Precast concrete parts

Adhesives used in the manufacture of precast concrete parts are expected to provide a very good adhesion and a fast build-up of strength, while also facilitating a clean removal from the sheating elements after the concrete has dried. Jowat has developed two new assembly adhesives especially for this application that are characterised by excellent adhesion to sheating elements with rough as well as smooth surfaces, for instance plastic, wood or sheet metal. The fast build-up of strength of the PO-based hot melts facilitates a fast manufacturing process in which the concrete can already be poured into the forms a few minutes after bonding. In addition, the adhesives are resistant to vibrations and provide a flexible bondline with high strength values, which can compensate for the vibrations when the concrete is compacted with plate vibrators and keeps the formwork elements in place. A key characteristic of the PO hot melt adhesives: They can be removed relatively easy from the formwork elements when cold. This means the formworks can be reused for the casting of concrete parts and facilitates a superior appearance of the bond – a major benefit in the manufacture of exposed concrete. Jowat supplies adhesive alternatives with different open times which are designed for lower and for higher ambient temperatures respectively.