Recycling of plastics

The use of plastics within European countries is approximately 44 million tonnes per year, with products for the construction industry accounting for over a half of the consumption of PVC. Currently most waste disposal is within landfill sites. However, certain thermoplastic products can be recycled into construction products. Expanded polystyrene waste can be recycled by solvent extraction into a material, which has the appearance and many characteristics of wood. PVC bottles can be recycled...

Recycling Fibrereinforced Polymers

Currently, the majority of waste fibre-reinforced polymers (FRPs) are disposed into landfill sites. One alternative is to grind the material into powder and use this ground GRP in conjunction with other binders however, this process is difficult where embedded metal fixings were incorporated into the original components. The recyclate powder can be blended with other recycled plastics to produce GRP plastics lumber, which can be used for lightly loaded piles, decking, fencing and similar...

Monocoque construction

The Lord's Cricket Ground Media Centre (Fig. 5.19) was the world's first semi-monocoque building in aluminium. The media centre is a streamlined pod raised 14 m off the ground on two concrete support towers, giving journalists and commentators an uninterrupted view over the cricket ground. The structure consists of a curved 6 and 12 mm aluminium-plate skin welded to a series of ribs. Thus acting together, the skin and the ribs provide both the shape and the structural stability, a system...

Extensive Green Roofs

Extensive green roofs are designed to be lighter in weight, relatively cheap, not open to recreational use and to require the minimum of maintenance. Their prime purpose is either ecological or for the environmental masking of buildings. Planting should be of drought-tolerant, wind- and frost-resistant species such as sedums, herbs and grasses. Instant cover can be created by the installation of pre-cultivated vegetation blankets where the immediate visual effect is required. Alternatively, a...

Intelligent glass facades

An intelligent glass building facade changes its physical properties in response to sensors detecting the external light and weather conditions, thus reducing the energy consumption necessary to maintain the appropriate internal environment. Therefore intelligent facades have ecological significance in reducing global greenhouse emissions and also in reducing operational building costs to clients and users. Truly intelligent facades capitalise on the incident solar energy striking the facade of...

Carbon Content Of Ferrous Metals

The quantity of carbon alloyed with iron has a profound influence on the physical properties of the metal due to its significant effect on the microscopic crystal structure (Fig. 5.8). At ambient temperature a series of crystal forms (ferrite, pearlite and cementite) associated with different proportions of iron and carbon are stable. However, on increasing the temperature, crystal forms that were stable under ambient conditions, become unstable and are recrystallised into the high temperature...

Deterioration Of Timber

The major agencies causing the deterioration of timber in construction are weathering, fungi, insects and fire. The natural durability of timber is defined into five categories in relation to the resistance of the heartwood to wood-decaying fungi (BS EN 350-1 1994). On prolonged exposure to sunlight, wind and rain, external timbers gradually lose their natural colours and turn grey. Sunlight and oxygen break down some of the cellulose and lignin into water-soluble materials which are then...

Intensive Green Roofs

Intensive green roofs are generally designed to accept recreational activity and to include the widest range of vegetation from grass to shrubs and semi-mature trees. Depths of soil are typically between 200 and 300 mm, which together with the necessary minimum 50 mm of water reservoir and drainage systems generate an additional imposed load of typically 400 kg m2 on the existing or proposed structural system. Intensive green roofs may incorporate both soft and hard landscaping and slopes up to...

Manufacture Of Steel

The production of steel involves a sequence of operations which are closely inter-related in order to ensure maximum efficiency of a highly energy-intensive process. The key stages in the production process are the making of pig iron, its conversion into steel, the casting of the molten steel and its formation into sections or strip. Finally, coils of steel strip are cold rolled into thin sections and profiled sheet. The raw materials for the production of iron are iron ore, coke and limestone....

Standards

BS 144 1997 Specification for coal tar creosote for wood preservation. BS 373 1957 Methods for testing small clear specimens of timber. BS 476 Fire tests on building materials and structures Parts 3, 4, 6, 7, 10-13, 15, 20-24, 31-33 BS 644 2003 Timber windows. Factory assembled windows of various types. BS 1088 Marine plywood Part 1 2003 Requirements. Part 2 2003 Determination of bonding quality. BS 1186 Timber for and workmanship in joinery Part 2 1988 Specification for workmanship. Part 3...

Thermosetting Plastics Phenol formaldehyde

Phenol formaldehyde (PF) was the original, and remains the cheapest thermosetting resin. Currently, its main use is in the production of laminates by the hot pressing of layers of resin-impregnated paper, fabric or glass fibre. The cured resin is brown, but heat-resistant laminates for working surfaces and wallboards are laminated with a decorative printed paper film and coated with a clear melamine formaldehyde finish. Phenol formaldehyde is resistant to ignition, but produces a phenolic smell...

Building Research Establishment Publications

SD2 2002 Timber frame dwellings U-values and building regulations. BRE Digest 208 1988 Increasing the fire resistance of existing timber floors. BRE Digest 299 1993 Dry rot its recognition and control. BRE Digest 301 1985 Corrosion of metals by wood. BRE Digest 307 1992 Identifying damage by wood-boring insects. BRE Digest 327 1993 Insecticidal treatments against wood boring insects. BRE Digest 340 1989 Choosing wood adhesives. BRE Digest 345 1989 Wet rots recognition and control. BRE Digest...

Chemical attack and aggressive ground

The resistance of cured concrete to acid attack is largely dependent upon the quality of the concrete, although the addition of granulated blastfurnace slag GGBS or fly ash pulverised-fuel ash PFA increases the resistance to acids. Limestone-aggregate concrete is more vulnerable to acid attack than concretes with other aggregates. The resistance of cured concrete to chemical attack is defined by the design chemical class number, ranging from DC1 low resistance to DC 4 high resistance . The...

Rammedearth and cob construction

Earth construction is one of the oldest forms of building used by mankind. Rammed-earth buildings can be found in most countries, and many have survived hundreds of years. The ideal material is a well-graded mixture of gravel, sand, silt and clay fines. The clay content should be sufficient to act as an efficient binder, but not in excess to cause large moisture movement or cracking of the finished construction. In modern rammed-earth construction Portland cement is frequently incorporated as a...