The quality of the concrete is checked and provided in the two following ways:
- Quality Assurance (QA)
- Quality Control (QC)
Quality assurance is always done before or during production and includes the below-mentioned items for any product, such as concrete, its content, concrete parts, and the structure. Controlling the quality of raw materials or the components of a product will assure the quality of that product.
- QC tests for consumable raw materials
- Human resource training
- Human resource quality control
- Proper organization and management for production
- Proper quality management for production
- Equipment control and measurement instrument calibration
- Production procedures control
Given the instructions, regulations, technical specifications and current operating rules, the Quality Assurance advantages can be enumerated as follows:
- probability of product rejection decreases
- manufactured product is qualified and more economical
- number of samples for quality control decreases
- confidence in the product decreases
- costs of QC of the product decreases
- quality control time deceases
- natural resources and raw materials preserve and resource waste decreases
- environmental pollution reduces
- use of manpower and equipment becomes optimized
Quality control is always done after manufacturing of any product. The quality control implementation procedure is as follows:
- sampling the final product with the predicted frequency according to the standard procedure
- testing the final product
- comparing the results with standard or desirable features
- creating relative confidence in the quality of production, according to statistics and probability
- numerous sampling and increasing it to achieve greater reliability
- spending a lot of money on sampling and testing
- spending considerable time for controlling and judging the final product
The Quality Assurance of the concrete as a particular product is as follows:
- controlling the quality of concrete content (cement, aggregate, water, additives and fibers) after preparation or production
- controlling the procedure of concrete components storage in the site
- controlling the quality of concrete content after long or incorrect storage
- controlling the efficiency, skills and knowledge of the personnel who are involved in the concrete production
- controlling the quality of concrete production equipment and devices
- calibrating scales as well as weight or volume measurement systems of concrete components
- controlling amounts and ratios of the concrete during construction
- controlling the moisture of aggregates and the water-cement ratio
- controlling the mixing devices, procedures and duration of mixing
- controlling the procedures of concrete transportation, unloading and temperature control
