The effects of fly ash,ground granulated blast-furnace slag and water-binder ratio(m_w/m_b) on the hydration heat and the hydration exothermic process of paste in ultra high strength concrete at low m_w/m_b were investigated by the test system of hydration heat.According to the experimental results,the hydration exothermic process of paste,with the replacement level of 10% fly ash or slag,is similar to that of the control.However,with the increasing addition of fly ash or slag to 30% or more,the highest hyd...