SSC JE Civil Engineering 25-Sep-2019 Shift 1 Solved Paper

The shape and texture of aggregate affects the properties of fresh concrete more than hardened concrete. Concrete is more workable when smooth and rounded aggregate is used instead of rough angular or elongated aggregate. So rounded aggregate produces concrete with high workability and low strength. Most natural sands and gravel from riverbeds or seashores are smooth and rounded and are excellent aggregates. Crushed stone produces much more angular or elongated aggregates, which have a higher surface-to-volume ratio, better bond characteristics but require more cement paste to produce a workable mixture. So angular aggregate produces concrete with low workability and high strength.