Page 22 - LWFC Catalog

PRESENTATION ABSTRACTS
PRESENTATION ABSTRACTS

10AM - Use of Geofoam Blocks for Retaining Wall and Bridge Approach
10:50AM Backfill for Transportation Projects As repairs, improvements or new
construction projects are planned over difficult or sensitive ground, the
use of lightweight fill materials provides an attractive alternate to owners
versus conventional tied-back retaining walls. Our presentation will focus
on the use of Expanded Polystyrene (EPS), or “Geofoam” blocks, for use
as backfill for significant height retaining walls and bridge approaches
Thursday with both airport and roadway applications. Recent case histories in
West Virginia and Tennessee will be discussed including design methods,
October construction processes and performance monitoring.

10AM -
21 10:50AM Cellular Concrete as Retaining Wall Backfill Test Section Cellular
concrete is an alternative form of lightweight fill that can greatly reduce
settlements, is extremely fast to place, and may reduce stresses on the
wall facing and reduce the need for reinforcement. The University of
Kansas, in partnership with the Kansas Department of Transportation and
Cematrix, constructed and instrumented a retaining wall test section as
part of the expansion of I-35 near 75th Street in Merriam, Kansas in the
fall of 2020. The test section consisted of a panel retaining wall 50 feet
in length and backfilled with approximately 11 feet of cellular concrete
with a unit weight of 30 pcf and topped with base course and concrete
pavement. The concrete mix consisted of cement, fly ash, water, and
foaming agent. The metallic reinforcement extended approximately 12
feet back into the fill. Settlement, wall deflection, temperatures, strains in
the reinforcement, and pressures at the base of the fill and back of the wall
face were monitored throughout construction. Pullout tests of sacrificial
reinforcement strips were conducted periodically after construction and
compared with laboratory tests. Preliminary results suggest the fill has
performed well with very limited vertical and horizontal deflections and
consistent strength development that is comparable with laboratory tests.

10AM - Mixing for Quality and Profit: The Time is Now An in depth look into the
10:50AM past, present and future of cellular concrete and how the right production
processes, combined with proper mix design theory, will increase industry
acceptance and broaden cellular concrete’s use across multiple
disciplines of construction. Utilizing these design principles, contractors,
engineers and owners will experience tighter product quality control,
and increases in material strengths and placement performance while
benefitting from value engineering and increased bottom lines.

11AM - Long-Distance Annulus Backfilling of Rehabilitated Sewer Tunnel with
11:50AM Limited Grouting Access The Colsman Tunnel is owned and operated
by the Southgate Sanitation District (the District), located in Centennial,
Colorado. The 7,614-foot-long tunnel was constructed circa 1977. The
shotcrete-lined tunnel has a typical cross section of approximately
69-inches wide by 75-inches tall, and transmits daily average flows of
approximately 10 MGD. The District and their Owners Advisor (Burns &
McDonnell) retained the design-build team of Garney Construction,
Dewberry Engineering, and Shannon & Wilson to rehabilitate the aging
tunnel. Rehabilitation was achieved by sliplining the tunnel with a 48-
inch nominal diameter HDPE SDR 13.5 pipe during live flow conditions,