• RMC India
  • RMC India
  • RMC India
QA-QC Practices
The properties of the ready-mixed concrete in the fresh and hardened states are prone to variations on account of a number of factors. These properties are dependent upon the properties of different ingredients used in concrete, the process control measures, optimization efforts in mix proportions and the degree of quality control exercised by the producer.
Four Pillars of Quality
RMC-India attaches immense importance to provide highest level of quality assurance to its customers. Following are the four main pillars of quality systems practiced by RMC -India:
Strict control on the quality of all input materials used in production through rigorous in-house or third-party testing
Stringent process control measures involving thorough inspection, good upkeep of equipment, monthly scale calibration of weighing devices, etc.
Continuous monitoring of the key properties of concrete in the fresh and hardened states, including their statistical analysis
Adopting the world-renowned Quality Scheme for Ready-Mixed Concrete (QSRMC) from U.K, for ensuring QA & QC. This involves continuous monitoring on all stages of production and supply i.e. order processing, purchase/control on input materials, concrete mix design, process control, sales, delivery and statistical quality control.
Cusum Technique
Another key feature of the QA system practiced by the Company includes the use of Cusum (cumulative summation) technique. This technique is used for monitoring trends in:
Mean strength,
Standard deviation, and
Relationship between early-age and 28-day strengths.
The essential principle of Cusum is that differences between results and their target values are calculated and added cumulatively to form a cumulative sum (Cusum). When Cusum is plotted graphically against the sequence of results, a visual presentation of the trend relative to the target level is produced. The system assists in quick detection of changes in the properties, and indicates when action should be taken to increase the probability of meeting the specifications or to reduce the material cost of the concrete. RMC-India. is probably the only producer in the country to implement and use Cusum system to ensure batch-wise consistency in concrete quality.
Innovative and Cost-effective Design
The Company adopts an innovative approach to designing concrete mixes; this is basically based upon the practices adopted by the erstwhile RMC, UK. The crux of the approach is the adoption of “family” concept of concrete mixes which has been proved to be extremely effective in controlling quality. A concrete family is a group of concrete compositions for which a reliable relationship between relevant properties is established and documented. Where a concrete cannot be included into a family it is treated as ‘individual concrete’. The main benefit of adopting the family concept is that changes in quality can be detected rapidly and effective action can be taken to ensure that the production remains in a state of statistical control.
Thus, when you order your concrete from RMC (India) Division you can rest be assured of the following crucial advantages:
Concrete mix design is technically sound and cost-effective,
Process control parameters are checked frequently and rigorously, and
High level of quality assurance is obtained through the adoption of family concept and Cusum technique
Laboratory testing
The Company’s production facilities in different locations are supplemented with a state-of-the-art central laboratory for testing of concrete and its ingredients. All central laboratories are fully equipped with latest testing equipment conforming to the requirements of relevant codes of the Bureau of Indian Standards. The routine tests done in the laboratories include the following:
Aggregate gradation (once in a week)
Moisture content (at least twice in a day)
Silt content
Plastic Density
Compressive strength of concrete: at 28 days ( 7/56/90 - day testing optional, depending on customer requirement)
mix (India) Pvt. Ltd.  
The properties of cement and chemical admixtures are monitored by insisting on the suppliers to furnish test certificates. When in doubt, the materials are sent for testing in a third-party lab. At certain locations, some physical tests on cement are also carried out.
Moisture content of sand and crusher fines is evaluated by Microwave oven, at least two times in a day and appropriate moisture correction is effected. This helps in keeping a proper control on the water-binder ratio of the mix and hence on strength and other properties of concrete.
The Company’s central laboratories at Mumbai, Bangalore and Chennai possess sophisticated testing facilities like the Rapid Chloride Penetration Test (ASTM C 1202), Accelerated Curing test, and Water Permeability Test (DIN 1048). The quick binder test which establishes cement and admixture quality and compatibility is also used regularly.
mix (India) Pvt. Ltd.  
The Company’s Central Concrete Testing Laboratories in Bangalore and Mumbai have secured the coveted NABL Accreditation under ISO/IEC: 17025: 2005, in the field of Mechanical Testing of Aggregates & Concrete. The certification for Bangalore is the first of its kind for any RMC manufacturer. The National Certification Scheme for RMC Plants was launched during May 2013 jointly by QCI and BMTPC (Building Material and Technology Promotion Council). RMC India is the FIRST Indian company to receive this prestigious quality certification at its Kochi RMC unit, and has now completed similar audits at many of its other units as well.