Asphalt storage pad
I'm extending my driveway (12' wide) by 17 feet so I can park my 33' Forest River 5th wheel on it for a few days before and after our trips. We have an offsite storage facility for long-term storage. ...
Forum Discussion
Fun aside: In regards to why highways don't hold up like they seemed to in the past? It's controversial, but almost certainly is not lack of rebar, much less lack of wire mesh. In the past, total traffic volume was much lower, which probably is the biggest factor.
In my opinion, the next biggest factor is that we've used 28 day old compressive strength as the largest quality control factor in Portland cement concrete for many decades. The problem with that is that in the 1960's factory economics were such that cement granules left the factory coarser than they do today. That meant you needed more of it to hit your 28 day strength because coarse granules gained strength slowly. Today, ultra fine cement results in very fast strength gain, so they use less of it to get the same 28 day strength. The downside is that the 90 day strength today is much lower than the 90 day strength of 1960's concrete. But nobody checks that. Our admixtures have gotten better, but we've become stupidly short-sighted about ultimate strength and it's effects on longevity. Others in the industry see it differently, but that's my opinion.
This is why you sometimes see "1890" stamped on concrete railroad bridges that are in fine shape next to interstate concrete bridges built in 1990 that are dropping chunks off as you watch traffic go over...
In my opinion, the next biggest factor is that we've used 28 day old compressive strength as the largest quality control factor in Portland cement concrete for many decades. The problem with that is that in the 1960's factory economics were such that cement granules left the factory coarser than they do today. That meant you needed more of it to hit your 28 day strength because coarse granules gained strength slowly. Today, ultra fine cement results in very fast strength gain, so they use less of it to get the same 28 day strength. The downside is that the 90 day strength today is much lower than the 90 day strength of 1960's concrete. But nobody checks that. Our admixtures have gotten better, but we've become stupidly short-sighted about ultimate strength and it's effects on longevity. Others in the industry see it differently, but that's my opinion.
This is why you sometimes see "1890" stamped on concrete railroad bridges that are in fine shape next to interstate concrete bridges built in 1990 that are dropping chunks off as you watch traffic go over...
