HOT POUR SEALING

Hot pour Sealing is used for maintenance of joints in concrete and asphalt carriageways and airfield pavements. This type of sealant is particularly beneficial for creating flexible, durable seals that can accommodate the movement of the pavement while remaining intact and functional over time. As members of the ESA Shepherd & Sons operatives use a polymer-modified bituminous joint sealant that complies with the requirements of BSEN14188, specifically Types N1 and N2.

Type N1: A higher-grade sealant with 25% elasticity, designed for more demanding conditions.

N2 has stricter requirements for resilience and temperature resistance and is typically used in more trafficked or higher-stress areas, such as airfields or high-traffic highways.

Type N2: A standard grade of sealant with 20% elasticity, that is typically used in areas where moderate traffic conditions are expected. It will have certain flexibility and flow resistance requirements but may not be as resilient as Type N2.

BSEN 14188-1:2004 is a European Standard that defines the specifications and testing requirements for bituminous joint sealants used in highway and airfield pavements. This standard ensures that the materials are appropriate for long-term performance and can handle the stresses placed on them by traffic, environmental conditions, and joint movements.

Application Process

shepherd & Sons use a thermostatically controlled heated extruded boiler. which is used to heat the sealant to the appropriate application temperature.

The sealant starts of as solid and it then slowly heated with indirect heat transfer to around 160°C and 190°C.
which ensures that the sealant is evenly heated without risk of burning or degradation.
Material control with thermostatic regulation ensures precise temperature management for optimal application conditions.
Continuous agitation in the main melting pot keeps the sealant mixed and evenly heated, preventing inconsistencies.
Application using a heated hose and hand lance allows the operator to control the flow and speed of the sealant for precision, ensuring the correct amount of sealant is applied at the right temperature.

STEP BY STEP

Preparation of the Joint: Before applying the sealant, the joint must be cleaned thoroughly. This includes removing any dirt, debris, oil, or moisture that could interfere with the adhesion of the sealant. This can be done using air blowers, wire brushes, or vacuum equipment.The joint may also need to be heated to ensure that the surface is dry and warm enough for the sealant to bond properly.
Heating the Sealant:Load the boiler with solid hot-pour sealant and allow it to heat until it reaches the recommended temperature.
Application of Sealant: Once the sealant is ready, the lance is attached to the boiler and position the nozzle over the joint. an operative then uses the lance to apply a smooth and controlled flow of sealant into the joint.
Cooling and Curing: After the joint is filled, the sealant begins to cool and solidify. The cooling time will depend on the environmental conditions and the type of sealant used. However, once the sealant has cooled sufficiently, it forms a durable, flexible seal that can accommodate the movement of the surafce.

Advanatges of hot pour sealant

Dirt and Grit Resistance: Resilient to the ingress of dirt and grit, especially on trafficked pavements.
Wide Temperature Range: Resistant to plastic flow over a wide range of service temperatures, ensuring durability in various weather conditions.
Strong Adhesion: Exhibits good adhesion to both concrete and asphalt surfaces, ensuring a secure and long-lasting seal.
Compliance with Specifications: Conforms to the DOT Specification for Highway Works clauses 1016 and 1017.

DOT Specification for Highway Works focus on ensuring the proper selection, application, and performance of joint sealants for both concrete and asphalt pavements.The two clauses address similar aspects—material properties, application conditions, performance requirements, and testing methods—but are adjusted to accommodate the specific characteristics of concrete and asphalt pavements.The guidelines ensure that the joint sealants used in highway and airfield applications can perform effectively, withstanding traffic loading, temperature fluctuations, and environmental factors.

Health & Safety

Applying hot-pour sealant using a boiler and lance requires strict adherence to health and safety protocols to protect workers from burns, inhalation hazards, and fire risks. The following key measures—wearing appropriate PPE, following safe equipment operation, ensuring proper ventilation, and adhering to fire safety procedures—are essential to maintaining a safe working environment. our operatives are trained in emergency procedures, including how to manage burns, spills, and exposure to harmful fumes.