5.5　Construction Joints

5.5.1　Construction joint shall be provided for lining application for one of the following cases:

1　Lining applied by ramming for equipment or piping placed in horizontal position；

2　Lining applied section by section；

3　Interruption of lining application exceeds the initial setting time of lining concrete.

5.5.2　Construction joint shall be provided in the middle of two rows of anchors，and the joint pattern of lining concrete shall be in accordance with Figure 5.5.2.The staggered distance at the joint between heatinsulating concrete and abrasion-resistant concrete of double layer lining shall not be less than 200mm.

Figure 5.5.2　Joint patterns of lining concrete

For equipment and piping lined section by section，lining should not be applied within an extent in 200mm beyond their joint at each side.And at least three rows of mesh openings or ring anchors shall be left at each side of lining installed with hexmesh or ring anchors.

5.5.3　Application restoration at construction joint shall comply with the following requirements:

1　Loose or residual lining concrete on the joint face shall be removed；

2　The joint face of hydraulic-bonded lining concrete shall be fully wetted；

3　A coating of binder solution shall be uniformly applied on joint face of chemical bonded lining concrete.