beam and block imagebeam and block imagebeam and block imagebeam and block image

Beam and Block Floors

 Technical Data

Milbank Beam and Block floors comprise 150mm and 225mm deep prestressed beams with standard 100mm deep building blocks, spanning between the beams. By varying the beam centres, a variety of loading conditions can be accommodated. Milbank Beam and Block floors provide a quick and economical solution for most structural flooring situations, both at ground and upper floor levels. This type of flooring is also suitable for refurbishment contracts or sites with restricted access, where easily handled components are required.

Roll over a number on the floor plan to view illustrated details.


1. Narrow spacing 7. Staggered bearing on internal wall
2. Alternate spacing 8. Non loadbearing partitions
3. Wide spacing 9. Bearing on external wall
4. Internal garage wall 10. Internal cantilevers
5. External garage wall 11. External wall parallel to span
6. Blocks built into flank walls  

 Design

Milbank prestressed floor units are designed to the requirements of BS 8110. The standard Milbank prestressed sections are designed for moderate exposure and to meet the requirements of Class 2 members. High tensile steel wire is used for the prestressing tendons, the configuration of which will vary depending on the span and design loadings. Standard Milbank prestressed beams have a minimum fire resistance of 30 minutes, (in accordance with BS 8110 Part 2). This can be enhanced by using a suitable suspended ceiling.

See Load Span - Beams for more details

 Manufacture

Milbank prestressed beams are manufactured within an enclosed factory environment, "wet cast" in fixed moulds, giving a superior finish and dimensional tolerance. All materials used in the manufacturing process conform to the requirements of the relevant British Standards. Water-reducing admixtures are used to achieve the correct workability.

 Dimensions

All Milbank prestressed beams are manufactured to comply with the cross sectional tolerances set out in BS 8110. Length tolerances: ±20mm.

Units are manufactured to the following nominal dimensions:
beam dimensions image See Unit Details - Beams for more details

 Infill Block Specification

Block Density: Standard building blocks used as infill between the beams can have densities ranging from 650kg/m³ to 1900kg/m³ to suit thermal or sound requirements. The advantage of using lightweight blocks is that the dead load on the floor is reduced, enabling greater spans for the same imposed loads to be achieved.

Block Strength: Either a block strength of 3.5N/mm² with a transverse load capacity of 3.5kN on a 420mm span or a block strength of 7.0N/mm².

(The Load/Span tables are based upon using 1450kg/m³ blocks, for domestic loading the maximum span could be increased by approximately 300mm if 650kg/m³ blocks were used).

 Layout Drawings

Milbank will provide layout drawings and standard data sheets for the floors. The drawings show the structure supporting the precast floor, the location of partitions carried by the floor, service entries such as S.V.P.s and the design loadings, including the density of the infill blocks.

 Installation

Beam and Block floors can be installed, in most weather conditions, by a variety of methods, (e.g. by hand, using site plant, "Hiab" type lorry or mobile crane) depending upon site conditions. Once the beams have been set out according to the layout drawings, infill blocks are placed in the rows between the beams.

Insitu make-up can be avoided by cutting infill blocks to suit using either a block splitter or disc cutter. Milbank can provide 20N/mm² slip bricks to complete the perimeters of the floors.

See Installation for more details.

 Grouting

When all the blocks have been installed, the floor should be grouted with 4:1 sand / cement grout brushed into the joints between the beams and blocks to stabilise the floor.

 Camber

All prestressed units will have an upward camber. The degree of camber is dependent upon the prestressing force and the span; Levelling Screeds may be required prior to laying floating finishes.