Rockite Fast Setting Hydraulic Cement, 5 lb. Box expands as it sets, ensuring it comes loose or shrinks. This versatile cement mixes easily with water and is applied cold, setting stronger than concrete in just one hour. I for both interior and exterior DIY projects, it is for anchoring bolts, screws, and railings. It also works well for patching concrete and brick surfaces, as well as feathering light cracks and gaps. The cement dries to an off-white color and is conveniently packed in plastic bags within a carton, making it easy to handle and store. Model Number: