| 摘要 |
<p>The prodn. of an agent for controlling shrinkage, expansion and for increasing setting time at low temps. of cement, mortar, concrete without impairing other properties and consisting of calcined, dry Al2(SO4)3 in addition to diluent, an alkanolamino accelerator i.e. ethanolamine and inorganic binding agent i.e. sodium silicate. Additive pref. comprises 90-30 wt.% Al2(SO4)3, 10-70% retarder i.e. calcium sulphate. Hydrated Al2(SO4)3 is calcined alone or with cement clinker at 400-480 degrees C, ground with calcium stearate and used at a level 0.2-10%.</p> |
