Concrete Face Dam Waterstop: SR Plastic Filler, GB Flexible Filler and EPDM Composite Cover Plate Construction Guide

SR plastic filler, GB flexible filler, and EPDM composite cover plate

Installation method for EPDM composite cover plates

Construction process for plastic filler

Within the secondary waterstop system of concrete face dams, this step plays a central role

The anti-seepage cover sheet creates a complete waterproofing system

and is essential to the safe operation of the face dam.

However, on real projects, filler application still faces practical issues

Many construction teams are not fully familiar with the material

and have limited knowledge of the detailed installation steps

After the waterstop groove between the plinth and the face slab is leveled

the corrugated waterstop is then installed

Neoprene rods are connected in a butt joint

Joints are reinforced with adhesive and tape

To prevent slipping or displacement

fine lead wire is used to secure them to the asphalt cedar board inside the groove.

During the installation of filler and EPDM cover plates

the key control points are

keeping the interface clean and dry

ensuring dense bonding between filler layers and between filler and concrete

and achieving firm adhesion between the EPDM cover plate and the concrete substrate

During work, the interface is first roughened and cleaned with an angle grinder and wire brush

then wiped clean with cotton yarn

For wet or damp areas

dry them first and then apply a wet-surface adhesive

On dry concrete surfaces, a dry-type adhesive is applied

Dry-type adhesive generally needs to be left to dry

The open time depends on temperature, wind speed, and other factors

It is ready for covering when it feels tacky but does not stick to the hand

Wet-surface adhesive does not require drying and can be covered directly with filler.

During application, the release paper is removed from the packaging

A piece of filler is first split into two halves

and placed at the bottom of the groove

Pressure is applied to bond it firmly

Additional layers are then bonded one by one

working from the center toward both sides for a dense bond

Air is expelled while bonding

Filler joints are overlapped

so that the filler and interface form a dense, integrated whole.

Before installing the EPDM cover plate, inspect

the quality of the filler installation

At 10–20 m intervals

perform a destructive check

Open up the completed section

and check for air pockets or debris between filler layers

verify whether bonding is tight

Also check the bonded area ratio against the concrete substrate

If the bonded area ratio is lower than

the specified requirement, the section must be reworked

The cover plate is placed symmetrically along the filler centerline

and pressed gradually from the center toward both sides

A rubber mallet is used to tamp it down

to drive out trapped air

This creates a tight bond between the filler and the EPDM cover plate.

The edge area where the cover plate bonds to the concrete substrate must first be treated according to the process

This helps the cover plate adhere more tightly and securely to the concrete surface.

EPDM composite cover plate

Joints between cover plates are handled as butt joints

At the lap area

primer is applied to the filler, then a piece is laid over it

The cover plate is then placed neatly over the composite board

and tapped tight with a rubber mallet.

The original EPDM cover plate fixing design used, on both sides,

unequal angle steel with expansion bolts

Because the concrete surfaces on both sides of the cover plate cannot be perfectly uniform

angle steel is highly rigid

and cannot accommodate such deformation

The original angle steel specification was therefore changed

The result improved to a certain extent

but more joints were added

and the joint areas were difficult to compact

After a design revision, the angle steel was replaced with an alternative solution

Source: China Packaging Network (pack.cn); original link: http://news.pack.cn/show-345672.html