May 30, 2017

ASTM Approves Wetcast Large Block Standard

New standard helps guarantee large blocks for projects

ASTM approves new standard for wetcast large blocks

Redi-Rock Intl. announced the approval of the first American Society for Testing and Materials (ASTM) standard specification for large wetcast retaining wall units: ASTM C1776. The standard specification was created by a work group that included large block companies, practicing design engineers, concrete manufacturers and trade organizations.

"Recon Wall Systems, Stone Strong Systems, and Redi-Rock all played an active role in developing the new standard," said Jamie Johnson, P.E., director of operations and engineering for Redi-Rock. "There was strong industry-wide support and we were proud to be part of the development process.”

The new standard specification is extremely important to the growth of the large block industry. According to Clint Hines, P.E., president of J.C.Hines & Associates, who formed and chaired the work group, "For the first time, large wetcast precast retaining wall units have their own spec. That's significant because what we were doing before as an industry was using the only ASTM standard available for concrete modular block retaining walls, which was for drycast small blocks. Having only one standard didn't translate well and caused conflicts when working with large wetcast blocks."

When a project owner or design engineer chooses to use the new standard specification for a project, they are selecting a high-quality, large-block solution. Instead of allowing other systems like small, dry cast blocks or concrete panel walls with steel soil reinforcement, this standard guarantees the project takes advantage of the durability, strength and design flexibility that comes with large, wetcast retaining blocks, Johnson said.

The new standard specification includes detailed provisions for concrete testing. Tests and testing frequency are based on requirements in existing standard specifications, such as ASTM C94 and industry trade association recommendations. The new standard specification also requires the use of first-purpose concrete.

"High-quality concrete with superior durability is the heart of the large block solution. It was very important to the entire work group that blocks made from anything but first purpose concrete be specifically excluded from the new standard specification," said Johnson.