On-Demand Course: Managing Alkali-Aggregate Reaction Expansion in Mass Concrete

Price: $ 39.00 USD

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INSTRUCTIONS: View the recorded webinar. Complete 10-question quiz with a score of 80% or higher to receive a certificate for 0.1 CEU (equivalent to 1.0 PDH).

Continuing Education Credit: 0.1 CEU (1 PDH)

Approved by AIA (LU/HSW) and ICC

Access Period: 30 days


This is a recorded webinar from October 6, 2015.

When the alkalis in cement react with susceptible aggregate particles, a reaction rim of alkali-silica or alkali-carbonate gel is formed around the aggregate (AAR). If this gel is exposed to moisture, it expands, causing an increase in volume of the concrete. In mass concrete structures, the expansion can cause wide cracks and major operation and maintenance problems, such as inoperable gates and misalignment of hydropower generators. Maintenance and repair ranges from monitoring the AAR-affected concrete to complete removal and replacement, but mitigation methods are also available. Crack injection, post-tensioning, and slot-cutting can be implemented to reduce the impact of the AAR on the structure. Effective maintenance can accommodate continuing expansion, thus allowing most structures to achieve a long service life.


Document Details

Author: Marjorie Lynch

Publication Year: 2015


Categories: Architectural Concrete

Formats: Online Learning

Table of Contents

Learning Objectives:

1. Understand the mechanisms of deterioration and prevention of AAR in new construction.

2. Describe the methods of identifying AAR in existing mass concrete structures

3. Identify the repair techniques for mass concrete structures damaged by AAR.

4. Explain the ongoing process of monitoring of mass concrete structures after repair.


Any applicable errata are included with individual documents at the time of purchase. Errata are not included for collections or sets of documents such as the ACI Collection. For a listing of and access to all product errata, visit the Errata page.

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Printed / Hard Copy Products: The full and complete returned product will be accepted if returned within 60 days of receipt and in salable condition. A 20% service charge applies. Return shipping fees are the customer’s responsibility.

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