Composition of Concrete

Questions and Answers

What percentage of the total composition of concrete is made up of aggregates by weight?

70%

60%

50%

80% (correct)

What is the primary function of cement in concrete composition?

To add color to the concrete

To provide thermal insulation

To increase airflow within the mixture

To bind coarse and fine aggregates together (correct)

At what temperature does the point of incipient fusion occur during the cement production process?

1350°C

1480°C (correct)

1450°C

1600°C

Which material is primarily responsible for creating Portland Cement after being burned?

Argillaceous and Calcareous materials Signup and view all the answers

What is formed when the burnt product of Portland Cement is mixed with Gypsum?

Portland Cement Signup and view all the answers

Which of the following is true of hydraulic cement?

It hardens under water. Signup and view all the answers

Who is credited with the invention of modern Portland cement?

William Aspdin Signup and view all the answers

What is the heat generated from the reaction between cement and water called?

Heat of Hydration Signup and view all the answers

What is the primary component that fills the voids in fine aggregates according to the composition of concrete?

Water Signup and view all the answers

Why was Portland Cement named so?

It resembles a type of stone quarried in England. Signup and view all the answers

Study Notes

Composition of Concrete

Composed of three main components: 14% Cement, 80% Aggregates, and 6% Water by weight.
Aggregate classification: Coarse Aggregates account for 50% while Fine Aggregates consist of 30%.
By volume distribution: 10% Cement, 70% Aggregates, 15% Water, and 5% Air.

Functions of Cement

Binds Coarse Aggregates (CA) and Fine Aggregates (FA) to form a durable mass.
Fills voids between CA and FA for compactness and stability.

Portland Cement

Made by calcining a mixture of argillaceous and calcareous materials at approximately 1480°C, resulting in a product known as clinker.
Clinker is combined with Gypsum and pulverized to create Portland Cement.
Named after Portland stone, which resembles the cement, and patented by Joseph Aspdin in 1824; modern formulations credited to his son William Aspdin in the 1840s.

Hydraulic Cement

Reacts chemically with water through a process called Hydration.
Hardens even when submerged underwater, demonstrating resistance to water effects.
Gains strength continuously in the presence of moisture.

Heat of Hydration

Refers to the heat generated during the chemical reaction between cement and water.
The heat produced varies based on the cement's chemical composition and factors such as fineness, chemical structure, and temperature during hydration.

Description

This quiz explores the composition of concrete, including the roles and proportions of its key components: cement, aggregates, and water. Understand the classifications of these materials and their functions in creating a solid structure. Test your knowledge on the active and inactive groups within concrete's make-up.