504R-90
Guide to Joint Sealants for Concrete Structures (Reapproved 1997)
1990, 44 pp.
$91.50

Most joints, and some cracks in concrete structures, require sealing against the adverse effects of environmental and service conditions. This report is a guide to better understanding of the properties of joint sealants and to where and how they are used in present practice. Described and illustrated are: the functioning of joint sealants;required properties, available materials and applicable specifications for field-molded sealants and pre-formed sealants such as waterstops, gaskets or compression seals; determination of joint movements, widths, and depths; outline details of joints and sealants used in general structures, fluid containers, and pavements; methods and equipment for sealant installation including preparatory work; performance of sealants; and methods of repairing defective work or maintenance resealing. Finally, improvements needed to insure better joint sealing in the future are indicated. New developments in field-molded and preformed sealants and their use are described together with means of measuring joint movements. Appendix C provides a list of specifications and their sources.

Contents:
Chapter 1--General

1.1--Background

1.2--Purpose

1.3--Why joints are required

1.4--Why sealing is needed

1.5--Joint design as part of over-all structural design

1.6--Types of joints and their function

1.7--Joint Configurations

Chapter 2--How joint sealants function

2.1--Basic function of sealants

2.2--Classification of sealants

2.3--Behavior of sealants in butt joints

2.4--Malfunction of sealants

2.5--Behavior of sealants in lap joints

2.6--Effect of temperature

2.7--Shape factor in field-molded sealants

2.8--Function of bond breakers and backup materials

2.9--Function of fillers in expansion joints

2.10--Function of primers

Chapter 3--Sealant materials

3.1--General

3.2--Required properties of joint sealants

3.3--Available materials

3.4--Field-molded sealants

3.5--Preformed seals

Chapter 4--Joint movement and design

4.1--Discussion

4.2--Determination of joint movements and locations

4.3--Selection of butt joint widths for field-molded sealants

4.4--Selection of butt joint shape for field-molded sealants

4.5--Selection of size of compression seals for butt joints

4.6--Limitations on butt joint widths and movements for various

types of sealants

4.7--Lap joint sealant thickness

4.8--Shape and size of rigid waterstops

4.9--Shape and size of flexible waterstops

4.10--Shape and size of gaskets and miscellaneous seals

4.11--Measurement of joint movements

Chapter 5--Joint details

5.1--Introduction

5.2--Structures

5.3--Slabs on grade, highway, and airports

5.4--Construction and installation considerations

Chapter 6--Installation of sealants

6.1--Introduction

6.2--Joint construction with sealing in mind

6.3--Preparation of joint surfaces

6.4--Inspection of readiness to seal

6.5--Priming, installation of backup materials and bond breakers

6.6--Installation of field-molded sealants, hot applied

6.7--Installation of field-molded sealants, cold applied

6.8--Installation of compression seals

6.9--Installation of preassembled devices

6.10--Installation of waterstops

6.11--Installation of gaskets

6.12--Installation of fillers

6.13--Neatness and cleanup

6.14--Safety precautions

Chapter 7--Performance, repair, and maintenance of sealants

7.1--Poor performance

7.2--Repairs of concrete defects and replacement of sealants

7.3--Normal maintenance

Chapter 8--Sealing in the future and concluding remarks

8.1--What is now possible

8.2--Advancements still needed

Chapter 9--References

Appendix A--Layman's glossary for joint sealant terms

Appendix B--Key to symbols used in figures

Appendix C--Sources of specifications