Material guides / Concrete ingredients
Cement, Sand and Granite: What Really Makes Concrete Strong?
A truckload of good granite and several bags of cement do not, by themselves, guarantee good concrete. Strength and durability depend on how the ingredients work together—and how the concrete is mixed, placed, compacted and cured.
For builders, contractors and Nigerians managing a Lagos project from abroad, understanding the purpose of each material makes it easier to ask useful questions before ordering. This guide explains cement, sand, granite and water, the differences between concrete and mortar, and the records worth keeping when materials arrive.
Concrete starts with four ingredients, not three
Conventional concrete contains cement, water, fine aggregate such as sand, and coarse aggregate such as gravel or crushed stone. The cement and water form a paste that binds the aggregate particles. Some specified mixes also contain supplementary cementitious materials or admixtures. The Concrete Society explains the constituent materials.
| Ingredient | Principal role | What the buyer should clarify |
|---|---|---|
| Cement | Forms the binding paste when it reacts with water. | Specified cement type and condition. |
| Sand | Fine aggregate that contributes to particle packing and fresh-mix behaviour. | Required grading, cleanliness and moisture control. |
| Granite or other coarse aggregate | Provides a substantial part of the concrete’s volume and aggregate framework. | Specified size range, source and testing requirements. |
| Water | Participates in cement hydration and influences workability. | Water quality and the controlled amount in the mix. |
1. Cement forms the binder
Cement is the powdered binding ingredient; it is not another name for concrete. When hydraulic cement reacts with water, hydration products develop and bind the surrounding material. Hardening is therefore a chemical process, rather than simply the mixture drying out. Read about cement hydration and curing.
Calling cement the “glue” of concrete is a useful starting analogy. It does not mean that adding more cement automatically corrects every problem. A structural mix must balance its ingredients and performance requirements. A buyer should ask for the specified product, rather than selecting solely by bag price or an informal claim that a particular brand is always strongest.
2. Sand is fine aggregate, not just a gap filler
Sand helps form a workable mixture with the coarser particles. Its grading matters: too little suitable fine material can produce a harsh mix, while changes in the aggregate balance can alter water demand. Mix design therefore considers the whole combination, not the appearance of one sand heap. See the Concrete Society’s principles of mix design.
On a Lagos order, “sand” alone is an incomplete description. Ask whether the requirement is for concrete sand, plaster sand or filling material, then put the agreed specification on the quotation. Colour and a hand sample may help identify a delivery, but neither demonstrates compliance with a project specification.
Our sharp sand guide explains the ordering information to provide. For a comparison of product names, read sharp sand, plaster sand and filling sand.
3. Granite contributes bulk and an aggregate framework
Granite chippings are one form of crushed-stone coarse aggregate. They contribute to the concrete’s overall structure, but should not be described as providing all—or automatically most—of its strength. Concrete performance depends on the paste, aggregate characteristics, proportions and workmanship together. The American Cement Association describes concrete as a combined material system.
A familiar trade name is not a complete grading specification. Ask for the required size range in the written order, particularly when different suppliers use the same shorthand differently. In Pamitadz’s price lists, “¾-inch down” means the ⅝-inch granite grade. It is distinct from our separately listed ¾-inch chippings. Your order should identify which product is intended.
Our granite specifications and delivery guide includes the sizes we list. A lower price for another size is not a reason to substitute it without approval from the project team.
4. Water and workmanship can change the result
Control the water rather than adding it by eye
Water is needed for hydration and workable concrete. However, water demand must be managed within the specified mix. ACI identifies the water-to-cementitious-materials ratio as a major influence on strength, alongside suitable aggregate and workable proportions. Adding water merely to make placement easier can change that balance. Read ACI’s explanation of aggregate proportions and strength.
Plan compaction and curing before the pour
Buying the ingredients is only the beginning. Batching, mixing, placing, consolidation, finishing and curing are all part of producing sound concrete. These operations should be planned as one sequence, with the right people and equipment available. The introduction to Design and Control of Concrete Mixtures covers this process.
Curing helps maintain the moisture and temperature conditions needed for strength development. A surface that looks dry or feels hard is not evidence that the specified concrete strength has been achieved. Keep the agreed curing arrangements in place and follow the project’s testing and loading instructions. ACI’s curing guide explains the purpose of curing.
What happens if one ingredient is missing?
