In some mass concrete foundations, boulders of say 150 mm size up to 30% of the total quantity of concrete, are mixed in the wet concrete.
This adds to economics and saves heat generation. Such concretes are called plum concretes.After at least two layers of wet concrete is completed, well-shaped and thoroughly washed, angular rock pieces using a maximum size of not more than 60% of a layer of pour thickness are placed in the concrete, keeping a distance of more than one-and-a-half times of the biggest size of aggregates in the concrete.
The bottom of the boulders should be embedded in the wet concrete to avoid voids at the bottom. Concreting is continued without stopping.
These rock pieces become an integral part of a concrete structure
Plum Concrete
Plum Concrete normally use on the uneven surface of the ground and another area. This uneven surface level by plum concrete.
This method reduce the cost of construction. Because of plum concrete, you are using large material part near about 60% of Stone and 40 % of concrete so this method to use cost-efficient in construction. Plum concrete original concept by the aggregate in concrete.
This plum concrete use a maximum of 300 mm size aggregate