Phân Biệt Cát Xây Dựng, Cát San Lấp, Cát SôngConstruction Sand vs Fill Sand vs River Sand

Construction Sand, Fill Sand, and River Sand: What Businesses Should Understand Before Ordering

In construction material estimates, “construction sand,” “fill sand,” and “river sand” are three terms that often get mixed up, even though they are not actually classified along the same axis — river sand refers to the source the material is dredged from, while construction sand and fill sand are two categories defined by intended use. As a supplier of both construction sand and fill sand to a range of large-scale projects, Phuc Hung has found that understanding these three terms correctly helps investors avoid ordering the wrong material, which can affect both construction quality and cost efficiency.

What Is River Sand?

River sand is sand dredged from riverbeds, valued for being relatively low in salinity and generally cleaner of organic impurities compared with sand from other sources, such as sea sand. However, river sand is not a uniform grade of material — depending on the location, depth, and screening process, river sand can meet the standard required for construction sand, or it may only be suitable as fill sand. River sand is also the primary source Phuc Hung sources and grades before supplying it to job sites.

Construction Sand (Concrete Sand)

Construction sand is screened sand that meets the technical requirements of TCVN 7570, Vietnam’s standard for aggregates used in concrete and mortar — the most important criteria being fineness modulus (the coarseness or fineness of the sand grains) and the allowable limits on silt, clay, and organic impurities. This grade of sand is used for:

Mixing concrete for foundations, columns, beams, and slabs, where high structural strength is required.
Masonry and plastering work, where fineness and cleanliness are needed for adhesion and surface finish.
High-strength concrete components on industrial projects and major infrastructure.

On projects such as the VinMetal Ha Tinh steel complex or the infrastructure within the Hanoi International Sports City, the volume of construction sand needed for concrete work is typically substantial and requires consistent quality throughout — a standard Phuc Hung controls closely from the sand-screening stage onward.

Fill Sand

Fill sand carries significantly lower technical requirements than construction sand — it does not need to meet the fineness modulus standard required for concrete, and it may contain a permitted level of impurities, as long as it achieves adequate compaction density. This grade of sand is suitable for:

Site grading and leveling ahead of main infrastructure construction.
Filling ponds, low-lying areas, and depressions to bring a site to its designed elevation.
Components that do not require direct load-bearing capacity in the way construction sand does.

With a lower cost while still meeting compaction requirements, fill sand is a practical choice for large-scale site-grading work — the type of work Phuc Hung has carried out across several major grading packages within the Vingroup project ecosystem.

Quick Summary of the Differences

Classification basis: river sand refers to the source of extraction, while construction sand and fill sand are classified by intended use and applicable technical standard.
Technical standards: construction sand must meet TCVN 7570 for fineness modulus and impurity limits; fill sand only needs to meet compaction requirements, with no concrete-grade standard required.
Main applications: construction sand is used for concrete and masonry work; fill sand is used for site grading, leveling, and filling.
Cost: construction sand costs more due to the screening required to meet concrete standards; fill sand is more economical and suited to large volumes.

Why Choosing the Right Sand Matters on Large-Scale Projects

Using fill sand to mix concrete can prevent the structure from reaching its designed strength, creating a safety risk. Conversely, using construction sand across an entire large-scale grading package results in unnecessary budget waste, since it offers no meaningful advantage over fill sand for that purpose. This is why many investors on large projects choose to work with a single supplier like Phuc Hung for both construction sand and fill sand, ensuring the right grade is recommended for each application while maintaining consistent quality from extraction and screening through to delivery at the job site.

(The classification and technical standard details in this article are based on TCVN 7570:2006 and common industry practice in Vietnam’s construction materials sector, provided for general reference; the specific technical specifications of each shipment follow its accompanying quality inspection certificate.)