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Adhesive anchors

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 The use of adhesives for fixing anchors such as bolts, steel dowels increased recently. We can see many adhesive anchors in the market. However, not all products are suitable for the various adhesive anchoring applications. The anchoring of adhesive can be horizontally, downward, upward and inclined in terms of orientation. In terms of working environment, the adhesive anchors can be used in dry conditions, water-saturated and submerged conditions. Therefore, the selection of adhesive products should consider all these factors to ensure the durability and safety of used anchors. 

Figure no:1


The adhesive anchoring system consists of adhesive material, anchors such as dowel reinforcing bars, drilling equipment, and the equipment used for cleaning such as wire brush and air compressor. 

There is a various methods used for drilling the holes for adhesive anchors. the hammer drilling machine can be used to drill the hole. it is preferred to use the hammer drilling machine because it is providing a rough surface which improve the bonding of adhesive to concrete. we should always ensure that the drilled holes diameter and length are exactly as specified in drawing or in adhesive material technical sheet. 

Figure no:2
Diamond core drilling are used sometimes to drill the hole for the anchor. the resulted hole will be smooth unlike the hammer drilling. Therefore, it is preferred to use to hammer drilling. upon completing the drilling of holes to required depth and diameter. The holes should be cleaned properly as specified in the adhesive material technical sheets. The purpose of cleaning is to remove dust and any other materials that can prevent the bonding of adhesive to concrete. This stage is very important and improper cleaning can significantly reduce the adhesion of anchor to concrete. We should also ensure that the hole is dry before filling the hole with adhesive. 

Figure no:3


The next step is to fill the hole with adhesive. Some products are composed from two components as shown in the figure no:4. The two component is mixed through a nozzle as shown in the figure below. Prior to filling the holes we should pour some material outside until the adhesive color become consistent. Then the holes should filled properly with adhesive. Before pouring the adhesive we need also to ensure that the base material temperature is complying with what specified in adhesive material technical sheet.

Figure no:4

The anchors should be ready for installation before the work time of adhesive material elapsed. The anchor will be placed inside the hole. The anchor should not be disturbed until the curing time of adhesive materials is elapsed. the loading or disturbing of the anchor anytime before the completion of cure of adhesive material will result in reducing the capacity of the anchors which may result in failure of the adhesive material in future. 
we should always ensure the selection of suitable adhesive materials and we should read and comply with what specified in technical sheet in terms of hole diameter, hole length, hole cleaning, base material temperature, material working time, material curing or setting time, etc.




Comments

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Mohammad
My name is Mohammad Hamdan, and I am a Civil/bridge Engineer with extensive professional background and experience in the field of construction. I have 10+ years of experience in the construction field. During my professional career, my emphasis has been placed on structural projects, mainly bridges, infrastructure and roads. Reading and practicing the design of structures is my passion.i was lucky to be a part of a big team that executed major highway interchanges. I believe in spreading the knowledge, thus, i compose these courses to share my experience and knowledge. My course focuses on the practical side of construction field. On other word, i am sharing some of what new engineers need to know about construction field. Beside working on construction field, i love writing some articles on my website ( curious civil engineer) Moreover, i wrote some engineering papers, you can check them  by searching my name on Google (Mohammad mamon Hamdan)