| 摘要 |
<p>Preparation of an additive comprises suspending a type of clay containing clay materials (5-30, preferably 10-12 dry solid wt.%) in water during stirring and adjusting pH to 6.5-8, preferably 7 to obtain consistency matching the dosing equipment used for dosing additive when mixing concrete or mortar and allowing mixture to mature for 1-7, preferably 1-2 days with stirring before use. The clay minerals are smectite, vermiculite and/or chlorite. Independent claims are also included for: (1) an additive for a self-compacting concrete or mortar comprising an aqueous suspension matured and stabilized for 1-7, preferably 1-2 days, and having a consistency adapted to the dosing equipment used for dosing the additive when mixing concrete or mortar, and having a pH value of 6.5-8, preferably 7, and containing a type of clay comprising clay minerals, i.e. smectite, vermiculite and/or chlorite group; and (2) self-compacting concrete comprising the above mentioned additive in addition to the conventionally employed components in concrete and mortar, i.e. cement, other additions having a puzzolane effect e.g. fly ash and microsilica; and coarse aggregates, sand, mineral fines without puzzolane effect, additives e.g. plasticizers, super plasticizers and air-entraining agents and water, the amount of the type of clay calculated on the content of the dry solid is 0.1-0.4, preferably 0.25 wt.% in relation to the amount of powder (binder) in the concrete or mortar.</p> |
