I.S. 20-1:1987

Foreword
Declaration
SECTION 1 - INTRODUCTION
1.1 Scope
1.2 Definitions
SECTION 2 - MATERIALS
2.1 Cement
SECTION 3 - PHYSICAL PROPERTIES
3.1 Dimensions
3.2 External shell thickness of hollow blocks
3.3 Form
3.4 Surface texture and appearance
3.5 Blocks with special faces
3.6 Drying shrinkage
3.7 Density
3.8 Standard block strengths
SECTION 4 - SAMPLING
4.1 Sample sizes
4.2 Rate of sampling
SECTION 5 - STRENGTH ASSESSMENT
5.1 Manufacturer's strength assessment
5.2 Independent strength assessment
SECTION 6 - CERTIFICATES AND MARKING
6.1 Certificate of compliance
6.2 Marking
Appendix A Test method for checking the dimensional tolerances
           of blocks
Appendix B Methods for the determination of nett block mass and
           concrete density
Appendix C Method for the determination of drying shrinkage
Appendix D Method for the determination of strength
           (softboard capping method)
Appendix E Method for the determination of strength
           (mortar capping method)
Appendix F Reference standards
Notes to Users

Applicable to solid or hollow concrete building blocks made with the materials specified in Clause 3.