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For the mathematical concept, see Cyclic permutation. A two-stroke (or two-stroke cycle) engine is a type of internal combustion engine that completes a power cycle with two strokes of the piston (one up and one down movement) in one revolution of the crankshaft. A four-stroke engine requires four strokes of the piston to complete a power cycle ...
The oil is dyed blue to make it easier to recognize in the gasoline. It appears black in this bottle because it is not diluted. Two-stroke oil (also referred to as two-cycle oil, 2-cycle oil, 2T oil, or 2-stroke oil) is a special type of motor oil intended for use in crankcase compression two-stroke engines, typical of small gasoline -powered ...
The ultimate strength of concrete is influenced by the water-cementitious ratio (w/cm), the design constituents, and the mixing, placement and curing methods employed. All things being equal, concrete with a lower water-cement (cementitious) ratio makes a stronger concrete than that with a higher ratio. [2]
(2) The thermal expansion coefficients of concrete and steel are so close (1.0 × 10 −5 to 1.5 × 10 −5 for concrete and 1.2 × 10 −5 for steel) that the thermal stress-induced damage to the bond between the two components can be prevented. (3) Concrete can protect the embedded steel from corrosion and high-temperature induced softening.
Creep and shrinkage of concrete are two physical properties of concrete. The creep of concrete, which originates from the calcium silicate hydrates (C-S-H) in the hardened Portland cement paste (which is the binder of mineral aggregates), is fundamentally different from the creep of metals and polymers. Unlike the creep of metals, it occurs at ...
Roller-compacted concrete ( RCC) or rolled concrete ( rollcrete) is a special blend of concrete that has essentially the same ingredients as conventional concrete but in different ratios, and increasingly with partial substitution of fly ash for Portland cement. [ 2] The partial substitution of fly ash for Portland Cement is an important aspect ...
EN 1992-1-2 deals with the design of concrete structures for the accidental situation of fire exposure and is intended to be used in conjunction with EN 1992-1-1 and EN 1991-1-2. This part 1-2 only identifies differences from, or supplements to, normal temperature design. Part 1-2 of EN 1992 deals only with passive methods of fire protection.
On the other hand, for completely dry concrete, the chemical reaction of carbonation cannot occur. Another influencing factor for CO 2 diffusion rate is concrete porosity. Concrete obtained with higher w/c ratio or obtained with an incorrect curing process presents higher porosity at hardened state, and is therefore subjected to a higher ...