Hollow Core Slab Load Span Tables

[Merlino Riviere]

Hollowcorefloor slabs have excellent sound-reducing qualities, durability and inherent fire resistance making them the ideal solution for apartments, care homes, hospitals, schools, universities, hotels, custodial facilities, industrial and commercial projects.

Our solid floor prestressed units provide effective solutions for projects in a variety of sectors. They are manufactured in 100mm, 150mm and 200mm depths and are suitable for use in high-rise apartments, stadia, industrial and commercial projects.

Bearings can be taken from brickwork, blockwork, steel beam flanges or shelf angles and concrete. Longitudinal joints: the sides of the slabs are cast with a shear key profile which when filled with C25/30 grade concrete distributes loads to adjacent units.

To provide effective lateral restraint, slabs are built into parallel spanning walls with a continuous bed of mortar between slab and wall. This not only seals the joint but ensures wall loads are transferred through the slab.

For walls narrower than 190mm, slabs must be tied together to allow for construction and manufacturing tolerances. Typically, two cores per 1200mm-wide slab are formed open so that a reinforcement bar can be inserted across the slabs.

To accommodate service voids and column notches, the hollowcore can be pre-formed to individual requirements. Large openings may require steel trimming supports. It is recommended that holes of less than 100mm diameter are drilled on site, on the centreline of cores.

A number of ceiling finishing options are suitable for hollowcore units: soffits can be plastered using a suitable bonding agent. Proprietary suspended ceiling systems can be hung from supports located between units. Counter battens can be screw-fixed to the soffit for a plasterboard finish.

Bison Precast is able to offer several solutions to incorporate balconies within a floor layout: additional reinforcement can be incorporated into hollowcore slabs to accept bolt-on steel balconies. 100mm-thick solid prestressed slabs can be used as permanent formwork for a cast in-situ balcony. We have 150mm-thick solid prestressed slabs that incorporate top reinforcement to form the balcony and backspan slab as a single unit. Alternatively we can supply RC units cast with integrated thermal breaks.

Our precast hollowcore composite combines hollowcore slab with a composite structural concrete topping. Ideal for applications where enhanced structural performance and lateral load distribution is required, such as in industrial buildings, and multi-storey buildings and car parks.

Our solid composite floors combine solid prestressed units with a composite structural concrete topping that is applied after the solid slabs have been installed. Solid prestressed units are manufactured in 100mm depths and are suitable for many commercial applications.

Leading building products manufacturer, Forterra aided the uncovering and documenting of Must Farm, an incredibly well-preserved bronze age settlement found close to its Kings Dyke clay quarry in Peterborough. read more

They deliver outstanding thermal properties and offer improved thermal efficiency in buildings. We manufacture a large range of hollowcore concrete floor depths, from 85mm to 500mm (other bespoke depths can be manufactured subject to project size).

Our flooring can be used on residential, commercial, education, infrastructure and car park projects. We offer competitive pricing, fast installation and reduced site risks making Creagh precast concrete flooring the obvious choice. Floor slabs can be installed at ground floor, first floor and multi-story levels with ease. This reduces the associated risks with time on site and the use of in-situ alternatives. You can trust our experienced installation team to meet the requirements of your project

To compliment the beam flooring systems Stressline offer two sections of Hollowcore flooring, with spans in excess of 9 metres, either 150mm deep or 200mm deep to resolve many specification problems. Our hollowcore floors all have a self-weight of 300 kg/m2 which complies to the latest sound regulations.

Hollowcore flooring is available in both standard and heavy duty. Full technical support and advice is available, and we can provide full quotations without additional charge and offer a full installation service as well.

The product and design information contained herein are provided for general design assistance and preliminary product sizing. Complete calculations and details, including custom solutions shall be provided to meet project specific requirements.

The Double Tee is the most versatile product for large and small deck penetrations. The 10ft unit can easily accommodate 4ft wide openings, with general penetrations having little impact on capacity. Standard stem penetrations can be provided in the Double Tee for running smaller utilities.

