Abstract: This digest describes the gradual replacement of allowable stress design by limit states design as a basic calculation tool for designing and evaluating civil engineering structures. It also explains the principles and advantages of limit states design.
Abstract: The operation of an air exhaust system or fuel-burning appliance removes air from the house, creating a negative pressure in the building. If too much air is removed and the negative pressure becomes large enough, the natural flow of gases up the furnace chimney can be reversed. The flow of combustion products into the home can create a danger of carbon monoxide poisoning. The digest describes a study conducted to determine the relationship between carbon monoxide poisoning and the air tightness of a house.
Abstract: Concrete lends itself to a variety of innovative designs as a result of its many desirable properties. Two characteristics, however, have limited its use: it is brittle and weak in tension. Recent developments in fibre- reinforced composites in the plastics and aerospace fields have provided a technical basis for eliminating these deficiencies. This digest describes the general properties and application of fibre-reinforced concrete used in construction.
Abstract: Deterioration of indoor parking garages has become a very serious problem in recent years. In many cases, major repairs are needed after only five years of service. The cause of the deterioration is usually corrosion of the reinforcing steel due to the action of de-icing salts carried in by the vehicles. The process of deterioration and methods of improving durability are provided.
Abstract: The causes of the deterioration of garage floors and guidelines which should be followed to achieve durability are described in CBD 224. Given a deteriorated floor, the extent, degree and type of deterioration must be evaluated. Five different approaches are outlined and the technique for repairing concrete is described.
Abstract: There are three basic methods for controlling fire hazards in buildings: prohibition, isolation and protection. It is often difficult for a designer to choose the most appropriate method or combination of methods. A fire protection analysis is required to evaluate the fire hazards and their effects on the building, the occupants and the contents. The fire hazard is defined in terms of the fuel load and fire growth. The impact of the fire on the structure is assessed with respect to the ability of the structure to continue to carry imposed loads and the ability of the building elements to act as barriers to fire and smoke. The impact of the fire on the occupants is examined with respect to the mobility of the occupants and the relative locations of the fire and the occupants. Control of the fire hazard with respect to the contents is based largely on economics. The digest discusses each of the factors which must be considered in a fire protection analysis and describes the control system employed at the Royal Bank Centre in Ottawa.
Abstract: This digest is the last in a series of three on plastic pipe. Reinforced thermosetting plastic-based pipes, because of their higher cost, constitute only a small percentage of the total plastic pipes in use. These pipes are used where higher strength or resistance to higher temperatures are required. The digest describes the general nature of reinforced thermosetting materials with respect to composition, fabrication, properties and applications, and discusses in detail two major types of pipe products in this class, glass-fibre reinforced polyester (GRP) and glass- fibre reinforced epoxy (GRE).