What is the density (specific gravity, bulk density) of cement-sand screed kg m3

A common component of construction projects is cement-sand screed, which offers a level and sturdy foundation for floors in residential, commercial, and industrial buildings. To create a strong and long-lasting surface, a thick layer of a mixture of cement, sand, and water is applied. The density of cement-sand screed is a crucial factor that influences its overall performance, stability, and strength.

Density, also known as bulk density or specific gravity, is basically the mass of the screed per unit volume; it is commonly expressed in kg/m³, or kilograms per cubic meter. It is important to comprehend a cement-sand screed’s density as it affects the screed’s performance in a variety of scenarios, such as load bearing and resistance to deterioration.

Depending on the application technique and mix proportions, a cement-sand screed’s density can change. To make sure the screed will meet the requirements for a project, builders and engineers should be aware of the typical density range. With this information, one can choose materials, mix designs, and installation methods with confidence, knowing that the screed will function as planned over time.

SNiP cement-sand screed

Floor leveling cement-sand mortars are widely used in civil, industrial, and residential construction. In the latter scenario, work is not always completed in accordance with the design documentation, and the owners frequently take on responsibility for material selection and base leveling implementation, depending on their own knowledge, recommendations from friends, or information found online. Consulting publicly available construction industry standards is one way to guard against potential mistakes in the absence of a project.

The document SP 29.13330.2011 "Code of Practice. Floors" governs the requirements for the design of floors in buildings serving a variety of purposes. It updated the previous set of rules in 1988 by accounting for the introduction of new safety requirements as well as the emergence of new building materials and technologies. SNiP 2.03.13–88 "Levels." The code of rules contains sections that outline general requirements for floor design solutions as well as for the component elements—coating, interlayer, vapor barrier, waterproofing, screed execution, underlying layer, and base soils.

As the primary standard by which technical judgments are made The nature and degree of mechanical impacts on the floor, the degree of exposure to liquids or harsh environments, the operating temperature regime, and the requirements for sanitary and hygienic conditions are all determined by SP 29.13330.2011. Special considerations are also given to industrial spaces, taking into account the unique characteristics of the building such as the potential for dust accumulation, the buildup of static charges or sparks, and the ease of cleaning and tidying up.

When selecting a floor type, covering, materials, and carrying out tasks, such as installing a leveling screed, individual developers may find the information contained in the document’s text and the tables in the appendices to be helpful.

Screed density and specific gravity of cement and sand

A cement-sand screed (CSS) can be installed using a variety of materials with varying compositions, densities, and strengths, contingent upon the operating conditions’ requirements:

  • concrete with heavy filler;
  • concrete with light filler;
  • cement-sand mortar;
  • dry building mixes.

The type of filler or aggregate used in the cement-sand mortar—which can include sand with different fractions and grain sizes, granite screenings, mineral and polymer additives—determines the density or specific gravity of the mixture.

With heavy filler — granite screenings

The finished product of producing commercial crushed stone with fraction up to 10 mm is filler based on granite crushed stone screenings. Industrial construction uses concrete screed with granite filler because of its high strength and resistance to frost. It is utilized in ground floor and basement construction, garage construction, utility construction, and warehousing construction for locations with heavy operational loads.

Concrete made with granite screenings has a density of 1400–2200 kg/m³, making it a heavy mixture. For the given density range, the bulk weight of a 5 cm thick screed is between 70 and 110 kg per 1 m2, which is a substantial additional load on interfloor ceilings, floors with a soil or wooden base.

Light types of solutions – perlite, polystyrene, granules

In many situations, using a lightweight screed will yield better results. It is employed when installing pipelines and communications beneath the floor, when leveling removes a significant height differential, and when a screed is required to provide the floor with extra sound and heat insulation.

Depending on the type and proportions of filler used in the mixture, the density of lightweight solutions for screeds can vary from 500 to 1800 kg/m³. Lightweight screed is sometimes used as an intermediate layer with final leveling using stronger solutions because its strength is not as great as mixtures with heavy filler.

For lightweight screeds, a variety of materials are used as filler; by adding these materials to the mixture’s mass, you can obtain different technical characteristics:

  1. Perlite is a porous rock, has good heat and sound insulation, high absorption capacity, fire resistance, chemical inertness. For the preparation of construction concretes and mortars, expanded perlite with a density of about 100 kg/m³ obtained by heat treatment of the initial raw materials is used, the density of the mixture, depending on the composition of other components, is from 400 to 1000 kg/m³.
  2. Vermiculite is a natural mineral with a layered structure, expanded rock is used in construction. As a filler for mortars and concretes, it has properties and characteristics similar to perlite.
  3. Expanded clay with a bulk density of 150 to 800 kg/m³, obtained by firing clay or clay shale. Its characteristics are high strength, frost resistance, chemical resistance, non-flammability, environmental friendliness. Expanded clay crushed stone with a fraction of up to 10 mm is used as a filler or serves as raw material for the preparation of expanded clay sand.
  4. Granulated polystyrene foam (from polymer raw materials). The density of CPS based on it is from 150 to 600 kg / m³, they have a high degree of sound and heat absorption, frost resistance, but low in comparison with other light solutions with strength.

Type of Screed Density (kg/m³)
Standard Cement-Sand Screed 2000-2200
Lightweight Cement-Sand Screed 1600-1800

The strength, longevity, and general performance of a floor are all directly impacted by the density of a cement-sand screed. Knowing the average density values, which typically fall between 1800 and 2200 kg/m³, will help you choose the right screed type and mix ratio for your project with greater knowledge.

The ratio of sand to cement, water content, and sand type are some of the variables that impact a cement-sand screed’s density. You can customize the screed to match the unique requirements of your construction by adjusting these variables, regardless of whether you need a denser mix for greater strength or a lighter screed for decreased load.

In the end, choosing the appropriate density will guarantee a sturdy and steady base for your flooring, which will help your building project last a long time. Regardless of your level of experience, whether you’re a contractor or a do-it-yourselfer, getting a long-lasting, high-quality finish depends on paying close attention to the density of your screed.

The strength and durability of a cement-sand screed are largely dependent on its density, which is commonly expressed in kilograms per cubic meter (kg/m³). These screeds typically have a specific gravity of 1,800–2,200 kg/m³, depending on the type of sand and cement used, as well as the mix proportions. Since density directly affects the screed’s load-bearing capacity and resistance to cracking over time, knowing it helps ensure that the screed provides a stable and solid foundation for flooring.

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