Ready Mixed Concrete (RMC) is concrete that is manufactured in a batching plant according to a set recipe and then delivered to a worksite in a truck-mounted transit mixer. It is mixed at a central plant under controlled conditions, ensuring consistent quality and eliminating the need for on-site mixing.
Consistent Quality: Precise batching ensures uniform strength and properties
Time Saving: Eliminates on-site mixing time and labor
Space Efficient: No need for material storage on site
Cost Effective: Reduces wastage and labor costs
Quality Control: Advanced testing at batching plant
Environment Friendly: Reduced dust and noise pollution
Technical Support: Expert guidance from RMC supplier
RMC is typically priced per cubic meter. Factors affecting cost include: concrete grade (strength), distance from plant to site, quantity ordered, special admixtures required, delivery schedule, site accessibility, and pumping requirements. Larger orders and favorable site conditions generally result in better pricing.
While Kalokhe RMC can supply small quantities, the typical minimum order is 2-3 cubic meters. Smaller orders may attract additional charges due to logistics and setup costs. For optimal efficiency and cost-effectiveness, orders of 5 cubic meters or more are recommended.
It is recommended to place orders at least 24 hours in advance for standard concrete grades. For special concrete mixes or large volumes (above 100 cum), 48-72 hours notice is advisable. However, Kalokhe RMC can accommodate urgent requirements subject to availability.
Required information includes: Concrete grade (M20, M25, M30, etc.), Quantity required (in cubic meters), Delivery date and time, Complete site address with landmarks, Site accessibility details, Pumping requirements (if any), Workability requirements (slump), and Contact person details.
Concrete should ideally be discharged within 90-120 minutes from the time of adding water at the plant. In hot weather, this time may reduce to 60-90 minutes. The transit mixer keeps rotating to prevent the concrete from setting, but extended transit time can affect workability and strength.
No. Adding water at site is strictly prohibited as it adversely affects the water-cement ratio, significantly reducing the strength and durability of concrete. If workability needs adjustment, contact the RMC supplier for proper admixture-based solutions that don't compromise quality.
Cement should ideally be used within 90 days of manufacturing. At Kalokhe RMC, we maintain strict inventory rotation to ensure only fresh cement (less than 30 days old) is used in concrete production. We regularly test cement properties to verify compliance with IS standards.
Yes! All Kalokhe RMC transit mixers are equipped with GPS tracking systems. This enables real-time monitoring of delivery status, ensures timely delivery, prevents unauthorized stoppages, and helps in better logistics management for your project.
Kalokhe RMC is certified by ISO 9001:2015 (Quality Management System), BIS (Bureau of Indian Standards) License No. RMCPWRO1-2023065176-0, and QCI RMCPS (Quality Council of India - Ready Mixed Concrete Production System). These certifications ensure consistent quality and adherence to international standards.
Calculate volume using: Length × Width × Height (for slabs), or use our online Concrete Volume Calculator. For beams, columns, and complex structures, consult our technical team. Always add 5-10% extra to account for wastage and uneven surfaces.
You will receive a delivery challan containing: Concrete grade, Quantity delivered, Time of loading at plant, Vehicle number, Batch number, Water-cement ratio, Slump value, and other relevant technical parameters. This document is crucial for quality records and cube testing.
Yes, RMC can be supplied during monsoon with proper precautions. Ensure the site has adequate protection (tarpaulins), proper drainage, and immediate covering arrangements. In extreme heat, we can provide temperature-controlled concrete. Avoid concreting during heavy rain.
Inform the RMC supplier immediately. Delays beyond 90-120 minutes may result in concrete rejection. Keep the mixer rotating, avoid adding water, and consult the supplier for admixture solutions. Extended delays may incur additional charges and could result in concrete being rejected for quality reasons.
Concrete Grades & Specifications
The 'M' stands for Mix and the number represents the characteristic compressive strength of concrete in N/mm² (or MPa) after 28 days of curing. For example, M25 means the concrete will have a minimum compressive strength of 25 N/mm² after 28 days when tested as per IS:516.
