SIST EN 772-4:1999

Overview

SIST EN 772-4:1999 is a European Standard developed by CEN that outlines standardized methods for testing natural stone masonry units. This part of the EN 772 series specifically addresses the determination of real density, bulk density, total porosity, and open porosity of natural stone masonry units. Accurate measurement of these physical properties is essential for assessing the quality, durability, and performance of natural stone materials used in construction and masonry works.

The standard provides clear procedures to quantify the densities and porosities that influence the mechanical strength, water absorption, and long-term stability of natural stone building elements. This facilitates consistent evaluation criteria across projects and helps manufacturers and engineers ensure that masonry units meet required specifications.

Key Topics

• Real Density Determination
  Measuring the true density of the stone material excluding pore space, reflecting the material’s intrinsic mass per unit volume.

• Bulk Density Measurement
  Determining the density that includes the volume of pores within the unit, providing an indication of how the stone behaves as a complete masonry element.

• Total Porosity Calculation
  Assessing the total volume percentage of pores, including both open and closed pores, which is critical for understanding material durability and resistance to environmental effects.

• Open Porosity Assessment
  Measuring the volume of interconnected pores accessible to water or air, important for evaluating moisture permeability and frost resistance.

• Standard Testing Procedures
  Detailed guidelines on sample preparation, weighing, volume measurement, and calculation formulas to ensure repeatability and accuracy.

Applications

• Quality Control in Masonry Production
  Enables manufacturers to verify the physical properties of natural stone masonry units, ensuring compliance with product specifications.

• Construction Material Selection
  Assists architects, engineers, and builders in selecting the appropriate stone units based on density and porosity parameters relevant to structural and environmental demands.

• Durability and Weathering Assessments
  Supports the evaluation of natural stone’s resistance to weathering processes, freeze-thaw cycles, and moisture-related degradation through porosity analysis.

• Research and Development
  Facilitates laboratory testing for new types of natural stone or treatments aimed at enhancing material performance in construction applications.

• Regulatory Compliance
  Provides a harmonized European testing methodology to meet national and international construction standards and building codes.

Related Standards

• EN 772 Series - Methods of Test for Masonry Units
  EN 772-1 to EN 772-11 cover various testing methods including compressive strength, water absorption, and dimensional tolerances for masonry units.

• EN 993 - Tests for Natural Stone
  Complementary standards for natural stone testing, focusing on mechanical, physical, and durability characteristics.

• EN 998-2 - Specifications for Masonry Mortar
  Standards that ensure compatibility of mortar with masonry units, influenced by unit porosity and density.

• ISO 1920 - Testing of Concrete
  May be relevant when natural stone units are part of composite masonry or concrete elements.

By adhering to SIST EN 772-4:1999, stakeholders in the construction and masonry sectors can ensure reliable, precise evaluation of natural stone properties, thereby optimizing material performance and longevity in building applications.