Tender for Supply of Ready-Mix Concrete by the South African Department of Water and Sanitation

Tender Project: Supply of 15MPa/19mm local content ready-mix concrete exclusively for the MCC construction project at Mthatha Dam

Tender Number: WTE193CE

Project Overview: This project aims to procure ready-mix concrete meeting specific technical standards for the MCC construction project at Mthatha Dam. The core objective is to support local manufacturing, requiring the use of 100% locally produced concrete and strict compliance with South African regulations on local content.

Procurement Details:

Product Name: 15MPa/19mm Local Content Ready-Mix Concrete

Estimated Quantity: 240 cubic meters

Detailed Technical Specifications:

Core Performance Indicators:

Strength Grade: Specified as 15MPa concrete.

Minimum 28-day Compressive Strength: Must achieve the strength specified in the mix design. According to the tender documents, the target average compressive strength at 28 days for 15MPa concrete is 20MPa.

Maximum Aggregate Size: 19mm.

Technical Standards and Compliance Requirements

General Concrete Standard: SANS 50197
All supplied concrete, including its raw materials, mix design, production process, performance testing, and conformity assessment, must fully comply with the South African National Standard SANS 50197 "Concrete — Part 1: Specification, performance, production and conformity for general concrete" and all its supporting specifications.

Aggregate Standard: SANS 878
All coarse and fine aggregates (including but not limited to crushed stone, gravel, manufactured sand, natural sand, etc.) used in producing concrete for this project must comply with the explicit requirements of the South African National Standard SANS 878 "Aggregates for concrete".

Coarse Aggregate (19mm): Should be crushed stone from sound, durable, and clean rock, with particle shape approaching cubical, and flaky and elongated particle content minimized. Reactive aggregates that may cause alkali-silica reaction or adversely affect concrete durability must not be used.

Fine Aggregate: Clean, well-graded river sand or compliant manufactured sand should be used. Fine aggregate must not contain excessive clay, mica, organic matter, or other harmful impurities to ensure concrete workability and strength development. The fineness modulus of the sand should be within the specified range to ensure the concrete mix has good cohesion, water retention, and minimal segregation or bleeding.

Cement Standard and Authorization: NRCS Sales Permit
Cement used in concrete is the key binding material determining its strength. All cement must comply with the technical requirements of SANS 50197-1 for the corresponding cement type (e.g., CEM I, CEM II, etc.).

Mandatory Requirement for Manufacturers: If the bidder is a cement manufacturer, they must attach a valid "Sales Permit" issued by the NRCS for the bid product and production plant in the tender documents.

Mandatory Requirement for Distributors/Suppliers: If the bidder is a cement distributor or concrete producer (procuring cement from a third party), they must hold a certified copy of the "Sales Permit" provided by their cement supplier. Cement without a valid NRCS permit will be considered illegal and is strictly prohibited for use in this project.

Mix Design and Technical Parameter Requirements

Concrete Mix Design

Mandatory Submission: All bidders must submit a detailed concrete mix design report signed and confirmed by their technical responsible person as part of the tender documents.

Design Basis: The mix design should be based on the SANS 50100 series standards (Guide for concrete mix design), fully considering the required strength grade (15MPa), workability, durability, and characteristics of the raw materials used. The design process should involve laboratory trial mixes to optimize the most economical mix ratio that meets the 28-day target strength.

Report Content: Design strength grade, target strength, water-cementitious material ratio, sand percentage, precise quantities per cubic meter of concrete for each material (cement, water, fine aggregate, coarse aggregate, admixtures), type, brand, origin, and key performance indicators of raw materials, slump, density obtained from trial mixes, and 7-day and 28-day compressive strength test reports.

On-site Water-Cement Ratio Control (0.38 - 0.85)

Specified Range: The tender documents explicitly state that the water-cement ratio of concrete upon delivery to site is anticipated to be between 0.38 and 0.85.

On-site Control and Adjustment: The buyer emphasizes that the final water-cement ratio will be instructed on-site by the site engineer based on construction conditions (e.g., temperature, humidity, pumping height, rebar spacing) and specific placement locations (e.g., foundation, beam, slab, column). The supplier must have the capability to flexibly adjust the mix (changing slump by adjusting admixture dosage without altering the water-cement ratio) to quickly respond to real-time on-site instructions.

