amardeep singh sohal

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Cold Weather Concreting – Any operation of concreting done at about 5 O C atmospheric temperature or below. EFFECTS OF COLD WEATHER ON CONCRETE Delayed Setting – When the temperature is falling to about 5 o C or below, the development of concrete strength is retarded compared with the strength development at normal temperature. Freezing of Concrete at Early Ages – When concrete is exposed to freezing temperature, there is a risk of concrete suffering irreparable loss and other qualities that is, permeability may increase and durability may be impaired. Repeated Freezing and Thawing of Concrete – If the concrete is exposed to repeated freezing and thawing after final set and during hardening period, the final qualities of concrete may be impaired. Stress Due to Temperature Differentials – It is a general experience that large temperature differentials within the concrete member may promote cracking and have harmful effect on the durability. Such differentials are likely to occur in

California bearing ratio (CBR).  A simple test that compares the bearing capacity of a material with that of a well-graded crushed stone (thus, a high quality crushed stone material should have a CBR 100%).  CBR is basically a measure of strength.  It is primarily intended for, but not limited to, evaluating the strength of cohesive materials having maximum particle sizes less than 0.75 inches (AASHTO, 2000).  It was developed by the California Division of Highways around 1930 and was subsequently adopted by numerous states, counties, U.S. federal agencies and internationally.  Most agency and commercial geotechnical laboratories in the U.S. are equipped to perform CBR tests. Resistance value (R-Value).  A test that expresses a material's resistance to deformation as a function of the ratio of transmitted lateral pressure to applied vertical pressure.  It is essentially a modified triaxial compression test.  Materials tested are assigned an R-value. The testing apparatus used in t

The downward force of gravity is opposed by an outward centrifugal force due to the planet's rotation, which is greater at the equator than at a higher latitudes. (The centrifugal force is "fictitious" in the sense that the real force caused by rotation is the centripetal force; however, it is a convenient fiction for the sake of calculations.) By itself, this effect would result in a range of values of g from 9.789 m/s2(32.116 ft/s2) at the equator to 9.823 m/s2 (32.228 ft/s2) at the poles. This discrepancy is further accentuated because of the Earth's equatorial bulge, which causes objects at lower latitudes to be further from the planet's center than objects nearer the poles and hence subject to a slightly weaker gravitational pull. Overall these two effects result in a variation of 0.052 m/s2 (0.171 ft/s2) in the value of g, which leads to a variation in the weight of an object by about 0.5% depending on whether it is weighed at the equator or at one of the p

Maximum size. The smallest sieve through which 100 percent of the aggregate sample particles pass.  Superpave defines the maximum aggregate size as "one sieve larger than the nominal maximum size" Nominal maximum size. The largest sieve that retains some of the aggregate particles but generally not more than 10 percent by weight.  Superpave defines nominal maximum aggregate size as "one sieve size larger than the first sieve to retain more than 10 percent of the material"