, it is well known that the evaluation of pore structure by MIP is not totally accurate.The main reasons are the ink-bottle effect and the destruction of pores due to excessive highpressure. A unique method that can be used to determine volumes of continuative pore anddiscontinuative pore structure is proposed. Furthermore, according to this method, a suitablemaximum intrusion pressure can be selected. In this study, boundary pore between capillaryand gel pores is found using the results of the proposed method.