Limestone Aggregate Sizes Chart: Complete Guide to #8, #57, #89, and #4 Grades

Choosing the right limestone aggregate size can make or break your construction project. Whether you’re building a driveway, laying a foundation, or creating drainage systems, understanding limestone grades is essential for success.

Limestone aggregate comes in standardized sizes ranging from fine #8 (3/8 inch) to large rip rap (6-18 inches). Each grade serves specific purposes, with #57 limestone being the most popular choice for driveways and drainage, while #4 works best for concrete mixing and road base applications.

Quick Fact: The number system for limestone grades corresponds to screen sizes, with smaller numbers indicating larger stones. #57 limestone passes through a 1-inch screen but is retained on a 1/2-inch screen.

Standard limestone aggregate sizes and specifications

Understanding limestone aggregate starts with knowing the standard sizing system. The American Society for Testing and Materials (ASTM) establishes these specifications to ensure consistency across the industry.

The numbering system works inversely to what you might expect. Lower numbers like #4 represent larger stones, while higher numbers like #89 indicate smaller aggregate. This system helps contractors and suppliers communicate precisely about material requirements.

Here’s how the most common limestone grades break down:

Each size serves distinct purposes based on its compaction properties, drainage characteristics, and load-bearing capacity. The key is matching the right grade to your specific project needs. For a more detailed exploration of different limestone sizes and their applications, consider how each grade performs in various construction scenarios.

Applications and uses by limestone grade

Different limestone grades excel in specific applications. Understanding these uses helps you select the most cost-effective and functional option for your project.

#57 limestone dominates residential and light commercial projects. Its size allows excellent drainage while maintaining good compaction. You’ll find #57 used extensively in driveway construction, French drain systems, and as bedding material for pavers. The stones lock together well, creating a stable base that won’t shift under normal traffic loads.

#89 limestone works best when you need uniform sizing for precise applications. This grade mixes exceptionally well in concrete, providing consistent strength throughout the mixture. Utility companies prefer #89 limestone for pipe bedding because its uniform size prevents damage to underground infrastructure while allowing proper drainage around pipes.

Pro Tip: For residential driveways, #57 limestone typically costs 15-20% less than #89 while providing superior drainage and stability for most applications.

#4 limestone handles heavy-duty applications where maximum strength matters. Road construction crews use #4 as a base course because larger stones distribute weight more effectively. This grade also excels in large drainage projects where high water flow rates require bigger void spaces between stones.

#8 limestone serves specialized surface applications. While too small for structural use, #8 creates attractive walkways and provides excellent material for thin concrete applications where larger aggregate would create problems.

How limestone aggregate sizes are produced

The journey from quarry to your project site involves precise crushing and screening processes. Understanding this production helps explain why certain sizes cost more and perform differently.

Limestone production begins with blasting large rock faces in quarries. These massive chunks then enter primary crushers, typically jaw crushers that reduce stones to roughly 6-8 inches. This initial crushing creates the raw material for all smaller grades.

Secondary crushing refines the material further. Impact crushers or cone crushers break down the primary crushed stone into the size ranges needed for different grades. The crushing equipment settings determine the final size distribution, which is why consistent quality matters when selecting suppliers.

Screening separates the crushed limestone into specific grades. Vibrating screens with different mesh sizes sort the material, ensuring each grade meets ASTM specifications. Stones that don’t fit the target grade get recycled back through the crushing process.

Quality control throughout production ensures consistent sizing. Reputable suppliers test their aggregate regularly, checking gradation curves and ensuring each shipment meets specifications. This consistency directly impacts how well the limestone performs in your project. Understanding the difference between gravel and limestone can help you appreciate the unique properties that make crushed limestone ideal for specific applications.

Choosing the right limestone size for your project

Selecting the correct limestone grade depends on several key factors that affect both performance and cost. Getting this decision right saves money and prevents project delays.

Load requirements should guide your initial selection. Light foot traffic areas work fine with #8 or #89 limestone, while vehicle traffic demands #57 or larger. Heavy commercial applications typically require #4 limestone for adequate load distribution.

Drainage needs significantly influence size selection. Projects requiring rapid water movement benefit from larger grades like #4, which create bigger void spaces. Surface drainage applications often work best with #57, balancing drainage with stability.

Compaction characteristics vary dramatically between grades. Smaller limestone like #89 compacts tighter, creating denser surfaces with less permeability. Larger grades like #57 maintain more void space even after compaction, preserving drainage capabilities. For foundation work, understanding crushed limestone versus crushed granite for base course applications can help you make the best material choice.

Cost Consideration: Larger limestone grades typically cost less per ton because they require less processing, but you may need more material to achieve proper coverage and stability.

Installation method also affects size choice. Hand-placed applications work better with smaller, more manageable sizes like #57 or #89. Machine-spread applications can handle larger grades like #4 more efficiently.

Consider your local climate when making selections. Areas with freeze-thaw cycles benefit from grades that maintain drainage, preventing ice damage. Hot climates may prioritize compaction and stability over drainage in certain applications. To explore the full range of options, review a comprehensive guide to limestone gravel sizes for detailed specifications and recommendations.

The right limestone aggregate size transforms good projects into great ones. By matching grade specifications to your specific needs, you ensure optimal performance while controlling costs. Whether you’re tackling a weekend driveway project or managing commercial construction, understanding these limestone grades gives you the knowledge to make confident material decisions that deliver lasting results.

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