Aggregates for Concrete (Part 2)-Aggregates for Concrete (Part 2) (PDF)

Aggregates for Concrete (Part 2) (PDF)

Pdf Summary

The document "Aggregates for Concrete" by the American Concrete Institute (ACI) explores the significance of aggregates in concrete production. It highlights how aggregate properties, including grading, shape, texture, and density, influence the workability and strength of both fresh and hardened concrete. Key discussions include the effects of aggregate gradation, fineness modulus, moisture absorption, and bulk density on concrete properties.<br /><br />The publication addresses the classification and quality testing of aggregates, with recommendations for ASTM (American Society for Testing and Materials) standards in evaluating aspects like soundness, abrasion resistance, and harmful substances. These tests ensure aggregates meet necessary specifications to prevent issues such as alkali-silica reactions or freeze-thaw cycling, which can compromise concrete integrity.<br /><br />The document also details various aggregate types, including natural and manufactured options, such as blast-furnace slag and lightweight aggregates. Emphasis is placed on the sustainable practice of utilizing recycled concrete as aggregate, presenting advantages such as reduced waste and resource conservation.<br /><br />Furthermore, the bulletin covers practical aspects of concrete production, including how to calculate and adjust mixture proportions to account for aggregate absorption and moisture, thereby maintaining desired water-cementitious ratios for optimal concrete performance. Methods for proper aggregate sampling and testing ensure consistency in quality and performance across construction projects.<br /><br />This comprehensive guide, while technical, is crucial for engineers, construction managers, and materials specialists to understand the vital role of aggregates in concrete technology, aiding in the production of durable, high-quality concrete structures.

Keywords

aggregates

concrete production

ACI

grading

ASTM standards

recycled concrete

sustainable practices

mixture proportions

aggregate testing

concrete durability