Tarrant Regional Water District commissioned the installation of this 108-inch steel pipeline between Kennedale Balancing Reservoir and Arlington Outlet with an attendant research program for the use of Controlled Low Strength Materials (CLSM) trench backfill.
Gorrondona & Associates, Inc. assisted TRWD through our contract with Freese & Nichols, Inc. (FNI) in order to evaluate the potential use of native excavated trench materials with various stabilizing agents for pipe bedding and backfill.
G&AI worked in tandem with the contractor, the contractor quality control laboratory and the University of Texas at Arlington to evaluate the compressive strength of the various design mixes for CLSM tested.
G&AI prepared numerous CLSM cylinder specimens in accordance with ASTM D-1633 Standard Test methods for Compressive Strength of Molded Soil-Cement Cylinders. Curing and testing was performed for 3, 7, 14 and 28-day breaks under tightly controlled strain-controlled tests. Comparative laboratory tests by the other parties were evaluated to select the best cement / admixtures ratios for production with native excavated soil.
G&AI prepared field CLSM cylinders, cured in the lab and performed compressive strength tests. G&AI instructed contractor personnel to prepare CLSM cylinder test specimens. G&AI witnessed CLSM blending in a pug-mill before placement.