Spacing Of Construction Joints In Concrete Walls

Chapter 9 liquid retaining structures p.

Spacing of construction joints in concrete walls.

Residential basement walls usually are placed without con s t r uction joints. 9 1 introduction 9 2 contraction joints 9 3 isolation or expansion joints 9 4 construction joints. The pre planned cracks will provide a better finish concrete product and will be formed in specific locations where those cracks could be monitored. Joint spacing that is greater than 15 feet require the use of load transfer devices dowels or diamond plates.

Thus for a 10 foot high wall control joints should be. Plan out your control joint spacing 24 36 times the depth of your concrete slab. Construction joints must be designed in order to allow displacements between both sides of the slab but at the same time they have to transfer flexural stresses produced in the slab by. It is best to cut joints as early as possible either while finishing with a concrete groover or within 6 18 hours after finishing with a concrete saw.

Construction joints use construction joints when the c o n c r ete placement cannot be done at one time. Chapter 10 mass concrete p. Joint spacing in meters. Unplanned joints also occur on many jobs when equipment bre a k s down or concrete supply is interru p t ed.

8 2 types of joints in concrete walls 8 3 contraction joints 8 4 isolation or expansion joints 8 5 construction joints. Control joints are not intended to stop cracking but rather control cracking. Concrete joints are normally used to prevent cracks when the concrete shrinks by creating forming tooling sawing and placing joint formers. Concrete joints are used to compensate when concrete expands or shrinks with changes in temperature.

While these attributes are the primary basis for concrete masonry s. Let s discuss the advantage of construction joints in concrete structures. A complete or monolithic con s t r uction joint. Providing construction joint in concrete limits the area to be concreted in a one pour.

For example in the construction of a concrete wall we cannot avoid construction joint just above the base. When no joint reinforcing is used national concrete masonry association ncma tek 53 design of concrete masonry for crack control recommends spacing control joints in straight wall sections without openings no farther apart than twice the height of the wall 40 feet maximum. Joints are commonly spaced at distances equal to 24 to 30 times the slab thickness.