Matériaux de construction l'analyse de la taille et de la forme des particules pour améliorer les performances des produits

Building materials are required for a wide range of construction work including carpentry, roofing, structural reinforcement, insulation, and plumbing. The particle size and particle shape of the raw materials influence quality and performance of the end product, and therefore require quality control by particle characterization. Microtrac analyzers are successfully used to determine the size and shape of various building materials.

Building materials range from naturally occurring substances such as rock, clay, sand, and wood to synthetic polymers and multiple combinations of both (composites). Concrete or mortar are for example mixtures of cement and aggregates like sand or gravel.

Why are particle properties so important for building materials?

Problematic effects due to oversized particles

• Poor quality of the final product (grains sticking out of the plaster, rough surfaces of tiles, inhomogeneous materials may break)
• Changes in the “look and feel” of the final product
• Changes in the flow behavior and other process parameters of the final product
• Blockage of production sieves
• Removal of material from the production process, and recycling (additional costs and effort)

Problematic effects due to undersized particles

• Change of the “look and feel” of the final product
• Dust (pollution) in the work place
• Filter blockage
• Changes in the flow behaviour and other process parameters of the final product 

Exemple 1 Sieve correlation with sand samples

In most cases the particle size distribution of sand used in building materials is analyzed by sieve analysis. Microtrac's CAMSIZER series can replace this time-consuming and error-prone technique with a quicker, more reliable method that provides a higher resolution of particle size results as well as additional particle shape information.

Exemple 3 Effective dispersion of plaster samples

Typical result from a particle size analysis of a plaster sample. The size range is fairly wide, ranging from 2 microns to about 1 mm. The graph shows the result of the CAMSIZER X2 in X-Jet mode, measured with a dispersion pressure of 150 kPa (red curve).

The plaster particles are agglomerating and “sticky”, thus the results of a conventional sieve analysis shows much coarser data (black curve), especially for the fine particles. However, if the particles are dispersed properly with an air jet sieve (AS 200 jet, blue curve), the results agree perfectly with the CAMSIZER X2.