The problem

Concrete shrinkage during drying

If a joint con­s­truc­tion is instal­led in new flo­or slabs, it is sub­jec­ted to a gre­at deal of stress in the first 6 months. On the one hand due to move­ment cau­sed by tem­pe­ra­tu­re chan­ges, but pri­ma­ri­ly due to the shrin­kage of the dry­ing con­cre­te.

An over­si­zed joint could com­pen­sa­te for the­se move­ments. But sin­ce most of the move­ment is lost after 6 months, the high instal­la­ti­on cos­ts would be was­ted money. The approach of wai­ting 6 months befo­re instal­ling a joint is also not an alter­na­ti­ve, as the sur­face is usual­ly alre­a­dy in use befo­re then.

Bowls of the concrete slab

In addi­ti­on to shrin­kage, con­cre­te flo­ors also tend to cup­ping during the dry­ing pro­cess: The flo­or slab bends upwards at the edges and the­r­e­fo­re also at the joints. Built-in joint con­s­truc­tions are bent upwards as a result and now repre­sent a high point.

The solution

The QUIFLEX^® new con­s­truc­tion joint is instal­led during the con­s­truc­tion of the flo­or. It con­sists of the usu­al metal sub­s­truc­tu­re, which pre­vents a height off­set, and two hea­vy-duty pla­s­tic pro­files. In the first 6 months, when the con­cre­te has the lar­gest part of its shrin­kage and swel­ling, the­se repre­sent the joint con­s­truc­tion. The two pro­files are then sim­ply remo­ved and repla­ced with the QUIFLEX^®. This com­pen­sa­tes for the increase in height cau­sed by the bowl.

References