Which sand is better to choose for making concrete: river, sea, quarry

Selecting the proper sand is essential to producing high-quality concrete. Sand is more than just a filler; it also contributes significantly to the concrete’s strength and endurance. But how do you choose the best option when there are alternatives like sea sand, quarry sand, and river sand available?

Because of its naturally occurring granules and smooth texture, river sand is frequently regarded as perfect. It is pure because it has undergone natural filtering. This kind of sand gives concrete structures good workability and a smooth finish.

On the other hand, sea sand is plentiful and could seem like a practical option. It does contain salt, though, and salt can cause corrosion in reinforced concrete. Over time, this may weaken the structure’s strength. The salt must be removed with special treatment, which can be expensive and time-consuming.

Crushed sand, sometimes referred to as quarry sand, is made by finely grinding rocks. It’s a less expensive option that’s gained popularity recently. It may not be as smooth as river sand, but it still has good binding qualities and is useful for building projects.

Every kind of sand has advantages and disadvantages of its own. Your decision will be influenced by variables such as availability, price, and the particulars of your project. You can choose the ideal sand for your concrete requirements by being aware of these variations.

Type of Sand	Advantages
River Sand	Clean, less impurities, good for strong concrete
Sea Sand	Abundant, but needs washing to remove salt
Quarry Sand	Affordable, widely available, but might contain clay

The function of sand in concrete

You must be aware of the functions that sand for concrete serves before selecting which kind to use for preparation.

Sand serves the purpose of a fine aggregate in concrete mortar. Its purpose is to strengthen the structure and lessen internal stress during the concrete’s hardening process.

However, this material’s usefulness for concrete is only recognized when all prerequisites for both its quantity and quality are satisfied:

• If the volume of added sand is excessive, then the concrete will acquire a granular structure at the output, which is easy to destroy.
• If the amount is insufficient, cracks will appear during the drying of the solution, and depressions may appear on the finished product.

Types of sand

The location of extraction has a significant impact on the parameters and composition of sand. It’s critical to understand that there are various types of sand for concrete, including river, sea, quartz, and quarry sand.

Features of river sand

River sand is smooth and polished because it is continuously washed by streams of water, giving its grains a pronounced rounded shape. Because you can control the substance’s density in the concrete and the particles are dispersed uniformly, this is crucial for creating a high-quality solution.

People frequently choose river sand because it has fewer stones and doesn’t contain clay when considering which sand is best for concrete. As settling happens naturally and quickly when using the river type for concrete preparation, it needs to be continuously mixed. The documents for it state that the amount of silt and clay contamination of the sand cannot be greater than 0.3%.

When determining the type of sand required for concrete, you need to consider whether the cost or strength of the finished product is more important to you.

Features of quarry mountain sand

Given the characteristics of quarry sand (mountain and ravine), it is typically utilized in the manufacturing of bricks, screed mixtures, and backfill for sites and roads. Products made with quarry type have a high internal bonding force and are very durable because of the irregular shape of the grains and clay additives.

Low-quality results will result from preparing concrete using the quarry version. The material in the solution is dispersed unevenly and settles too quickly, and the sand grains are very small and have little plasticity. Although the alluvial type of quarry origin has a slightly lower volume of clay additives, it still plays no significant role in the production of concrete.

Only the backfill for foundations or concrete screeds should be prepared using this method because the quarry contains stones and clay additives.

Concrete preparation also uses the quarry type, but only after it has been immediately cleaned with water after mining. This process lets you get rid of dust and clay particles.

Sea and quartz

Like the sand in rivers. The composition’s homogeneity is its primary advantage. One could refer to this choice as the cleanest. Because there should be a lot of shells present, extra cleaning might be required. These particles are uniformly shaped and roughly the same size as a result of frequent washing with salty seawater. Sea sand is the most expensive because it must be mined at great depths on the seabed, which requires expensive technologies.

Is replicated by mechanically grinding quartz-containing rocks. This option’s sand grains are all the same size and shape, and it is completely chemically inert. Artificial means are used for extraction.

Properties and characteristics of sand

The documents list all the specifications that must be met for the grade of sand that is used to prepare concrete. Although specific properties of this material can only be investigated in a lab setting, some are visually verified prior to construction.

Particle size

The size of the grain is one of the most crucial characteristics of the material, so choosing the right sand for concrete preparation requires some thought. The size of the particles in this substance differentiates the following types:

• consisting of large particles (grains of sand have a size exceeding 3.5 mm);
• of increased size (grain size from 3 to 3.5 mm);
• large (within 2.5-3 mm);
• medium size (2-2.5 mm);
• fine fraction (1.5-2 mm);
• very fine (1-1.5 mm);
• fine (0.7-1 mm);
• very fine (up to 0.7 mm).

