Is there a detrimental effect caused by welding a new column base plate to an existing base plate anchored into the surface of a floor slab? We have a building designed in concrete with provision for future addition to be built of steel. Will the high temperature generated in welding steel to existing anchored base plates cause deterioration of the concrete in which they are anchored?
The most serious effect to be expected from welding a new column base plate to an embedded base plate is the temperature expansion of the embedded plate during welding. Deterioration of the concrete would not be expected in a normal welding operation. If the embedded plate is close to an edge of the concrete, the expansion may cause concrete to spall. Such cases have been observed in welding to inserts embedded in precast concrete elements. However, if the plate is embedded in a large concrete slab (one in which the dimension between the edge of the plate and the edge of the concrete is greater than eight inches) the concrete will possibly be able to absorb the expansion of the steel plate.