a concrete sleeper british english or concrete tie american english is a type of railway sleeper or railroad tie made out of steel reinforced concrete . concrete sleepers. concrete sleepers were used for the entire length of the adelaide-darwin railway line. concrete sleepers are less elastic, and consequently noisier than wooden sleepers .
an airport crash tender known in some countries as an airport fire appliance is a specialised fire engine designed for use in aircraft rescue and firefighting at aerodromes, airports, and military air bases. wikimedia commons has media related to airport crash tenders.
gypsum concrete is a building material used as a floor underlayment used in wood-frame and concrete construction for fire ratings, sound reduction, radiant heating, and floor leveling. it is a mixture of gypsum plaster, portland cement, and sand. the brand name gyp-crete, a maxxon corporation trademark, has come into general use as a term for .
for tall concrete buildings, where neither explosive nor high reach demolition with an excavator is safe or practical, the 'inside-out' method is used, whereby remotely operated mini-excavators demolish the building from the inside, whilst maintaining the outer walls of the building as a scaffolding, as each floor is demolished.
roman concrete, also called opus caementicium, was a material used in construction in ancient rome.roman concrete was based on a hydraulic-setting cement.it is durable due to its incorporation of pozzolanic ash, which prevents cracks from spreading.by the middle of the 1st century, the material was used frequently, often brick-faced, although variations in aggregate allowed different .
the 'skimmel' is a heavy recovery vehicle which is fitted with a tow arm, a winch, a crane and various other equipment. the 'zebra' is a maintenance and repair variant of the truck. the 'kameelperd' version carries the army air defence artillery's esr220 thutlwa mobile battery fire control post and early warning radar. the trucks also have tank transport and bridge layer variants.
these values have to be used cautiously as there is strong evidence that chloride diffusion and surface electrical resistivity is dependent on other factors such as mix composition and age. the electrical resistivity of the concrete cover layer decreases due to: increasing concrete water content
a concrete saw also known as a consaw, road saw, cut-off saw, slab saw or quick cut is a power tool used for cutting concrete, masonry, brick, asphalt, tile, and other solid materials.there are many types ranging from small hand-held saws, chop-saw models, and big walk-behind saws or other styles, and it may be powered by gasoline, hydraulic or pneumatic pressure, or an electric motor.