BS 8006-1995 + A1 Code of practice for Strengthened/reinforced soils and other fills

This British Standard contains guidelines and recommendations for the application of reinforcement techniques to soils, as fill or in situ, and to other fills. The standard is written in a limit state format and guidelines are provided of safety margins in terms of partial material factors and load factors for various applications and design lives.The code is divided into nine sections. Section1 identifies the scope, definitions and notation of the code. Section 2 describes the concepts and fundamental principles of reinforced soil. Section 3 provides recommendations for the use of materials where existing standards are available. Where materials are used which are not covered by existing standards or where known materials are to be used in ways not covered by existing standards section 4 gives recommendations for the testing and approval of such materials.Sections 5 to 9 relate to design, construction and maintenance of walls and abutments, slopes and foundations. They include specific recommendations for characterization of the soils to be used and other factors affecting the design and performance of the structures. Emphasis is placed on quality control both with regard to the consistency of the properties of the fill and reinforcing materials and to the handling of the materials on site.Much of the existing practice of reinforced soil is based on the use of limit equilibrium design methods which incorporate a global factor of safety. In keeping with the principles of limit state design, consistent structural dimensions and materials quantities have been maintained with existing practice by calibration of the partial factors in the limit state design relationships in this code. This approach is different to that adopted by some concurrent codes of practice, e.g. BS8002:1994, which rely on the use of “worst credible” parameters to develop an adequate margin of safety.The clauses are supplemented by a substantial list of references to enable the user to consider in greater depth the applications of the technique.

BS 5925:1991 Code of practice for Ventilation principles and designing for natural ventilation

This British Standard gives recommendations on the principles which should be observed when designing for the natural ventilation of buildings for human occupation. The standard is in three sections, as follows:
Section 1. General
Section 2 outlines the main reasons for the provision of ventilation and, where possible, recommends quantitative air flow rates. It is shown that these form the basis for air supply recommendations for different types of buildings and rooms characterized by usage. The basis for the choice between natural and mechanical ventilation is given. The design of mechanical ventilation systems is dealt with in BS 5720.
Section 3 gives recommendations on the design of natural ventilation systems and on the estimation of air infiltration rates in housing.
Appendix A is a bibliography and reference to publications listed in it are shown as:
(see Appendix A [15]).
Appendix B gives recommendations on evaluating contamination risks.
Appendix C gives recommendations on calculating ventilation rates to reduce the risk of surface condensation under steady state conditions.
Appendix D gives recommendations on determining ventilation requirements.
Appendix E gives recommendations on calculating reference wind speed.
Appendix F gives recommendations on calculating natural ventilation rates for a simple building.
This standard does not attempt to address thermal comfort aspects of ventilation such as indoor air movement, temperature stratification, exact position of ventilation openings etc.
NOTE The titles of the publications referred to in this standard are listed on the inside back cover.

Evaluation and Repair Procedures for Precast/Prestressed Concrete Girders with Longitudinal Cracking in the Web

Systematic, well-designed research provides the most effective approach to the solution of many problems facing highway administrators and engineers. Often, highway problems are of local interest and can best be studied by highway departments individually or in cooperation with their state universities and others. However, the accelerating growth of highway transportation develops increasingly complex problems of wide interest to highway authorities. These problems are best studied through a coordinated program of cooperative research. In recognition of these needs, the highway administrators of the American Association of State Highway and Transportation Officials initiated in 1962 an objective national highway research program employing modern scientific techniques. This program is supported on a continuing basis by funds from participating member states of the Association and it receives the full cooperation and support of the Federal Highway Administration, United States Department of Transportation. The Transportation Research Board of the National Academies was requested by the Association to administer the research program because of the Board’s recognized objectivity and understanding of modern research practices. The Board is uniquely suited for this purpose as it maintains an extensive committee structure from which authorities on any highway transportation subject may be drawn; it possesses avenues of communications and cooperation with federal, state and local governmental agencies, universities, and industry; its relationship to the National Research Council is an insurance of objectivity; it maintains a full-time research correlation staff of specialists in highway transportation matters to bring the findings of research directly to those who are in a position to use them. The program is developed on the basis of research needs identified by chief administrators of the highway and transportation departments and by committees of AASHTO. Each year, specific areas of research needs to be included in the program are proposed to the National Research Council and the Board by the American Association of State Highway and Transportation Officials. Research projects to fulfill these needs are defined by the Board, and qualified research agencies are selected from those that have submitted proposals. Administration and surveillance of research contracts are the responsibilities of the National Research Council and the Transportation Research Board. The needs for highway research are many, and the National Cooperative Highway Research Program can make significant contributions to the solution of highway transportation problems of mutual concern to many responsible groups. The program, however, is intended to complement rather than to substitute for or duplicate other highway research programs.

EFFECT OF FILLERS ON BITUMINOUS PAVING MIXES

Elastic and plastic behavior of soil