BUILDING MATERIALS & CONSTRUCTION
2014-1-23 · Page 6 Building Materials & Construction 1.4.2 Balast 1. Igneous rock 2. It is compact, hard and heavy 3.Available in red, yellow grey, blue and greenish black colour 4. Specific gravity is 3 and compressive strength varies 1530 to 1890 kg/cm2. 5. Used for ornamental, rail road ballast, aggregates for