Abstract
Hydration pressure of hardened cement paste containing blast furnace slag with 30％ or 45％ replacement of base ordinary Portland cement with water to binder ratio of 0.40 and 0.55 was determined experimentally. The experimental study is composed of measuring adsorption and desorption isotherm, length-change isotherm, Young's modulus and Poisson's ratio, and density of hardened cement paste.
It is experimentally confirmed that 1）the desorption isotherm of hardened cement paste containing blast furnace slag has the larger water content than those of hardened cement paste with Portland cement, 2）Drying shrinkage of hardened cement paste containing slag with a condition of W/B＝0.55 is larger than those of hardened cement paste with Portland cement especially in the range of relative humidity lower than 60％RH, 3）the drying shrinkage of hardened cement paste containing slag with a condition of W/B＝0.40 showed almost the similar amount compared to those of hardened cement paste with Portland cement.
Based on the hydration pressure theory which is proposed by the first author is adopted to this experimental result, and, according to this result, it is presented that the surface of hardened cement paste containing blast furnace slag has the larger interaction with water than that of hardened cement paste with ordinary Portland cement.
This is the main factor for that hardened cement paste with blast furnace slag exhibits the large drying shrinkage.
