Concrete, floors, foundations, pads, slabs, walls and footings can be found on all building sites throughout NZ. The correct mixing and placement of concrete is vital to the products performance and longevity the enclosed pictures depict two apparatus essential to the process of placement and performance consistency. Research these two apparatus, determine their correct application and the necessity for each.
Concrete vibrators consolidate freshly poured concrete so that trapped air and excess water are released and the concrete settles firmly in place in the formwork. The vibrator head is immersed in the wet concrete. They are important as improper consolidation of concrete can cause product defects, compromise the concrete strength, and produce surface blemishes such as bug holes and honeycombing.
ReplyDeleteA concrete slump cone is used to measure the behaviour of a compacted inverted cone of concrete under the action of gravity. It measures the consistency or the wetness of concrete. There are usually 3 results for the test. A collapse slump where the concrete completely collapses means the concrete is too wet. A shear slump is when the top portion of concrete shears off and slips. A true slump is where the concrete slumps to an even level usually about 10-40mm meaning it is a good consistency to use.
Concrete vibrators are used in compacting the concrete. The vibration emitted from the head of the concrete vibrator allows the release of air pockets that may have been trapped when laying the concrete down. This is an important process and failure to do this may affect the strength of the concrete.
ReplyDeleteA concrete slump is used in the process of a slump test. The purpose of the slump test is to test the consistency between the different truck loads of concrete that may be brought to the site. If they are of different consistencies it will affect the strength and dry time of the concrete. The cone is filled with the concrete and a rod is used to settle it. Once filled in three parts, the cone is removed and placed next to the concrete that was previously in the cone. The difference in height will determine the slump level. The loads that arrive to the site from then on are measured in the same manner to ensure they have the same slump level and are therefore of the same consistency.