It is composed of two pre-dosed components: part A is a resin, part B is a hardener. After mixing the two components, the product becomes a cohesive pourable mixture. When large voids have to be filled, PU 500 can be mixed with quartz sand up to a maximum ratio of 1:1 by weight. The addition of an aggregate enhances the mechanical characteristics of friction resistance and the thixotropy of the product, but the sealant deformability is decreased. PU 500 is solvent free and the slight smell, that can be noticed, is only due to the resin. PU 500 cross-links because of the reaction between resin and hardener. The substrate temperature and the environment can influence anyway the cross-linking time of the sealant: high temperatures reduce the workability time of the mixture and accelerate the setting time. Low temperatures make the reaction time longer. The curing time of the sealant may be reduced if required by adding the specific accelerator PU 500 Catalyst. After crosslinking, PU 500 becomes an elastomeric substance characterized by a high surface hardness which can deform under compressive, tensile and shear loads. PU 500 is suitable to support vehicular traffic, on roads, freeways and highways. PU 500 is the ideal product to carry out sealing substrates subject to limited movements and heavy loads.
Field of Application
PU 500 is a two-component polyurethane elastomeric sealant, specifically developed for highway construction joints and for filling and sealing anchoring heads made from pre-formed rubber, reinforced rubber and steel road joints between adjacent decks and between deck and abutments of road substructures, such as roads, railways, airports. Due to its physical and mechanical properties, PU 500 can be used as a connection sealant between prefabricated road joints and the adjacent bituminous conglomerate, creating a seal between the two elements while guaranteeing considerable surface hardness and mechanical resistance to friction. PU 500 is resistant to bad weather conditions and deformability due to compression, with good tensile and shear strength. PU 500 can be used for surface sealing of the anchoring bolts in pre-formed rubber sections. PU 500, after mixing the two components A+B, can be added to specific mineral fillers which allow it to obtain different mechanical and deformation properties depending on the different foreseen stresses.
COVERAGE / CONSUMPTION
Preparation of substrate
All the surfaces must be dry, sound and free of dust, crumbling parts, oil, grease, wax and old paint. To guarantee that the sealant works correctly, the joint must be free to expand and contract.
Preparing the product
PU 500 comes in separate packaging of 10 kg plastic drums (A+B). Homogenize the single components, pour component B into component A, mix with a drill with low rotation speed without entraining air, avoid partial mixing as it will not guarantee the correct ratio between resin and hardener. Immediately after mixing the two components, pour the product, without entraining air, directly from the drum into the joint with a metallic trowel. The product can be mixed with a quartz aggregate till a ratio of 1:1 by weight.
Applying the product
The application is done by pouring the product, without entraining air, directly from the drum into the joint and smoothened with a metallic trowel.