Concrete Topping Thickness. According to en 1994 1 12005 composite slab is composed of profiled steel decking with an in situ reinforced concrete topping. The amount of camber will usually depend on the length of the plank.
All aggregates should pass from us standard sieve no8 238mm and sieve no. Thin topping slabs tend to crack. When laid monolithically thickness is in the order of 15 5mm whilst the optimum recommended thickness for separate bonded wearing screeds is between 25mm and 40mm.
The recommended minimum design thickness is 50mm.
Bonded and unbonded toppings are placed after the concrete has hardened. Bonded toppings are generally 20 mm thick while unbonded toppings are generally a minimum of 70 mm thick. However most precast concrete planks will have a built in upwards camber. Usually steel fabric reinforcement mesh will be required in the concrete topping.