| 摘要 |
<p>Water-insoluble organic residues of acid sludges obtained in the refining of mineral and tar oils are used as waterproofing ingredients in concretes and mortars and in gypsum and Sorel cement compositions. They are obtained by diluting and filtering or centrifuging the sludges, after which alkaline substances may be added to neutralize remaining acid. Germicides such as fluorides and fluosilicates may also be added. The residues may be mixed with known waterproofing agents such as aluminium sulphate, paraffin wax, &c. They are used in the proportion of 0,1-1,5 per cent of the weight of the binding agent.</p> |
