Agggregates

• Minerals filler materials 
• Collection of small particles 
• 60-70 percent of concrete are aggregates ( 3/4 volume ) 
• Cheap : - economical to have more aggregates in concrete 
•  High volume of stability 
• Reduce the heat of hydration of concrete 
• Better durability 
• Classified under 2 categoris 
• Coarse aggregates - pass through 75mm mesh sieve and are entirely retained on 4.75mm ( 3/16 in ) 
• Aggregates greater than 75mm known as cyclopean aggregates 
• Fine aggreates ( sand ) - size smaller than 4.75mm but completely retained on 0.07mm mesh . 
• Silt - 0.06 -0.02 mm 
• Clay - smaller than 0.02mm