Abstract: Some of the common air conditioning systems are described with emphasis on their capabilities and limitations. The extent to which the building and the inside conditions specified affect the cost and complexity of the system is discussed.
Abstract: The nature of the ventilation process in controlling the level of contaminants in a space is reviewed and various factors determining ventilation requirements are discussed. High rates are needed to provide relief from summer-time over-heating in non-air conditioned buildings; otherwise, requirements for control of odour levels usually dominate.
Abstract: The author indicates some of the moisture conditions and moisture sources that must be considered in the design of wood roof decks and describes consequences of some design decisions and how to avoid vapour traps in wood roof systems.
Abstract: The rapid expansion of cities requires accurate knowledge of subsurface conditions to ensure good planning. Study of local geology is an essential first step. Test borings and study of adjacent excavations can provide further information. Recording such subsurface exploration is an important civic service.
Abstract: When professional competence is always available at the design stage of a building, as is the case with structural adequacy, a building code is not necessary. Fire protection engineering has not yet developed to this extent so that a regulated and therefore restrictive approach must be accepted until it becomes possible to deal with fire safety adequately as an inherent feature of design.
Abstract:This Digest discusses how the useful life of a material in place is always related to the particular combination of environmental factors to which it is subjected. The Digest discusses these factors and stresses the importance of understanding behaviour of materials from the standpoint of their chemical and physical properties and the understanding of the chemical and physical processes involved in deterioration and change. The Digest closes with a short discussion of performance and testing.
Abstract: Concrete can be made to withstand the extremes of our Canadian winter provided that certain measures are taken. Recommended practices are discussed in terms of the basic nature of the material and its response to environmental factors.
Abstract: The composition of organic compounds and the types used in building materials are briefly reviewed. The main elements of weather -- radiation, moisture, heat and gases -- are described and their individual actions on organic materials discussed. The additional effect from combined weather factors is illustrated.
Abstract: Tests used to evaluate durability are classified as to whether they examine a single property of the material, incorporate a single factor of the environment, or include several factors and one or more properties. Examples are given and the advantages and disadvantages of each type are discussed.
Abstract: The various types of volume change starting from when concrete is placed to when the hardened state is attained are discussed. It is pointed out that volume changes may lead to complications externally because of structural interaction as well as internally which results in cracking. Cracking impairs the ability of a structure to carry its design load and affects its durability.
Abstract: Design or manner of use determines the functions to be performed by materials; is the key factor establishing the environment at and in the materials; and must recognize and compensate for material properties if long service life is to be realized.