LAW: Witnessing history

June 5, 2015

U.S. COE, contractor thought first-time use had more experience

Most civil contractors have experienced failing concrete compressive strength tests and faced the expensive and time-consuming prospect of removing and replacing the work.

The concrete supplier and the installer are typically at odds over whether the concrete mix was defective or the concrete was improperly placed and finished. This was the case in San Benito Supply v. KISAQ-RQ 8A 2 JV, 2015 WL 375014 (N.D. Cal. January 28, 2015)

San Benito Supply involved a project for the U.S. Army Corps of Engineers (COE) for construction of a heavy equipment repair facility in California. Because some of the equipment to be repaired in the facility was extremely heavy, a section of the floor slab was required to achieve 6,000-psi compressive strength at 28 days following placement. The specifications for the concrete slab did not identify a particular mix design to be used by the contractor. Rather, they specified the ultimate compressive strength required and included some general parameters (i.e., required steel fibers) and limitations (e.g., no more than a certain percentage of fly ash). The specifications also contained permissible ranges for air volume, water-to-cement ratio, etc. The contractor was responsible for devising a design mix that would achieve the required compressive strength and otherwise meet the stated parameters and limitations. Under the specifications and relevant industry standards, this meant that the contractor must either produce laboratory tests proving that its mix would produce the specified strength or submit for approval a mix design the contractor used in the past that actually produced those strength results. 

Before placing the concrete, the supplier submitted its intended mix design along with several PDF files, which were labeled “mix . . . history.” The history for the 6,000-psi mix showed 21 individual test results after 28 days of curing that exceeded 6,000 psi. The COE and contractor assumed the word “history” meant that this was historical data from past jobs and not data from laboratory testing. In other words, the concrete supplier was representing that the 6,000-psi mix design it was proposing to use was actually utilized on a previous project and achieved the desired strength. The COE eventually approved the mix and the contractor began placing concrete.

A week or so after placement of the first major section of the heavy-duty floor, the COE and contractor noticed that the surface of the concrete was peeling, what is regarded in the industry as “delaminating.” On the 28th day after placement, the test cylinders revealed the concrete was well short of the required 6,000-psi strength. Additional compressive strength test cylinders were tested at the 56-day mark and the strength had not increased significantly. After considering various fixes that were determined to be either ineffective or more costly than removing and replacing the slab, the COE ordered the contractor to remove and replace the concrete altogether. The supplier declined to participate in any of that work, and the contractor performed the job using concrete from another supplier. The contractor incurred $312,430.90 in additional costs and refused to pay the remaining balance otherwise due the supplier for concrete it had supplied to the project, which amounted to $303,357.04. The supplier sued.

At trial, the contractor did not dispute the unpaid supplier’s invoices, but argued that the supplier supplied nonconforming ready-mix concrete that ultimately had to be torn out at substantial additional expense. The contractor thus counterclaimed against the supplier for about $300,000, and argued that any monies it lawfully owed to the supplier should be set off against the contractor’s damage recovery. The supplier’s only argument, which the court dismissed, was that the purchase order’s assignment of responsibility for quality assurance to the contractor meant that the contractor—not the supplier—was responsible for the adequacy of the mix design. The court correctly determined that quality assurance applies to on-site testing, not to devising mix designs. The court also determined that the supplier had not—contrary to its representation—used the 6,000-psi mix on a previous project and that the mix history consisted of results obtained from laboratory testing that was not conducted in accordance with published standards. Finally, the court determined that the supplier had inappropriately added air entrainment to the mix, which caused the delamination and impacted the ultimate strength of the concrete. The court thus awarded the contractor the full costs of removing and replacing the concrete. R&B

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