Concrete lightweight

C Q—C g-ethoxylated quaternaries surfactants for coating polystyrene beads in the manufacture of lightweight concrete 17... 

Lightweight concrete is made from prefoamed EPS beads, Pordand cement, and organic binders. Precast shapes ate being used to provide stmctural strength, thermal insulation, and sound deadening. 

Short, A., The use of lightweight concrete in reinforced concrete construction, The Reinforced Concrete Review, 5 (3), September 1959. 

S. Chandra and J. Aavik, Influence of proteins on some properties of portland cement mortar, Int. J. Cement Compos. Lightweight Concrete, 9, 91 94 (1987). 

The fire test room is 3.6 m long, 2.4 m wide and 2.4 m high with a doorway measuring 0.8 m wide and 2.0 m high. The walls are of lightweight concrete, 150 mm thick. The ignition source was... 

Lightweight concrete uses very light aggregate, such as vermiculite or perlite (instead of gravel), with cements that are resistant to high temperatures. Dry densities range from 25 to 80 Ib/ft (400 to 1,300 kg/m ). 

Lightweight concrete is usually sprayed on, but may be troweled or formed-in-place using reinforcing mesh. Pneumatically applied material is about 20% heavier than poured-in-place lightweight concrete. As with all concretes, moisture creates a corrosive condition at the surface of the steel. Protective coating of the substrate surface is needed to protect against corrosion. 

Satisfactorily applied by most contractors Disadvantages of lightweight concrete materials include ... 

Several different materials and installation systems are available and include various types of proprietary materials, plasters containing perlite or ver-miculite, concrete mixtures, or lightweight concretes. The selected material and installation system, encasement, or surface application should provide protection for the expected fire duration. For more information refer to Chapter 7, Section 7.3.2. 

POLYETHYLENE FOAM WASTE UTILISATION FOR LIGHTWEIGHT CONCRETE PRODUCTION... 

Vermiculites are formed by the decomposition of mica. They contain layers of water and magnesium ions in place the potassium ions. When heated to 800°C-1100°C, vermiculite expands because of the conversion of the water to gas. The expanded vermiculite has a low thermal conductivity and density, and is used as a thermal and sound barrier as well as an aggregate in lightweight concrete. It is also used as a moisture-retaining soil conditioner in planting. 

There are many specialty cements including reinforced concrete, lightweight concrete, prestressed concrete, gypsium, and heavy glass. 

The two applicational areas above are normally associated with minor quantities (less than 8% by volume) of entrained air. However, using different chemical types of materials, much larger quantities (up to 30% by volume) can be entrained to lower the density, enhance the thermal insulation properties, or to produce lightweight concrete in conjunction with... 

The alkyl-aryl sulfonates find application in both the production of lightweight concrete and for enhancing the freeze-thaw durability of normal concrete. The usual raw material is orthododecylbenzene sulfonate, which is a basic surfactant used in a variety of industrial and domestic detergents. The formula is shown in Fig. 3.3. 

Typical activities of building materials, such as bricks and concrete, in the UK and USA are in a similar range (20 to 50 Bq kg-1) (Nero, 1983), but granite used in older houses in Cornwall has about 100 Bq kg -1 of radium (O Riordan et al., 1982). In Sweden, Hultqvist (1956) found about 1000 Bq kg-1 radium equivalent gamma activity in lightweight concrete made from alum shale. 

Lightweight concrete and cement and production of gypsum plasterboard Alcohol ether sulphates Betaines Alkylphenol ether sulphates Foaming agents... 

Two homes are identical, except that the walls of one house consist of 200-imn lightweight concrete blocks, 20-mm air space, and 20-ram plasterboard, while the walls of the other house involve the standard R-2A in °C/W frame wall construction. Which house do you think is more energy efficient ... 

Artificial coarse aggregates These are mainly slag and expanded shale, and are frequently used to produce lightweight concrete. They are the by-product of other manufacturing processes, such as blast-furnace slag or expanded shale, or pumice for lightweight concrete. 

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