Protection of rebar against corrosion
Protection of rebar against corrosion
(OP)
Background
CSA S413 requires rebar in corrosive environments to be protected against corrosion. One of the acceptable protection methods listed in CSA S413 is waterproofing membrane. In a structure for which we are doing a condition survey report, there is an entrance driveway with precast one foot square (300 mm) precast concrete pavers underlain by granular drainage layers and protection board and Bituthene membrane. The membrane is 40 years old and remains pliable. There is no evidence whatever of any past leakage on the slab soffit.
Question
Does anyone have personal experience with Bituthene, and how long its service life is expected to be? For hot-applied rubberized asphalt membranes in our area, the design service life is generally taken as 20 to 30 years, and they start leaking and lose pliability etc. Some people say that we should rip out the seemingly perfectly performing Bituthene membrane because it is 40 years old now when we are installing new pavers, while others say it could go another 40 years. Does anyone have personal experience with Bituthene, and can suggest how long it will last?
CSA S413 requires rebar in corrosive environments to be protected against corrosion. One of the acceptable protection methods listed in CSA S413 is waterproofing membrane. In a structure for which we are doing a condition survey report, there is an entrance driveway with precast one foot square (300 mm) precast concrete pavers underlain by granular drainage layers and protection board and Bituthene membrane. The membrane is 40 years old and remains pliable. There is no evidence whatever of any past leakage on the slab soffit.
Question
Does anyone have personal experience with Bituthene, and how long its service life is expected to be? For hot-applied rubberized asphalt membranes in our area, the design service life is generally taken as 20 to 30 years, and they start leaking and lose pliability etc. Some people say that we should rip out the seemingly perfectly performing Bituthene membrane because it is 40 years old now when we are installing new pavers, while others say it could go another 40 years. Does anyone have personal experience with Bituthene, and can suggest how long it will last?






RE: Protection of rebar against corrosion
I don't know about its longevity; it may be approaching 'end of life'. Best you check with a supplier to see what it lifetime is.
Dik
RE: Protection of rebar against corrosion
Before posting this question, we of course did check with the two manufacturers of Bituthene membranes and neither could give us an expected service life. So that was why I then posted the question on this forum. But I suppose that waterproofing specialists who might have an answer, would not be on this forum, but I don't know if there is such a waterproofing specialists forum.
Thanks you for your info that you have never seen it "dry out" which I take to mean that you have not seen it lose pliability. Good to know that. That would seem to indicate that it is better than hot-applied rubberized asphalt which does lose pliability.
(Since you and I have both had more than 50 years experience, I guess that we are roughly about the same age!)