Texas Asphalt - Fall 2017 - 26

feature: SAFETY

PHOTO CREDIT: 1956/TXDOT

Exit to northbound
1-35 from inbound
1-10 (1956).

SAN ANTONIO

DOWNTOWN Y STANDS
THE TEST OF TIME
By Christopher Curry

I

n San Antonio, the asphalt upper
deck of the "Downtown Y" interstate
exchange has stood the test of time.
The durability of the pavement on
this y-shaped branch that Interstate 10
and Interstate 35 make west of downtown,
and along several additional miles of each
of interstate, is the product of forwardthinking decisions in the 1980s to use a
specially designed asphalt mix instead of
concrete during the construction of the
deck's original road surface.
"We wanted something that would ride
well and be skid resistant and what we put
down has really worked," said John Kight,

26 texasasphalt.org

who was the TxDOT district design engineer
for the project.
The reconstruction of the Downtown Y
interchange, which included the addition
of the upper deck in order to accommodate
heavy traffic flows within the confines
existing right-of-way, stretched from the
mid-1980s into the early-1990s.
In an innovative and unique design
choice at the time, the upper deck was
built as a segmental bridge. A series of
approximately 20-foot long concrete sections were precast off-site, trucked to
the construction site and erected with a
launching truss. The sections were held

together by cable tendons running through
the trapezoid-shaped hollow space inside
each section and down into the support
bridge structure's columns.
Using a segmental bridge design cut
down on construction time because the
sections were precast off-site, Kight said.
But it also meant a bridge that was less
thick and more flexible than the bridge
designs more widely used at the time. Kight
expected the bridge was so flexible that
a heavy truck running along edge of the
roadway could cause four inches of deflection push down on that side and push up
another four inches on the opposite side.


http://www.texasasphalt.org

Table of Contents for the Digital Edition of Texas Asphalt - Fall 2017

President’s Message
NAPA
Associate Member Forum
The Major’s Perspective
TXAPA Scholarship Program Changes Produce Big Results
Partnering Opportunities for Quality
San Antonio Downtown Y Stands the Test of Time
The Pros and Cons of Expectations
U.S. Polyco
HMA Labs
Calendar of Events
New Members
Products & Services Marketplace
Advertisers Index
Texas Asphalt - Fall 2017 - Intro
Texas Asphalt - Fall 2017 - cover1
Texas Asphalt - Fall 2017 - cover2
Texas Asphalt - Fall 2017 - 3
Texas Asphalt - Fall 2017 - 4
Texas Asphalt - Fall 2017 - 5
Texas Asphalt - Fall 2017 - 6
Texas Asphalt - Fall 2017 - President’s Message
Texas Asphalt - Fall 2017 - 8
Texas Asphalt - Fall 2017 - NAPA
Texas Asphalt - Fall 2017 - 10
Texas Asphalt - Fall 2017 - Associate Member Forum
Texas Asphalt - Fall 2017 - 12
Texas Asphalt - Fall 2017 - The Major’s Perspective
Texas Asphalt - Fall 2017 - 14
Texas Asphalt - Fall 2017 - TXAPA Scholarship Program Changes Produce Big Results
Texas Asphalt - Fall 2017 - 16
Texas Asphalt - Fall 2017 - 17
Texas Asphalt - Fall 2017 - 18
Texas Asphalt - Fall 2017 - 19
Texas Asphalt - Fall 2017 - 20
Texas Asphalt - Fall 2017 - Partnering Opportunities for Quality
Texas Asphalt - Fall 2017 - 22
Texas Asphalt - Fall 2017 - 23
Texas Asphalt - Fall 2017 - 24
Texas Asphalt - Fall 2017 - 25
Texas Asphalt - Fall 2017 - San Antonio Downtown Y Stands the Test of Time
Texas Asphalt - Fall 2017 - 27
Texas Asphalt - Fall 2017 - The Pros and Cons of Expectations
Texas Asphalt - Fall 2017 - 29
Texas Asphalt - Fall 2017 - 30
Texas Asphalt - Fall 2017 - 31
Texas Asphalt - Fall 2017 - 32
Texas Asphalt - Fall 2017 - U.S. Polyco
Texas Asphalt - Fall 2017 - 34
Texas Asphalt - Fall 2017 - HMA Labs
Texas Asphalt - Fall 2017 - 36
Texas Asphalt - Fall 2017 - Calendar of Events
Texas Asphalt - Fall 2017 - 38
Texas Asphalt - Fall 2017 - New Members
Texas Asphalt - Fall 2017 - Products & Services Marketplace
Texas Asphalt - Fall 2017 - 41
Texas Asphalt - Fall 2017 - 42
Texas Asphalt - Fall 2017 - Advertisers Index
Texas Asphalt - Fall 2017 - 44
Texas Asphalt - Fall 2017 - 45
Texas Asphalt - Fall 2017 - 46
Texas Asphalt - Fall 2017 - cover3
Texas Asphalt - Fall 2017 - cover4
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