Bricks & Blocks

Bricks & Blocks

1. Type of Bricks

   • Clay bricks
   • Calcium silicate bricks
   • concrete bricks
   • glass bricks and blocks

2. Brick physical properties

   • compressive strength
   • water absorption and suction
   • thermal and moisture movement
   • movement due to differential settlement
   • appearance
   • frost resistance

3. Dimensions

   • 102.5 x 65 x 215 mm

4. Brick Types

   • Facing
     • very common, chosen for appearance and strength
   • Common
     • not suitable for facing purposes or areas subject to saturation or freezing
   • Engineering
     • stronger, frost resistance, dense and low water absorption
       • Class A
         • >70 N/mm2 compressive strength
         • <4.5% water absorption
       • Class B
         • >50N/mm2 compressive strength
         • <7% water absorption

5. Voids in bricks

   • solid
     • no holes, depressions or cavities
   • frogged
     • depressions not greater than 20% of total volume
   • perforated
     • holes not exceeding bears on 2 bricks below

6. Bonding Bricks

   • each brick bears on 2 bricks below
   • Types of bond
     • Stretcher
       • cavity wall ; most common
     • English
       • alternate header and stretcher ; ensures load is spread evenly
     • Flemish
       • creates a strong wall

7. Durability issues of Bricks

   • sodium, potassium, magnesium and sulfates exist in fired bricks
   • slowly attack hardened mortar
   • In wet conditions, soluble salts can combine with a cement by-product to form a chemical which attacks the mortar joints resulting in the expansion and gradual disintergration

8. Durability of Bricks

   • Frost Resistance
     • F0
       • passive exposure - laible to damage by freezing and thawing - internal use only
     • F1
       • moderate exposure - sutiable unless repeated freezing and thawing - facing work above DPC
     • F3
       • severe exposure - durable in weather conditions - ideal below DPC
   • Soluble Salt Content
     • S0
       • intended for use in situations where total protection against water penetration is provided
     • S1
       • these bricks have limits on soluble salts
     • S2
       • lower limits than S1

9. Blockwork

   • Properties
     • made of concrete or clay
     • larger than a brick
     • 440 x 215 mm
     • commonly used for load bearing and non loadbearing walls
   • Types of blocks
     • Dense
     • Lightweight
       • good insulating properties against transfer of heat
       • used for inner leaf of cavity walls
   • Performance characteristics
     • Dense
       • 1900 kg/m3 density
       • 1.28 W/mK thermal conductivity
       • 10.4 N/mm2 compressive strength
     • Light
       • 470 kg/m3 density
       • 0.11 W/mK thermal capacity
       • 2.8 N/mm2 compressive strength

Bilder und Dateien der Mindmap