Beginner
Concrete Technology Basics
What concrete is made of and how its strength is judged.
STEP 1 · INGREDIENTS
Cement, fine aggregate (sand), coarse aggregate and water. Admixtures tweak behaviour.
STEP 2 · WATER–CEMENT RATIO
Lower w/c ratio gives stronger, denser concrete — but it must stay workable.
STEP 3 · GRADES
M20 means characteristic compressive strength of 20 N/mm² at 28 days.
WORKED EXAMPLE
M25 concrete: a 150 mm cube tested at 28 days should reach at least 25 MPa for most samples.
Formulas
Water–cement ratio
w/c = mass of water / mass of cement
typical 0.4–0.6
Practice questions
Q1.In M20 concrete, 20 refers to…
Concrete Technology Basics · Easy
Q2.Increasing w/c ratio generally…
Concrete Technology Basics · Easy
Q3.Standard cube size for compression test (IS)?
Concrete Technology Basics · Medium