In this article i have highlighted the concrete inspection and the test procedure related to concrete inspection are give step by step.
Concrete construction activities shall be performed in accordance with job site specifications, procedures and drawings. Concrete inspection and testing shall be performed by qualified personnel who shall verify that requirements of the specifications, procedures and drawings are being met. Tests of concrete required to determine compliance to specifications shall be made by a certified Concrete Field
Unless specified elsewhere in the specifications and/or drawings, a minimum of six concrete cubes shall be made and will be considered a set. Unless stated elsewhere, the cubes will be tested as follows: 2 cubes at 7 days, 2 at 28 days and 2 held in reserve. Test results should be recorded on a spreadsheet and in a manner consistent with QC procedure: Statistical Techniques.
Unless noted otherwise in plan specifications or drawings, one set of cube shall be made for every 150 cubic yards of concrete placed as outlined in building codes. At least one set of cubes shall be made on each day concrete is placed regardless of the quantity of concrete.
Using QC procedures: Process Control as a guide, Contractor should schedule a meeting with the subcontractor prior to the first concrete pour. The purpose of this meeting is to allow the subcontractor to describe his plans for the concrete pour including all the areas listed in this section of the procedure.
Batch Plant Inspection
Contractor reserves the right to inspect any and all concrete batch plants that will be supplying concrete to the construction site. A “walk through” inspection should be performed prior to the start of concrete production. If deemed necessary, inspections may be performed during concrete production. Following are key inspection items for each type of batch plant inspection:
- verify that aggregates are loaded in correct bins
- verify that aggregates are not contaminated
- verify that scales and measuring devices have current calibration stickers and appear to be working properly
- verify that the plant has a current local authority approval certification
- verify that concrete trucks are in good working condition
- Verify that overall operation of the plant appears to be professional, orderly, reasonably clean, well maintained, etc.
- verify that batch plant operators appear knowledgeable (look for certificates or certifications)
- Verify that batch tickets will supply necessary information (amount of hold back water, list of ingredients, batch times, size of load, indication of mix ordered, etc.)
- verify that the plant and delivery equipment can produce uniform concrete per the requirements of ASTM C-94
- insure that the plant and delivery equipment can meet the capacity requirements of the job
During Concrete Production (if required):
- verify that correct mix has been loaded into the batch plant computer
- verify that equipment is working properly (admixture dispensers, scales, moisture indicators, etc.)
- verify that truck counters have been reset to zero once the mixing water has been added to the mix
- verify that water used to “wash down” the concrete truck prior to leaving the plant area does not enter the concrete mix
- verify that the amount of hold back water is indicated on the batch ticket
- have a reasonable level of confidence that the concrete leaving the plant will meet specifications for temperature, air content and slump (testing at the plant should be done as deemed necessary)
Concrete Mix Design
All proposed concrete mixes must be submitted to Consultants through main contractor for review and acceptance prior to use. The proposed mixes submitted for use shall include a concrete strength break history as specified in ASTM and shall contain acceptable test results and/or certificates of conformance on all ingredients that will be used in the particular concrete mixes