The properties of concrete are broadly divided into how many categories?

Detailed Explanation: Two Categories of Concrete Properties

Why C (2) is correct: All concrete properties are classified into exactly two major categories based on the state of the concrete: fresh concrete properties (relevant during production, transport, and placing) and hardened concrete properties (relevant during service life after setting and curing).

Two Categories of Concrete Properties

Category	Definition	Key Properties
1. Fresh Concrete Properties	Properties during the plastic state: from mixing to initial setting (~30–45 min for OPC)	Workability (slump, compacting factor, Vee-Bee time), Consistency, Mobility, Cohesion, Bleeding, Segregation tendency
2. Hardened Concrete Properties	Properties after setting, hardening, and curing; relevant during service life	Compressive strength, Tensile/flexural strength, Modulus of elasticity, Creep, Drying shrinkage, Durability, Impermeability, Abrasion resistance

Workability Tests (Fresh Concrete)

Test	Standard	Measures
Slump test	IS 1199 Part 1	Consistency; most common site test
Compacting factor test	IS 1199 Part 3	Workability; more sensitive for stiff mixes
Vee-Bee test	IS 1199 Part 4	Workability; best for very dry mixes
Flow table test	IS 9103 / EN 12350-5	Flow; used for self-compacting concrete

Strength Tests (Hardened Concrete)

Test	Standard	Measures
Cube crushing test	IS 516	Compressive strength (150 mm cube)
Cylinder test	ASTM C39	Compressive strength (150×300 mm cylinder)
Split tensile test	IS 5816	Indirect tensile strength
Non-destructive tests (NDT)	IS 13311	In-place strength estimation; rebound hammer, UPV

• Concrete properties are divided into exactly 2 categories: fresh and hardened.
• Fresh concrete properties govern placement quality; hardened concrete properties govern structural performance.
• The transition between the two states occurs at initial setting time (≈ 30–45 min for OPC per IS 4031 Part 5).