Mechanical properties and acoustic behaviour of screed Essay

Mechanical properties and acoustic behaviour of screed - Essay ExampleThe topping thus made is a layer of high speciality concrete, with better mechanical properties than other finishing matrial phthisisd ordinarily on the surface bases........(1)However, due to the poor surface finishes available at sites, it is advisable to use screed adequately while making correct takeing for the place of screed to get the required round off finish. Proper tools like trowels are used for this purpose. The general guidelines for laying a screed layer provide that there should not be any deviation of more than 3mm over a length of 3 meters, to get the smooth and level al-Qaida of good quality. The figure shows the deviation curve for the screed layer on a concrete surface over a 3-meter length, with datum level as reference point...........(2)There are mainly two types of screeds, bonded and monolithic screeds. The difference lies in their application. While bonded screed is applied to a hard ened concrete al-Qaida surface, monolithic screed is applied at the time of laying the concrete flooring itself.This type of screed is applicable only on strong and hardened concrete that has a characteristic strength of more than 20MPa, as the bonding of adhesive is not possible for screed with weak concrete. Moreover, the screed layer cannot fill any cracks on the base floor and therefore the crack will show up over a period. The base concrete surface should be smooth and level to allow a screed layer of approximately 25 mm. thickness, being in the range of 15 to 40 mm..The preparation of base concrete should be such that it is hardened uniformly, sluttish of oil or dirt, If there is a presence of any earlier screed layers, then same need to be removed by scrapping allover, as the cleanup position at edges or pecking at intervals will not be sufficient. The surface should be vacuum cleaned with high air pressure to free it of all ashes particles.For this purpose, a mixture of s and and cement should be