Floor slab specific weight: weight of hollow and solid slabs

Reinforced concrete floor slabs do not always occupy the main position in the overall construction estimate, but this structural element cannot be ignored by mass. At the project development stage, it is necessary to calculate what loads the walls and foundation of the building can withstand, and then choose a suitable type of intermediate floor.

Types of Reinforced Concrete Floor Slabs

Serial reinforced concrete floor slabs are produced according to standards, design series or the manufacturer’s technical documentation. Safe use depends not only on slab type and weight, but also on load-bearing capacity, bearing scheme, reinforcement, concrete grade and design loads.

• A solid floor slab is a monolithic product without large internal voids. The weight of a 120 mm thick slab is from 4300 to 7100 kg. The higher the concrete grade, the greater the strength and weight of the floor element. The weight of a 160 mm thick floor slab can reach 8700 kg.

A type of solid floor slab is the supplementary element. The length of such products is standard for full-size slabs, 1.8-5 m, but the width is much smaller, as is the weight, up to 1500 kg.

• Hollow-core, or lightweight, floor slabs have less weight because their body is penetrated by technological openings of a certain shape. Mostly these are round chambers with diameters from 140 to 159 mm, PC1 and PC2. There are also hollow-core floor types with elliptical chambers, PG, and differently shaped ones, PB.

The presence of voids in the slab body makes it possible to reduce the mass of standard 6-meter floors to 3 tons. The advantage of hollow-core slabs is good thermal and sound insulation.

• Ribbed reinforced concrete products can be classified as monolithic because they have no internal cavities. These are slabs with increased load-bearing capacity, obtained thanks to side cast-in-place stiffening ribs. Standard 6-meter slabs weigh from 1500 to 3000 kg, while industrial 12-meter giants reach 7000 kg.

• A polystyrene concrete floor slab is a lightweight slab option where thermal insulation material is used as filler. The strength of such slabs is lower than that of classic reinforced concrete products, so allowable loads must be checked according to the manufacturer’s documentation and design calculation. Polystyrene concrete slabs weigh less than classic solid slabs, while their thermal insulation characteristics are higher.

How Much Do Different Floor Slabs Weigh?

Slab weight depends on many factors, in particular the grade of concrete used, the number of reinforcing elements, recesses, voids and other factors.