| 摘要 |
<p>PURPOSE:To reduce cleaning treatment to a large extent or to dispense with cleaning treatment and to prevent the generation of curing obstruction even when old paper pulp is added to a cement composition by a method wherein opened old paper pulp is used as a reinforcing fiber and the pulp fiber is subjected to wetting treatment using a solution having cement curing accelerating action prior to the mixing with other compounding material. CONSTITUTION:Old paper pulp contains a cement curing obstructing substance and, when the pulp is added as it is, curing reaction receives adverse effect though there is difference in degree. Then, the old paper pulp is subjected to wetting treatment using a solution having cement curing accelerating action prior to the mixing with other compounding material. By the solution having the curing accelerating action, the cement component around the pulp fiber begins to cure at an early stage before the cement curing obstructing substance contained in the old paper pulp fiber is eluted. Therefore, adverse effect due to the obstructing substance is not generated. As the solution having the curing accelerating action, there are CaCl2, NaOH, KOH, water glass and a water reducing agent having cement curing action.</p> |
