Los Angeles lab report Essay Example | Topics and Well Written Essays - 1000 words

Los Angeles lab report - Essay ExampleThe test of reference is do on the instalment size 10/14mm. In order to understand the operation of the Los Angeles test, an experiment was set to determine the electric resistance to fragmentation. Apparatus The setup that would be delectationd in this experiment include Los Angeles Machine Recycled concrete hoard up Scale Tray Sieve Method. A 5kg of Recycled Concrete Aggregate was introduced in the cylinder via a hatch. The thecharge of eleven brand balls, with each ranging between 45mm and 49mm in diameter, while weighing in totallity between 4690g to 4860g was also added. The hatch palpebra was bolted in place with the cylinder being rotated about 500 revolutions at a devoted rate of 31 to 33 RPM (Revolution Per Minute). The machine was operated in a soundproofed cabinet. A built-in call stopped the machine after 500 revolutions. The hatch was opened, and the contents of the cylinder were emptied into trays set underneath the openin g. The balls were take away and the aggregate was sieved using a 1.6mm sieve. For the fraction that was retained on the sieve, was weighed. The result, the Los Angeles Coefficient, was figure using . All the information collected was recorded in table 1. Table 1 Data collected. subject of aggregate Recycled Concrete Aggregate Initial mass of sample (g) 5000 Mass retained on the 1.6mm sieve (g) 3790 g Type of aggregate Thames Aggregate Initial mass of sample (g) 5000 Mass retained on the 1.6mm sieve (g) 3943 Calculations The Los Angeles Coefficient, LA, was calculated as follows Aggregate with a LA value of less than 30 (LA30) is considered strong enough for use in coating and road surface treatments (i.e. surface dressing). For example, a faulty scale or a faulty Los Angeles machine may automatically affect the readings of the experiment. It is recommended that for experimental errors to be reduced the following locomote should be followed. During the experiment one should ensu re that at least three readings for a particular timber are taken then an average of the reading obtained to decrease the errors of parallax. The experiment needs to be done at least twice to confirm the recorded values and minimize the errors. The Los Angeles Machine and all the apparatus used for the experiment should always be checked before the start of the experiment to ascertain their cleverness (BS 1377-4, 1990). The experiment could also be done in an area with vacuum fountains in order to minimize the interferences in obtaining the readings demonstrated to air resistance. Whenever the capacitor is by-passed by an emitter, and capacitance of the coupled capacitor is large in regards to the AC frequency sign of the zodiac, the capacitors would be approximated as a circuit that is short (BS EN 1097-2, 1998). Whenever the input signal or voltage is increased the output voltage and the signal would be further vary somewhat the dc bow point that has been established (Highw ays Agency , 2009). This effect would continue up to when the assigning condition of the voltage is reached. For the current in the circuit, the limiting condition would be VCC/RC, at the end, considered to be high, and a postcode at the end considered to be low of the swing. The voltage of the emitter collector and the supply limit reaches a limit when they have a zero and VCC. Additionally, the voltage output and the varying current around the point of bias gives out ac power towards the rouse (Highways Agency, 2009). The delivered ac power is made to go through the load referred to as RC. AC signal, on