The term 'sidewalk surface' can refer to two different materials commonly used in the construction of sidewalks: CEMENT and ASPHALT. CEMENT is a hard, durable material made from a mixture of limestone, clay, and other materials that is typically used in the construction of sidewalks. ASPHALT is a black, sticky material made from petroleum products that is often used for paving roads and sidewalks. Both materials are strong and durable, making them ideal for use in sidewalk construction.