ARDEX ARDURAPID A 45 is a rapid drying and hardening, slump free mortar for internal repairs. Features and benefits: Receives finishes after 90 minutes regardless of thickness. Slump free - ideal for vertical and horizontal repairs. Ideal for the rapid repair of internal concrete, screeds, renders and concrete steps. Other applications include forming ramps, falls and coves, patching around fittings/pipework, and filling cracks and gaps.