M50-M60: Pre-stressed concrete, special structures
M60+: High-performance applications, skyscrapers
Yes, you can use a higher grade, but it's not cost-effective and may not be structurally beneficial without redesigning. A higher grade means more cement, which increases cost. Always consult your structural engineer before upgrading. However, never use a lower grade than specified.
Nominal Mix: Fixed proportions (like 1:1.5:3) suitable for small works, not precise. Design Mix: Scientifically designed proportions based on material testing and specific requirements, ensuring precise strength and durability. All RMC is design mix concrete.
Characteristic Strength: The strength below which not more than 5% of test results are expected to fall (95% confidence level). This is the grade designation (M25, M30, etc.). Target Strength: The average strength aimed for in production, which is higher than characteristic strength to account for variations. Target strength = Characteristic strength + 1.65 × Standard deviation.
Slump is a measure of concrete workability (flow). Standard slump ranges:
25-50mm: Very low workability (foundations, roads)
50-100mm: Medium workability (slabs, beams)
100-150mm: High workability (columns, walls, congested reinforcement)
150mm+: Very high workability (flowing concrete, SCC)
Maximum aggregate size depends on application:
20mm: Standard for most structural works (beams, columns, slabs)
12.5mm: For thin sections, heavily reinforced sections
10mm: For very thin sections, architectural finishes
Maximum size should not exceed 1/5th of minimum member dimension or 3/4th of clear spacing between rebars.
No. It's not advisable to pour different grades simultaneously as it leads to confusion and potential errors. Complete one grade before starting another. If absolutely necessary, use clear marking, separate teams, and maintain strict supervision to avoid mixing.
OPC (Ordinary Portland Cement): Fastest strength gain, used for urgent works. PPC (Portland Pozzolana Cement): Contains 15-35% pozzolanic material, better durability, lower heat, economical. Most commonly used. PSC (Portland Slag Cement): Contains slag, excellent for marine structures, superior durability.
Admixtures are chemicals added to modify concrete properties:
Plasticizers/Superplasticizers: Improve workability without adding water
Retarders: Delay setting time (hot weather, long transit)
Accelerators: Speed up setting and strength gain
Air-entraining: Improve freeze-thaw resistance
Waterproofing: Reduce permeability
Hot Weather (>35°C): Faster setting, increased water demand, potential strength loss, more cracks. Use retarders and cure properly. Cold Weather (<5°C): Slower strength gain, risk of freezing. Use accelerators and protect from freezing. Optimal Range: 20-30°C for best results.
SCC is a highly flowable concrete that spreads into place under its own weight without vibration. It's ideal for heavily reinforced sections, complex shapes, and areas where vibration is difficult. SCC requires specialized mix design and careful quality control.
HPC is concrete designed to provide enhanced performance in one or more aspects: higher strength (M60+), better durability, improved workability, or faster strength gain. It typically uses superior materials, lower w/c ratio, and advanced admixtures. Used in high-rise buildings, bridges, and special structures.
While you can specify cement brand, it's not usually necessary if the RMC supplier uses IS-certified cement. All cement used at Kalokhe RMC is from reputed brands and tested for conformance to IS:269, IS:1489, or IS:455. Specified strength and quality parameters are more important than brand.
Water-cement ratio (w/c) is the weight of water divided by the weight of cement in concrete. It's crucial because:
Lower w/c ratio = Higher strength and better durability
Higher w/c ratio = Lower strength, more porous, less durable
Typical range: 0.35-0.60 (lower for high-strength concrete)
Never add extra water at site as it increases w/c ratio
Quality Control & Testing
As per IS:456, take one sample (6 cubes - 3 for 7-day test, 3 for 28-day test) for every 50 cum of concrete or every shift or for each grade poured. For smaller works (less than 50 cum), take at least one sample per pour. Additional samples may be needed for critical structures.
