I went out and had a look at the bridge and think the fault lies with the cement supplier.
Attached are a couple of pictures. They show that the concrete literally turned into small pieces and "dust".
There was a lot of re-bar. The top cord seemed to have a lot. The bottom cord was not visible so who knows.
The bridge is arched slightly about 8-12" over a 60' span which looks about right IMO. The concrete would be in bulk modulus (compression mode) and should no have failed.

I met an Aussie that makes concrete paving stones for driveways and sidewalks. He got a batch of bad cement and his paving stones literally crumbled in his hands. The cement was manufactured on Cebu island. The factory actually replaced his 250 bags of bad cement and gave him another 250 bags to make up for his troubles. The cement factory said they only had 500 bags of the bad batch. Maybe there was more defective product and some of it may have ended up here.

At least the bridge failed before it was completed and people were using it.

 

Here is some more info about the area being opened for the road to proceed.


Oscar and Rosario Yutangco-Torres family donated the years-long unresolved obstacle in the south diversion road in Junob that paved and cleared the way for a four-lane highway from Bacong to Sibulan. The Mangacop family also gave way of their fence to let the City diversion road pass. Thanks to the families said Councilors Lani Ramon, Michael Bandal, Jose Kenneth Arbas and Karissa Tolentino who witnessed the demolitions led by Mayor Felipe Remollo who took only two weeks to clear the way “with gentle persuasion.”

 

When I had some bricklaying done in the UK my builder use FEBMIX. He said some washing up liquids contain soluble salts which can weaken the cement.

 

Why don't they just put up a Bailey Bridge. There are lots of them all over the world and many have been there since the second world war. Most of the concrete bridge here appear to need repairing after a very few years. You often see them removing the concrete from around the rebar, which indicates to me that the original concrete was sub standard. If you were sarcastic you might think this is deliberate, otherwise a regular source of income for the politicos might disappear.

 

He's already lost face in front of UyCondev and the general public, I reckon you're right. Hopefully, their houses are better constructed than their bridges.

 

That's one of the reasons for the rerod, at least when I've seen skyscrapers being built they can't do complete pours. How is the concrete work done there? Not saying it didn't contribute, but I think it could be the design as well. Concrete is very strong under compression, but not so strong under tension, hence the rerod which gives it additional tensile strength. Generally a bridge is built with some curvature to insure that the concrete is always under compression. This bridge looks like it was flat and essentially sagged. Could also be things like the quality of the concrete and/or shoddy workmanship. In the Philippines.....say it isn't so.

 

Just goes to show building a house and a bridge aren't necessarily the same thing. Better it failed before it was completed, instead of after it was completed. I wonder whose palms got greased on this one.