Rectangular Beams and One-Way Slabs

Abstract

This chapter provides several methods including blasting, crushing, and cutting to remove concrete for a repair. Blasting is done with boreholes that use rapidly expanding gas to create controlled fracture and concrete removal. The use of explosive blasting is usually not considered for jobs that require the removal of less than 10 inches of concrete from the face of a structure. Crushing is done with hydraulically powered jaws. Boom-mounted mechanical crushers and portable mechanical crushers are both used. When total demolition is desired, a boom-mounted crusher is normally used. This type of equipment is most effective when not used for partial removal. Portable crushers work best when the shearing plane depth is 12 inches or less. Cutting is used to remove full sections of concrete. Stitch cutting is used when the cut depth is greater than what can be reached with a diamond saw blade. This is most often the case when only one face of the concrete is accessible. If two faces are accessible, a wire cutting is more likely to be used.