03 33 00 - 008 - PVC Waterstop - Garney Construction

h. The final results of the trial mix design shall be submitted to the Engineer at least 10days prior to the scheduled beginning of concrete placement and shall be approvedby the Engineer prior to the placement of any concrete.4. Revisions to concrete mixtures:2.10 OFF SITE BATCH PLANTa. When less than 15 compressive strength tests results for a given class of concreteare available from the current project:1). If any of the If any of the following criteria are met, take immediate steps toincrease average compressive strength of the concrete.a). A 7-day compressive strength test result multiplied by 1.5 falls below therequired 28-day compressive strength.b). A 28-day compressive strength tests result is deemed not satisfactory.b. When at least 15 compressive strength test results for a given class of concretebecome available from the current project:1). Calculate the actual average compressive strength, standard deviation andrequired average compressive strength using the previous 15 consecutivestrength tests. Submit results in graphical form with each 28-day test result forthat class of concrete.2). If any of the following criteria are met, take immediate steps to increaseaverage compressive strength of the concrete.a). A 7-day compressive strength test result multiplied by the average job-todateratio of 7-day to 28-day compressive strength falls below the required28-day compressive strength.b). A 28-day compressive strength tests result is deemed not satisfactory.c). The average compressive strength falls below the required averagecompressive strength.c. When revisions to the mix design are required, notify the Engineer in writing of thecorrective actions taken.A. Batch plants shall be an established concrete batching facility meeting the requirements ofthe Concrete Plant Standards of the Concrete Plant Manufacturers Bureau.2.11 CONCRETE MIXINGA. Mixers may be stationary, truck, or paving mixers of approved design. They shall be capableof combining the materials into a uniform mixture and of discharging without mixturesegregation. Stationary and paving mixers shall be provided with an acceptable device tolock the discharge mechanism until the required mixing time has elapsed. The mixers ormixing plant shall include a device for automatically counting the total number of batches ofconcrete mixed. The mixers shall be operated at the drum or mixing blade speed designatedby the manufacturer on the name plate.Cast-In-Place Concrete 03 30 00 - 14CMD11269 – Ward County Transmission System Expansion – Contract C6 – Below Slab TPS, OPS, and WPS