The extrusion process produces a machine finished top surface that does not receive additional roughening. Per ACI 318, the design of hollowcore slabs for composite action is usually limited to a horizontal shear strength of 80 psi. Full scale testing has confirmed this surface meets these requirements.

Prestressed beams and soffits are designed to complement the available flooring products. Utilizing the standard form sections will generally provide a more economical solution. The use of prestressing for these products assists with section depth, performance, and often eliminates the need for shoring.

Some best practice items are:

Consult GPRM Prestress. Availability of form sections and current details can produce real project economies.

Consider Prestressing. Prestressed walls and columns not only produce much more robust units for handling, they can also provide for more economical use of materials and achieve design solutions that may not available with mild steel reinforcing.

PLANT

Standard products often have dimensional and detailing constraints due to casting methods and steel forms. The following pictures show some typical plant used to produce some of the products discussed.

Kilsaran Precast provides hollowcore in a range of thickness, from 150mm to 500mm. As the name implies, hollowcore has a series of hollow cores within the cross section that results in a lightweight product. This, along wiht the prestressed tensile reinforcement, allows for long clear spans to be acheived.

The hollowcore products are slip formed on 1.2m wide production beds. The side of the hollowcore units have a profiled edge. This creates a shear key between individual slabs that allows for distribution of load between slabs when filled on site. This feature can be seen in the product gallery below

Precast concrete hollowcore slabs are used in structural floor systems where limited head room is available. Using precast hollowcore products allows for quicker construction schedules, which is ideal for short summer construction seasons. Producing hollowcore concrete in our heated facility allows for better control of placement, curing and quality during winter construction projects. The hollow voids help reduce weight and material cost while still providing superior strength, fire protection and sound mitigation. These benefits make hollowcore slabs perfect for schools, hotels, condominiums, parking garages and much more. Bringing Haywood Concrete Products into the early project stages helps ensure a cost effective, functional and aesthetically pleasing end result.

Every job is different, so we work closely with your architect and structural engineers. This ensures that we are working well within the structural capabilities of hollowcore planks.

Floorspan Contracts are a precast concrete manufacturer based in Wisbech, Cambridgeshire. Decades ago, we began our life as block and beam floor suppliers, and we have grown into one of the largest suspended concrete flooring specialists in the region.

Precast Hollowcore products help shorten construction schedules due to their rapid installation, no propping required, the possible absence of any need for further finishing and the fact that the floors create an immediate working platform.

Slabs are available in 100, 120, 150, 200, 250, 300 and 400mm thicknesses. Other thicknesses available upon request. Download the Precast Hollowcore brochure below for easy to read span tables to see how this product can save you time and money on your next project.

Building with Hollowcore flooring is a well established construction method used throughout Australia and overseas. Download the Hollowcore Flooring Technical Manual published by the National Precast Concrete Association of Australia to see typical details, design information and other information relating to this exciting building product.

DELTABEAM is designed to be used as a structural element combined with all general concrete slab types: hollow-core slab, filigran slabs, composite steel decking, trapezoidal steel decking slabs, and cast-in-place concrete slabs. It enables the usage of shallow element structures and strengthens the frame structure inside the slab.

Chapter 4 of the "PCI Manual for the Design of Hollow Core Slabs", Second Edition is a standard reference that engineers use to calculate horizontal shear transfer elements, i.e. collectors, chords, and drag struts. When considering the connection at the D-BEAM, typically, the hollow core shear strength is less than the grouted beam's shear strength.

For designing the GIRDER-SLAB system in RAM engineers will let RAM select a standard WF shape but ignore the output. The engineer will then size the D-BEAM girders from the D-BEAM girder Design Tool located on our website. Since the D-BEAMs are not normally used in a braced frame this procedure works well. If the D-BEAM girders were located in a braced frame, engineers would again model it as a WF beam to obtain the axial load in the beam due to the lateral load. Then the engineer will check the D-BEAM girder, manually, for the combined axial and bending stresses.

3a8082e126