Auxiliary Materials and Quality Control

Admixtures, Plasticizers, and Retarders

Performance Requirements: To improve concrete workability, pumpability, setting time, or durability, the use of chemical admixtures such as high-range water reducers, retarding water reducers, or pumping aids compliant with the SANS 50900 series standards is permitted.

Fly Ash / Ground Granulated Blast-furnace Slag (GGBS)

If supplementary cementitious materials like fly ash or GGBS are used in the concrete mix design to improve performance or reduce heat of hydration, these materials must also comply with the requirements of the SANS 50450 series standards.

Continuous Quality Control and Testing

Process Control: The supplier must establish and operate an effective quality control system at the production plant to ensure the final product consistently meets contract specifications.

On-site Witness Sampling: The buyer or their designated third-party inspection agency has the right to randomly sample and test delivered concrete at the placement site.

Testing will include, but is not limited to:

Workability: Detecting concrete fluidity through slump tests.

Strength: Making 150mm cube specimens, curing them under standard conditions, and determining their 7-day and 28-day compressive strength. The 28-day strength must consistently reach or exceed the target average strength of 20MPa.

Other Properties: Such as air content, density, setting time, etc., may be tested as needed.

Disposal of Non-conforming Products: Any concrete found non-compliant upon inspection (e.g., slump outside allowable range, strength failure, or use of unapproved raw materials) will be rejected by the buyer. The supplier must, at their own expense, remove the rejected concrete from the construction site within 48 hours and immediately replace it with compliant products free of charge. Any resulting project delays and other losses will be borne by the supplier.

Quality Control and Inspection:

Process Control: The supplier must establish a comprehensive quality inspection system to ensure the final product meets specification requirements. Concrete strength and slump at the placement point must be continuously monitored to ensure compliance.

Verification: Upon award, proof of 28-day compressive strength test results must be provided to the Department of Water and Sanitation.

Non-conforming Product Handling: Any product not meeting specifications will be rejected and must be removed and replaced at the awarded supplier's expense.

Application Scenario:

This batch of concrete will be used for road concrete structures within the MCC construction project at Mthatha Dam, specifically including bridges, end walls, culverts, chutes, etc.

Mandatory Participation Conditions:

Bidders must attend the mandatory site briefing scheduled for March 17, 2026, at 10:00 at the Mthatha Dam site office in Ncisi Village.

Must fully complete, sign, and submit standard bidding documents SBD1, SBD 3.1, SBD4, etc.

Must submit a concrete mix design.

Local Content Requirements:

This tender only considers cement products manufactured using local raw materials, with a minimum threshold of 100% for local production and content of cement.

Bidders must calculate the imported content based on the exchange rate published by the South African Reserve Bank at 12:00 on the day the tender notice is issued and calculate the local content percentage according to SATS 1286:2017.

Must submit a complete Local Content Declaration.

Key Contract Terms:

Delivery: The successful bidder must commence supply within 14 days of receiving a formal purchase order. All transportation costs must be included in the bid unit price.

Payment: Monthly payments based on the actual cubic meters delivered and accepted. Payment via electronic transfer within 30 days of invoice review and approval. No advance payments or cash/cheque payments are accepted.

Penalties: For late deliveries, liquidated damages will be charged based on the contract price and the number of days delayed.

Warranty: The supplier warrants the materials to be free from defects in design, material, or workmanship.

Technical Support: In case of issues, a supplier representative must be on-site within 24 hours and provide a solution or replacement product within 48 hours, at the supplier's expense.

Bid Document Requirements:

Bid documents must be sealed and clearly marked "Original Tender: Supply of 15MPa/19mm local content ready-mix concrete exclusively for the MCC construction project at Mthatha Dam" along with the bidder's name.

The latest B-BBEE certificate or affidavit must be submitted with the bid.

Must ensure the company is registered on the National Treasury's Central Supplier Database and is tax compliant.

Bids submitted via telegram, telex, or fax are not accepted.