27
3210.003
Bremner, T.W.
Energy and Resource Conservation in the Cement and Concrete Industry
Paper
Canada Centre for Mineral and Energy Technology
1976
November
1-19
Y
High interest rates and high energy costs [1976] have encouraged the building designer to reappraise the materials he uses and to look at other uses for existing materials. Lightweight aggregates such as expanded shale are becoming more readily available and in many areas its use can result in reduced construction costs as well as reduced heating and cooling costs for many buildings. Also lightweight aggregates can be used to minimize the heat losses around building foundations. Though manufactured aggregates require more energy to produce than natural aggregates the energy saved when the life cycle of the structure is considered may be sufficient to justify their use.A description of the various types of lightweight aggregates available in Canada is given as well as the properties of lightweight aggregates and of the concrete and masonry products made from them that are of interest to the building designs.
Lightweight aggregates because of their voided structure have good insulating values and designers have used this material to reduce the annual heating and cooling costs for the building when they are used in exterior wall construction. Lightweight aggregates can be used for the aggregate toppings for the inverted roof system and in so doing can further reduce the heat loss through the roof. The heat loss around the base of a building is significant and lightweight concrete and lightweight masonry can be used for the foundation wall. To further reduce the heating loads at the foundation, backfilling around buildings and under the edge of slabs on grade can be used to further reduce heating losses.