WILLITS, 1/18/17 — In recent days some people have taken to social media to raise the alarm about a “crack” in the viaduct section of the Willits Bypass that crosses Valley Rd. — which is apparently growing. But don’t worry! This supposed “crack,” that has gotten a lot of attention, including some drone footage yesterday, is actually an expansion joint — a normal part of concrete structures.
Concrete, like most things, expands and contracts with heat or cold. Because this expansion can place strains in structural concrete, potentially even causing it to buckle, engineers have long included “expansion joints” to allow the concrete to swell and contract. These have the added benefit of giving bridges and viaducts some sway in a quake.
The Mendocino Voice inquired about these expansion joints with CalTrans. A spokesman there contacted the resident engineer for the Willits Bypass Project, Geoffrey Wright, who said, “ I would not be surprised that at this time of year the expansion joints look wider. The concrete for the viaduct was poured during the summer, and in the winter the concrete shrinks due to the lower temperatures. The expansion joints allow for the expansion and contraction during temperature changes. I drove across the viaduct yesterday and did not note anything of concern.”
Here is some drone footage of the expansion joint courtesy of Steven Difazio:
So enjoy your day, and regardless of how exactly, where, or in what shape it’s poured, let’s all toast that marvelous expanding and contracting material from which the Roman Forum, Hoover Dam, the Burj Khalifa and your own house’s foundation are all built — concrete!