Hello,

I got to build a bridge and the consultant specify a waterproof layer on the bridge deck. Can i use admix as waterproof agent by mixing waterproofing admixture with the concrete deck to make it impermeable.

Due to some error in level by the consultant, they instruct me to raise the finish level of the asphalt but in the process of not making the cost too expensive, they specify to use a layer of crusher run approximately 150mm above the bridge deck followed by 70mm of asphalt. (note the asphalt is to be done in 2 course, i.e. 40mm base course and 30mm wearing course). If i was to use a fully bonded elastomeric bitumen single layer system such as PARAFOR PONTS as waterproofing on the bridge deck, then i got a problem? normally i would have to seal the concrete with a primer basically siplast primer to seal the concrete deck before torching the PARAFOR PONTS membrane.After i have to lay 150mm crusherrun 0/20 on the deck and compact to 98% heavy duty, followed by primer and base coarse 40mm thick and then tack coat followed by wearing course 30mm thick.

I think something is wrong but i can't figure it out. The crusher layer above the waterproofing membrane seem odds to me. Do i rather put a primer coat before applying the crusher run layer. Next i will have to compact to 98% Max dry density and then apply another layer of prime coat before 40mm thick 0/14 base course is laid. Is that right?

If i was to waterproof the concrete with an admix then how to do with the crusher run on the deck? Shall i use a prime coat before laying the crusher run and then compact and then re-add a layer of prime coat before doing the base course 40mm thick. (base course is 0/14 and 40mm)

Can someone provide me a good explanation on such as this is the first time i heard we add a layer of crusher run on a bride deck.