Aggregate and Admixtures

Introduction

Aggregate is a rock like material, used in many civil engineering and construction applications including:

§  Portland cement concrete

§  Asphalt concrete

§  Base materials for roads

§  Ballast for railroads

§  Foundations ...... See More:-

Classification of Aggregates:

The aggregates can be classified based on size, according to ASTM as:

1. Coarse Aggregate (CA) ....... See More:-

Gradation of Aggregates

Grading refers to the distribution of particle sizes present in an aggregate. The grading is determined in accordance with ASTM C 136, “Sieve or Screen Analysis of Fine and Coarse Aggregates.” A sample of the aggregate......  See More:-

Free Moisture and Absorption of Aggregates

The moisture content and absorption of aggregates are important in calculating the proportions of concrete mixes since any excess water in the aggregates will be incorporated in the cement ...... See More:-

Soundness

Aggregate is considered to be unsound when volume changes in the aggregate induced by weather, such as alternate cycles of wetting ....... See More:-

Admixtures

In concrete, a substance other than active and inert matter, added in small quantities to the mix to alte....... See More:-