Transverse Joint.

• The concreting of dam is usually placed in blocks.

• The size of blocks will depend upon the size of dam and necessity of contraction joints.

• Their width is usually more than 15 morso, in large dams.

• Maximum height of a single pour o concrete (called lift) is usually about 1.5 morso.

• The alternate blocks of very first layer which is immediately over the rock foundation is taken as 0.7 m deep.

• Dam sections are poured alternately so that each block is permitted to stand several days before another layer is poured.

• Curing must be done carefully.

• After the shutters are removed, the lateral surfaces of each section are painted with a phaltic emulsion paint so as to prevent its adherence to adjoining sections.

• The vertical joints so developed are called as ‘TRANSVERSE JOINTS’.

LONGITUDINAL JOINTS.

• The horizontal joints are developed at each lift height and will extend through entire width of dam section.

• Such joints are called as longitudinal joints.

• They shall run through the entire length of the dam but shall be staggered between transverse joints.

Construction and Contraction Joints.

• Truly speaking, every joint which so ever is left the dam, shall be constructed joint and every construction joint which opposes contraction stresses are known as contraction joint.

• Therefore, there should be no difference between the two.

• In other words, horizontal joints which were a must from consideration of lift are called as construction joints.

• While the joints which are mainly left for shrinkage of concrete are called as contraction joints.