(SEM V) THEORY EXAMINATION 2023-24 CONCRETE TECHNOLOGY

Subject Code: KCE051

Subject Name: Concrete Technology

Course: B.Tech (Semester V)

Maximum Marks: 100

Duration: 3 Hours

Exam Year: 2023–24

Sections: A, B, and C

 SECTION A – Short Answer Questions (2 × 10 = 20 Marks)

Attempt all questions briefly.

a. Define heat of hydration.
b. What is called clinker?
c. What is the application of an accelerator in concrete?
d. What is pozzolana?
e. Explain curing of concrete.
f. What do you mean by shrinkage?
g. What is Abram’s law?
h. What is mean strength?
i. Discuss self-compacting concrete.
j. What do you understand by high strength concrete?
 

SECTION B – Medium-Length Questions (10 × 3 = 30 Marks)

Attempt any three of the following.

Explain the effect of impurities in mixing water on concrete.

What is air-entrained concrete? Explain factors affecting air entrainment.

Describe various steps in the manufacturing of concrete in detail.

What do you mean by Rheology of fresh concrete?

Explain fibre-reinforced concrete (FRC) and describe its applications.
 

SECTION C – Long / Analytical Questions (10 × 5 = 50 Marks)

Attempt one part from each question.

Q3. Cement Composition

a. What are Bogue’s compounds of Portland cement? Explain each compound in detail.
OR
b. Explain bulking and soundness of aggregates.

Q4. Mineral Admixtures & Plasticizers

a. What is fly ash? Discuss its advantages and disadvantages.
OR
b. Explain the effect of superplasticizers on the properties of fresh and hardened concrete.

Q5. Workability and Segregation

a. Define segregation. Explain factors affecting segregation of concrete.
OR
b. Define workability. What are the factors affecting workability of concrete?

Q6. Mix Design

a. Explain step-by-step IS method of mix proportioning.
OR
b. Design a concrete mix for M20 grade using ACI method, given data:

Cement: OPC 43 grade

Max agg. size: 20 mm

Target strength = 30 MPa, Standard deviation = 4 MPa

Bulk density of coarse aggregate = 1600 kg/m³

Fineness modulus of fine aggregate = 2.80

Slump = 50 mm

Sp. gravity: Cement = 3.15, CA = 2.70, FA = 2.65

Water absorption: CA = 1%, FA = 2%

Q7. Ready Mix & Recycled Concrete

a. Define Ready Mix Concrete (RMC). Explain components of an RMC plant.
OR
b. Explain Recycled Aggregate Concrete (RAC) and its properties.
 

Key Topics to Prepare

Cement Chemistry

Bogue’s compounds (C₃S, C₂S, C₃A, C₄AF) and their roles in strength development.

Heat of hydration — significance in mass concreting.

Concrete Properties

Workability, segregation, bleeding, shrinkage, and curing methods.

Abram’s Law: relationship between water-cement ratio and strength.

Special Concrete Types

Self-compacting, high-strength, fibre-reinforced, and air-entrained concretes.

Role of admixtures (plasticizers, superplasticizers, pozzolanas).

Testing & Mix Design

IS 10262: Mix design process (target strength, w/c ratio, adjustments).

ACI method of mix proportioning.

Bulking of sand and soundness tests.

Sustainability & Advanced Materials

Fly ash, GGBS, silica fume — advantages & limitations.

Recycled aggregate concrete and its eco-benefits.

Ready Mix Concrete (RMC) — batching, transportation, quality control.

Study Tips

Revise definitions from Section A — short and direct (2–3 lines each).

Draw simple diagrams — e.g., hydration curve, mix proportioning flowchart, RMC plant layout.

Memorize Bogue’s compounds and their functions.

Understand relationships — water-cement ratio vs strength, curing vs durability.

Practice mix design numericals for both IS and ACI methods.

Include recent developments — sustainable concretes and green materials for bonus marks.