I haven't really done any concrete repair work in my career until now, so I am looking to get an opinion on concrete patching details. In my specific case, I have 7 areas on a concrete pedestrian bridge that have spalled and need to be repaired. Each spall is approximately 14 inches by 14 inches and is about 4 inches deep, and all are located at the transverse edges of the bridge. The overall thickness of the bridge is 9 inches and it is lightly reinforced with #4 transverse bars at 12 inches o.c. top and bottom. There are no longitudinal bars where the patches will be. The bridge is located in Minnesota. The spalls all occur around existing guardrail posts that are embedded in the concrete. We will be removing and replacing the guardrail posts with surface mounted posts, and we will be moving the locations of the posts away from the patches. I have included the typical patching detail that my previous employer used concrete repair Salt Lake City. Yesterday (1-19-18) someone posted a whole bunch of details from the New York City Transit Authority. Similar details were found in that set. One of my questions is, why do some details include a series of anchors embedded into the existing concrete (identified as "D" in the attached detail) with a layer of welded wire fabric (identified as "C" in the attached detail) attached to it, and other details do not include any new reinforcing? I don't believe these bars are for strength because they aren't properly lapped with the existing bars nor would they be the same size. Are they for temperature and shrinkage? Do large patches contain this reinforcing and small patches don't? Also, what type of patching material would be the best to use? I have read up on latex modified concrete, epoxy modified concrete, and concrete carefully designed to control shrinkage. I am leaning on going with carefully designed concrete because it can be placed in one lift and the fact that the other products requires a more skilled laborer to execute. Do you agree/disagree? Any comments would be appreciated. Thank you!