Using a grout into the back of the hole ensures that the material flows out around each bar, fully encasing it. Do not coat one end of the bar with grout or epoxy and then insert the bar into the hole – the air pressure inside the hole will force the grouting material back out of the hole, leaving a void around the bar.
For guidance, omission of dowels should be based on the consideration any load transfer requirements, geometry and size of the reinstatement. Consideration of the use of low shrinkage concretes, including proprietary products for concrete repair, is recommended for discussion in this case.
