Expansion joint profile Dewmark SG 63

The use of base plates was the development of the evolution of Omega profiles for concreting work joints. Due to the quick-detachable casing, adjacent to the body of the base plate, and an increase in the area of ​​contact between the base plate and concrete, it was possible to increase the load-bearing loads of the floor.

The support plates carry and transfer the load between two adjacent sections of the concrete floor, that is, the loaded equipment moves along the finished floor without causing stress in the concrete slab. A concrete slab usually has only about 50% of its bearing capacity at the edges, so the dowels support the slab at the edges and help to support and transfer weight from one slab to another, allowing the slabs to bend slightly, gently transferring the load along its surface.

Calculation of the bearing capacity of the base plates is given in the British methodological manual TR34 ver. 4 clause 6.5.

The force on the shear of the base plate is determined by the formula:

$$P_{sh\: plate} =A\ast 0.9 \ast 0.6\ast P_{y}$$

Where $А$ - cross-sectional area of the base plate

$P_{y}$ - steel yield strength

Bearing / bending load on the base plate:

$$P_{max\: plate} =0.5\left [ \left ( b_{1}^{2}+c_{1}^{2}\right )^{0.5}-b1 \right ]$$

Where $b_{1}=2ek_{3}f_{cd}P_{b}$

$c_{1}=2k_{3}f_{cd}P_{b}^{2}t_{p}^{2}f_{yd}$

$e$ - distance of load application from the concrete surface; with a symmetrical arrangement, this is equivalent to half the seam opening (see fig.)

$k_{3}=3$ (constant)

$f_{cd}$ = concrete strength = $\frac{f_{ck}}{y_{c}}$

$P_{b}$ - base plate width

$t_{p}$ - base plate thickness

$f_{yd}$ - the strength of the steel of the base plate (taken equal to the yield strength of the steel)