- Without the specified binder: a loose sand-and-stone mixture is not conventional cement concrete. It may have another use as an unbound material, but that does not make it a substitute for structural concrete.
- Without sand: the mixture changes substantially. Specially designed no-fines concrete exists, so saying that all concrete without sand must fail would be inaccurate. It is a different specified system, not an improvised way to save on sand. See the Concrete Society’s no-fines concrete guidance.
- Without coarse aggregate: a cement-and-sand mixture is generally mortar rather than conventional coarse-aggregate concrete. Mortar has useful applications, but its suitability must be judged for the intended work. Read the Mortar Industry Association’s explanation.
- Without adequate water and curing: the intended hydration and strength-development process is affected. The answer is controlled water management, not either extreme of a dry, unworkable mix or uncontrolled additional water.
The practical lesson is to avoid removing or substituting an ingredient from an approved mix without an authorised revision. The cost saving on one delivery can be a poor comparison with the consequences of unsuitable material or rework.
Why one popular mix ratio is not an answer for every project
A ratio shared on a building forum does not identify the required concrete grade, aggregate properties, exposure conditions, water content or quality-control arrangements for your site. It also needs a clear measurement basis: a ratio by mass is not automatically the same as one by loose volume.
Ask your project team for the specification before requesting supplier quantities. For contractors ordering repeatedly, keep the approved material descriptions consistent across enquiries, invoices and receiving records. For a project managed from abroad, nominate one responsible local receiver and keep changes in writing.
Seven checks before ordering sand and granite in Lagos
- Identify the work. State whether the material is for a concrete pour, rendering, filling, road layers or another specified task. Do not combine these into one vague request for “building sand”.
- Write the specification. Record the product, grade or size range, source requirements where applicable, and any sampling or laboratory documents requested by the project.
- Use an explicit quantity. State tonnes or cubic metres. A truck description is a vehicle arrangement, not proof of the material’s weight.
- Compare the delivered total. Match the material, quantity, truck and destination. Ask how gate fees, tolls, waiting and unloading arrangements are treated.
- Prepare the receiving point. Send the entrance pin, receiving contact and access information. Confirm space for the selected vehicle and a safe unloading position.
- Keep products identifiable. Arrange receiving areas so different materials and successive deliveries can be distinguished against their order records.
- Reconcile the documents. Check the quotation, invoice, truck details, loading evidence, weighbridge ticket and delivery note together. Raise a discrepancy promptly with the supplier and site team.
What Pamitadz provides with material orders
For materials ordered by weight, we provide the quarry weighbridge ticket so customers can see the recorded net tonnage. Net weight is the material weight after subtracting the vehicle’s recorded tare weight from its gross loaded weight. Keep the ticket with the relevant truck and order records; a load photograph alone cannot establish tonnage.
For bulk orders only, we also provide standard laboratory grading reports from Lagos State Materials Testing Laboratory. A material grading report and a weighbridge ticket answer different questions. Neither, on its own, certifies the strength of the concrete subsequently mixed on site. Agree any project-specific concrete testing with the responsible team.
View real weighbridge-ticket examples, compare material prices by Lagos delivery area, and check the delivery-area guides before enquiring.
Frequently asked questions
Are cement and concrete the same material?
No. Cement is the binder used with water and aggregates to make conventional concrete. Concrete is the combined material.
Can plaster sand replace the specified concrete sand?
Do not substitute by product name or price alone. Ask the project team to approve the actual grading and relevant test results for the intended mix.
Does a larger granite size always mean stronger concrete?
No. Specify the aggregate size range required for the mix and placement conditions. A trade size is not a concrete-strength rating.
Does a weighbridge ticket prove concrete quality?
It records weights for a particular vehicle and load. It does not establish aggregate grading or the strength of finished concrete.
What should I send to request a quote?
Send the material specification, quantity and unit, exact site location, preferred date and proposed truck type. Additional information such as gate fees and access restrictions is helpful where applicable.
Order the right material before comparing the lowest price
A useful quotation begins with a clear specification and an exact delivery address. Pamitadz supplies sand, granite and related construction materials across Lagos for individual builds, contractor projects and customers arranging work from abroad.
Call 0906 889 0583 · Email the quote team · Contractors: projects@pamitadz.com · Diaspora projects: diaspora@pamitadz.com.