Use of Expansion Joints in Construction Projects Washington DC

Due to temperature and moisture fluctuations, materials tend to expand and contract accordingly. To avoid cracks developing in the materials and eventually compromising the integrity of the building, expansion or seismic joints are placed in strategic positions to accommodate such changes and movements.

Expansion joints are simple assemblies that are ingeniously designed to accommodate contraction and expansion caused by heat on construction materials safely. Bridges and railway tracks are always constructed with sealant joints or seismic joints, as are other structures like piping systems.

One of the foremost reasons why buildings, especially high-rise buildings have expansion joints is that they help eliminate cracks and the aftereffects of these cracks. Movements in a building caused by moisture, elastic deformation, temperature, creep and other factors can slowly develop stress points that can weaken the entire structure. These cracks are a lurking danger. On the other hand, restraining these movements can also result in cracking. Thus to avoid cracking it is important to accommodate differential movements between the different assemblies and materials used in the construction as opposed to prevent movement. Minimizing volume change by use of seismic joints can help eliminate cracks and all the problems that come about because of this.

As a result, of using high-grade cement and specifying the use of mortars with high compressive strengths, this has come at an expense. The stronger units with increased compressive strength being constructed have made the building of thinner walls possible, which are more susceptible to spalling and cracking. This danger is even higher if differential movements are not taken into consideration. It is also important to remember that all materials expand and contract as a result, of moisture or temperature, location, use and the expansion or sealant joints design. The architect or designer should consider this fact at the time of making the original building designs.

Expansion joints are mostly recommended where the designer has provided expansion joints in the structural system. Where the assembly and structural supports change direction, expansion joints should be placed in all these areas. It is also recommended that they be placed where intersections between an old and a new building exist or where there is a change in the type of adjoining deck material. Junctions also tend to experience changes in their interior temperature. In these areas, expansion joints can prove crucial. In addition, they should also be placed in areas that are larger than 50 meters in whichever direction of a construction.

Montgomery Mechanical Services

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