Developments in the Formulation and Reinforcement of Concrete

Sidney Mindess

• Publisher: Woodhead Publishing
• Year: 2014
• eBook ISBN: 9781845694685
• Topic: Technology & Engineering
• Subtopic: Materials Science
• Index: Technology & Engineering

Concrete is the most widely-used construction material in the world. This important book summarises the wealth of recent research on improving qualities such as durability and sustainability as well as the emergence of a new generation of specialist concretes for particular applications.A number of chapters discuss new types of concrete such as autoclaved aerated concrete, high-strength concrete, sprayed concrete, fibre-reinforced concrete, lightweight concrete, self-compacting concrete, foamed and polymer concrete, together with their characteristics and applications. Other chapters review the development of concrete especially suited for particular conditions such as radiation protection, hot weather and underwater conditions, as well as the increasingly important area of recycling.With its distinguished editor and international team of contributors, Developments in the formulation and reinforcement of concrete is a standard reference for civil and structural engineers. - Summarises a wealth of recent research on improving qualities such as sustainability and durability - Discusses new concrete types together with their characteristics and applications - Reviews the development of concrete especially suited to particular conditions such as hot weather and under water

1

Autoclaved aerated concrete

R. Klingner University of Texas at Austin, USA

1.1 Introduction to autoclaved aerated concrete

Autoclaved aerated concrete (AAC) is a concrete-like material with very light weight, obtained by uniformly distributed, closed air bubbles. Material specifications for this product are prescribed in ASTM C1386.

Because AAC typically has one-sixth to one-third the density of conventional concrete, and about the same ratio of compressive strength, it is useful for cladding and infills, and for bearing-wall components of low-to medium-rise structures. Because its thermal conductivity is one-sixth or less that of concrete, it is energy-efficient. Because its fire rating is slightly longer than that of conventional concrete of the same thickness, it is very fire-resistant. It is not susceptible to mold. Because of its internal porosity, it has very low sound transmission, and is acoustically very effective.

1.1.1 Historical background of AAC

AAC was first produced commercially in Sweden, in 1923. Since that time, its production and use have spread to more than 40 countries on all continents, including North America, Central and South America, Europe, the Middle East, the Far East, and Australia. This wide experience has produced many case studies of use in different climates, and under different building codes. Background material on experience with AAC in Europe is given in RILEM (1993).

In the US, modern uses of AAC began in 1990, for residential and commercial projects in the southeastern states. US production of plain and reinforced AAC started in 1995 in the southeast, and has since spread to other parts of the country. A nationwide group of AAC manufacturers was formed in 1998 as the Autoclaved Aerated Concrete Products Association (http://www.aacpa.org/). Design provisions for AAC are provided in the Code and Specification of the Masonry Standards Joint Committee (MSJC), and in the technical manuals available on the web site of the AACPA. The AACPA includes one manufacturer in Monterrey, Mexico, and many technical materials are available in Spanish as well as English.

1.1.2 AAC elements

AAC can be used to make unreinforced, masonry-type units, and also factory-reinforced floor panels, roof panels, wall panels, lintels, beams, and other special shapes. These elements can be used in a variety of applications including residential, commercial, and industrial construction. Reinforced wall panels can be used as cladding systems as well as load-bearing and non load-bearing exterior and interior wall systems. Reinforced floor and roof panels can be efficiently used to provide the horizontal diaphragm system while supporting the necessary gravity loads.

1.1.3 Materials used in AAC

Materials for AAC vary with manufacture and location, and are specified in ASTM C1386. They include some or all of the following: fine silica sand; Class F fly ash; hydraulic cements; ...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright page
• Contributor contact details
• Introduction
• 1: Autoclaved aerated concrete
• 2: High-density and radiation-shielding concrete
• 3: High-strength concrete
• 4: Sprayed concrete (shotcrete)
• 5: Hot weather concreting
• 6: Underwater concrete
• 7: Fibrous concrete reinforcement
• 8: Lightweight concrete
• 9: Self-compacting concrete (SCC)
• 10: Recycled materials in concrete
• 11: Foamed concrete
• 12: Polymer concrete
• 13: Future developments in concrete
• Index