Prestressed hollow core slab

HCU floor elements are widely used in industrial, residential, single-family and commercial buildings because they can bear heavy loads with a low dead weight and achieve a high load-bearing capacity.

Load-bearing capacity
High floor load-bearing capacity with relatively low construction height (high slenderness)
Span
Possibility to use large spans of up to 19 metres
Fire resistance
High fire resistance, up to REI240, without any additional protection
Weight
Relatively low construction weight
Installation
Quick installation (we offer the possibility of renting the spreader)
Modularity
standard product modularity - 120 cm (or 60 cm) wide

TECHNICAL DETAILS

Proces produkcyjny sprężonych płyt kanałowych HCU

Production process of prestressed hollow core unit

We produce hollow core units on special process lines designed for the production of prestressed elements. The production of units begins with the placement of pre-stressing tendons with a specified tension force and quantity for each reinforcement variant. The prestressed element has tendons located in the lower part (sometimes in the upper part) of the cross-section to balance the structural loads acting from above. Tensioning of the tendons (strings) is done through external resistance elements before concreting. The slabs are formed by extruding the concrete mix in the form of a ribbon. After heat treatment and achieving the required concrete strength, the tension is released, transferring forces to the concrete, followed by cutting the slabs to the desired length.

Możliwości produkcyjne sprężonych płyt kanałowych HCU

Production capabilities of prestressed hollow core unit

The pre-tensioned prestressed concrete floor HCUs manufactured in our plant have a thickness of 160 ÷ 500 mm. Our basic range includes six slab thicknesses (160, 200, 265, 320, 400 and 500 mm) available in two fire resistance ratings: REI 60 and REI 120. For the 320 mm slab, it is possible to provide a fire resistance rating of REI 240. We have 6 production tables for HCUs, each 150 meters long. Each element can be up to 20 metres in length. It is possible to make side or central rectangular recesses near supports or spans. Recesses can only be made in solid slabs that have not been previously cut lengthwise.

Możliwości projektowe sprężonych płyt kanałowych HCU

Design capabilities of Prestressed hollow core unit

Y1860 steel tendons and reinforcement steel are used in standard prestressing elements. Concrete must be of at least class C50/60. Openings and recesses can be designed in slabs according to the perforation guidelines for hollow core slabs. Side and central recesses can be made near supports and spans, following the HCU instructions of the prefabrication plant.

Transport sprężonych płyt kanałowych HCU

Transport of Prestressed hollow core unit

HCU panels are transported on flatbed vehicles whose length cannot be shorter than the length of the transported element. The prefabricated elements should be stacked horizontally, similar to the storage method, i.e. separated from each other by special wooden spacers. However, in the case of transporting two stacks of slabs next to each other on one platform, it is advisable to top both stacks with at least one slab connecting both stacks (placed in the middle). This arrangement improves the load stability while driving. The stack height is generally limited by the vehicle's load capacity. Slabs should be secured against sliding off the platform by stabilising the load with ropes or straps.

Installation of Prestressed hollow core unit

Slabs must be supported evenly across their entire width. The installation should be based on the slab layout scheme developed in the design documentation. Slabs should rest on a layer of cement mortar, at least M5, or on specially designated plastic pads, according to design guidelines. Before concreting, it should be checked whether each slab has end caps to prevent the concrete mix to enter the channels. Installation of hollow core units is done using a traverse beam with special jaw grips that latch onto the edges of the slab. In the case of slabs cut longitudinally or with recesses, installation is done using straps attached to the traverse beam or hooks embedded in the slab.

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