Fly Ash can be replaced by cement. If there are shortage of cement you can use it with cement to fulfill the required quantity. There are fewer chances of cracking in the base because fly ash has the power to make the foundation stronger. It is better to use fly ash along with the cement for the long-lasting result.
The steel was not used in the building foundation in the olden days but nowadays it is utilized in the industrial or commercial infrastructure. In the manufacturing industry, various heavy plants are placed on the floor for functioning. That’s why steel is the best option for a strong foundation.
The sand is utilized along with other materials. The quantity of sand depends on the area. Some areas are watery which can make the foundation weaker then sand is not used in much quantity. The stone is effective in that area. The low watery areas have stable soil due to which you can use more sand.