Roadway Repair for School Zone in San Antonio
Problem
Biz Engleman Road in San Antonio, Texas, is a two-lane asphalt roadway that runs past a school. The pavement of the road had become soft and flexible after the supporting soils were compromised due to drought and culvert drainage problems. The local school district decided to repair the damaged roadway. URETEK was asked to stabilize the base and subbase soils prior to asphalt overlay of a 2900-foot section of Binz Engleman Road. URETEK needed to repair approximately one mile in both the eastbound and westbound directions from Woodlake Parkway to the driveway at the school entrance.
Analysis
Two culvert drainage crossings and one bridge served as receptors for the drainage ditches on each side of the pavement system. During major rain events, water gathered in the flat “valley” areas of the road and caused slow drainage and water absorption. With this knowledge, URETEK performed Dynamic Cone Penetrometer (DCP) testing to identify the weak soil depths down to 20 feet.
Solution
The school district needed URETEK to initiate and complete the project during a spring break recess period. With DCP data in hand, URETEK targeted the soils at depths of four and seven feet with the URETEK Deep Injection® (UDI) process. Crew members arrived on location and began work.
Result
URETEK completed the soil stabilization in one day with zero days of down time. Results of the pre- and post-injection DCP testing showed significant improvement at the four- and seven-foot soil depth levels. URETEK offered a fast, cost-effective, and long-term solution to the San Antonio school district. The job required no tear outs, haul offs, or backfills. URETEK completed the job 20 days faster and with a cost savings of $125,000 compared to traditional repair methods. URETEK crews took advantage of the lower-than-normal spring break traffic flow, yet still maintained one open lane on Biz Engleman Road throughout the project. URETEK guaranteed a two-year warranty against re-settlement of the pavement.
URETEK Deep Injection® (UDI)
Widely referenced throughout our industry, UDI involves the injection of structural polymer into base and subgrade soils to increase the load bearing capacity. This is achieved by injecting the polymer through small holes drilled directly through the pavement structure to depths determined by site-specific analysis. Our URETEK 486 Star® material flows easily into voids and weak zones within the soil mass below. Through a controlled chemical reaction, the expanding polymer compacts surrounding soils and applies a controlled pressure on targeted areas of the affected pavement above. If needed, a multi-injection design plan is utilized to gently return the pavement to its original grade. The composite material quickly cures into a strong, dimensionally stable, and water-resistant geo-material, providing years of reliable service.
URETEK 486 Star®
URETEK 486 Star® polymer is a two-component, high-density, expanding thermoset polyurethane system. It was developed to be the ideal solution for under-sealing, void filling, lifting of settled pavement, stabilization and stiffening of weak soils, and for encapsulating and sealing buried infrastructure. URETEK 486 Star® is environmentally inert, non-toxic, and resists underground water erosion or weakening due to its industry-leading hydrophobic properties.
