Expansion Joint Concrete Block Wall

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Expansion joint concrete block wall. Concrete joints are used to compensate when concrete expands or shrinks with changes in temperature. Expansion joints are provided in slabs pavements buildings bridges sidewalks railway tracks piping systems ships and other structures. This article emphases on need of expansion. This is unavoidable and perfectly natural for most construction products based on.

These joints will absorb the pressure created by the expansion by giving the masonry wall flexible space to expand. National concrete masonry association 2014. The pre planned cracks will provide a better finish concrete product and will be formed in specific locations where those cracks could be monitored. Concrete joints are normally used to prevent cracks when the concrete shrinks by creating forming tooling sawing and placing joint formers.

Control joints are typically used in concrete masonry to reduce the occurrence of shrinkage related cracking. It is a continuous vertical joint filled with mortar but with a bond breaker on one side so that tensile stress cannot develop across the joint. Expansion control joints to control the expansion and protect the wall structure from cracking under pressure masons install vertical control joints at specific locations. As mentioned in the expansion joints discussion the design of control joint spacing and location is the responsibility of the designer.

Other constru c tion joints coincide with or function as contraction or expansion joints. Details of this butt type con s t r uction joint are shown in figure 4. Joint sealants for concrete masonry walls tek 19 6a. Expansion joints are placed in concrete to prevent expansive cracks formed due to temperature change.

1 for more detailed information. Thomas armstrong s technical guidance provides industry standard information on movement control on vertical and horizontal joints as well as concrete block wall ties in terms of spacing and positioning. Control joints are typically required in exposed above grade concrete masonry walls where shrinkage cracking may detract from the appearance of the wall and to limit moisture or air infiltration. Standard specification for nonrigid vinyl chloride polymer and copolymer molding and extrusion compounds astm d2287 12.

Aggregate concrete blocks position of movement joints consideration for the location of movement joints should be given at. S t r uction joint restricts wall move ments and should be as strong as the wall without joints. Concrete blocks regardless of manufacturer will dry out and shrink slightly once the building is complete. If control joints are not provided a concrete masonry wall may crack as it shrinks over time.

Shrinkage cracks in concrete masonry are not a structural concern. National concrete masonry association 2009. The simplest vertical constru c t i o n joint is formed using a bulkhead b o a r d.