Experts run the material through a sieve with the right hole diameter to determine the size of the sand grains.

Actually, this kind of division is merely documented and more conditional.

The size of the particles in real sand can be used to differentiate three types: fine, medium, and large fractions.

What kind of sand is needed to prepare mortar for concrete? A large type is required, but it must have a large number of small sand grains for the structure to be truly durable.

If not, there will be a significant amount of visible voids in the concrete, which could weaken the final structure. Furthermore, the voids that result can be filled with cement, raising the cost of the final product. It is an indisputable fact that there are far more voids because particles of the same size do not fit together tightly. In light of this, the primary method for achieving the highest density possible between the constituent parts of concrete at the output is to mix sand with varying sizes.

The material itself can be separated into two classes according to the size of the sand grains. There aren’t any particles in the first class with a diameter smaller than 1.5 mm. Because the presence of such fine aggregate inhibits the settling of larger sand grains, this is the best material for construction. The existence of tiny particles characterizes the second class.

Volume weight

The weight of one cubic meter of natural sand is represented by this indicator. Typically, a cubic meter of this element weighs between 1.5 and 1.8 tons. A lower value for this indicator is preferred.

Composition

Based on the components that make it up, sand can be separated into:

• Granulometric (combines a combination of sand grains of different sizes).
• Mineral: quartz, dolomite, feldspar and limestone.
• Chemical (the intended scope of application is determined in accordance with the components present in the composition).

Humidity

This indicator is typically 5%. The substance’s humidity will be 1% when it is dry, and 10% when moisture is added in the form of precipitation. The amount of water required to be mixed into the concrete mixture depends on humidity.

You can independently determine the sand’s moisture content right before using it. If it crumbles when squeezed in your palm, the humidity level is ideal; if not, the indicator is higher than 5%. However, it is preferable to examine this trait in a lab.

Porosity coefficient and bulk density

The coefficient describes how well concrete and sand can withstand the infiltration of moisture. This coefficient is only measured in a lab setting.

The ideal density should be kept between 1.3 and 1.9 t / cubic meter on average. A lower indicator indicates the presence of superfluous additives, while a higher indicator indicates high humidity. Every detail needs to be included in the pertinent paperwork.

Calculation of quantity

The specifications for the use of each of its components must be met for the concrete grade to be high. The ratio 1:3:5, which stands for cement, sand, and crushed stone, is frequently utilized. Water is progressively added until 50–70% of the cement’s total weight is reached. However, precise calculations must be followed in order to prepare high-quality concrete for the construction of high-rise buildings or load-bearing floor slabs.

• To prepare concrete of brands 100, sand with grains of sand with a diameter of not more than 2.5 mm is used in a proportion of 1: 7: 4.6 (cement, crushed stone, sand, respectively);
• for grade 150 – proportions 1:5.7:3.5;
• for 200 – 1:4.8:2.8;
• for 300 – 1:3.7:1.9;
• for grades above 400 and 450, sand particles over 3.5 mm are used, the proportions will be 1:2.7:1.2 and 1:2.5:1.1.

Frequently, the significance of fine sand in concrete mortar is overlooked. And in vain, since you can lower the cost of concrete (by using less cement), raise its strength, and improve its grade by accurately selecting this element and figuring out how much of it to add to the solution.

Ideally, you want to use coarse river sand with a significant amount of small particles to get a high-quality solution. Additionally, it is anticipated that washed quarry sand will be added, which can drastically lower the price of concrete. However, we must remember that excessive savings can cause concrete products to deviate significantly from high indicators in terms of strength and stability.

For concrete to have the appropriate strength and durability, the right sand must be used. River sand is frequently the best option since it’s pure, smooth, and devoid of contaminants, which makes it perfect for sturdy, premium concrete.

Despite being widely available, sea sand is typically not advised because it contains salt, which can cause corrosion in concrete. If utilized, it needs to be thoroughly cleaned to get rid of the salt, which will add time and expense to your project.

Quarry sand works well as a substitute. It provides better cement bonding because it is more angular and rough. But, it might contain contaminants like clay, so before using it, make sure it’s thoroughly cleaned and processed.

In the end, the type of sand you choose will depend on availability and the particular requirements of your project. River sand is the best because it is the purest; sea sand can be used if it is cleaned properly; and quarry sand is an affordable alternative that should be properly inspected for quality.

It’s important to know the differences between river, sea, and quarry sand when selecting sand for concrete. Because of its clean, smooth texture, river sand is frequently chosen for use in strong, premium concrete. Even though sea sand is plentiful, it typically contains salt, which over time can erode steel reinforcement and weaken the concrete. Even though quarry sand is less refined and coarser, it can still be a good substitute if it is thoroughly cleaned and screened. River sand typically offers the best balance of quality and durability, but the best option ultimately depends on the particular project requirements and local availability.

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