New Standard Guarantees Large Blocks for Projects

ASTM Approves Wetcast Large Block Standard

Charlevoix, Michigan- Redi-Rock International is proud to announce 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 leading 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, PE, Director of Operations and Engineering at Redi-Rock. "There was strong, industry-wide support and we were proud to be part of the development process," Johnson said.

The new standard specification is extremely important to the growth of the large block industry. According to Clint Hines, PE, 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 is 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.

"This standard raises the bar. It takes already high quality products and makes them even better," Johnson said. "We've seen the advantages that large blocks supply, and we want to bring that to people in the best way possible."


In 2000, the Manthei brothers Mark, Jim, and Ben created a series of massive, stackable retaining-wall blocks, interlocking like giant Legos to respond to a customer's request in their heavy contracting business. The brothers soon realized there was a huge need for a retaining-wall system that would rely solely on gravity to hold back the earth, and Redi-Rock was born.

Today, the company has 130 manufacturers across North America, Europe, Asia, and New Zealand. Family owned and operated, the Redi-Rock International team in Charlevoix, Michigan, designs, creates, markets, and licenses the steel forming system to create Redi-Rock concrete blocks.

Get Pricing

Redi-Rock Has a Large Block System for You

Gravity Retaining Wall Blocks - Massive, one-ton Redi-Rock gravity blocks rely on the sheer mass of each block to hold back the earth.

Reinforced Retaining Wall - The Positive Connection System has a massive amount of connection strength.

Freestanding Wall - Textured on two or more sides so the wall looks great from all angles.