BT-SRA400 is an additive that reduces the plastic and drying shrinkage of ready-mixed concrete.
BT-SRA400 reduces the surface tension of the concrete micropores in the concrete, which occurs when water is dried. This in turn reduces the internal tensile stresses that cause the cement paste to shrink. The shrinkage of the drying is reduced by about 30… 50%. The BT-SRA400 does not contain chlorides or otherwise increase corrosion. BT-SRA400 is added to the fresh concrete mix.
The dosage of BT-SRA400 is generally in the range of 0.5 – 1.5% by volume of cement. The exact amount depends on the concrete class, environmental class and field of application.