Take samples from the discharging concrete, not from the first or last portions
Collect within 15 minutes of concrete discharge
Fill moulds in 3 layers, compacting each layer with 25 strokes
Level the top surface and label clearly
Store at site for 24 hours, then transfer to curing tank
Ensure cube moulds are clean, oiled, and IS certified (150mm × 150mm × 150mm)
As per IS:456, concrete is acceptable if:
Mean strength of 4 consecutive samples ≥ fck + 0.825 × S.D. (established)
OR Mean strength ≥ fck + 3 N/mm² (if S.D. not known)
AND Individual sample strength ≥ fck - 3 N/mm²
Where fck = characteristic strength, S.D. = standard deviation
First, verify if sample collection, storage, and testing were done correctly. Common reasons for low results: improper sampling, poor curing of cubes, testing machine errors, or site water addition. If results are genuinely low, options include: retesting at later age, core testing from structure, load testing, or structural strengthening. Consult structural engineer.
28-day strength is the standard for concrete specification. 7-day strength is an indicator of concrete progress. Typically, 7-day strength is 60-70% of 28-day strength for OPC concrete, and 50-60% for PPC concrete. Early strength testing helps detect problems before final results.
Slump test measures concrete workability. Procedure: Fill slump cone in 3 layers (each rodded 25 times), lift cone vertically, measure vertical settlement (slump). Test should be completed within 2 minutes. Standard slump cone: 300mm height, 200mm base, 100mm top diameter.
Yes! Kalokhe RMC has a state-of-the-art testing laboratory equipped for standard and advanced tests including compressive strength, flexural strength, water permeability test, rapid chloride permeability test (RCPT), and material testing. Contact our technical team for testing services.
NDT methods assess concrete without damaging it: Rebound Hammer (surface hardness), Ultrasonic Pulse Velocity (UPV test for uniformity), Core Testing (extract small cylindrical samples), and Penetration test. These are useful when cube results are questionable or for old structures.
Clean moulds immediately after use with wire brush and water. Check for damage - discard if cracked or warped. Apply thin coat of oil before use. Store in dry place. Calibrate dimensions periodically. Use only IS certified cast iron moulds (150mm × 150mm × 150mm). Replace old/damaged moulds.
Core testing involves extracting cylindrical concrete samples (typically 100mm or 150mm diameter) from the hardened structure for strength testing. Required when: cube test results are unsatisfactory, checking old structures, quality disputes, or when proper cube samples weren't taken. Core strength is typically 85-90% of cube strength.
Daily quality control tests include: Cement physical properties, Aggregate gradation and moisture content, Slump test for each batch, Compressive strength (28-day cubes), Admixture dosage verification, Water quality testing, and Regular equipment calibration. All tests follow IS specifications.
Durability is concrete's ability to resist weathering, chemical attack, and other degradation over time. Ensured by: Adequate cement content, Low w/c ratio, Proper cover to reinforcement, Good quality aggregates, Appropriate concrete grade for exposure conditions, Proper curing, and Use of durability-enhancing admixtures.
RCPT measures concrete's resistance to chloride ion penetration, indicating durability. A current is passed through the specimen, and charge passed is measured. Lower charge = better durability. Categories: <100 coulombs (negligible), 100-1000 (very low), 1000-2000 (low), 2000-4000 (moderate), >4000 (high permeability). Kalokhe RMC lab is equipped for RCPT.
Standard testing ages are 7 days and 28 days from the date of casting. Keep cubes immersed in clean water at 27±2°C throughout this period. Remove from water just before testing (surface dry). Testing tolerance: ±2 hours for 7 days, ±6 hours for 28 days. Additional tests can be done at 3, 56, or 90 days if required.
Essential records include: Delivery challans with all technical parameters, Cube casting register (date, location, grade, sample identification), Cube test results (7-day and 28-day), Slump test results, Pour details (quantity, time, weather conditions), Non-conformance reports if any, and Material test certificates. Maintain for minimum 5 years.
Still Have Questions?
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