Specific weight of concrete mix and types of concrete mixes
At the early stages of construction it is important to consider not only the future concrete strength, but also the mass of the mix that will be placed in a foundation, slab, floor or other structural element. Concrete mix weight affects foundation load, transport, pumping and work volume estimates.
In common searches this value is often called the specific weight of concrete mix, although values in kg/m³ are technically density or unit weight. Mass is calculated by the formula:
mass = volume × densityFor example, 2 m³ of concrete mix with a density of 2400 kg/m³ will weigh about 4800 kg.
Types of concrete mixes
Concrete mixes differ by density, aggregate type, purpose and workability. By mass of one cubic meter, several groups are usually distinguished:
- Heavyweight mixes are used in special structures and shielding elements. The mass of 1 m³ is usually above 2500 kg. Heavy aggregates may include barite, magnetite, hematite or metal materials.
- Normal-weight mixes are the most common option for foundations, slabs, columns, beams and cast-in-place structures. With dense aggregates, 1 m³ usually weighs 2200-2500 kg.
- Reduced-weight mixes are a transitional group with lower density due to composition and aggregates. They are used where structural load needs to be reduced.
- Lightweight mixes are made with porous aggregates such as expanded clay, pumice, perlite, tuff or slag. The mass of 1 m³ is usually within 500-2000 kg.
- Ultra-lightweight mixes are used mainly for insulation and non-load-bearing fills. Their density can be below 500 kg/m³.
The lower the mix density, the better its thermal insulation usually is, but the lower its load-bearing capacity. For structural elements, use the design mix, not only a reference density.
Concrete mix specific weight table
Concrete mixes differ by aggregate, so the mass of a cubic meter can vary significantly. The table gives approximate density values for different mix types.
| Mix type / aggregate | Concrete mix density, kg/m³ |
|---|---|
| Reinforced concrete mix | about 2500 |
| Concrete mix with gravel and crushed stone | about 2400 |
| Tuff concrete | 1200-1600 |
| Pumice concrete | 800-1600 |
| Concrete mix with volcanic slag | 800-1600 |
| Expanded-clay foam concrete, mix with expanded-clay sand | 500-1800 |
| Expanded-clay concrete with quartz sand | 800-1200 |
| Expanded-clay concrete with perlite sand | 800-1000 |
| Shungizite concrete | 1000-1400 |
| Perlite concrete | 600-1200 |
| Slag-pumice concrete, thermosite concrete | 1000-1800 |
| Slag-pumice foam concrete and slag-pumice aerated concrete | 800-1600 |
| Concrete mix with granulated blast-furnace slag | 1200-1800 |
| Agloporite concrete with boiler or fuel slag | 1000-1800 |
| Concrete mix with ash gravel | 1000-1400 |
| Gas-ash concrete and foam-ash concrete | 800-1200 |
| Aerated concrete, foam concrete, gas silicate and foam silicate | 300-1000 |
| Vermiculite concrete | 300-800 |
What affects concrete mix weight
Concrete mix mass depends not only on aggregate, but also on water, cement, sand, admixtures, air entrainment and compaction. Fresh mix, dry concrete and hardened concrete can have different weights because some water evaporates and moisture content changes.
Reference ranges are suitable for preliminary estimates. For delivery, structural load calculations and ordering, use the density from the specific mix certificate or confirm the data with the supplier.
Frequently Asked Questions
How much does 1 m³ of concrete mix weigh?
A normal-weight concrete mix usually weighs about 2200-2500 kg/m³. Lightweight mixes with porous aggregates may weigh 500-2000 kg/m³, while heavyweight mixes exceed 2500 kg/m³.
Why can fresh concrete mix weigh differently from hardened concrete?
Fresh mix contains water, air and a workable structure. After hardening, part of the moisture evaporates and moisture content and density change, so dry concrete mass can differ from fresh mix mass.
How do you calculate concrete mix mass for ordering?
Multiply the required volume by the density of the specific mix. For important orders, use the density from the mix certificate or confirm it with the producer.