What key factor dictates the selection of a crack sealing material in a cold climate?

In a cold climate, the key factor dictating the selection of a crack sealing material is its flexibility at low temperatures. The material must maintain its ability to stretch and deform without cracking or becoming brittle as temperatures drop below freezing. This is essential to accommodate the expansion and contraction of the pavement due to temperature changes. If the crack sealant becomes too stiff or brittle at low temperatures, it will lose its bond with the pavement and fail, allowing water and debris to enter the crack. This water can then freeze and expand, further widening the crack and accelerating pavement deterioration. Therefore, crack sealing materials used in cold climates must be specifically formulated to withstand low temperatures and maintain their flexibility and adhesive properties. Materials like polymer-modified asphalt or silicone-based sealants are often used because they retain their flexibility at low temperatures and provide a durable seal that can withstand the harsh conditions of a cold climate. The sealant's ability to undergo repeated cycles of freezing and thawing without losing its effectiveness is crucial for long-term performance.