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.
• There width is usually more than 1.5 more so, in large dams.
• Maximum height of a single pour of 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 0.75 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 asphaltic emulsion paint so as to prevent its adherence to adjoining sections.
• The vertical joints 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 whichsoever is left the dam, shall be construction 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.