Re-Constructed Portion of I-96

[GPCharles]

To start off with, I know nothing at all about concrete.

But, why is some of the new concrete white and some is cream colored? Differences in the curing process?

[mkhopper]

I wonder the same thing. There's just something about it when driving that looks wrong or, and I hope not, rushed.

Some years back when they completely rebuilt the stretch of 96 from Telegraph heading east, it still all looks solid and "complete" today.

But, we'll know for sure in a few months about how well the new 96 holds up.

[animatedmartian]

From what I can gather, new concrete takes a month to fully cure. The discoloration is basically the concrete curing different rates and within a months time, it should start looking like a solid color.

[ghettopalmetto]

To start off with, I know nothing at all about concrete.

But, why is some of the new concrete white and some is cream colored? Differences in the curing process?

There are several things that affect the color of concrete: moisture, aggregate, and admixtures. Concrete cures through hydration, where water molecules bond to the cement. Prior to bonding, the unhydrated water may give concrete a darker color than if the same concrete were cured. Color can also depend on the aggregate [[in particular, the sand) that is used in the mix, and whether or not any pigments have been added for aesthetic reasons.

Hope this helps.

[DetroitPlanner]

Paint also affects it. Much of the walls bridges were painted so that you could not tell the difference between what was replaced and what was not.

[artds]

I drive it every day and have wondered the same thing. i suppose the most important thing is that it's a very smooth ride. It's also a pleasant drive with all the landscaping/trees/mulch they're adding.

[DTWflyer]

Two things:

1) On the roadway surface - much of the difference could to to timing and conditions when it was poured. It was poured over multiple months so there is some variance in cure time between sections. Sometimes due to other bridge and utility work they may have add to come in and do a small section much later than the surrounding sections.

2) The bridge, retaining walls, medians, and non-roadway surfaces now are applied with a sealant/paint that is intended to reduce the pourous-ness of the surface and help to extend the life of the concrete. Basically a water sealant. It looks like they used a cream colored paint here. On some of the other highways like the Lodge or Southfield they've used a more beige color.