Phân Biệt Đá, Base A, Base B Trong Xây Dựng | Phúc HưngCrushed Stone vs Base A vs Base B Explained | Phuc Hung

Crushed Stone, Base A, and Base B: What Businesses Need to Know Before Ordering Foundation Materials

In construction drawings and cost estimates, the terms “crushed stone,” “Grade A graded crushed stone,” and “Grade B graded crushed stone” often appear side by side, leading many investors and contractors to mix them up when planning procurement. As a supplier of all three materials to a range of large-scale projects, Phuc Hung has found that understanding the difference clearly not only prevents technical missteps but also helps businesses control costs more accurately from the estimating stage onward.

What Is Crushed Stone?

Crushed stone is produced by crushing and screening solid rock (limestone, granite, basalt, and similar materials) into distinct particle sizes, without blending to a specified gradation. It is a versatile material category, graded by particle size for a range of uses:

0x4 crushed stone and screened fines: used for base lining, fine concrete additives, and bedding layers.
1x2 crushed stone: the main aggregate in medium- to high-strength concrete, foundations, and floor slabs.
2x4 and 4x6 crushed stone: used in lower-strength concrete, revetments, foundation lining, and temporary roads.
Boulder-sized stone: used to reinforce slopes and embankments and prevent erosion.

Phuc Hung currently supplies the full range of crushed stone sizes above, meeting both residential construction needs and the large volumes required for industrial and infrastructure projects.

What Is Graded Crushed Stone — and How Does It Differ from Ordinary Crushed Stone?

Unlike single-size crushed stone, graded crushed stone is a blend of multiple particle sizes combined in a standardized gradation, designed to achieve a dense, stable structure once compacted — used specifically for road base layers, building foundations, and industrial yard surfaces. In Vietnam, graded crushed stone is classified into two types under technical standard TCVN 8859:2011, commonly referred to in the market as Base A and Base B.

Base A (Type I Graded Crushed Stone): Material for Higher-Specification Base Layers

Base A is produced entirely from crushed stone sourced from solid rock (with no natural gravel blended in), offering high compressive strength, low Los Angeles abrasion loss, and superior load-bearing capacity (CBR). These properties make it the typical choice for:

The upper base layer of higher-grade roads and routes carrying heavy truck traffic.
Industrial yard foundations, container yards, and areas subject to large, repeated loads.
The base layer beneath asphalt concrete pavement on projects with demanding technical requirements.

On projects such as the VinMetal Ha Tinh steel complex or the infrastructure within the Hanoi International Sports City, the volume of Base A required is typically substantial and must maintain consistent quality across the entire site — a standard Phuc Hung prioritizes closely when controlling the stone sources it draws from.

Base B (Type II Graded Crushed Stone): Material for Sub-Base Layers and Site Grading

Base B allows a portion of crushed or semi-crushed natural gravel in its composition, with moderately lower technical requirements than Base A, making it suitable for:

The sub-base layer in multi-layer pavement structures.
Site grading and leveling ahead of main infrastructure construction.
Access roads, internal site roads, and areas not subject to direct operational loads.

With a more economical cost than Base A while still providing the compaction and stability required, Base B is a common choice for large-scale site-grading packages — the type of work Phuc Hung has carried out across several grading packages within the Vingroup project ecosystem.

Why Choosing the Right Material Matters on Large-Scale Projects

Using the wrong grade — for instance, substituting Base B for Base A in a load-bearing base layer — can lead to uneven settlement, premature pavement cracking, and costly repairs down the line. Conversely, using Base A across an entire large-scale grading package results in unnecessary budget waste. This is why many investors on large projects choose to work with a single supplier like Phuc Hung for all three materials — crushed stone, Base A, and Base B — ensuring the right material is recommended for each application while maintaining consistent quality control from quarrying and crushing through to delivery at the job site.

(Note: the classification and technical standard details in this article are based on TCVN 8859:2011 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.)