Abstract: Various types of membrane control joints are used in roofs to provide for expansion and contraction and to prevent splitting and excessive shrinkage at roof edges, but they frequently do not perform satisfactorily. The use of roof area dividers and expansion joints is discussed, and guidelines are given for the improved design and positioning of joints in a conventional roofing system.
Abstract: A superplasticizer is one of a class of admixtures called water-reducers that are used to lower the mix water requirement of concrete. Normal water-reducers are capable of reducing water requirements by about 10 to 15 per cent whereas superplasticizers are capable of reducing water contents by about 30 per cent. They are variously known as superplasticizers, superfluidizers, superfluidifiers, super water-reducers or high range water-reducers. Their applications and effects on concrete are discussed
Abstract: This Digest presents a state-of-the-art summary of some studies on the fire resistance of various structural members now being conducted at the Division of Building Research. For example, the fire resistance of beams, columns and walls can be determined by calculation which is far less expensive and time-consuming than by testing. Several fire resistance formulas are now available for making design calculations.
Abstract: Glass fibre-reinforced polyester composites are extensively used in buildings as panels, skylights, luminous ceilings and canopies. The nature, general properties, applications and durability of GRP composite materials are discussed.
Abstract: This Digest discusses several factors that need to be considered in applying and using quarry and other ceramic tile floors. These include the nature of the base to which tiles are applied, the properties of the tiles, their bonding agents as well as proper maintenance practice.
Abstract: In a poorly ventilated space the occupants may be exposed to hazardous air conditions of reduced oxygen content or increased carbon dioxide concentration. If unvented fuel- burning appliances are used for heating or cooking there is the possibility of further danger from carbon monoxide poisoning. The effects of these gases in varying quantities upon smokers and non-smokers are enumerated and a method is outlined for the determination of the ventilating requirements for specific quantities of toxic gas production. Results are given of tests of typical unvented camping and boating appliances using a variety of fuels, and these indicate that certain models warrant special ventilation precautions. Guidelines are suggested for users of such equipment to avoid hazardous atmospheres in confined spaces.
Abstract: This Digest presents a general outline of some of the technical information available on seismic activity, seismic risk as well as some of the trends in the design of earthquake resistant structures. The summary is intended for the non-specialist in earthquake engineering who need an appreciation of the building problems connected with earthquakes and the design of structures to resist them.
Abstract: This Digest briefly outlines how energy conservation programs can be implemented in existing school buildings. It deals with energy audits, operation and maintenance practice and the upgrading that may be needed to reduce the consumption of energy in schools.
Abstract: This Digest discusses some of the problems and limitations of performance codes and specifications for buildings. It points out some of the difficulties in devising test methods that will represent real situations and the need to supplement such tests by judgement. The authors stress that there is no quick and easy way to predict performance and that the person making a prediction must always know as much as possible about the product under review and its use.